U.S. FOOD AND DRUG ADMINISTRATION
CENTER FOR DEVICES AND RADIOLOGICAL HEALTH
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MEDICAL DEVICES ADVISORY COMMITTEE
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OBSTETRICS AND GYNECOLOGY DEVICES PANEL
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69th MEETING
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TUESDAY,
MAY 17, 2005
The Panel
met at 8:30 a.m. in the Walker/Whetstone Rooms of the Holiday Inn, Two
Montgomery Village Avenue, Gaithersburg, Maryland, Dr. Kenneth L. Noller,
Chair, presiding.
PRESENT:
KENNETH L. NOLLER, M.D., Chair
RALPH B. D'AGOSTINO, Ph.D., Consultant
MARCELLE I. CEDARS, M.D., Consultant
AMIR H. GANDJBAKHCHE, Ph.D., Consultant
ELISABETH GEORGE, Industry Representative
MELVIN V. GERBIE, M.D., Consultant
EVELYN R. HAYES, Ph.D., R.N., CS-FNP, Member
PAULA J.A. HILLARD, M.D., Member
YULEI JIANG, Ph.D., Consultant
THOMAS M. JULIAN, M.D., Consultant
HUGH S. MILLER, M.D., Member
CHRISTINE MOORE, Consumer Representative
JOSEPH S. SANFILIPPO, M.D., Consultant
RUSSELL R. SNYDER, M.D., Consultant
JONATHAN W. WEEKS, M.D., Member
MICHAEL T. BAILEY, Ph.D., Executive Secretary
FDA REPRESENTATIVES:
NANCY C. BROGDON
JULIA CAREY-CORRADO, M.D.
BRANDON D. GALLAS, Ph.D.
SUSAN GARDNER, Ph.D.
GENE PENNELLO, Ph.D.
COLIN POLLARD
JOYCE WHANG, Ph.D.
SPONSOR REPRESENTATIVES:
RONNIE ALVAREZ, M.D.
BRENT BLUMENSTEIN, Ph.D.
J. THOMAS COX, M.D.
ROSS FLEWELLING, Ph.D.
WARNER K. HUH, M.D.
JOAN L. WALKER, M.D.
THERESA WINGROVE, Ph.D.
THOMAS C. WRIGHT, Jr., M.D.
A-G-E-N-D-A
Call to Order................................... 4
Office of Surveillance and Biometrics (OSB)
Presentation -- Role of OSB in the Review of
Postmarket Study Designs
Susan
Gardner, Ph.D....................... 9
Introductory Remarks
Colin
Pollard............................ 15
Open Public Hearing
Dr.
Diane Solomon........................ 21
Dr.
Mark Schiffman....................... 27
Sponsor Presentation
Theresa
Wingrove, Ph.D................... 37
J.
Thomas Cox, M.D....................... 43
Ross
Flewelling, Ph.D.................... 49
Joan
L. Walker, M.D...................... 55
Thomas
C. Wright, Jr., M.D............... 60
Brent
Blumenstein, Ph.D.................. 74
Warner
K. Huh, M.D....................... 81
FDA Presentation
Joyce
Whang, Ph.D....................... 108
Julia
Carey-Corrado, M.D................ 113
Gene
Pennello, Ph.D..................... 129
Panel Discussion.............................. 167
Question
1.............................. 188
Question
2.............................. 205
Question
3.............................. 209
Question
4.............................. 210
Question
5.............................. 216
Question
6.............................. 225
Question
7.............................. 233
Question
8.............................. 241
Question
9.............................. 246
Question
10............................. 250
A-G-E-N-D-A
Open Public Hearing
Dr.
Mark Spitzer........................ 260
Dr.
Mark Schiffman...................... 266
Sponsor Final Comments........................ 275
Panel Deliberations and Vote.................. 284
P-R-O-C-E-E-D-I-N-G-S
8:34
a.m.
CHAIR
NOLLER: Good morning. I'd like to call this meeting of the OB/GYN
Devices Panel to order. My name is Ken
Noller. I'm the chairperson of this
panel. I'm an obstetrician-gynecologist
generalist. I work at Tufts University
School of Medicine.
Everyone
in the room, if you haven't done so, please sign in on one of the attendance
sheets that are on the tables outside the doors. I will note for the record that the voting members present
constitute a quorum of the panel as required by 21 C.F.R. Part 14.
We
will start in just a moment. I'm going
to ask everyone at the table to introduce themselves. I'd ask you to state your name, your area of expertise, your
position, and affiliation. We'll start
at this end, please.
MS.
BROGDON: Good morning. I'm Nancy Brogdon. I'm not a member of the panel.
I am the director of FDA's Division of Reproductive, Abdominal, and
Radiological Devices.
DR.
SANFILIPPO: I'm Joe Sanfilippo, a
reproductive endocrinologist, the University of Pittsburgh School of Medicine.
DR.
GERBIE: I'm Melvin Gerbie. I'm at Northwestern University Medical
School in gynecology.
DR.
JIANG: Yulei Jiang. My interest is in computer-aided diagnosis
and radiology. I'm here temporarily. I'm assistant professor at University of
Chicago.
DR.
GANDJBAKHCHE: My name is Amir
Gandjbakhche. I am a section chief in
the National Institutes of Health. My
area of expertise is biomedical optics.
DR.
MILLER: Hugh Miller. I'm a maternal-fetal medicine
specialist. My affiliation is with the
University of Arizona, and Obstetrics Medical Group.
DR.
HILLARD: My name is Paula Hillard. I'm at the University of Cincinnati where I
do pediatric and adolescent gynecology.
DR.
BAILEY: I'm Mike Bailey. I work for the Food and Drug
Administration. I am the executive
secretary for this panel.
DR.
CEDARS: Marcelle Cedars. I'm a reproductive endocrinologist at
University of California, San Francisco.
DR.
WEEKS: Jonathan Weeks. I'm a maternal-fetal medicine specialist at
Norton Healthcare in Louisville, Kentucky.
DR.
JULIAN: Tom Julian, gynecologist,
University of Wisconsin.
DR.
D'AGOSTINO: Ralph D'Agostino,
biostatistician, Boston University.
DR.
SNYDER: Russell Snyder. I'm the division director of gynecology at
University of Texas Medical Branch in Galveston. I'm a general OB/GYN.
I've also fellowship trained in gynecologic pathology.
DR.
HAYES: Good morning, Evelyn Hayes,
University of Delaware, Department of Nursing.
MS.
MOORE: Good morning. I'm Christine Moore, consumer member of the
panel, actually appointed to the gastroenterology panel and on loan here. I am the retired dean of student services
from the Baltimore City Community College.
MS.
GEORGE: I'm Elisabeth George, vice
president of quality regulatory from Phillips Medical Systems, and I'm the
industry rep.
CHAIR
NOLLER: Thank you. Now for any press that might be present,
your FDA contact is Colin Pollard.
Colin, would you raise your hand?
Fine.
Now,
we run these meetings according to a relatively tight schedule. We have a lot to accomplish today. We want everybody to be heard. What we would also hope is that everyone
would stick to their timeframe, those of you that have been assigned times, so
that the panel has its time to discuss matters. We also would ask all of you to turn off your cell phones and
your pagers, please. Also, you may
address the panel only from the table.
If you wish to speak, you need to be recognized by me. Once I recognize you, you need to come
forward, sit at the table, and then speak.
I'm
going to turn the meeting over now to Mike Bailey.
DR.
BAILEY: All right. First I'd like to give you a little update
on upcoming meetings for the panel. The
next meeting of this panel will be on June 23, 2005. The remaining tentative panel dates we have in addition to that
one are for August 15-16, and November 15-16 of this year.
Transcripts
of today's meetings will be available from Neal Gross & Company. And information on purchasing videos of
today's meeting can be found on the table outside the door. Presenters to the panel today who have not
already done so should provide FDA with hard copies of their remarks, including
overheads, to Michelle Byrne. Michelle,
would you stand or raise your hand? And
she will collect these from you at the podium if I have not received them in
advance of the meeting. Dr. Noller?
CHAIR
NOLLER: Thank you, Mike. Dr. Susan Gardner, of the Office of
Surveillance and Biometrics, will now give a presentation to the panel
regarding the role of OSB and the review of postmarket study designs.
DR.
GARDNER: Thank you. Good morning. Due to a small communication glitch, you're going to have to
follow your hard copy if you'd like to see a copy of my slides. Or you can just watch me, whichever you
prefer. But it's short, so.
I'm
going to tell you about a major programmatic change in CDRH. And operationally, that is the move of the
condition of approval study program from the Office of Device Evaluation to the
Office of Surveillance and Biometrics.
Briefly, the Office of Surveillance and Biometrics is involved both in
the premarket and postmarket activities of the Center. We're involved in the premarket activities
by virtue of the fact that the statisticians are in our office, and you hear
from the statisticians at all your panel meetings. And also the epidemiologists are in our office, and you'll be
hearing more from the epidemiologists as time goes on. We're also responsible for signal detection
of adverse events by use of various monitoring tools, including the MDR system,
the Medical Device Reporting System, and our MedSun program, which is the
Medical Device Safety Network. We're
responsible for analysis of the signals that we see, the characterization of
product risk, and the coordination of Center response to major postmarket
issues, including risk communication to the health care professionals. And we're also responsible for the
interpretation of the MDR regulation.
The
legislative authority for condition of approvals comes from 21 C.F.R. 814.82,
and it says the post-approval requirements can include continuing evaluation
and periodic reporting on the safety, effectiveness, and reliability of a
device for its intended use. So that's
our legislative basis.
So
a couple of years ago we decided to do an internal evaluation of our condition
of approval study program, and take a hard look at how we were doing. We looked at all the PMAs that were approved
through 1998 and the year 2000. That
was 127 PMAs, and 45 of those had condition of approval studies. We then went and -- for the original purpose
of the study was to look at the quality of the condition of approval studies we
had ordered. And the problem was that
we found that we didn't have a very good tracking system, and we were unable to
locate a number of these studies and find out whether they were completed or
not. We realized that often the lead
reviewers went on to have other jobs.
And so the lack of having a standardized tracking system, and having
people move throughout the program left us, again, without a good way to track
these studies. And we also realized
that the lack of premarket resources made it difficult for the folks in that
shop to do this job because they're really involved in the premarket
piece. So again, we transferred the
program to OSB.
The
goal of the transfer, of course, was to improve the program, and to get better
postmarket information as a product enters the market, which is our chance to
see how the product -- what happens in real world use of the product. We want to better characterize the
risk-benefit profile that we learned about premarket, and of course add to our
ability to make good scientific decisions.
So on January 1 this year we transferred the program. But I will say this was done after having a
2-year pilot that had already been carried out. So many of the procedures that are now in place, again, have been
piloted for a couple of years.
The
first thing we did was develop and institute an automated tracking system,
which has gone live very recently. So
all condition of approval studies that have been ordered starting January 1 are
now in our tracking system for follow-up.
We've
also added an epidemiologist to PMA teams where we think that it's likely
there's going to be a condition of approval study as an outcome. Adding the epidemiologist means that there's
someone on the team that's tasked with coming up with a postmarket plan during
the pre-approval process. Because these
are obviously tied very close, hand in hand.
The epidemiologist will take the lead in developing a postmarket study
plan, and also in developing a postmarket study if that's going to be the
case. They're going to have a lead in
the design of the study protocol, and in the evaluation of the study results as
the study goes on. They'll continue to
work with the PMA team throughout the process.
And
now we also want to make sure that industry and CDRH has motivation for continuing
to get these studies done, and to do a better job than we think had been done
in the past. We think if we do a good
job of formulating the postmarket question, and we have a really solid study
design, that everybody is going to be more motivated to get these studies done,
and to follow them and track them as we go on.
We also think that having acknowledgement of the studies, and having
feedback on the studies to industry, and again, having conversations within
CDRH will motivate everybody to get these studies done, and to make sure that
the feedback is important.
We're
going to have a website in CDRH where we're posting the study results, and the
status of the studies as we go along.
And we also have an authority under Section 522 to mandate postmarket
studies if we have outstanding public health questions that we think need to be
answered. This authority also gives us
the ability to add civil money penalties if the studies aren't done. So hopefully we don't have to go down that
path, but if we do, we have the authority to do that.
So
what impact this will have on the advisory panel. First of all, during the approval process, postmarket questions
come up rather naturally during discussion.
And sometimes we'll have important questions that we're going to lay out
and ask you for feedback on. So again,
as you go through this process, as postmarket issues come up, we ask for your
feedback, and we ask for your advice on how -- and possible approaches for
getting these studies done.
And
finally, partly because you've asked for it, and partly because we think it's
important, we're going to continue to add to the program feedback to you on
condition of approval studies either by industry and by FDA. So after a product has been approved, if
there is a condition of approval study, someone will come back to the panel at
an appropriate period of time and give you an update on how the condition of
approval study is going. Thank you.
CHAIR
NOLLER: Thank you. Colin Pollard, Chief of the Obstetrics and
Gynecology Devices Branch would now like to make some introductory remarks to
the panel. Mr. Pollard?
MR.
POLLARD: Thank you Dr. Noller. And I'll try to be brief and keep us on
schedule. Good morning, ladies and
gentlemen of the panel, and distinguished audience. For the rest of the day we will be hearing about and listening to
you deliberate about a PMA for what for FDA is a first of a kind technology
using optical diagnostic spectroscopy to help detect cervical disease.
This
is an effort that dates back many years.
The panel actually visited this technology in a generic fashion several
years ago, and helped us write a guidance document. The sponsor, who you will hear from today, interacted with us
using early collaboration formats that are now available to industry. And you'll hear from both them and from FDA
reviewers about this. We look forward
to your deliberations, and I would just say in the interest of time we have
asked both the FDA reviewers and the sponsor to, when responding to questions,
to be brief and succinct, to give you the maximum amount of time for
deliberations. So with that I thank you
very much and we look forward to your discussion.
CHAIR
NOLLER: Thank you, Colin. For panel members, by the way, you need to
be relatively close to these microphones to be heard. Let me turn the meeting over to Mike Bailey again for a moment.
DR.
BAILEY: All right. We need to come back to and read the --
sorry. First we're going to read the
conflict of interest statement into the record. The following announcement addresses conflict of interest issues
associated with this meeting, and is made a part of the record to preclude even
the appearance of an impropriety. To
determine if any conflict existed, the agency reviewed the submitted agenda for
this meeting, and all financial interests reported by the committee
participants. The conflict of interest
statutes prohibit special government employees from participating in matters
that could affect their employers' financial interests. However, the agency has determined that the
participation of certain members and consultants, the need for whose services
outweighs the potential conflicts of interest, involved is in the best interest
of the government. Therefore, a waiver
under 18 U.S.C. Section 208 has been granted to Dr. Joseph Sanfilippo for his
consulting interest for which he receives less than $10,001 in an unaffected
subsidiary of the parent of a competing firm.
Because of a part of his grant to his institution for the sponsor's
study, Dr. Sanfilippo may participate but not vote in today's
deliberations. Copies of the waiver may
be obtained by submitting a written request to the agency's Freedom of
Information Office, Room 12A-15 of the Parklawn Building.
We
would like to note for the record that the agency took into consideration
certain matters regarding another panelist, Dr. Ralph D'Agostino, reported past
personal interests and current employee's interest with firms at issue, but in
matters not related to today's agenda.
The agency has determined, therefore, that he may participate fully in
the panel's deliberations. In the event
that the discussions involve any other products or firms not already on the
agenda for which FDA participant has a financial interest, the participant
should excuse him- or herself from such involvement, and the exclusion will be
noted for the record.
With
respect to all other participants, we ask in the interests of fairness that all
persons making statements or presentations disclose any current or previous
financial involvement with any firm whose products they may wish to comment
upon.
And
second, I will read the appointment to temporary voting member status. Pursuant to the authority granted under the
Medical Devices Advisory Committee Charter, dated October 27, 1990, and amended
April 20, 1995, I appoint the following as voting members for the Obstetrics
and Gynecology Devices Panel for the duration of this meeting on May 17,
2005. Dr. Marcelle Cedars, Dr. Ralph B.
D'Agostino, Dr. Amir Gandjbakhche, Melvin Gerbie, Dr. Yulei Jiang, Dr. Thomas
Julian, and Dr. Russell Snyder. For the
record, these people are special government employees, and are consultants to
this panel or another panel under the Medical Devices Advisory Committee. They have undergone the customary conflict
of interests review, and have reviewed the material to be considered at this
meeting. This was signed by Daniel
Schultz, director, Center of Devices and Radiological Health, on
4-20-2005. Dr. Noller?
CHAIR
NOLLER: Thank you. We will now proceed to the open public
hearing portion of the meeting. We have
30 minutes set aside this morning for open public hearing and we have some time
this afternoon. So far there are three
declared speakers. Two of these
speakers will present during this session now, while the third presenter has
requested to speak during the afternoon.
Prior to hearing from the first speaker, I will read the open public
hearing statement.
Both
the Food and Drug Administration and the public believe in a transparent
process for information-gathering and decisionmaking. To ensure such transparency at the open public hearing session of
the advisory committee meeting, FDA believes it is important to understand the
context of an individual's presentation.
For this reason, the FDA encourages you, the open public hearing
speaker, at the beginning of your written or oral statement to advise the
committee of any financial relationship that you may have with the sponsor, its
product, and if known its direct competitors.
For example, this financial information may include the sponsor's
payment of your travel, lodging, or other expenses in connection with your
attendance at the meeting.
Likewise,
FDA encourages you at the beginning of your statement to advise the committee
if you do not have such financial relationships. If you choose not to address this issue of financial
relationships at the beginning of your statement, it will not preclude you from
speaking.
The
first two speakers, Drs. Diane Solomon and Mark Schiffman, have asked to speak
together. Dr. Solomon, you have 15
minutes allotted for this presentation.
Dr.
SOLOMON: Good morning, panel and
guests. I'm Diane Solomon, and this is
my colleague Mark Schiffman. We're from
the National Cancer Institute. We're
also co-directors of the ASCUS/LSIL Triage Study, which was an NCI-sponsored
randomized clinical trial. I have no
personal financial affiliations with either the sponsor or direct
competitor. I believe I can speak for
Mark in that regard. In terms of the
ALTS Clinical Trial, I would like to disclose that ALTS did receive support in
the form of equipment and/or supplies at below cost from Digene, Cytyc,
TriPath, and National Testing Laboratories.
In
terms of ALTS, I'm sure many of you are very familiar with the trial. I would like to just very briefly go over
some aspects of ALTS, and then present some data on the relative contributions
of a first versus a second biopsy taken at colposcopy during the ALTS
trial. ALTS included just over 5,000
women who enrolled with a community cytology diagnosis of either ASCUS or
low-grade squamous intraepithelial lesion.
ALTS was comparing three different management strategies for women, one
being immediate colposcopy -- and this was included, actually, as a gold
standard for detection of disease, and was to be the benchmark by which the
other arms of the trial were to be evaluated.
The second arm was HPV triage, which depended on the results of an HPV
test to determine whether or not women went for colposcopy. Third arm of the trial was conservative
management, where women were followed with cytology, and a high grade finding
on cytology is what then referred women on to colposcopy.
And
colposcopy, clinicians were instructed to biopsy any suspect squamous
intraepithelial lesion. The number of
biopsies taken were at the clinician's discretion. Biopsy results were read by the clinical center pathologist. And it's that result that was used in the
management of women during the course of the trial. So when Mark presents data on colpo biopsy results, those are the
results as interpreted by the clinical site pathologist.
Women
were followed for two years intensively with cytology, as well as HPV testing,
and cervicography every six months for a time period of two years. At their exit from the trial, an exit
colposcopy was done on all women, regardless of their prior management. And we had a fairly low threshold for
LEEPing women to assure that no one left the trial with undetected disease. So women who had evidence of just persistent
low-grade disease were also LEEP'd.
Our
findings, just to touch on some of the summary findings. No test, triage test, was completely
sensitive for detecting what we call cumulative CIN3. And when we talk about cumulative disease for women, we're
talking not about the clinical center pathologist's read of individual colpo
biopsy results. We're talking about the
review of all histopathology taken for a woman. And the review of all of that histopathology by a pathology QC
group that reviewed all histopathology for all women at all clinical
centers.
The
finding, which was rather surprising, was that colposcopically directed biopsy
was much less sensitive than we previously had assumed. We also found that undetected CIN3 did not
regress, whereas CIN2 showed significant regression. And I'd like to show this diagrammatically, or with these
histograms. What we have here -- is
there a pointer? What we have here, if
you see the histogram on the left, the numbers of CIN3 that were detected in
the immediate colposcopy arm. The
colors show when the CIN3 was diagnosed.
Blue is during the enrollment period, red is during follow-up, and
yellow is at exit. You can see in the
immediate colposcopy arm just about half of CIN3 is detected at
enrollment. This performance was much
less sensitive than what we had assumed would be the case, and I think
highlights that colposcopy really is a weak link in this whole chain of events
from screening to detection, diagnosis, and management. Although all women went for colposcopy in
the IC arm, only just over half the cases of CIN3 were detected at
enrollment. In the conservative
management arm, many fewer cases were detected at enrollment, and we actually
anticipated this because we had a fairly high threshold for referral to
colposcopy in this CM arm. A woman had
to have a high-grade cytology for a referral to colposcopy.
But
although the enrollment detection was lower in the conservative management arm,
we see that there was some catch-up with more cases detected during
follow-up. But actually over a third
were not detected until that safety exit colposcopy. But what this shows is even though there was delay in detection
of CIN3, by the end of the trial we had equivalent numbers of CIN3 in the
immediate colposcopy, HPV triage, and CM arms, showing that CIN3 that was
present, even if undetected, did not regress.
We feel that CIN3 is actually a fairly good proxy of a true
pre-cancer.
And
I want to contrast that with the findings for cumulative CIN2. Again, this is the most severe diagnosis for
a woman during the two years of the trial, being CIN2. And we see that in the immediate colposcopy
arm, a majority of the cases were identified at enrollment. In the conservative management arm, many
fewer cases were diagnosed at enrollment.
And there was some catch-up at follow-up and at exit, but there's still,
at the conclusion of the two years of follow-up was a deficit of CIN2, we
presume attributable to the fact that undetected CIN2 actually regressed. So CIN2, in contrast to CIN3, is really not
a pre-cancer category, but probably a mixture of some true high-grade disease,
but also low-grade disease that looks more severe morphologically, but that is
destined to regress.
I'd
like to now turn the presentation over to Mark Schiffman, who's going to
present some data on comparing the first and second biopsies taken at
colposcopy.
Dr.
SCHIFFMAN: Thanks for listening. Well, every new technique that's added to a
first technique will increase sensitivity.
Just, it's an axiom. So the
question is compared to what? And so
we're trying to present some baseline of what a second biopsy adds when it's
done just by usual colposcopic direction, without any kind of adjunctive
device.
To
inform today's deliberations we evaluated the contribution of first and second
biopsies when two are taken in ALTS. As
an introductory observation, we saw that the first biopsy tended
non-significantly to be more sensitive than the second. However, the severity of the two biopsies
was positively associated. And that's
-- a weighted kappa of 0.37, given the overall inherent uncertainty of
histopathology, is pretty strong. We
focused on the second biopsy and its effect -- sorry for the typo -- on
clinical management, particularly on sensitivity, on adding to
sensitivity.
So
first. There were 719 paired biopsies
in ALTS. Here's a cross-tabulation of
the clinical center pathologist's diagnoses of the first and second of the
paired biopsies. And we're going to be
focusing on the top row in particular.
As Dr. Solomon noted, the clinical center diagnoses directed patient
management, while the pathology QC final diagnoses were used as study
endpoints. Sixty-six additional cases
were called CIN2 or CIN3 by the clinical center pathologist because of the
second biopsy alone, 53 plus 13. Please
note that not all clinical diagnoses of CIN2 are worse, or eventually
considered CIN2 or CIN3 final cases by the pathology QC group. So, on any table, even though you might see
a CIN3, or a CIN3-CIN3, it could still be downgraded in the eventual review if
the entire panel of core pathologists saw it and decided it should be
downgraded. In particular, CIN2 is not
optimally reproducible in line with its regression potential, as Diane showed.
So
let's look at how the 66 splayed out in terms of what they were eventually
called. Here are those cases eventually
downgraded and called less than CIN2.
That meant they were either nothing, or low grade at worse, in the final
analysis. So there were -- you see that
13 of the first biopsies that were less than CIN2 were picked up by a second
biopsy as CIN2 or worse. Thirteen were
called CIN2 and they were downgraded, showing that a lot of those were
eventually not called as worthwhile finds.
In fact, they were considered false positives. And this would be a decrease in specificity. And the decrease in specificity on a
percentage basis was not that high. So
we're not really going to be talking about decreasing in specificity as a main
problem in our view in the trial. It's
certainly on the order of a few percent in this context of triage. We're going to be talking more about sensitivity.
CIN2
is really problematic, and the reason it is because we're really not sure
whether these are improved sensitivity or decreased specificity in that the
actual cases, the work at picking them up is really not that certain in young
women like in ALTS. If CIN2 is
considered to be a valid endpoint, the second biopsy increased sensitivity by
35.3 percent among those women with CIN2 undiagnosed initially by the first
biopsy. But we observed that the kappa
for the clinical diagnoses of the first and second biopsies among this
heterogeneous group was basically null, it was -0.02. The first and second biopsies were almost interchangeable in
severity of diagnosis. And so since
CIN2 is characterized by error, we relied on CIN3 mainly.
And
this is the heart of the presentation.
With CIN3, you certainly want to find all these. They were confirmed CIN3 final
diagnoses. And so you see 27 additional
pickups. Now that 27 is the important
numerator of additional pickup for a colposcopically directed second biopsy in
people who took two biopsies. The first
biopsy tended to be more sensitive. P
was less than 0.1, was almost significant, suggesting the lesions were easier
to identify initially than for CIN2.
However, the second biopsy still increased sensitivity by 49.1 percent
among those women with CIN3 undiagnosed by the first biopsy.
Now,
if you see among the 152 total CIN3's that were found in the context of paired
biopsies, you see that 97, 47 plus 50, had been picked up by the first biopsy
already. So the absolute and relative
gain are the comparison of the 27 to the 97, either in absolute terms as an
addition, or relative terms. So it's
either 27 divided by 152, or 27 divided by 97.
We summarize that here. The
initial reduction in false negatives we called was 49.1 percent. But then if you talk about absolute
increased sensitivity, it's 17.8 percent.
Relative increased sensitivity, 27.8 percent. And graphically, we present this so you can see it. The first biopsy captured the bulk. The second biopsy contributed, and then some
remained, about an equal percentage, undetected.
Although
we don't have time to present the data, we saw no important differences in our
results when we stratified by whether the colposcopist was a gynecologist or a
nurse colposcopist.
So,
in summary, first of all, both Dr. Solomon and I see a clear need for improving
performance of colposcopy and localization of biopsy site. There's no question about that. That's a major concern. Our concern is that any additional test, any
additional biopsies, will increase sensitivity to some degree. And we wonder for any device what the proper
comparison is. We believe a proper
comparison will be not random punches of completely normal epithelium, because
with any kind of training, a colposcopist will direct the biopsies to at least
non-normal looking epithelium that could be a possible lesion. And we tried to give you some sense of what
that would do in the absence of a device as a form of control, if there's an
adjunctive cling. And hopefully we've
indicated what the yield would be, providing a point of comparison for your
deliberations. Thanks very much.
CHAIR
NOLLER: Thank you very much. That final question will be addressed by FDA
in their presentation. Does the panel
have any clarification? We don't really
want to discuss the matter at this point, but is there any question to address
to Dr. Schiffman or Dr. Solomon? Mel?
DR.
GERBIE: Is there any effort to add
improving performance of pathology at the initial reading of these?
DR.
SOLOMON: As a trained pathologist, let
me take that one.
CHAIR
NOLLER: Thirty seconds, please.
DR.
SOLOMON: We did have a pathology QC
group that was a panel composed of experts in pathology. What we found was that while there were
differences in the way the CC read versus the path QC, when we went back and
correlated many of these diagnoses with HPV results, we found that the
pathology QC group did read a little higher, meaning they tended to call things
CIN3 versus CIN2, but that there was no significant increase in sensitivity for
the path QC group compared to the CC group.
In other words, there's variability and non-reproducibility in
pathology, and that's simply part of the art of pathology.
DR.
SCHIFFMAN: But the CIN3 is a good
diagnosis. It's at the CIN2 level that
we have concerns.
CHAIR
NOLLER: Any other -- and please, as you
start to speak, introduce yourself. I
forgot to give your name for the transcriptionist. I have one question. Most
colposcopists, if they're going to take two biopsies do the posterior one
first. So if you do the anterior one,
the blood runs down over the site. And
so I don't -- it doesn't make sense to me that the order made would have been
the more severe versus the second. Did
you look at site?
DR.
SCHIFFMAN: We asked -- specifically the
instructions were worst site first.
CHAIR
NOLLER: To do the worst site
first? Thank you. Any other clarifications? Thank you.
DR.
JULIAN: I have one quick question.
CHAIR
NOLLER: Introduce yourself.
DR.
JULIAN: Tom Julian, University of
Wisconsin. What was the quality control
in the colposcopists in the study?
DR.
SCHIFFMAN: The quality control on the
colposcopists.
DR.
JULIAN: The qualifications. How did you know you had adequate
colposcopists?
DR.
SCHIFFMAN: Well, there was a
three-person colposcopy quality control group, including Daron Ferris, Tom Cox,
and Lou Burke. And there was an initial
training period, the CRA exam was administered, there was retraining, or an
attempt to bring up to speed people who didn't do well on CRA. That was not an exclusion criterion if they
failed. At that point there were
continued going around in ALTS to -- several times a year, I don't remember
exactly how many, with in-services, and basically hands-on training by the
three people. Each one divided the clinical
centers into particular areas of responsibility, and they continued to travel
like that throughout the entire study.
There was also offsite review of DenVu images. If there was a QC safety net meeting, something looked bad that
hadn't been called bad, it was signaled immediately back to the clinical
center, and then there was an attempt to make that known to the -- not an
attempt. The clinician was told that
that was a problem. So we attempted
quite rigorously to introduce an element of offsite static image
validation. But as you know, static
images alone are difficult.
CHAIR
NOLLER: Thank you. One last one.
DR.
SANFILIPPO: Joe Sanfilippo,
Pittsburgh. Did that evaluation include
all co-investigators for the testing process, and the so-called reeducation
process, or just the PIs in the study?
DR.
SCHIFFMAN: Everyone. There were over 40 colposcopists with widely
varying ranges of experience, from nurse colposcopist fellows. We did not allow, I do not believe, unless
there's something that slipped by, residents to participate. They had to be on the fellow level,
experience colpo, nurse colposcopists in places where nurse colposcopists are
used, attendings, junior and senior attendings, and they were all part of the
same process.
CHAIR
NOLLER: Thank you. Does anyone else from the public wish to
speak at this time? Seeing no one,
we'll proceed to the sponsor presentation.
Now,
let me just remind public observers that while this meeting is open for public
observation, public attendees may not participate except at the specific
request of the panel. The sponsors have
been given and agreed to limit their presentation to one hour and fifteen
minutes. We hope that you will do
so. The first speaker from MediSpectra
is Dr. Theresa Wingrove, Senior Director, Regulatory and Clinical Area. Dr. Wingrove?
DR.
WINGROVE: Thank you, Dr. Noller, ladies
and gentlemen of the panel, FDA staff, and distinguished audience. My name is Theresa Wingrove. I do work at MediSpectra as the Senior
Director of Medical Affairs there, and I do own stock in the company. And before I begin the sponsor presentation,
I would like to introduce the members of our clinical research team, starting
with some of the clinical investigators who will participate in the studies,
Dr. Joan Walker from the University of Oklahoma, Drs. Ronny Alvarez and Warner
Huh from University of Alabama, Diane Harper from Dartmouth Medical
School. Also we have Dr. Mark Stoler
from the University of Virginia who served as our study pathologist, Dr. Tom
Cox from the University of California, Dr. Tom Wright, Columbia
University. We also have Brent
Blumenstein and Phil Lavin, who some of you may recognize as they've served as
statisticians on many FDA panels. They
provided us with a biostatistical report.
And finally, Ross Flewelling, our Chief Technology Officer.
This
is the outline of our presentation today.
I'm going to give a brief regulatory history. Then I will be followed by Dr. Tom Cox, who has been practicing
and teaching colposcopy for over 30 years.
And he's going to talk about the effectiveness of colposcopy,
particularly with respect to ASCUS and LSIL subjects. Dr. Ross Flewelling will give a brief overview on the scientific
basis of tissue spectroscopy. Dr. Joan
Walker is going to describe how the device is used, and she will give an
overview of the two pivotal studies.
Dr. Tom Wright, an authority on cervical disease, and is also working
for us as a consulting medical director, will provide the results of Pivotal
Study I. This agenda is a little out of
order. He's going to be followed by Dr.
Brent Blumenstein, who is going to speak to the salient points of the
statistical analysis of Pivotal Study I.
Finally, Dr. Warner Huh, who will present Pivotal Study 2 results. And then finally Dr. Thomas Wright will wrap
things up with the risk/benefit analysis of LUMA.
This
is an overview of the clinical and regulatory history of LUMA. As Dr. Pollard has indicated, our
collaboration with FDA actually goes back to 1998 for our first discussions
regarding the product, its possible indications, and various study
designs. We submitted technical and
optical safety data to FDA in 2000.
After review of that data, FDA issued a non-significant risk
determination letter, which meant that studies would not require an IDE, though
all the studies did comply to good clinical practice, and followed the
regulations for non-IDE studies.
From
May 2001 to February 2002 we conducted a 753-patient pilot study. The purpose of that pilot study was to
create a pathology-based spectral library to create the algorithm. During this time we remained in active
discussions with FDA about the optimal study designs that would support
premarket approval. We looked at a
variety of different study designs, and after much deliberation with our
clinical and statistical advisors, the sponsor's decision was to use the gold
standard for clinical research trials, a randomized controlled trial that
compared LUMA and colposcopy versus colposcopy alone.
In
this Pivotal Study I trial, the colposcopist would use their colposcopic
judgment and LUMA to direct the biopsy, and the comparator would be the
standard colposcopic exam. We felt that
this design was the least biased, most easy to interpret, most informative, and
most ethical of the designs under consideration. Certainly one negative was the size and the cost of such a
study. We enrolled almost 2,300
subjects, though a study of this magnitude allowed us to -- offered us the
opportunity to test this device in many institutions and over 50
colposcopists.
While
the Pivotal Study I was ongoing we continued our discussions with FDA. FDA's position was that the sponsor quantify
the benefit of LUMA in a single arm study design in which the colposcopist went
first. In this design, LUMA results
would be displayed only after the colposcopist's assessment and commitment to
biopsy. MediSpectra agreed to conduct
this study as well, and an agreement letter was issued in February 2003 for a
multi-center, single-arm study which had a sample size of 576 subjects.
Pivotal
Study II began in July 2003. Later that
summer we contacted FDA when we observed a lower than expected disease
prevalence in the PSI study. This lower
prevalence caused us to modify slightly the thresholds, and obviously a lower
disease prevalence also meant that a higher sample size for PSII would be
necessary. And that sample size was
increased by 40 percent to 788 subjects.
The study was initiated in July 2003.
It was terminated in October of 2003, and you are going to have a
separate slide on that question. In
June 2004, the PMA was filed using the data from PSI and PSII. FDA granted expedited review status for this
application because this represents a breakthrough technology with potential
meaningful benefit in the diagnosis of pre-cancerous lesions.
Now
I would like to make the following key points with respect to the Pivotal Study
II termination. The study was
terminated by an independent board of directors for financial reasons on
October 16, 2003. At that point the
company had expended about $50 million in clinical research, and the remaining
financial resources were limited. And
in 2003, there was a very unfavorable investment climate, suggesting that
future financial challenges lie ahead.
So the only alternative was to terminate that study. I would like to make the point that neither
the board of directors nor the company were aware of any endpoints at the time
of the decision. In fact, most of the
data was still in progress. So the
analysis of the primary endpoints was done once, and only once, and that was
after the study termination decision.
The board of directors, however, had seen the results of PSI, and based
on the strength of those study results recommended the PMA go forward with both
clinical study data.
This
is the original indications for use.
Its fairly short. It has been
revised, and I'd like to move to what is now the proposed LUMA indication for
use. And I will read that to you. LUMA is indicated for use as an adjunct to
colposcopy in identifying high-grade disease in CIN2/3 patients referred to
colposcopy with an ASCUS or LSIL cervical cytology result. LUMA is not intended to replace colposcopy. A thorough colposcopic evaluation with the
identification or selection of biopsy sites must be performed independently and
prior to viewing the LUMA results.
I'd
like to note that there are two major changes in this indication since the
original indication. First of all, FDA
has asked and we agreed to emphasize and clarify the adjunctive nature of this
product. The second change was to limit
the indication to ASCUS/LSIL subjects.
It was our position that ASCUS/LSIL subjects would be expected to derive
the most benefit from this device, and this is where the greatest clinical need
was.
Now
I would like to introduce Dr. Tom Cox who will elaborate further on colposcopy
performance in ASCUS/LSIL patients.
DR.
COX: Good morning, I'm Tom Cox,
gynecologist at University of California, Santa Barbara. I have been reimbursed for my time and for
my travel. I have a very small equity
share in stock in this company. And I'd
like to thank Dr. Solomon and Schiffman for making my job somewhat easier in
terms of bringing attention to the fact that the sensitivity for colposcopy for
high-grade disease is not ideal, and that colposcopy is quite subjective. It's for that reason I think that we need an
adjunct to colposcopy to help improve its sensitivity and decrease its
subjectivity. And I believe the data
that you'll hear on the LUMA device today will be convincing that this is an
adjunctive procedure that can do these things.
I
have to differ somewhat from the previous discussion from the ALTS data
regarding taking more biopsies because
I think that we as colposcopists in the trial and always have the option of
taking more biopsies. And in the trial,
the imperfect sensitivity was demonstrated despite the option that
colposcopists had to take as many biopsies as they want. I think it's very difficult to change the
way we practice colposcopy, but I think having a device that brings our
attention to areas that we may have missed colposcopically, and reminds us that
there may be other areas to biopsy is likely to be the one thing that might
improve sensitivity.
It's
obvious that the goal of cervical cancer screening in the United States is to
detect CIN2/3 and to treat it. That is
how we have lowered the rates of cervical cancer in this country by about 70
percent. And it's our duty when we see
an individual with an abnormal Pap, try to make as sure as possible that when
they leave our examining room that we have detected all relevant CIN2/3.
Now,
in the United States, the majority of high-grade disease is detected in
follow-up, at ASCUS and LSIL cytology.
That is our most low-grade Pap abnormalities. It is the largest amount detected not because the individual risk
for each woman is that great, or certainly not nearly as great as it is for
AGUS or HSIL, but it is the preponderance of high-grade disease because of the
sheer dominance of these two Pap abnormalities in terms of numbers, because
they make up nearly 90 percent of the abnormal Paps that we see in the United
States. So it just makes it more
difficult to find the high-grade disease when you have a much larger number of
women that are normal, but a significant number who have high-grade disease
buried within that group.
ALTS
recognized this. The study was set up
as a randomized controlled trial to evaluate the management of women with ASCUS
or LSIL. And the beauty of this trial
in particular is it had a 2-year follow-up, which gave us the opportunity to
try to determine how much CIN2/3 was still either missed or newly incident to
be found over the following two years.
And it was determined that initial colposcopy identified only 60 to 70
percent of the cumulative CIN2/3 found over the two years in the ALTS
population. And in fact the main ALTS
study conclusion was that the imperfect sensitivity after colposcopic referral
in all arms is of concern. And there
have been a number of Papers sine then that expresses this concern.
If
we look at just the patients that were sent directly to colposcopy, that is the
arm that was immediate colposcopy for ASCUS and LSIL, we see that initial
colposcopy detected CIN2/3 in 14 percent of the women, and over the 2-year
follow-up, another third or 7 percent were found to have CIN2/3, for a total of
21 percent, and 79 percent of the referrals, of course, were normal.
I
think that it's important to remember a couple of things on this. One is that with 2 to 2.75 million women
referred annually in the U.S. to colposcopy for these Pap abnormalities, 7
percent is a significant burden of high-grade disease that needs to somehow be
detected in follow-up. And with high
levels of loss to follow-up, I think this is a significant risk for some
individuals. Secondly, as we look at
the LUMA data, we have to remember that the incremental increase in detection
of high-grade disease that we could possible achieve is probably limited by
this upper limit of 7 percent detection of CIN2/3 that was found over the two
years in ALTS.
Other
randomized trials have showed similar results.
This study by Dr. Alvarez who is here in the audience today was a
randomized trial 11 years ago in which 375 women with an SIL Pap were referred
either immediately to colposcopy with biopsy or to LEEP. LEEP, of course, ascertains the majority of
the cervix and is a truer standard for how much disease is really on the
cervix. And you can see that there is
approximately a 40 percent deficit in the colpo with biopsy group over the LEEP
only group, again indicating the imperfect sensitivity of colposcopy.
So
in summary, in terms of missed cases of CIN2/3 we can say that approximately 60
percent of CIN2/3 in the U.S. is found in follow-up with ASCUS and LSIL Pap
results, making this the most important group of Pap triage; that one-third of
the CIN2/3 is missed at initial colposcopy by experienced colposcopists. And we have to remember, all our trials are
always done in centers with high levels of -- colposcopy clinics with high
attendance, and that the majority of colposcopists in the United States do not
have the opportunity to have this level of experience. So this sets the bar much higher for an
adjunctive test, because we presume we're probably catching more in these
experienced colposcopy clinics than we do in general colposcopy. And two-thirds of the remaining missed
CIN2/3 in the ALTS trial was only detected during follow-up, and many of these
only with exit LEEP done very liberally for standards that we might not do in
the routine community. So many women
certainly must remain at risk in routine care.
And
finally, when you look at the data for the LUMA trial, keep in mind that the 7
percent is likely to be the upper limit of possible CIN2 detection so that when
you look at the percentage that LUMA provides as increased detection, keep it
with that bar in mind. And I'd like to
introduce Dr. Ross Flewelling who will talk about technology overview. Thank you.
DR.
FLEWELLING: Good morning, I'm Ross
Flewelling, the Chief Technical Officer of MediSpectra. I'd like to briefly review the basic science
and the mechanism of action underlying our optical detection system. I would like to review the algorithms used
in the system, and our non-clinical testing.
The
scientific basis of tissue spectroscopy in the LUMA system, it's been well
established over a number of years in that there's a great literature, which
it's been extensively investigated for more than 20 years in over 200
peer-reviewed publications. There are
currently three FDA-approved optical devices that assess in vivo tissue
dysplasia in endoscopy and bronchoscopy.
The LUMA system uses three combined optical measurements, fluorescence
excitation, white light backscatter, and video imaging. The fluorescence excitation is from a
337-nanometer laser that excites native fluorescence in the tissue, which we
pick up in the entire visible spectrum, from 320 to 720 nanometers. We also have white light backscatter or
reflectance, diffuse reflectance, which we also collect the data in the full
spectrum. And we do video imaging. Video imaging is used to provide an image of
the system, to align and focus the system, to identify and control for motion,
as well as to identify obstructions such as blood, mucus, vaginal wall, and so
on.
The
system stands 100 millimeters off of the cervix in a non-contact configuration,
and the complete scan takes 12 seconds.
The scanning probe head is shown on the right. A disposable cover is placed on the probe head, and a bar code
allows for unique identification. It's
positioned 100 millimeters from the cervix, outside of the speculum. The system is shown on the right. Inside the console are all the light
sources. The light is conveyed out
through fiber optics to the probe head.
Mirrors are used to scan the cervix, collect the light back into the
probe head, back through fiber optics, into spectrometers in the base
system. On the upper left is shown the
cervical scan itself. It's a
25-millimeter diameter area, 499 points at 1-millimeter resolution in a dense
hexagonal path array. We do full
spectroscopy at each point, and again that takes 12 seconds.
On
the left is an image taken with the system in two different areas determined by
pathology. In the upper left is a
normal squamous area determined by pathology that gives rise to the spectrum on
the right, the blue curves, the fluorescence on the top, and the reflectance on
the bottom. In the area near the
cervical os is CIN2/3 by pathology is shown on the red curves. And for comparison you see, and this is a
consistent observation, in normal squamous tissue and fluorescence is
significantly higher than the diseased tissue.
In reflectance it's the reverse.
The CIN2/3 has higher reflectance than normal squamous tissue, and
that's consistent with acetowhitening effect.
The
biological basis as contained on this slide, the areas in blue, are the ones
that we're particularly interested in with our system. In reflectance, or white light backscatter,
we're looking at light scattering and hemoglobin. So hemoglobin would be associated with vascularity or angiogenesis,
changes associated with dysplasia.
Also, cell nuclei and organelles, the size, the crowding, the chromatin
content of the cells, lead to higher light scattering, acetowhitening effect,
which we pick up in reflectance. In
fluorescence, what we see are both functional components and structural
components in the tissues. In particular,
in our spectra, with 337 nanometer excitation, we believe we're looking at
NADPH, a metabolic protein, and collagen, a structural component.
We
then take that information and we use a multi-spectral, multivariate
integration of those three optical measurements. Again, the video imaging is used for multiple purposes, to align
and focus, to control for motion, but we also use it in the processing to
identify non-epithelium. We look for
the smoke tube, the vaginal wall, fluids, foam, and mucus. And that's identified by video imaging.
We
use the fluorescence and reflectance spectroscopy in an integrated algorithm to
identify tissue. So we've developed a
classification algorithm, but on implementation it is a deterministic system
that provides the output shown on the right, which is an image of the cervix
where blue areas with the false color overlay, with the blue indicating
high-grade disease, or high probability of high-grade disease. This algorithm was established through a
pilot clinical study conducted in 2001.
It involved colposcopy referral patients, 433 patients with one or more
biopsies, an additional 133 patients with LEEPs. Those LEEPs were sectioned into 12 different slices, and the
pathology was read along the full surface.
So we could correlate detailed pathology to the optical measurements
themselves. In total, we had pathology-qualified
measurements on over 1,500 individual samples that could be correlated with our
optical measurements into five diagnostic categories: CIN2/3, CIN1, metaplasa,
normal squamous, and normal columnar, although in the end we are only
identifying CIN2/3 as distinct from the other categories. And that was published last year in the Gray
Journal.
In
establishing the algorithm, as with any diagnostic device there's a tradeoff in
sensitivity and specificity for the system.
The LUMA algorithm was optimized to provide enhanced sensitivity with
comparable specificity compared to colposcopy.
The algorithm was then locked.
We conducted Pivotal Study I. The
algorithm itself consisted of over 70,000 lines of code, and during the two
years it took to plan and execute Pivotal Study I we did identify some coding
errors during that time. Those were
fixed before we started Pivotal Study II.
And then we conducted Pivotal Study II.
We have reviewed those changes in greater detail with the FDA, and we
are in agreement that they did not materially affect the outcome of Pivotal
Study I.
And
finally, we conducted a battery of tests in non-clinical testing, environmental
testing against recognized standards that are shown on this slide. Now both electrical and optical safety
against recognized standards also shown here.
Now I'd like to introduce Dr. Joan Walker, who was a principal
investigator for our studies.
DR.
WALKER: Good morning. My name is Joan Walker. I'm a Section Chief of Gynecologic Oncology
at the University of Oklahoma. I have
no financial ties to MediSpectra except that they've paid for my time and
travel for preparation of this meeting.
I
worked with Mark and Diane on the ALTS trial from 1995 to 2000 as a clinical
center PI, and then after that trial was over began working with MediSpectra on
their trials. And I assert my purpose
here is to show how wonderful this device is at helping me to become a better
colposcopist, identifying alternative sites for biopsy in hopes that I can
detect that disease that I was previously missing and hopefully won't have to
watch that lady die of cancer 10 years afterwards.
I'm
going to go over the LUMA system and go over the clinical trials briefly. The clinical use of this LUMA device shown
here is going to be shown in a video.
That video was shortened considerably so you won't have to sit through
15 or 30 minutes of colposcopy. I'll
demonstrate the system setup, how the patient is prepared, how the scanning
steps are integrated with the colposcopic examination, and then how those LUMA
results are visualized.
The
LUMA cervical imaging system is a self-contained mobile unit. A picture of it is going to be shown
here. That device has a scanning probe
which is on an articulating arm which allows you to move that probe into
position to visualize the cervix. The
probe is stored in this calibration port, and it also is calibrated for each
individual patient. The patient
information is placed in the system with the keyboard. And this is a completely hands-free device
with foot pedals which can control the device.
Each patient has a disposable probe cover which is applied to the probe,
and then it is calibrated before each exam.
The
patient is then prepared as a usual colposcopic exam. Speculum is placed in the vagina, the cervix is bathed in
vinegar, the vinegar timing device is initiated on the instrument by pushing
the foot pedal, in order to make sure that enough time has elapsed to allow the
development of that acetic acid picture.
Then the probe is visualizing the cervix, and then it is aligned with
some special alignment dots. They have
three alignment dots which have to be placed inside of the yellow focus circles
in order to get the appropriate image, and then if the acetic acid timer has
passed the 30-second mark but before the 120-second mark, the probe is asked to
take the scan, and then the probe is pushed aside, and the usual colposcopic examination
proceeds as you would ordinarily do. So
the patient's cervix may be reapplied with vinegar, the examination can take as
long as it needs to in order to find the appropriate places to biopsy. The colposcopist then biopsies as many times
as is necessary in order to do the usual colposcopic examination.
Then
they visualize the scanning results.
And this is an image that's just without the scan on top. And then when you ask the machine to show
you the scan, you can see blue highlighted areas that you may not have noticed
at your initial colposcopic examination.
And so then you can direct additional biopsies on top of the ones you
already selected based on how intense this blue light is showing. So you might choose to biopsy here, and you
might choose to biopsy here. You also
can flip this on and off with the foot pedal in order to identify anatomic
landmarks, in order to get the biopsy placed in the proper location on the
cervix using the colposcope.
I
hope that I have demonstrated how easy this instrument is to use. It is a non-contact device. It's easily integrated into your everyday
practice. It has a very simple-to-use
clinical interface, and there's a very straightforward interpretation of
displaying these results.
I
am going to now briefly go over the studies that we've conducted. There were two separate studies performed,
2,500 and 2,600 patients were enrolled.
There were two completely different study designs which ended up with
similar results. They were conducted
over 15 months in 13 different practice center using 52 colposcopists. There were local full IRB approvals, and
this was a non-significant risk study, and was IDE exempt. The inclusion criteria were age greater than
18 years or age of consent, the patients were referred in order to detect
CIN2/3 in patients that had abnormal Pap smears, ASCUS, LSIL, HSIL, or even
cancer. The exclusion criteria were
pregnancy, heavy menstrual flow, or a biopsy if it had been performed since the
last Pap smear had been performed. The
Pap smear must have been at least seven days old but no greater than six months
old. And this is the sites of all of
those study centers, showing that it is very representative of the United
States population. And these are the
PIs at each of those sites, many of which you may be familiar with. The colposcopic characteristics that doctors
-- there were 46 OB/GYN physicians, 15 of which were GYN oncologists, many of
which were also on the ALTS trial, three family practice physicians, three
nurse practitioners. All investigators
were required to have experience and training in colposcopy.
The
pathology material was blinded. It was
sent to two pathologists who had to adjudicate their slide review. If they disagreed, a third pathologist was
brought in. The diagnostic categories
of each biopsy was no evidence of disease, CIN1, CIN2/3, or cancer. But the patients were categorized as either
having CIN2/3 or not. These are the
pathologists who visualized these specimens.
I
will now introduce Dr. Wright. Thank
you.
DR.
WRIGHT: Good morning, I'm Tom
Wright. I'm the Medical Director of
MediSpectra. I have a financial
interest with stock in the company.
What
I want to present are the results of the Pivotal Study I. This study was a dual arm randomized
trial. All patients entering into this
study were randomized to receive either -- the cervix was washed with acetic
acid. They then performed a LUMA scan. The patients were then randomized to either
have that scan blinded, or to have the scan un-blinded. In the arm in which we had a blinded scan,
the clinicians performed routine colposcopy as they would normally do in
practice. In the arm in which was LUMA
with colposcopy, the clinician saw the scanned results. At the time, they selected sites for
biopsy. So they performed routine
colposcopy while looking at the sites, and would take additional biopsies as
needed.
Patients
were referred to colposcopy because of an abnormal Pap result. This included ASCUS, LSIL, or HSIL. It's important to note that we began the
study in 2002. Not all sites were
separating ASC-H away from ASCUS, and therefore we have a mixture, with some
patients listed as ASCUS only, and you have some ASC-H's also. This was prior to the widespread adoption of
HPV-DNA testing, so we do not have HPV testing results on these patients. Randomization was done by entry Pap to
ensure balance between the arms. Study
endpoints were true positive. That was
a patient with at least one biopsy diagnosis of CIN2/3. True positive rate is directly proportional
to sensitivity and false positives, which are patients with all negative, no
CIN2/3 biopsies. So a patient with CIN1
would be considered to be a false positive.
Our
study hypothesis for true positive rate was that the true positive rate is
greater for LUMA with colposcopy than for colposcopy alone. Therefore, the lower bound of the 95 percent
confidence interval needs to be greater than zero to meet the study hypothesis. Our study hypothesis for false positive rate
is that the false positive rate for LUMA with colposcopy is no more than 8
percent greater than for colposcopy alone.
Therefore, the upper limit of the 95 confidence interval for the
difference between the arms needs to be no more than 8 percent.
We
also determined that we needed to perform joint consideration of true positive
and false positive rates. This was
stipulated in the initial protocol, although we did not specify the
method. True positive and false
positive rates will be simultaneously considered to determine that the
incremental gain of true positives merits a change in the false positives. So to look at the tradeoffs.
We
enrolled 2,299 patients. This was a
very large study. Only 113 were
excluded. The major reason for
exclusion was incomplete pathology.
Leaving us with 1,096 patients in the colpo arm, and 1,090 in the LUMA
arm. When we look at patient
characteristics across arms you can see that the two arms are well
balanced. Identical median ages. We have a strong minority representation in
this trial, and balancing of Paps as to ASCUS, LSIL, and HSIL across the two
arms.
This
slide shows true positive outcomes by arm, where are comparing the true
positives in the LUMA plus colposcopy versus colposcopy alone. And if we look overall at the difference, we
had a 1.9 percent increased true positive rate in the LUMA plus colposcopy
compared to colposcopy alone. This was
not as high as we expected. The reason
we do not believe it was as high as expected is when you look in the HSIL arm,
what you see is no increase in true positives among the LUMA patients. When you look, however, at the ASCUS/LSIL
arm, what you see is that we have a 3 percent increase in true positives in the
LUMA plus colposcopy arm compared to colposcopy alone.
We
recognize that combining the ASCUS/LSIL strata is in fact a post hoc
consideration. Having said that, there
is a very strong clinical reason for combining patients with ASCUS and
LSIL. First, we know that the disease
prevalence among patients with ASCUS and patients with LSIL is quite
similar. They were almost identical in
this study, the TP, true positive, rates.
These are markedly different than what we see in patients with
HSIL. In addition, as you've already
heard from Dr. Cox, the ASCUS/LSIL population is a predominant population which
is seen at colposcopy. It comprises
approximately 80 percent of all patients referred to colposcopy. And the clinical management guidelines are
quote different between patients with ASCUS and LSIL, and patients with
HSIL. Patients with HSIL tend to get a
LEEP irrespective of what is found at colposcopy, whereas patients with ASCUS
and LSIL do not.
I've
shown you already the true positives in terms of absolute difference. What I'd like to now do is focus on true
positives in terms of relative gain.
When we look at the ASCUS/LSIL category, there were 99 women with
biopsy-confirmed CIN2/3 in the colposcopy-only arm, and there were 126 women,
27 additional cases of CIN2/3 identified in the LUMA plus colposcopy arm,
giving you an absolute gain of 3 percent, and a 26.5 percent relative
gain. If you remember back to the
discussions of ALTS, what was shown though, approximately one-third of the high-grade
cases were missed at the initial colposcopy.
Here we are seeing a 26.5 percent relative gain in detection of true
positives.
This
slide plots the standard error bars, looking for the Pivotal Study I true
positive outcomes overall and in the ASCUS/LSIL group. And what you can see is that in the
ASCUS/LSIL group, the 3 percent absolute gain does not quite meet statistical
significance. It is very close, but it
just simply does not quite meet statistical significance. When we look at Pivotal Study I in terms of
false positive outcomes, overall we meet the study hypothesis. However, when we look at the ASCUS/LSIL
group, again, we do not meet statistical significance, but it is very close
again.
Another
way to look at false positives is to look at the mean biopsies which are taken
with and without LUMA. When we look
either overall or in the ASCUS/LSIL strata and we look at the differences in
the mean biopsy rates between the two arms, what we find is only a 0.27 or a
0.31 increase in the number of mean biopsies per patient. So the number of biopsies in the LUMA arm is
greater in the ASCUS/LSIL strata by only 0.3 biopsies per patient.
When
we look at positive predictive value, which is another way of looking at the
efficiency of biopsies, what we see is that in every single case, in the LUMA
and colposcopy arm, we ask the clinicians to designate whether or not an
individual biopsy was taken on the basis of the LUMA result, or on the basis of
the colposcopy result, or on the basis of both. When we look at the positive predictive value of biopsies which
were taken because they were only colposcopy positive, we found that the
positive predictive value is 10.8 percent.
When you look at the biopsies which were taken only on the basis of the
LUMA result, the colposcopy was not considered to be abnormal, they had a
positive predictive value of 8.6 percent.
This is greater than what has been seen in studies which have looked at
random biopsies.
In
addition, and very importantly when we talk about the benefits of using LUMA,
when we look at the positive predictive value of biopsies that were both
LUMA-positive as well as colposcopy-positive, they went from 10.8 percent for
colposcopy only to 18.1 percent for those biopsies which were also
LUMA-positive. So a significant
increase in the positive predictive value of biopsies which are taken on the
basis of also being LUMA-positive.
I'd
now like to walk you through a couple of cases, because for clinicians I think
cases are really important to see what we're talking about. Here you can see the colposcopic image in
the patient referred for ASCUS. You can
see there's some very faint acetowhitening on this case. Very small areas of acetowhitening. The colposcopist did not think these were
significant, and did not feel that they needed to take a biopsy. Here you can see the LUMA overlay, and you
can see areas of blue present in the 7 o'clock position, and a biopsy taken at
7 o'clock turned out to be CIN2/3. The
clinician did not feel they needed to take a biopsy.
When
we look at another case, this is a case with a reasonably broad area of
acetowhitening present around much of the cervix. Again, this was a patient with an ASCUS Pap smear. The colposcopist -- and remember, these are
all trained colposcopists. Many of
these were colposcopists who participated in the ALTS trial. They felt there was no need for a
colposcopically directed biopsy in this patient. However, when you look at the LUMA overlay, you can see that LUMA
identified a number of areas of dark blue in this patient, indicating high
probability for a disease, and a LUMA-directed biopsy taken at 10 o'clock
turned out to be CIN2/3.
I'd
now like to turn to false negatives.
Remember that the LUMA algorithm was tuned in order to try and make it
equivalent to colposcopy in terms of sensitivity and specificity. And we do not expect that every true
positive will be positive using the LUMA device. Just like colposcopy, there are going to be cases which are not
positive. There were 126 true positives
in the ASCUS/LSIL arm in the LUMA -- in the ASCUS/LSIL strata, in the LUMA plus
colposcopy arm, and 26 of those 126 were colposcopy-positive but were
LUMA-negative. So 20 percent of
them. You need to recognize, however,
that there were also 15 cases which were LUMA-positive but which were
colposcopy-negative. 11.9 percent. And it's because of this that we feel that
LUMA's role is as an adjunct to colposcopy.
The role of LUMA is not to replace colposcopy.
In
terms of safety, I think it's critical that we recognize there were absolutely
no device-related effects out of 2,299 patients. We had four patients with minor adverse events. These are events typical of what we see in
any colposcopy which can occur.
We
preformed additional analyses, looking at learning curve, cervicitis. No significant effect of those were seen on
LUMA performance. We've also done
random biopsy comparison. We've looked
at colposcopists and site variability, joint analyses, and age.
I'd
like to focus first on age. The FDA and
MediSpectra performed post hoc analyses to evaluate any possible age
effects. The FDA performed a Bayesian
analysis that identified a possible age effect in PSI. This was very sensitive to the particular
age cut, and it was the only analysis which it found any age effect for
LUMA. MediSpectra has analyzed the data
using multiple methodologies, and did not identify any age effect, including
looking at age as a continuous variable.
And important to recognize, in PSII, which you are going to hear about
in a minute, there was no age effect which was seen.
The
reason that I think we have to be cautious about evaluating the effect of age
is that here you can see when you make the cut at less than 21, it appears to
be a much greater impact of LUMA than at the other ages. However, when you look at the distribution
of patients in our study, what you find is that it's very skewed, and there are
a lot of patients between the ages of 18 and 24 who are enrolled into this
study. If instead of making the
somewhat arbitrary cut at age 21, instead we divide the population into the
true tertiles in terms of the population and break it at 23 and at 33 into true
tertiles, what we see is that their LUMA has an increased TP rate across all
three age groups.
Another
way of looking at this is to actually remove patients under the age of 23 and
only look at the patients who are over the age of 23. And what we find is that the true positive, the increase in true
positives is 3 percent among women over the age of 23, which is identical to
what we see with the overall population, as well as a group of women under the
age of 23.
Finally
with respect to age, we've looked at this in terms of true positive rate. We recognize that this is not adjusted for
prevalence of disease, but you can see that there is a similar true positive
rate in the LUMA-only increment across all ages. So in summary with respect to age, we believe that LUMA has shown
the ability to identify true positives across a wide range of ages. Multiple statistical tests performed by the
sponsor have not found an age effect, and no age effect is seen in PSII.
Colposcopist/site
variability. Analysis supports pooling
for true positive outcome across sites and colposcopy. The sponsor has assessed confidence
intervals using fixed and random effects, and it appears that random effects
confidence intervals are slightly wider.
Joint
considerations. We pre-planned to
perform joint consideration of true positive and false positive increase in
order to weigh tradeoffs. These
considerations take into account the fact that the three possible outcomes of
true positive, false positives, and no biopsies are interrelated, not
independent. And what we find in these
joint consideration analyses is that a statistically significant difference
between arms for both the overall and the ASCUS/LSIL group.
So
to conclude, our true positive rate increases in the ASCUS/LSIL strata are 3
percent, which corresponds to 26.5 percent relative gain. Our false positive rate in the ASCUS/LSIL
strata is moderate. It is only 3
percent. And we see with the use of
this device an increase in positive predictive value from 10.8 percent for
colposcopy-only biopsies to 18.1 percent for biopsies which are identified by
both LUMA and by colposcopy, indicating that this device is identifying sites
of high-grade disease. So in overall
conclusions, we found a substantial increase in the relative number of true
positives. LUMA clearly identifies
cases of CIN2/3 which are missed by colposcopy. You've seen two of those.
LUMA improves positive predictive value compared to colposcopy. There are absolutely no safety concerns, and
only a minor increase in false positives.
And we believe that Pivotal Study I shows that the risk/benefit profile
of LUMA is compelling.
We
are now going to go into further depth on the joint inference testing. Dr. Brent Blumenstein.
DR.
BLUMENSTEIN: I'm a consultant to
MediSpectra, but I do not own stock. So
I'm going to talk a little bit about an analysis that we did that focused on
the outcome for a patient as a trichotomy; that is, the patient is either
considered to be true positive, false positive, these two being a result of
having had a biopsy, or no biopsy was taken for the patient.
The
original protocol specified separate analyses for TP and FP. And all of the results that you've seen up
until now do those separate analyses.
But the protocol also talked about the idea of doing joint
analyses. The trichotomist analysis
that I'm going to show you now accounts for the outcome dependencies between
these three outcomes. The confidence
intervals and other things like that that you've seen up until now do not take
into account those outcome dependencies, and are therefore broader than they
need to be because they are insensitive to the value of the other parameter
being discussed. The joint inference is
true to the original objectives of the protocol, and that is to assess the LUMA
benefit relative to an expected increase in the number of biopsies.
The
data structure in the trichotomist analysis is just a 2x3 frequency table. There are two arms by three possible
outcomes. The sum of these three
frequencies to the total for that row is the thing that induces the dependency
of these outcomes. The samples for the
arms, M, the N patients in the colpo only arm and the N patients in this arm,
are independent, but the samples this ways are not independent. The endpoint dependency is induced by the
sum requirement.
The
2x3 table can be analyzed simply as a contingency table using chi-square or
exact tests. We use a more
sophisticated modeling methodology called the Grizzle-Starmer-Koch method for
things like addressing interactions, and so forth. This is the 2x3 table for all strata in PSI. And this is the trichotomist analysis of
this. The Cochran-Mantel-Haenszel test,
which is a stratified test in this table, gives a p-value of 0.0112, and an
exact test that's not stratified gives a p-value of 0.0132. Both of these are significant, and we prefer
to look at these as gatekeepers for subsequent analyses, although these do
establish a result in PSI that's not specific to any kind of outcome, but
rather tests whether there's homogeneity in the probabilities within the
arms. And this is part of the purpose
of this analysis is to assess the between-arm difference, and then to focus on
what those between-arm differences mean.
Now
this is the detailed analyses that were done following this initial
analysis. This first row just repeats
the previous slide. These are the
p-values that you saw for the overall test.
At that point after we have done this we wanted to find out if there was
an arm-by-strata interaction. That is,
testing whether the arm effect that is -- the arm differences are uniform
across the strata. We find that we had
a p-value of 0.0175 here, indicating that there are significant arm-by-strata
interactions. Now you've already heard
about the clinical rationale for treating the HSIL patients differently, and
this provides the statistical rationale for that.
So
we chose to drop the HSIL data, and focus on the remaining data, that is the
ASCUS and LSIL. The first step in that
was to assess whether there was an arm-by-strata interaction within the
remaining data. And the p-value for
that is 0.1737, indicating that there is no evidence of an arm-by-strata
interaction. Finally, the p-values for
the remaining data, without HSIL, the primary analysis of between-arm
differences are given here. Now these
p-values are measured against a standard of 0.00714, which is 0.05 divided by
7. This correction in the significance
level to be used is made because we have now re-stratified the data in order to
focus on the relevant strata.
The
consequences of this joint test is that we have between-arm differences, and
now we have to characterize these between-arm differences with respect to
measures of effect. We can choose two
measures of effect. You've seen
previously the TP rate difference, and the FP rate difference as measures of
effect. The joint p-value is not
dependent on our choice of measures of effect, however. So we can choose different measures of
effect to understand the between-arm differences. One of the things I'm going to show you in a minute is an odds
ratio. This is something statisticians
like but other people don't like so much, but there's a particular insight that
I want to communicate to you about that.
The
joint tests say that one or both measures of effect between the arms
differ. It's important now to assess
the direction and magnitude. Now this
is a contour plot. On the horizontal
axis is the FP difference. On the
vertical axis is the TP difference. And
if you can think of coming out of this screen are the probability of every
possible table that is in that 2x3 contingency table, the probability of every
possible table comes out from this. And
these contours show the boundary such that everything outside of this inner
boundary here has a probability of 0.05.
Everything outside of this outer circle has a probability of
0.00714. This is the adjusted criteria
for significance. The result of this
trial is right here. This is the 3
percent TP difference and the 4 percent FP difference. And you can see that it is outside of the
boundary, the 0.00714 boundary, and that's why it's significant. You can also see that this outcome for this
trial is in the upper right quadrant, which is what you would expect for an
adjuvant therapy. It's not over here,
it's not down here, it's not down there.
It's here, which means that the TP difference is positive, favoring
LUMA. The FP difference is as expected,
higher than zero, but it doesn't approach the 0.08 criterion that we had in the
protocol as being undesirable. So this
is the representation of the outcome of the trial with respect to TP difference
and FP difference. Two measures that
are imposed on the 2x3 table that was analyzed.
We
an choose two other measures. Here are
some odds ratios. Now, I know that most
of you are going to have a little trouble with this, but I'll -- bear with me. The TP odds is basically related to the TP
rate difference, and it's just the ratio of the odds of having a true positive
between the arms. And this is 1.31,
which is in favor of the LUMA arm, a number greater than one favors LUMA. Now, the interesting one is this. This is the TP to FP odds, basically the
ratio of the TP outcome within an arm to the FP outcome in an arm. And it represents the efficiency with which
the biopsies taken yield a TP result.
Now, if we take the ratio of those odds, we get 1.19. This is a relative efficiency measure of the
biopsies taken. And the fact that this
relative efficiency measure is greater than one is an indication that the
biopsies taken in the TP arm are more efficient at identifying true positives
than are the biopsies taken in the colpo only All right. So these measures are just alternative ways
of viewing the outcome from the trial after we have tested for between-arm
differences.
So,
the joint inference provides strong evidence that there's a significant
difference between the arms. The methods
that we used here matches the actual data.
While it wasn't pre-specified exactly in the protocol, it does match the
actual data, it's more rigorous than the methods that we previously presented,
and it's true to the original objectives of the protocol. So the end, finally, depending on which
measure we use, the direction and magnitude are consistent with LUMA patient
benefit.
Finally,
we also see from the joint analysis that we have a significant result both for
overall, that is including all strata, and after we have eliminated the HSIL
strata. Thank you. Now Warner Huh will present the PSII data.
DR.
HUH: My name is Warner Huh. I'm a GYN oncologist at the University of
Alabama at Birmingham. I served as the
PI for Pivotal Study II at our institution.
I also was a study colposcopist for the ALTS trial at the UAB site. I've been reimbursed for my time, for
preparation, and travel to this meeting, and I do not have financial interests
or stock in MediSpectra.
Pivotal
Study II is different from Pivotal Study I in that it's a single-arm internally
controlled design trial. I think it's
important for the panel to know that each patient served as their own control
in this study. So after subjects were
consented, the cervix was washed and acetic acid was applied, a LUMA scan was
performed, but blinded to the investigator.
At this point, standard-of-care colposcopy was performed with biopsy
commitments, and these biopsy commitments were annotated on the screen, and
locked into place, and could not be changed later on. And at this point, the scan was un-blinded to the investigator,
and this committed to take biopsies at LUMA-indicated sites. These were also locked into the computer and
could not be changed later. All biopsy
sites were revealed. They were asked to
take all biopsies, and these were sent off to the reference pathologist.
I'd
like to briefly just kind of go over the annotation sites and how this worked
in Pivotal Study II. Again, this is an
image of the cervix after acetic acid had been applied. At this point, a blinded LUMA scan has been
performed, and a colposcopy is performed at this point. In the yellow circle was an area that was
deemed to be clinically or colposcopically significant to the investigator, and
this was locked into place and annotated.
At this point, the scan was revealed to the investigator, and asked to
take a LUMA-indicated biopsy, and note this on the screen as well. And this is marked by the green circle. And again, this was locked into place and
could not be changed later on.
All
biopsy sites were revealed.
Investigator was asked to take a biopsy at the yellow circle, and the
green circle, and these biopsies were sent off to the pathologist. And we'll review this case later on in the
presentation.
In
terms of subjects and controls, all patients were referred to colposcopy for an
abnormal Pap smear, including those patients with ASCUS, LSIL, and HSIL. And as previously discussed by Dr. Wright,
these ASCUS patients include those patients with ASC-H and ASCUS under the new
terminology. And again, each patient
served as her own control in the study, unlike PSI.
In
terms of the study endpoint definitions.
The LUMA true positive rate is defined as follows. Incremental true positive patients are
colposcopy patients without CIN2/3 as a percent of the total population. For the LUMA false positive rates as
follows. The incremental false positive
patients are among colposcopy no-biopsy patients, again as a percent of the
total population. And these constituted
the study endpoints.
The
following is a diagram breaking down the true positive definitions. After enrollment, all patients underwent
colposcopy, and these patients were split into those patients who were
colposcopy-positive, those patients who identified with CIN2/3, and
colposcopy-negative. And this includes
those patients without biopsies, and those patients without CIN2/3. The LUMA increment is based on the
colposcopy-negative patients only, as shown in this diagram, and are broken
into LUMA-positive and LUMA-negative patients.
Again, LUMA-positive patients are those patients who are identified with
additional cases of CIN2/3.
The
study hypothesis are as follows. The
LUMA incremental true positive rate was set at least 2 percent for the overall
population. In other words, the lower
95 percent constant was greater than or equal to 2 percent. For the LUMA incremental false positive
rate, this was set at less than 15 percent for the overall population. In other words, the upper 95 percent
constant was set at less than 15 percent for this study.
In
terms of the patients enrolled and excluded, there were 227 total subjects that
were enrolled in this study. Fifteen
percent, or 34 subjects, were ultimately excluded, with the most common reason
being incomplete pathology. I think
it's important for the panel to note that there was a lot more stringency in
terms of the pathology, and if the pathology was incomplete for any reason that
subject was ultimately excluded from the final analysis. And in terms of the patients analyzed, the
overall majority of these patients had ASCUS and LSIL, with the remaining 14
percent of patients having HSIL.
In
terms of the patient characteristics, the mean age for this study was 28.5
years. And in terms of race breakdown,
we had an excellent distribution in terms of minorities and other racial
breakdown. This is similar to that seen
in Pivotal Study I. And again, in the
Pap smear distribution, the overwhelming majority of patients had ASCUS and
LSIL. It is important to note, however,
in the HSIL group we had fewer HSIL patients than that seen in Pivotal Study
I.
Reviewing
this slide again, I think it's important that the panel note again, the LUMA
increment is based on only those patients who are colposcopy-negative. We did not include the colposcopy-positive
patients. And again, it's broken down
into LUMA-positive and LUMA-negative.
To go over the numbers briefly, there were 193 subjects that were
enrolled in this study. Again, they all
underwent colposcopy. Forty-one
patients had a positive colposcopy for CIN2/3.
The remaining 152 subjects either had no biopsies or no evidence of
CIN2/3. There were nine additional
patients with CIN2/3 on the LUMA increment, and 143 patients were
LUMA-negative.
When
you use the protocol definition of a denominator of 193 subjects, the LUMA
increment rate was 4.7 percent for this study.
So in terms of overall true positive outcomes based on the original
protocol definition, there was a 4.7 percent LUMA increment compared to that of
21.2 percent for colposcopy. And our
overall study hypothesis was net greater than 2 percent. Again, the p-value for this was 0.0164.
Even
though the original protocol definition was set as the denominator of 193
subjects, or all subjects involved, we actually felt that a more perfect
definition would be those patients who would be eligible. In other words, those patients who were
colposcopy-negative, not the colposcopy-positive patients. And when you use 152 for the denominator,
the eligible population rate for true positives in the LUMA increment was 5.9
percent.
Again,
we feel that the eligible population is probably the more appropriate
definition, but irrespective of which definition you use, both the total
population and the eligible population met its study hypothesis, and the
following is a depiction of the standard error bars for both groups.
I'd
like to review some case studies as Dr. Wright had done for Pivotal Study
I. This was reviewed earlier in the presentation. Again, this is a patient who was referred to
the study with an ASCUS Pap smear, and underwent colposcopy and a blinded LUMA
scan. Again, there's an area that was felt
to be clinically significant right here by the colposcopist, and as such had
annotated a colposcopically interesting biopsy site with the yellow
circle. But if you note, an additional
LUMA-indicated biopsy site was taken from the blue spot, which is directly
adjacent but does not overlap the yellow circle. I think in reality, this probably represents one entire lesion,
and two separate biopsies of that lesion.
And of note, at the yellow site, the colposcopy site there was no
evidence of disease, and at the green circle there was evidence of CIN2/3.
The
following is another example. This
patient was referred to the colposcopy clinic with an HSIL Pap smear, and
again, underwent a blinded LUMA scan and standard care colposcopy. And in this example, at approximately 11
o'clock, the colposcopist felt that this was a clinically interesting or
colposcopically significant lesion that merited biopsy. But of note on the complete opposite side of
the cervix, perhaps an area that the colposcopist would not have picked up, was
a LUMA-indicated biopsy site. And in
the yellow circle, again, this was no evidence of disease, and in the green
circle was consistent with CIN2/3.
MediSpectra
and the FDA had agreed to adjust the overall true positive null hypothesis
based on the prevalence of disease from 2.5 percent to 2.0 percent. This was based on interim data from Pivotal
Study I. In that sense, the sponsor
also applied the prevalence adjustments to endpoints across study strata in
proportion to the study prevalence assumptions. And to review again, the overall was set at 2.0 percent, HSIL was
set at 4.0 percent, and ASCUS and LSIL was set at 1.5 percent.
When
you actually review the true positive outcomes for Pivotal Study II, both for
overall and the ASCUS/LSIL strata, again as previously mentioned, we met our
study hypothesis for overall group either when you use the total population
definition or the eligible definition.
For ASCUS and LSIL, we met our study hypothesis when you use the
eligible population definition with a set rate of 1.5 percent. This was not met for the total population
definition.
Again,
the following is a depiction of the standard error bars for the total
population and the eligible population.
And to reiterate, again for the eligible population we met our study
hypothesis.
The
following is an example or a review of the relative percent in gains for the
two different groups and for the strata involved. Again, for the total population under original protocol
definition for the overall group, we demonstrated a 22 percent relative percent
gain in the detection of CIN2/3. The
ASCUS and LSIL strata we demonstrated a 25 percent relative gain. For the eligible population of device
performance, for overall ASCUS/LSIL we demonstrated 27.8 percent and a 29.2
percent relative gain respectively.
In
terms of false positive outcomes, when you actually review the overall group,
including the ASCUS/LSIL and the HSIL strata, we did not meet our false
positive hypothesis, and for the overall group was 18.1 percent.
In
terms of mean biopsy rates, overall roughly one additional biopsy was taken in
this study. And this is also seen with
the ASCUS, LSIL, and HSIL strata. And I
think it's important for the panel to recognize that this is largely a function
of the study design. What I mean by
this is that the investigators were mandated and asked to take an additional
biopsy at a LUMA-indicated site. This
was actually specifically in the protocol as such, and as such would probably
explain why there's an additional biopsy in this study.
In
terms of safety, and I'd like to underscore this, and this cannot be
overstated, there were no device-related effects seen in the 227 subjects that
were involved in the study, similar to that seen in Pivotal Study I. There were two patients with minor adverse
events, but these are commonly seen in patients who are undergoing the
standard-of-care colposcopy.
So
in conclusion, LUMA identified significantly more CIN2/3, the false positive
rate increase was expected, largely given to the study design, but was not felt
to be clinically excessive. Again,
there were absolutely no safety issues related to this device, and PSII
confirms the highly favorable risk/benefit ratio of LUMA as previously seen in
Pivotal Study I.
I'd
like to turn to Dr. Wright again for the conclusion of risk/benefits of LUMA.
DR.
WRIGHT: I'm going to try and put this
all into perspective, and try and show you.
We've got two trials. Multiple
studies, I think, have shown that a single colposcopy misses 20 to 36 percent
of CIN2/3. So there's clearly a
clinical problem. Multiple studies have
also shown the potential for increasing the detection of CIN2/3 using
spectroscopic methods. So the objective
of both of our studies was to measure the adjunctive benefit of adding LUMA to
a standard-of-care colposcopic exam. So
it's only looking at adjunctive benefit.
When
you look at the two studies combined, we have enrolled 2,526 patients, 52
colposcopists. These studies had to be
large because when you remember to the ALTS trial, only about 7 percent of
patients referred with ASCUS/LSIL have missed high-grade disease. So we had to do large studies. However, the overall size of these studies,
their ethnic and racial mix, and their geographic distribution clearly assures
that device performance has been evaluated in an intended-use population. And I really want to stress there were no
device-related adverse events in either study.
There are no safety issues that we have identified with the use of this
device.
When
you look at the two studies together, they show a remarkable consistency in
outcomes. When you look at the absolute
TP, true positive rate gain, patients with CIN2/3 who were identified using
LUMA in Pivotal Study I it's 3 percent, and depending on which definition you
use it's 3.6 percent to 4.2 percent in Pivotal Study II. Two studies with completely different study
designs, and we find exactly the same result.
When you look at the relative true positive rate gain, you find 26.5
percent versus 25 or 29 percent. Again,
exactly the same relative gain obtained with the use of this device.
We
also have shown that the positive predictive value of biopsies, which are
obtained based on colposcopy with LUMA are statistically greater than what we
find with those obtained by colposcopy alone.
And you saw in the joint inferences talk that these biopsies are more
efficient when taken with the use of LUMA.
When
you look at the statistical outcomes, and you look at Pivotal Study I, the true
positive outcomes, what you find is that the 3 percent absolute gain is almost
statistically significant. It isn't
quite there, but it's almost. When you
look at Pivotal Study II in terms of the true positive gains for the population
overall, using either definition of measuring device performance, total
population or eligible population, we are significant. When you look at Pivotal Study II, looking
at the ASCUS/LSIL population, what you find is that in the eligible population,
which we feel is the appropriate population, we are statistically significant
in terms of our true positive outcome.
When
we turn to false positive outcomes, what we find is overall in PSI we hit the
significance. But when we focus on the
ASCUS/LSIL group, again, we are almost statistically significant. The bar just crosses 8. When we look at the study hypothesis results
for Pivotal Study I, and I want to focus on the ASCUS/LSIL population, what you
find is that in terms of the study hypothesis for true positives, we do not
meet statistical significance, but again we are very close. When you look at false positives, we do not
meet it, but again we are very close.
And when you use joint inference testing, we do meet statistical
significance for Pivotal Study I, both overall as well as in the ASCUS/LSIL
population, which is our intended-use population.
When
we look at the same table for PSII, and we look overall, and in ASCUS/LSIL, we
meet our statistical hypotheses for true positives, but we do not for false
positives. We believe this is due to
the instructions to the clinicians to take a biopsy whenever possible. We ended up with one additional biopsy per
patient, but only one additional biopsy per patient.
So
when you take the two studies together, I think you can clearly take home that
both studies found a 3 to 4 percent absolute gain, which translates to a 25
percent relative gain in the detection of CIN2/3, in the ASCUS/LSIL stratum,
and both found clinically acceptable rates of false positives and false
negatives, given the adjunctive use of this device.
I
want to take you back to the slide that Tom Cox showed you for the ALTS
results. Looking at patients with
ASCUS/LSIL in the immediate colposcopy arm, where there was 21 percent
high-grade disease in this arm, 14 percent of it was identified at the first
colposcopy, 7 percent was identified on follow-up. We do not know the precise prevalence of CIN2/3 in our
population, but when you look at what we found in Pivotal Study II, we found 14
percent CIN2/3 identified by the initial colposcopy, and LUMA identified 4
percent more, suggesting that we are detecting about half of the cases which
are missed with regular colposcopy.
So
multiple studies have shown that a single colposcopic exam misses 20 to 36
percent of CIN2/3. Adjunctive use of
LUMA identifies 25 percent more cases of CIN2/3 than colposcopy alone. And it's important to recognize that this
identifies these patients here and now, at the time of the examination, so
hopefully we will have lower rates of loss to follow-up of patients with true
cancer precursors. And therefore we
believe that LUMA will provide an important clinical benefit to women with
ASCUS/LSIL cytology results. Thank you
very much.
CHAIR
NOLLER: Thank you. First time in the history of the panel I
suspect the sponsor finished a little early.
(Laughter)
CHAIR
NOLLER: Seventy-five seconds
early. Thank you for keeping to
time. We are running just a few minutes
ahead of schedule, and we don't want to discuss the product at this point, but
if there are points that need clarification, if panel members have a question
or two to address to the sponsor. And I
will open it.
It's
not entirely clear to me, if you look at your Slide 97, patient disposition
summary, you enrolled 227 individuals, you excluded 34 for various reasons, and
analyzed 193. But then you did an
eligible patient calculation that lost 41 individuals, and it wasn't entirely
clear to me why you excluded those 41 for some of the analyses, the 152
eligible participants. Who were those
that were dropped? Who would to address
that? Please state your name as you
speak.
DR.
WINGROVE: Theresa Wingrove from
MediSpectra. Could you clarify again,
the question was?
CHAIR
NOLLER: Well, if you look at your Slide
97, you have 193 patients analyzed, but then later you talk about eligible
population that is 152 patients. I just
want to know who those -- when you're talking about eligible population.
DR.
WINGROVE: Right, that's actually the
wrong slide. Can you pull up the box
plot? The total for protocol population
is 193 subjects after exclusions. The
number that you are referring to I believe, when that slide is up, represents
the number of subjects who were not found to be CIN2/3 on colposcopy. Okay, so those are -- actually the next
slide -- those are your colpo-negative subjects.
CHAIR
NOLLER: Thank you.
DR.
WINGROVE: That is the pool of subjects
for which --
CHAIR
NOLLER: Thank you, that's all I needed
to know. Are there other clarifying
questions? Yes, again, give your last
name before you speak.
DR.
D'AGOSTINO: D'Agostino. I'm just curious in terms of the
interpretation, and it's going to be something that we're going to have to
grapple with, and I'd like to hear what the sponsor has to say. Isn't another interpretation of the data
that in the Pivotal Study I the false positive failed, so you have a negative
study. Excuse me, the true positive
failed so you have a negative study, and that moving on to the joint analysis
doesn't really necessarily clarify the issue.
It's a post hoc analysis which has major interpretation problems, and
one of the reasons we don't tend to see this too often in practice is because
after you see a significant result it's very hard to interpret why the
significant results in the joint.
So
anyway, you have a negative because of the true positive. In the false positive we have a result
that's in the favor of the company, but there's an 8 percent margin, so you
don't produce more than 8 percent false positives. And where did the 8 percent come from?
Another
question in terms of this -- again, I'm trying to grapple with how I'm going to
interpret the data. This is a large
study, and with a large study you tend to say that I'm going to see
significance, and you didn't see significance.
So I'm carried away, and I mean this sincerely, in Pivotal Study I, that
I have a negative study with a large sample size that I should have somehow
rather seen things work out well and they didn't. And the presentation of all the rates are all based on -- or less
of non-significance. With the second
pivotal study, I see some sense coming out in terms of what you're saying if
I'm willing to shift my criteria for added yield using the LUMA from 2.0 to 1.5
for a particular subset. And also if I
shift the definition of the analysis sets from this all to eligible. I mean, these all have a reasonableness to
it, but they're all post hoc, and once you start getting into that you destroy
the statistical interpretation. So I'd
really like to hear the company, if possible, give some response to the
negative studies, and the need to redefine things in order to really get what I
don't still see as necessarily a clear picture.
CHAIR
NOLLER: Dr. Wright, would you like to
address that, please?
DR.
WRIGHT: Tom Wright. Yes.
I think it's important to put this into clinical perspective. Pivotal Study I was originally designed
believing that we would identify a positive effect of LUMA in patients with
HSIL as well as in patients with ASCUS/LSIL.
Once we found that HSIL, we did not have a positive effect of LUMA, that
removes approximately half of these two positives out of the HSIL study. So it means there are fewer true positives
to reach statistical significance.
The
other point in terms of false positives is that the 8 percent bar was really a
clinically decided upon bar. And it's
very arbitrary. False positives in
colposcopy are not a real issue. We
have done studies looking at different colposcopists. There's wide variations in different colposcopists. We picked an 8 percent bar based on an
arbitrary criteria, that is 8 percent clinically any different than an 8.5
percent.
DR.
D'AGOSTINO: That's part of my concern,
that you win on the arbitrary number, you lose on the true positive
number. So much is driven by maybe the
8 percent --
CHAIR
NOLLER: We don't want to get into a
discussion.
DR.
D'AGOSTINO: I don't either, I'm sorry.
CHAIR
NOLLER: Thank you for addressing the
question, Dr. Wright. Are there
questions? Let's take a couple of
questions, but let's finish everything in five minutes, and then we'll take a
break. Yes, Amir?
DR.
GANDJBAKHCHE: Dr. Gandjbakhche. My question is related to the spectroscopy
in the Slide Number 21, and especially in the Paper that the first author is
Dr. Huh. And it's provided in the
material. There are Figure 1A and B
that shows the fluorescence intensity and the reflectance intensity obtained
thousands of sites. The mean value
seems is there. Could you provide us
the standard deviation of these spectra?
And
the second one is could you put some numbers on your ordinates, because I want
to see the relative differences between those spectra. Which when you don't put any numbers, number
of counts, or anything, that's the relative differences between the spectra and
the scene. This is one of my questions.
CHAIR
NOLLER: If you're prepared to answer
this question now, do so. If you'd like
to do it later we can arrange. Which,
later? They'll answer later. Another question. Dr. Julian?
DR.
JULIAN: I have just four simple yes or
no questions. One of the major side
effects of colposcopy in numerous studies is the anxiety level of the patients. Was there any measure of the anxiety level
with the introduction of this machine and the extra time?
CHAIR
NOLLER: Dr. Wright.
DR.
WRIGHT: Tom Wright. No.
DR.
JULIAN: Does it identify atypical
vessels? That's the most common mistake
made at colposcopy, the failure to identify atypical vessels. Does it do that?
DR.
WRIGHT: No. Colposcopy needs to be performed. This is an adjunct.
DR.
JULIAN: I understand from the materials
it can't be used in the vagina. Does it
always fit the cervix? Is there a limit
to the size of the field of this machine?
DR.
WRIGHT: This device stands back from
the vagina, and it has a 2.4 sonometer diameter. So if there's an exceptionally large cervix, the whole cervix
would not be entirely seen, although the central transformation zone would.
DR.
JULIAN: Are these biopsies, can they be
done in real time, or do you match it up with the image on the screen, you
know, kind of guess or estimate where it is?
DR.
WRIGHT: What we ask the clinicians to
do is to look at the screen -- first they perform standard-of-care
colposcopy. That's very important. They select the sites that they would
biopsy. They then look at the
image. They will see additional sites
based on the device output that they want to biopsy, and then they do their
standard approach to taking biopsies, which for most colposcopists is to look
through the colposcope, also looking up at the screen in order to make sure
that they are oriented and back.
DR.
JULIAN: But it's a static image. It isn't like an ultrasound where like
you're doing amniocentesis or?
DR.
WRIGHT: No, it's a static image at that
point.
DR.
JULIAN: All right.
DR.
WRIGHT: Thank you.
DR.
JULIAN: Thanks.
CHAIR
NOLLER: Was there another
question. Russ? Dr. Snyder?
DR.
SNYDER: Russ Snyder, OB/GYN. One simple question. There I know were studies done looking at
the effect across the menstrual cycle.
There was some mention about looking at the effects of an immediately
performed Pap beforehand. And I know
for Pivotal Study I you used an exclusion of seven days that a Pap couldn't
have been done. But is an immediately
performed cervical cytology completely, you know, excluded prior to performing
the LUMA?
DR.
FLEWELLING: Ross Flewelling. We did a series of studies to look at the
effect of an immediately preceding Pap on the output of the device. What we found in that study was that the
result of doing the Pap results in excessive bleeding, additional bleeding of
the tissue, and that bleeding can lead to obscuring some of the cervix. So the effect was not in the spectroscopy,
apart from the presence of blood, and there is some obscuring. And we did not address that, but you might
have saw the gray cross-hatching in some of those images. That's what we label as being
indeterminate. And so if there's
excessive blood, we'll pick that up in the spectroscopy, and we'll label that
as indeterminate. So it limits the area
in which the device can be effective.
CHAIR
NOLLER: I think at this point we'll
take a 10-minute break. I'd like to ask
FDA to be ready to present at 10:50, please.
(Whereupon,
the foregoing matter went off the record at 10:41 a.m. and went back on the
record at 10:56 a.m.).
CHAIR
NOLLER: Well, the best laid plans. We got delayed five minutes by moving the
room and bringing in chairs, but hopefully it's more comfortable. I would like to ask anyone that needs to
leave the room to now please use the back door instead of the center door, and
try to not come and go anymore than you have to.
We
will next move on to the FDA presentation.
And they also have one hour and fifteen minutes, so we should finish no
later than 12:10. And the first
presenter is Dr. Joyce Whang.
DR.
WHANG: Good morning, I'm Joyce
Whang. Dr. Virmani and I are the lead
reviewers for FDA on this PMA. To begin
FDA's presentations on this PMA, I will provide an overview of our review
process. Then our medical officer and
biostatistician will provide further details of their analyses of this
submission.
Let's
start with a brief regulatory history of the device. In August 2000, FDA issued a determination letter indicating this
device would be regulated as a Class III device under the premarket approval
process. FDA considered two types of
indications, one for triage following an abnormal Pap smear result, and one for
use as an adjunct to colposcopy. FDA
indicated the PMA should be supported by results from a randomized controlled
clinical trial for each proposed indication.
The trial should compare device results to results from
histopathological examination of biopsy tissue samples. The device's underlying algorithm must be
locked before the pivotal study was begun, and all study subjects must not have
been used earlier in the development or training of the algorithm.
In
February 2001, FDA decided that the planned use of this device in clinical
studies was what we called non-significant risk. In particular, FDA found that patients would not be put at
serious risk. We considered the
possibility of physical injury resulting from use of the device, and the impact
of study design on patient management.
Because of this designation, the clinical studies being described today
did not require regulatory approval from the FDA via the IDE process that is
often used with premarket clinical trials.
However,
MediSpectra did meet with FDA in a number of meetings targeted toward
developing agreements as to what would be needed to demonstrate the safety and
efficacy of this device. There was no
agreement letter for Pivotal Study I.
However, there was an agreement letter issued February 2003 which
defined a single-arm study, Pivotal Study II, which you are hearing about
today. At that time, the proposed
indication was as an adjunct to colposcopy in identifying regions of the
ectocervix that most likely represent CIN2/3+ for colposcopically directed
biopsy.
The
PMA was received June 18, 2004, and expedited review was granted. The current proposed indication has been
refined as is being presented by other speakers today.
MediSpectra
has described the LUMA cervical imaging system to you. It has three primary components, the console
and accessories, the illumination probe, and the disposable probe cover. The console contains the computer, control
electronics, lasers, flash lamps, and spectrometer. The illumination probe is connected to the console by an
articulating arm. For each patient, the
illumination probe is covered with the disposable probe cover, and calibrated
before being placed at the speculum.
The
device uses visible and ultraviolet light to illuminate the cervix. A scan of the cervix, which requires
approximately 12 seconds, provides fluorescence and reflectance spectra at 499
distinct sites. Based on the scan, the
device creates a color-coded image that indicates the likelihood of CIN2/3+
disease at different locations of the cervix.
Now
that you've heard about the device's regulatory history, I present the review
team. As you can see, a number of
people have been involved in the ongoing review of this PMA application in the
areas of clinical, statistics, epidemiology, electro-optics, algorithm
development, software, electromagnetic compatibility, electrical safety,
disinfection, mechanical design, manufacturing, and bioresearch
monitoring.
Here
are the primary aspects of our review.
I will summarize the findings regarding the first four topics listed
here: electro-optics, algorithm development, bioresearch monitoring, and
manufacturing. The last two subjects,
clinical and statistical reviews, will be addressed by other speakers.
The
electro-optics review included safety of the exposure levels of visible and
ultraviolet light, optical performance of the device, and calibration
methods. We considered the possible
impact of medications on LUMA's optical measurements, and the possible impact
of cervicitis on device effectiveness.
We also considered the possible interactions between UV light and
HPV. All of these review concerns have
been adequately addressed.
Regarding
the algorithm, we looked at how it was developed, how it works, and how it has
been changed since the pivotal studies began.
We especially looked at the changes made to the algorithms between
Pivotal Studies I and II. We concluded
that use of the revised algorithm would not have reduced the improvement of
true positives seen with LUMA in PSI, although it may have made the increase of
false positives seen in PSI slightly larger.
For
bioresearch monitoring we looked at study execution, including recordkeeping
and administration of informed consent.
There were inspections of clinical sites and of the sponsor's facility
for records related to the conduct of the clinical trial. There are no outstanding concerns about the
reliability or integrity of the scientific data submitted in the PMA.
For
manufacturing, we looked at compliance with design controls. The manufacturing facilities were also
inspected. On the basis of the
information reviewed, the firm has been found to have an acceptable GNP
program.
The
clinical and statistical reviews will now be addressed by Dr. Carey-Corrado and
Dr. Pennello.
DR.
CAREY-CORRADO: Thank you Dr.
Whang. I'm Julia Carey-Corrado, and I'm
going to present FDA's clinical review of this PMA. From time to time I'm going to draw the panel and the audience's
attention to the discussion questions that were in the materials that were
distributed this morning, just to help you focus on what we'll be talking about
this afternoon.
The
proposed indication for use is as follows.
LUMA is indicated as an adjunct to colposcopy in identifying high-grade
disease, CIN2/3+ in patients referred to colposcopy with an ASCUS or LSIL
cytology test result. LUMA is not
intended to replace colposcopy. A
thorough colposcopic evaluation with identification and selection of biopsy
sites must be performed independently of and prior to viewing the LUMA result.
I
realize that I've repeated the indication for use. You've already heard it today, but I think it bears repeating,
and I'd like to just highlight three aspects of the indication for use. As Colin Pollard mentioned earlier, this
type of technology has previously been evaluated for different uses, including
triage of abnormal Pap smears to determine who goes to colposcopy. And I just want to make that clarification
here. This is not triage, of course, it
is once the patient is in colposcopy.
As has been mentioned multiple times, ASCUS is inclusive of atypical
squamous cells of undetermined significance and also cannot exclude H
cell.
And
the indication for use reflects something that in FDA we refer to as the
always/never rule. This is not an
official rule, this is just an approach that we take to reviewing certain
devices. And what we mean by that is as
follows. We mean that the clinician
must always identify colposcopically directed biopsy sites prior to viewing the
LUMA image, and never eliminate a colposcopically directed biopsy after viewing
the LUMA image. Another way of putting
this simply is always commit, that is to the colpo biopsy, and never look back. And incidentally, FDA has applied this
approach to indications for use of other diagnostic devices.
We
have already heard that there were two clinical trials of the LUMA device. And with this slide what I'd like to do is
just compare and contrast them, because it really is important to look at them
individually and to understand how they differed. With respect to study design, let's see if I can do this. Pivotal Study I was a two-arm, it was a
randomized and controlled clinical trial.
Pivotal Study II was a single-arm paired design with the subject serving
as her own control. The treatment group
in Pivotal Study I was -- by "treatment group" I mean where was LUMA
used. It was used in one of the arms
simultaneously with the colposcopic evaluation. In Pivotal Study II it was used following a colposcopic
evaluation.
Now,
I already mentioned what we describe as this always/never approach. That approach was not followed in Pivotal
Study I, but it was followed in Pivotal Study II.
The
primary endpoints were true positive rates for both pivotal studies. The numbers are slightly different. Well, the numbers are frankly different in
Pivotal Study I compared to Pivotal Study II.
In Pivotal Study I, the hypothesis was that there would be a
statistically significant increase in the true positive rate in that combined
arm, LUMA plus colpo compared to colpo only.
And it bears mentioning that it was anticipated that there would be an
increase in false positive biopsies in both of these studies. And as Dr. Wright mentioned, it was agreed
that approximately 8 percent would constitute a clinically acceptable false
positive rate, but there was nothing magic about that number.
The
false positive hypothesis, as well as the true positive hypotheses, were
different in Pivotal Study II compared to Pivotal Study I. You'll note that in Pivotal Study II we were
looking for a statistically significant improvement over 2 percent in the true
positive rate increment, and we were looking for the upper bound on the
confidence interval for false positive to be less than 15 percent instead of
less than 8 percent.
The
sample size was obviously very different in the two studies, almost 2,300 in
Pivotal Study I. And although Pivotal
Study II was ultimately planned to evaluate 788 subjects, the study was stopped
early at around 29 percent. That is 227
subjects who were enrolled. The last
difference I want to make here, the last contrast I want to highlight is the
Pivotal Study I was not the subject of an agreement letter between the sponsor
and FDA, but the Pivotal Study II was the subject of an agreement letter.
And
I've already discussed the hypotheses for Pivotal Study I. True positive statistically significantly
greater than zero, and the false positive would be significantly less than 8
percent.
I'd
like to take a moment to talk about the definitions in Pivotal Study I. We're looking at true positive rates and
false positive rates. And it bears
mentioning that these rates, the denominators for both of these rates are the
total number of subject, as opposed to the total number of disease
subjects. Because with the two study
designs, it was impossible to know with certainty the disease status of all the
subjects.
This
slide is to make the point that although we've heard sensitivity mentioned
already, netiher study was designed to determine the sensitivity, in the
classical sense, of LUMA to detect CIN2/3+ in patients who are
disease-positive. To obtain that
measure directly, the gold standard would have to have been LEEP, that is Loop
Electrosurgical Excision Procedures, or some kind of surrogate, possibly
long-term follow-up. But the studies
were not designed to obtain that data.
Pivotal
Study I was stratified, the randomization was stratified by colposcopist as
well as by Pap stratum to get an equal distribution across the two study
arms. Subject accountability is
described in this slide. And one of the
things that we like to do when we look at subject accountability is take a look
at the numbers of subjects who are lost from each arm of the study. And we can see that within the entire
patient population, 49 subjects were excluded in the LUMA plus colpo arm, and
37 were excluded in the colpo only arm.
The distribution was 35 excluded in LUMA plus colpo within that ASCUS
and LSIL referral population, and also 26 were excluded within ASCUS and
LSIL. So again, the point I'd like to
make with this slide is just to help you see how many patients were lost from
each arm of the study, and then make the point that patients could be excluded
both prior to randomization and post randomization. The primary reasons were device malfunction that occurred in 1.6
percent of cases, and "no majority pathology" diagnosis which
occurred in 1.8 percent of cases.
A
minor point here is that the "no majority pathology" exclusion was
slightly different between the two pivotal studies. In Pivotal Study I that subject was excluded only if all biopsy
results were lost. And in Pivotal Study
II, it was as if one was lost.
This
slide presents the results for the entire study population for the two primary
endpoints, the true positive and false positive. The observed difference, or the observed improvement in the LUMA
plus colpo arm was 1.9 percent, which was greater than zero. However, the lower bound on the confidence
interval was -1.5 percent. Hypothesis
was not met.
With
respect to false positive, the observed increase in false positive between the
two arms was 3.1 percent greater in the LUMA plus colpo arm. The upper bound on that confidence interval
being 7.2, that hypothesis was met because the 7.2 percent upper bound was less
than 8 percent.
At
the ASCUS and LSIL evaluation, we've heard it was unplanned to combine those
two Pap referral strata. And the
company has presented their justification for this analysis. And so we're just going to look at these
numbers again. Within the ASCUS and
LSIL subgroups, the observed difference, or the observed improvement in picking
up CIN2/3+ in the LUMA plus colpo arm was 3 percent. It did not meet the statistical hypothesis that the lower bound
on that confidence interval would be greater than zero.
And
with respect to false positive, again we see that there was an increase in
false positive. It was 4 percent, which
in and of itself was obviously less than 8.
However, the upper bound in the confidence interval was 8.5
percent. So strictly speaking, those
hypotheses were not met per statistical analysis.
The
last thing I'd just like to mention is that although you've seen these numbers
before, and a lot more numbers as well, this is important because the
ASCUS/LSIL subgroup is the group for whom the indication for use has been
written, and it is to that referral group that the device would be targeted.
We
also did a false negative rate analysis.
Our analysis is mathematically we did a slightly different calculation
from the company, but fundamentally our results are not too different. We saw a false negative rate for LUMA of 23
percent, compared to a false negative rate for colposcopy of 15 percent. And the point that we want to make here is
that the LUMA device does not see some of the lesions, the CIN2/3+ lesions that
the colposcopist sees. And similarly,
the colposcopist doesn't find all the lesions that LUMA detects. So both the colposcopy procedure and the
LUMA device have a false negative rate associated with them.
And
now I guess I'd just like to draw your attention to the fact -- before I start
talking about Pivotal Study II, I'd just like to draw your attention to the
fact that Panel Discussion Question 1 has three subparts, and those subparts
cover a lot of what I've presented regarding the outcomes for the total patient
population, the outcomes for the ASCUS and LSIL referral group. Discussion Question 2 is related to
something I have not talked about. Dr.
Gene Pennello will talk about it after I finish, and that is the issue of a
possible age effect. And I'm raising it
now because it is going to be discussed in the context of the results of
Pivotal Study I.
So
now I'm going to change the topic and turn to Pivotal Study II. This is the slide that I showed before. On the right-hand side I've just highlighted
Pivotal Study II design. It was a
single-arm study with the patient serving as her own control. The colposcopy was performed with commitment
to biopsy sites that could not be reversed.
Only after this was done, the LUMA image was viewed. And this is, again, follows this
always/never approach that is sometimes taken with diagnostic devices.
The
threshold for success, the mathematical thresholds were slightly
different. The true positive rate
increment had to be statistically significantly greater than 2 percent here,
instead of greater than zero percent in Pivotal Study I. And the false positive rate, the upper bound
on that had to be less than 15 percent for study success. And as we have already heard, the study was
stopped early, but we're going to talk about the results for the 227 subjects
who were enrolled.
FDA
did agree with the company on the study design here, and I guess what I'd like
to say is that one of the reasons was we wanted to really see what the difference
was, what added, what incremental benefit LUMA contributed after a thorough
colposcopy was done. And we felt that
this study design allowed us to better evaluate that.
The
study design does require additional biopsies.
There was some discretion left in the investigator, but fundamentally
the investigators were told you should perform an additional biopsy based on
the LUMA overlay if the LUMA overlay indicates that there is tissue that is
suspicious for CIN2/3.
Because
the study design essentially was going to force an improvement, we felt that we
should raise the bar a little bit above zero percent to 2 percent. And because it was requiring additional
biopsies, or strongly urging additional biopsies, we felt it was acceptable to
increase the incremental false positive rate to 15 percent.
This
is an accountability slide to help you understand how many patients were
excluded in this study. And for the
entire patient population 34 were excluded.
Within the ASCUS/LSIL referral group 26 were excluded. As you can see, many of these were due to
one pathology biopsy having been for some reason uninterpretable, or
unavailable.
And
we know that the study was terminated early, so let's just go ahead and look at
the results. Once again, you've seen
the results before, but you've seen also a lot of sets of numbers, and I want
to focus just for a moment on the numbers based on the original agreement
letter with FDA. For the entire patient
population, the incremental increase in diagnosing CIN2/3 was 4.7 percent, and
that was the result of nine additional subjects who were found to have CIN2/3+
on the basis of the LUMA contribution.
Because the hypothesis was that it would be better than 2 percent, and
the lower bound on that confidence interval was 2.2 percent, that hypothesis
was met. In the false positive
analysis, we saw an observed increment in false positive of 18.1 percent, and
that did not meet our hypothesis that it would be less than 15 percent.
Within
the ASCUS/LSIL subgroup, we can see that the observed LUMA increment was 3.6
percent, and that was derived, that study population, from six additional
subjects who were referred for ASCUS or LSIL Pap results. The lower bound on that confidence interval
was 1.3 percent, and that did not meet the original hypothesis. Dr. Gene Pennello is going to discuss
further the different thresholds for what that hypothesis should have
been. The company has presented a
justification for lowering it from the original target from 2 percent to 1.5
percent, but there are additional analyses that have been done as well, and Dr.
Pennello the statistician is going to talk about these analyses. With respect to false positive, the increase
in false positives during that LUMA increment was 20 percent increase which did
not meet the original study hypothesis.
Panel
Discussion Questions 3(a) and 3(b) ask the panel to discuss the results of
Pivotal Study II. And as I mentioned,
Dr. Pennello was going to discuss some additional analyses performed by the
sponsor on both of these endpoints so that we can all understand what data are
being presented, and decide, or at least consider how they should be viewed.
There's
also a false negative analysis that can be done for Pivotal Study II. It's a frustrating one because it's a
biopsy-level false negative analysis.
And although the LUMA false negative analysis at the biopsy level was 22
percent, nevertheless there were nine additional subjects evaluated. And the sponsor's conclusion is that the
subject level -- or I'm sorry, the biopsy-level false negatives are not easily
or directly translatable to subject-level outcome. So I'm just showing you these results because I talked about
false negative in the context of Pivotal Study I, but it's less easy to
interpret in this study.
The
adverse event profile for both studies was as follows. There were two reports of cramping, and some
subjects made more than one complaint.
So the numbers in parentheses done pertain to subjects, but rather just
to complaints of different events. So
there were two complaints of cramping, one of vomiting, one of weakness, one of
vaginal bleeding, three of fainting, one complaint of abdominal pain, and one
complaint of dysuria.
The
most stark way to present the results of these two studies is as follows. Both studies had colposcopy-primary
endpoints. Neither PSI nor PSII met
both of those endpoints. We can see
that for all subjects, Pivotal Study I succeeded in the false positive
category. Pivotal Study II succeeded in
the true positive category for the overall subject population. And then according to the original
protocols, both studies failed within the ASCUS/LSIL. However, the confidence intervals -- I'm not presenting
confidence intervals here. I'm simply
presenting the most, again, the most stark analysis of the data.
I
think that it's important to note that the two pivotal studies were very
different in design. Pivotal Study II
was performed consistent with the current indication for use. That is, with the always/never rule in
place. We should also mention that the
current target population, the ASCUS/LSIL was not in either original protocol
as a primary endpoint.
So,
given the details of the results of these two studies, what we'd like to ask
the panel to consider with respect to risk/benefit is the following. And that is whether there is an incremental
increase in the detection of CIN2/3+ attributable to LUMA compared to
colposcopy alone, and whether this incremental increase justifies any
additional biopsies, including false positive biopsies, and the risk of false
negative. Now, when I say the risk of
false negative, that would only apply strictly if the device were performed
simultaneously, or instead of colposcopy.
If it is performed according to the always/never rule, the panel can
decide whether it poses any risk.
And
the risk/benefit analysis is the subject of Panel Discussion Question 7. And at this point I'm going to turn the
podium over to Gene Pennello, our FDA biostatistician, who's going to describe
additional and in more depth analyses the has performed on these clinical trial
data. Thank you.
DR.
PENNELLO: Good morning. My name is Gene Pennello, and I am the FDA
statistical reviewer for this device.
And I wanted to highlight some statistical design and analysis issues
for you for both of these two studies that were done on this device.
Here's
the outline of what I want to present.
What I'd like to do first is talk a little bit about diagnostics and how
they're normally evaluated, and compare that to what we have here in these two
studies. And talk a little bit about
the study designs, and then go through some analysis issues of the two studies,
and some other remaining issues that involve both studies. And then I want to summarize.
First,
for diagnostics, you have two outcomes.
The diagnostic test can either be positive for disease or it can be
negative for disease. And what we'd
like to do is evaluate the tradeoff between detecting the disease, which means
you want to test positive when the disease is present, versus falsely detecting
the disease, which means you test positive when the disease is absent. And just to give you the toy example of an
unacceptable tradeoff, suppose you want to LEEP everyone indiscriminately, then
everybody tests positive. You can
detect every disease with the LEEP in every patient that has it, but you would
be subjecting everybody without disease to that LEEP. So I think that would be clearly unacceptable tradeoff.
LUMA's
indicated as an adjunct to colposcopy, and what we have is we can think about
the test as either at the subject level or the biopsy level. So at the subject level this subject is test
positive if any biopsies are taken, and it's test negative if no biopsies are
taken. You can also think of it at the
biopsy level. Are the biopsies are test
positive and the rest of the cervix is test negative. But what we'd like to emphasize is that clinically it's more
important to detect more CIN2/3 subjects than more CIN2/3 biopsies. It doesn't do any good if colposcopy has
already -- it doesn't do any good to detect more CIN2/3 biopsies if colposcopy
has already detected that the patient has CIN2/3 with other
colposcopy-indicated biopsies.
So
the subjects have -- so the analyses, the primary endpoints were at the subject
level. And at the subject level you
really have three outcomes, true positive, false positive, or negative. And by true positive, biopsies are taken so
that the test is positive, and some are CIN2/3. And a false positive is defined as biopsies are taken, you test
positive, but none are CIN2/3. A
negative means you're test negative and no biopsies are taken. There's some limitations to this. In the false positive, subjects are not very
well defined because you could have CIN2/3 in places other than the ones that
you biopsied, so in that sense you really -- that patient would be a false
negative rather than a false positive.
So biopsy location matters. And
we don't know anything about the accuracy of the test negatives because there's
no follow-up on these patients and no biopsies are taken.
What
we have in the two studies is this endpoint pair on which to assess a tradeoff,
and that's the subject true positive rate and the subject false positive
rate. The number of true positive
subjects divided by the total number of subjects, and the number of false
positive subjects divided by the total of subjects. Now, these rates I want to make clear, these are not the same as
sensitivity and 1 minus specificity, even though in the literature, true
positive rate is often regarded as synonymous with sensitivity, and false
positive rate is regarded as synonymous with 1 minus specificity. We can't estimate the sensitivity and
specificity in these studies because we don't know all the patients who are
diseased and all the patients who are non-diseased. And that's how you would define sensitivity and specificity based
on those numbers. So what we have to
deal with is this tradeoff in these special definitions of true and false
positive rates, comparing LUMA plus colpo versus colpo alone.
So
as I've mentioned, neither specificity or sensitivity can be estimated in
Pivotal Studies I or II. Another
traditional endpoint pair I've mentioned is the positive and negative
predictive values. And we can't assess
the tradeoff here either because although positive predictive value can be
estimated, negative predictive value cannot be.
So
on to the designs of the two studies. I
just want to make two remarks about the two designs. Dr. Carey-Corrado had already presented this slide comparing and
contrasting the two studies. The first
study, Pivotal Study I, was a randomized controlled trial, and the arms were
the simultaneous evaluation of LUMA plus colpo, based on LUMA plus colpo. And then the control arm was colpo
only. What I want to bring to your
attention is that the colposcopist was not blinded to the arm to which the
subject was randomized. So they knew
which arm the subject was randomized to, and that could potentially create a
bias in this study in that -- just, it may or may not have it, we don't know,
but it's possible that because the colposcopist knew the subject was in the
LUMA plus colpo arm, the mere presence of LUMA could have stimulated him or her
to do a different colposcopy, maybe a better colposcopy in that arm, versus
colpo only, or it could have, because they were relying on LUMA for example,
they could have done a less vigilant colposcopy in that arm compared to colpo
only, and that could depend on the colposcopist. So there could potentially anyway, there could be bias. And any difference we see between the two
arms really confounds the LUMA effect with this any differential in the
colposcopy performance between the arms.
And I just wanted to make you aware of that.
Pivotal
Study II also has a design limitation.
Here in Pivotal Study II the subject was her own control. And initial colposcopy was performed
followed by the LUMA increment. If the
initial colposcopy was for some reason undercalled, that would bias the study in
favor of finding the LUMA effect.
Without presenting any numbers, we did -- what the sponsor has presented
to us did not, we felt there was really no evidence of undercalling, but I do
want to make you aware of this possibility.
Now,
I want to highlight -- I'm going on to the analyses, and I just want to
highlight some analysis issues with each study. So first, Pivotal Study I.
And I want to talk about the joint analysis and the possibility of an
age-related device effect. So talking
about Pivotal Study I now. And just to
recap, the dual hypothesis on the true positive and false positive rates was
not met for both the primary analysis.
And if you applied that hypothesis to the subgroup of ASCUS/LSIL to
which the sponsor is seeking an indication, you would also -- the dual
hypothesis is also not met.
The
sponsor has presented a joint analysis, and this is an unplanned analysis in
which you look at the three possible outcomes jointly together. You don't look at separately the true
positive rate and the false positive rate, but you look together at the three
rates in both arms, the true positive rate, the false positive rate, and the
negative rate. So I'm just providing
some numbers for both all subjects and for ASCUS/LSIL of these three
rates. And the p-values of the test
they presented show that in fact for all subjects there is a statistically
significant difference between the arms when you look at all three rates jointly. There's heterogeneity in those rates. And also, if you look at the ASCUS/LSIL
subgroup, the p-value there is 0.001, and that also indicates statistically
significant heterogeneity. However,
this kind of test is not specific on the primary hypotheses of interest, the
true positive hypothesis and the false positive hypothesis. So we don't know based on these tests
whether the true positive difference is significant, and whether the false
positive difference is no more than 8 percent.
Those were the two primary hypotheses in this study. So it's really rather vague, the inference
based on the joint analysis.
I
want to talk about a possible age-related device effect, or arm effect. In the original PMA, the analyses were
stratified by three age groups, age less than 21 years, age 21 to 29 years, and
age greater than 29 years. And we
noticed there was quite a bit of difference between -- the difference between
the arms in the true positive rate depended on which age group you were in, at
least the observed difference. And the
blue line here shows that for age less than 21 years, and I'm going over the
Pap strata of ASCUS/LSIL and HSIL, that you get a large difference between the
arms. The true positive rate was larger
in the LUMA plus colpo arm than in the colpo only arm. And this is consistent across the
strata. And then the last point here is
for all subjects. And I would -- these
circles here I want to say are proportional to the sample size, just to give
you an indication of how many subjects we're dealing with in each of these
groups.
There
didn't seem to be much going on in the other two age groups in terms of an
increase in the true positive rate. The
sponsor did a number of analyses when we pointed this out to them, and the
conclusion that they have made is that age did not have a significant effect on
the arm difference. They did look at
other age cuts, not the ones that were in the original PMA, but they looked at
tertiles, as they presented, and for other age cuts, the age affected is less
pronounced. They did present today a
plotted true positive rate as a function of age for, I think, Slide 70 in their
presentation, and they showed that the true positive rate in the LUMA plus
colpo arm was pretty consistent across age.
The problem with that is that, and they did mention this, is that the
prevalence, the CIN2/3 prevalence varies by age. And so the true positive rate would expect it to be lower for
lower age groups, because there's less CIN2/3 to detect. The prevalence is lower. So the fact that you have a consistent true
positive rate across all the age groups that they were presenting in that Slide
70 may indicate, if you factor in prevalence, that they actually are doing
better in young age groups. And there
also was no comparison with the true positive rate with colpo only in that
slide.
They
did a Grizzle-Starmer-Koch model to investigate the age by arm analysis. And this was on the LSIL/ASCUS population
only. They quickly excluded HSIL based
on an army by Pap stratum interaction.
And they presented some plots in Amendment 7 to the PMA that compared
the fitted values of the model to the observed values. And when I look at those, and it's just a
plot, and just eyeballing it, I see some lack of fit that's attributable to
this possibility of age by arm interaction.
And
they also did a logistic model which, instead of looking at age groups, they
modeled the true and false positive rates.
It's a function of continuous age.
And they looked at a linear term in the model for age, and there was no
age by arm interaction in the linear -- linear age by arm interaction. But they did not investigate a quadratic
effect, so possible curvature in the relationship between the true positive
rate difference and age was not investigated.
We
did our own analysis on the original three age groups in the PMA, and it's a
Bayesian trinomial or multinomial logistic model. These were the effects that were included. In this analysis we did see a significant
arm by age interaction. And I don't
want to alarm anybody by the word "Bayesian". There's nothing funny here. I didn't add any information from some prior
distribution into this, I just wanted to get some exact analysis, or some way
of investigating this age by arm interaction effect. But what the Bayesian analysis allows you to do is actually look
at the primary hypotheses of the study, which is that the true positive rate
difference is greater than zero, and the false positive rate difference is no
more than 8 percent, and calculate the Bayesian probabilities of these within
the age groups and by Pap strata. And
if you look at the under 21 years of age group, the probabilities are nearly 1
or 100 percent within each of the LSIL, ASCUS, and HSIL groups. And the probabilities for the false positive
rates, the difference being no more than 8 percent are quite high too. And in fact, within the under 21 years of
age group, you meet both hypotheses for ASCUS and LSIL according to this
analysis. I mean, if the threshold
would say that the probability had to be at least 95 percent, you almost meet
it for LSIL. You don't see anything
like that in the other age groups. The
probabilities are not that high. So
this disagrees with the sponsor's analysis.
So
I want to go on to Pivotal Study II and talk a little bit about -- highlight
some issues there. And again, just to
remind you that the dual hypothesis here was different because of the way the
study was designed, it was a colpo only followed by the LUMA increment. So you were going to take additional
biopsies based on LUMA. The true
positive rate could not decrease, the incremental true positive rate could not
decrease, so that's why they the hypothesis is 2 percent, not zero percent
here. And the dual hypothesis was not
met for all subjects, and in this ASCUS/LSIL subgroup it was also not met, if
you applied the same hypotheses to the LSIL/ASCUS.
I
want to be clear on what it means to be an incremental true positive and false
positive according to the protocol. So
you cannot be an incremental true positive if the initial colpo indicated
biopsies in which some of them were true positives. So if based on initial colpo the subject was a true positive
already, you could not get an incremental true positive. You could only get an incremental true
positive if based on initial colpo, the subject was a false positive or a
negative, in which you didn't take any biopsies. And so, based on the false positive and negative outcomes on
initial colpo, nine of those subjects were changed to true positives based on
the LUMA incremental biopsies, the 7 plus 2 here. And so that's where the incremental false positive rate comes
from. It's 9 out of 193.
Now,
you could not get an incremental false positive unless the subject was negative
based on initial colpo. In other words,
no biopsies were taken based in initial colpo, but then you took some biopsies
based on the LUMA results, and then all of those were negative, and so the
subject became a false positive. And
there were 35 of those, so the incremental false positive rate is 35 over 193.
Now,
there were some revisions to the protocol analysis. These were unplanned, and I refer you to Question 4 for that, the
Discussion Question 4 you'll be discussing later. There were two changes.
There were target value changes for the ASCUS/LSIL population and for
the HSIL, which I don't have here. And
also, this reduced denominator, or what the sponsor termed the eligible
population denominator for the true positive rate.
So
for ASCUS/LSIL, first the target value was changed from the original 2 percent
to 1.5 percent for an incremental true positive rate. And correspondingly, the threshold for the false positive
increment was changed from 15 to 16.1 percent.
And the rationale is that these rates, true and false positive rates,
are a function of prevalence, and if the prevalence is lowered, as it would be,
as you would expect if you go from all subjects to the ASCUS/LSIL population,
you would expect the incremental true positive rate to decrease, and the
incremental false positive rate to increase.
So there was a rationale for doing this. However, if you use these two revised target values and apply
them to the ASCUS/LSIL analysis, it still fails to meet the dual
hypothesis. And these are the numbers
that you've already seen. The lower
bound on the confidence interval for the incremental true positive rate is 1.3
percent, and so it does not meet the 1.5 percent threshold. And similarly for the incremental false
positive rate.
The
second change was this reduced denominator.
The denominator was changed from all subjects to all subjects minus true
positive subjects already detected by initial colpo. So what I already mentioned is that you can't get an incremental
true positive if initial colpo had already detected CIN2/3. So those subjects were eliminated from the
denominator. FDA believes this analysis
is invalid, unless you revisit the true positive and false positive hypotheses. This is a different denominator. And the agreement letter that we had with
the sponsor was based on the full denominator of all subjects, and not on the
reduced denominator. And you would have
to revisit these hypotheses in order to come up with an acceptable tradeoff
when you change the denominator.
However,
if you do change the denominator, these are the results for the ASCUS/LSIL
population with the revised target value of 1.5 percent. With the original denominator you can't show
at least a 1.5 percent incremental true positive rate. But with the reduced denominator you can
because 1.5 percent is lower than the 95 percent confidence interval.
You
can do the same thing correspondingly with the false positive rates. You can reduce the denominator to only those
subjects who could have gotten an incremental false positive. And the denominator gets reduced from 167 to
50 here. And the incremental false
positive rate is quite large if you take the same approach. And I should have emphasized here that for
the true positive, the denominator is reduced in the ASCUS/LSIL population from
167 to 143.
Now
some issues with both studies I want to go over, biopsy frequency in both
studies, subgroup testing with respect to the ASCUS/LSIL subgroup, site and
colposcopist variability, and biopsy-level positive predictive value.
This
is a chart of, well, if you recall, the true positive and false positive
increases were observed to be larger in Pivotal Study II than in Pivotal Study
I. Now that could be due in part to the
difference between the two studies, and the number of biopsies that were taken,
and the number of subjects that were biopsied.
So I'm trying to give you an outline here of this. For Pivotal Study I, in the colpo only arm,
the mean number of biopsies was about one.
In the LUMA plus colpo arm it was 1.3.
In Pivotal Study II, for initial colposcopy it was about the same as the
colpo only arm in PSI, it was 0.9. The
LUMA increment added, on average, another biopsy. And so the total number of biopsies was 1.91 versus 1.3 in the
LUMA plus colpo arm PSI. So there were
more biopsies taken. Also, the percentage
of subjects that were biopsied was larger in PSII than PSI, 92 percent versus
82. So this in part could explain the
larger true positive and false positive increases in PSII compared with PSI.
Now
I'd like to talk a little bit about subgroup testing, and in particular this
ASCUS/LSIL population for which the company is seeking an indication. The secondary analyses were pre-specified in
the protocol for ASCUS, LSIL, and HSIL.
There was a secondary endpoint that said that the analyses would be
stratified by these three groups of Pap strata, but not for combinations of
these groups. And if you look at all
possible groupings of the Pap strata, there's actually seven. If you include all subjects, there's an
ASCUS, LSIL, and HSIL. There's also
three combinations of two of this strata, one of which the company's looking
at, which is ASCUS/LSIL.
Statistically
when you look at subgroup testing, what you would like to do is control overall
with the multiple tests that are being made, you want to control overall the
chance of any falsely significant result to 5 percent. One way to do this, if you're going to do
the primary analysis, make it a 5 percent level test of the primary analysis,
one way to control the overall chance at 5 percent is a gatekeeping approach in
which if the primary analysis succeeds, in other words you find significance,
then you're permitted to test the subgroups.
And you would be permitted to test the subgroups at a level that could
be considerably less than 5 percent. It
would depend on the number of subgroups you're testing. Now what's happened in these two studies is
the primary analysis failed. And so
according to the gatekeeper analysis, you wouldn't even be permitted to test
the subgroups. And if you were
permitted to test the subgroups, the level of the test would be less than 5
percent. Now, what you've been
presented here today is testing of the ASCUS/LSIL subgroup at a level of 5
percent, not anything less than 5 percent.
And statistically with this gatekeeping approach, you wouldn't even be
permitted to go down to the ASCUS/LSIL subgroup and test it. Even if you tested at 5 percent the
ASCUS/LSIL subgroup, the dual hypothesis is not met. All this aside, there may be clinical reasons for looking at the
ASCUS/LSIL subgroup, so that's why it's being considered.
We
did ask the company to look at site variability and colposcopist
variability. I've got some site
variability results here. The
difference in the true positive rate was not -- there was no significant
variability in the difference in the true positive rate between the arms in
PSI. The p-value was 0.457, and there
also wasn't any significant variability in the difference in the true positive
rate in the PSII and the ASCUS/LSIL group.
There was some statistically significant variability in the difference
in the false positive rates. And the
analyses being presented are simply pooling the rates. They're not considering that these
differences might be different among the sites or among the colposcopists. And if you did analyses that allowed, for
example, the colposcopist to have his or her own LUMA effect that could vary by
each colposcopist, that would increase somewhat the confidence interval width.
And
finally, there was per biopsy analyses done.
So this is not on a per subject level but on a per biopsy level, and a
look at the positive predictive value, which is the percent of biopsies that
are confirmed to be CIN2/3. And in
particular, in PSI, there was a number of results that were presented to us,
but this highlights some results. In
PSI, in the LUMA plus colpo arm, the colposcopist was asked to annotate whether
the biopsies were based on colpo alone, or based on LUMA alone, or based on
both. And if you look at the positive
predictive values for these three, they're given here, you can see that for
biopsies that were based on colpo alone, the positive predictive value is 17.5
percent. And that jumps to 28.8 percent
when they were not only based on colpo but also LUMA found these biopsies. And the difference is statistically
significant. It's an interesting
finding. If LUMA was not doing anything
other than randomly selecting places to biopsy, you would expect these two
positive predictive values to be the same, but they're statistically
difference. However, it doesn't really
get at the indication for use of this device, which is an adjunctive
indication. You don't really care about
the biopsies that colpo has already identified. What you care about are the ones that LUMA has additionally
identified, and that's the middle column here for LUMA only, and the positive
predictive value is 11.3 percent. When
you compare that to the literature, at least what we've been presented, it
seems to be larger than random biopsies that have been done in difference
studies.
But
it's hard to even really assess what this means, because for LUMA only biopsies
are based on LUMA regions that have been identified, but there's some
discretion by the colposcopist on which regions which she's going to biopsy,
and where within those regions to biopsy.
So there's some colposcopy skill being built in to this positive
predictive value. So we don't really
know whether this -- it doesn't cleanly say what the LUMA positive predictive
value is. There's some colposcopy skill
involved in this result.
I
also want to mention there is no negative predictive value that can be
estimated from these studies. So
there's no tradeoff between positive predictive value and negative predictive
value. That's not available. All we're looking at is positive predictive
values.
And
finally, LUMA could be doing better than random on the biopsy level, but that
doesn't necessarily mean that more CIN2/3 subjects are detected. That's the whole reason why we looked at
subject level results as primary endpoints.
So
in summary, netiher PSI nor PSII was a success in both the true positive and
false positive endpoints because they both had to be met, and they either both
failed, or one passed and one failed.
And so for all subjects it wasn't a success, and it also wasn't a
success if you applied the same hypotheses to the ASCUS/LSIL population. The ASCUS/LSIL subgroup was unplanned, and
it made some statistical inference problematic. Combining the two studies is statistically difficult. Because they're designs are fundamentally
different, it's hard to know how to come up with a biostatistical model that
would allow you to combine them in a reasonable way.
There
did seem to be an age-related device effect in PSI. The true positive rate difference seemed to be a lot larger in
the younger age group than in the other two age groups that were
presented. This result was not
replicated in PSII. We didn't find any
evidence of this in PSII, maybe because of the smaller sample size, but we just
don't know.
And
finally, as Dr. Carey-Corrado mentioned, you could attempt to get a subject
level false negative rate for LUMA based on colpo as a reference for detecting
CIN2/3 subjects. And when you use that
colpo as the reference, you get a LUMA false negative rate of 23 percent. And this is based on the PSI study
results. So that concludes my
presentation, thanks.
CHAIR
NOLLER: Thank you very much. Thank you also for staying within the time
limit, well within it. We have a few
minutes now before we break for lunch, and I would like to first ask the panel
if they need any clarification of any of the issues that were raised by FDA, or
any questions to address the FDA directly.
If not, we will then go back to asking questions of the sponsor. Yes, sir.
DR.
GANDJBAKHCHE: Amir Gandjbakhche.
CHAIR
NOLLER: Closer please.
DR.
GANDJBAKHCHE: In the algorithm you
mentioned it is a black box. What do
you mean by that? In the executive
summary.
CHAIR
NOLLER: The executive summary prepared
by FDA. What page is that?
DR.
GANDJBAKHCHE: It is Page 11.
CHAIR
NOLLER: Page 11 of your summary. Black box.
DR.
GALLAS: So when it comes down to it,
the algorithm -- I'm sorry. I'm Brandon
Gallas. I did do the algorithm review. I have an applied math Ph.D. And so when I say it's a black box, there
are many components to the algorithm.
There are weights, there are statistical classifiers, there are masks,
there are lots of pieces to this problem that you can't track one thing from
the beginning to the end in a real coherent way where if you know the features
coming in, certainly they progress down to the final output. But to really know all the interactions of
all those components in that algorithm, it's just too complicated. So at that level we can't make any decisions
about the effectiveness of the device just based on looking at the
algorithm. So when I say that, I'm
saying we need to rely on the clinical study to make that evaluation of
effectiveness.
CHAIR
NOLLER: Thank you. Other questions for FDA? Yes, sir.
DR.
D'AGOSTINO: D'Agostino. This is a question for Gene. Gene, as you pointed out, and as was pointed
out by all the FDA presenters, the studies were negative in terms of the
statistical criteria. Sometimes when
they're negative, and there's an issue of maybe we should consider further,
there's a shift to the sort of clinical aspects where the effects seem
reasonable, and what kind of power do you have. Did you do any power calculations for this study? It's negative by the statistical analysis,
but is it doomed to negativeness because the sample size was too small? There was over 2,000 subjects in the first
sample, so it's -- intuitively I would say if there's something going on the
statistics should verify it. Did you do
anything to sort of move on that line?
Do you understand my question?
DR.
PENNELLO: Yes. Before these studies are conducted, we
always ask the sponsor to do a power analysis so they will adequately size the
study. And the size of the study is
based on the assumptions of the effect that you expect to see in the
studies. And evidently, the effect was
not as large as what was assumed, and that's why you got a negative result in
the true positive difference for Pivotal Study I.
I
would say that Pivotal Study II, the sample size was determined to be smaller
in part because you're using the patient as your own control, and so you're
eliminating the variation between patients when you're making the comparison.
DR.
D'AGOSTINO: We oftentimes hear in the
discussion now if only I had another 500 subjects I would have had
significance. I'm not sure I see any of
that going on here.
DR.
PENNELLO: Well the true positive rate
difference was in the right direction, so conceivably if you sampled long
enough you might see a statistically significant result.
DR.
D'AGOSTINO: Yes, but we don't have
it. Thank you.
CHAIR
NOLLER: Dr. Miller?
DR.
MILLER: My questions aren't
specifically directed to FDA. They're
more directed to the company. Do you
want to proceed?
CHAIR
NOLLER: Any more FDA questions before
we go to the company? Let me first --
did you have an FDA question? Yes. Dr. Jiang.
DR.
JIANG: Yulei Jiang, Chicago. I have a question about Slide Number 36, to
compare positive predictive value. So
this compares in the PSI trial of the colpo only when the colposcopy says it's
colpo only versus when the colposcopy says it's both. A more natural comparison to me would be comparing the two arms,
where one arm is colpo only, the other arm is colpo plus LUMA. Do you agree? I think that's more natural, to me, but the comparison here is
different. Can you elaborate on that?
DR.
PENNELLO: Yes, that would be an
interesting comparison. I don't
remember what the positive predictive value is for the colpo only, but I don't
believe it was 28.8, but I'd have to look.
CHAIR
NOLLER: No other FDA questions? We'll go back for the sponsor. First, do you want to address the question
about the units for the spectroscopy, or do you want to answer new questions?
DR.
WINGROVE: I think we'd like to defer
that question till after lunch.
CHAIR
NOLLER: Okay. Dr. Miller, what are your new questions, please?
DR.
MILLER: First of all, Hugh Miller,
maternal-fetal medicine. Couple of
questions. The issue of the LUMA device
not being as good as expected in detecting the HSIL lesions kind of got glossed
over. And I wondered why the company,
you know in retrospect, even if it's a post hoc sense, why it wasn't as well
detected, since a lot of the basis presumptions were based on that.
Secondly,
I wonder if there was any evaluation in the first trial, if there was any
evaluation of the colpo only arm since LUMA measurements were done, or a scan
was done, even though the investigator was blinded. I'm assuming that there was some mapping of where the biopsies
were done, and there was some potential for looking at where the colpo only
directed biopsies were done relative to what the LUMA evaluation would have
been. And although you don't have the
follow-up, there may have been some correlation possible, looking at those
evaluations.
There's
a lot mentioned about the fact that this trial was done in so many sites, but
in reality it was really only one non-academic site. And the presumption is that this technology would be used across
the country among a much broader array of colposcopic experience. So I'm curious about what kind of further
sense you have of how this technology would be used in environments where there
might not be as good colposcopic experience.
And there doesn't seem to have been good address to the level of
colposcopic experience. I noticed that
when the FDA asked that question, that was again kind of glossed over. I understand that there were attendings, and
nurse colposcopists, and an array, but I mean I wonder if you have some sense
of this relative to years of experience, or some other measure of experience?
CHAIR
NOLLER: Would the company, the sponsor,
like to address those three questions, please?
And then we will probably be at our lunch break. Introduce yourself as you speak.
DR.
WRIGHT: Tom Wright. I would like to address first the issue of
different colposcopists. We had a wide
range of colposcopists who were involved in this study. Determining expertise of colposcopists
though is very difficult. A lot depends
on experience, the number of cases, the complexity of the cases. And we looked to see whether or not there
was a variability with respect to colposcopists, and we did not see significant
difference in device performance. But
again, it's very hard to determine who is an expert colposcopist, who is a less
expert colposcopist.
In
terms of looking at the performance of this device in different clinical
settings, let's say settings where you have high quality, expert
colposcopy. We believe that our
clinical sites uniformly were very high standard colposcopy sites. Many of them were high volume, many of them
were members of the ALTS study, and we would expect to see, using an objective
measure for a highly subjective art such as colposcopy, increased performance
using perhaps less skill colposcopists.
But we don't have data to support that.
That is just a hypothesis, that the better the colposcopist is probably
the less benefit you would see of this device.
But we can't document that.
Dr.
Warner Huh wants to address the issue about why we did not see as much effect
in HSIL as we initially predicted.
DR.
HUH: Again, my name is Warner Huh. When the study as originally designed, it
was obviously designed to include all patients. But what we learned from the trial, and this is actually borne
out from the literature as well, is that those patients who were referred with
an HSIL Pap smear are more likely to have a clinically obvious and evident
lesion, one that's clearly evident and consistent with CIN2/3 to the
colposcopist, compared to that with someone with ASCUS and LSIL. So if you're going to biopsy that clinically
evident lesion, it's hard to expect that you're going to improve detection above
and beyond what the colposcopist is going to find on their exam. So that's probably the main primary reason
why there wasn't any difference seen in the HSIL group.
CHAIR
NOLLER: Thank you. Maybe one quick question we have time
for. Dr. Snyder?
DR.
SNYDER: Dr. Snyder, again, OB/GYN. In Pivotal I, one of the things I had the
most trouble getting my arms around was the fact that in the colpo plus LUMA
arm, the colposcopists were asked to retrospectively identify whether the basis
for their biopsies was based on the colpo, based on the LUMA, or based on
both. And my question is what were the
specific instructions that were given to the colposcopists in making that
ascertainment afterwards, and would there not be a tendency for people to say,
well, both things figured into my decision?
CHAIR
NOLLER: Dr. Wright?
DR.
WRIGHT: The clinicians were instructed
specifically, once you have looked and performed your colposcopy, and you look
at the images of the LUMA on the screen, and you have decided that you are
going to biopsy a given area, was that due to the fact that there's acetowhite,
or vessels, or any of the standard colposcopic lesions to biopsy there. Was it due to the fact that that
co-localized with the blue spot, or was it due to the fact that you only saw a
dense blue region which was not associated with acetowhitening.
DR.
SNYDER: What if they were separate but
actually in close proximity?
DR.
WRIGHT: In close proximity. In that case we really did not monitor
pictures on the colposcopist. The
instructions were to do as we said. If
they had an acetowhite lesion with a little bit of blue in it, and they took a
biopsy adjacent to directly where it's blue, would they have classified that as
a both, or as an independent. They were
instructed to do that as independent, but again, those are kind of subjective
calls.
CHAIR
NOLLER: Thank you. Yes, Dr. Weeks.
DR.
WEEKS: Jonathan Weeks,
maternal-fetal. I'm a little unclear on
the Pivotal Study II early termination at about 227 patients. The protocol, did it not, state that an
interim analysis would be done at 100 to 150 patients? There seems to be a disconnect there, and
I'm a little -- I just can't seem to understand how that came about.
DR.
WINGROVE: The protocol did specify an
interim analysis, I think 150 subjects or so.
The reason we didn't stop at that number to do the interim analysis is
because the clinical sites were coming online in sequence, and we were
concerned that the first two sites that were coming on would disproportionately
affect our interpretation. So we wanted
to have all of the sites, or a lot of sites online before we did an interim
analysis. So we delayed the interim
analysis for another month so that I think six or seven of the sites were
online, and we had data from a representative sample before we did the interim
analysis.
CHAIR
NOLLER: That was Dr. Wingrove. Dr. Gerbie, you had a question?
DR.
GERBIE: M. Gerbie from Chicago. Back to continue with numbers. PSII, it was decided you needed X number of
numbers 500. This was decided it wasn't
enough, you needed 700. And then we
ended up with 200 in the proximate. How
do you justify any of the three numbers and then the conclusion?
CHAIR
NOLLER: Dr. Wingrove.
DR.
WINGROVE: I'm going to play
statistician here. Our original protocol
made assumptions regarding prevalence of disease, the distribution of Pap SIL
in that population, and generated a null hypothesis based on assumed
presumption of disease. And under those
three assumptions, we came up with the number of 528.
Shortly
thereafter, after the study was ongoing we did have the Pivotal Study I data,
and what was clear from that data was that our prevalence was a lot lower than
we had predicted, from 33 percent to 27 percent. So as a result of that, we had to make adjustments. We clearly did not want to increase the
sample size to a greater number, but based on what we had seen that would be a
necessity. So that's what we did. We looked at the prevalence, adjusted the
sample size accordingly, and changed the thresholds accordingly as well.
DR.
GERBIE: But you didn't follow
them. You increased.
DR.
WINGROVE: Absolutely right. We increased the sample size.
DR.
GERBIE: I mean, you had the necessity,
just said, to increase it, and then you went below the initial.
DR.
WINGROVE: That's what our study
protocol would have predicted, but we did terminate the study, not for any
reasons related to any study findings, but simply out of financial necessity.
CHAIR
NOLLER: I think we'll break there. Dr. Wright, quick?
DR.
WRIGHT: Just a clarification on
that. Tom Wright. The board of directors decided on purely
financial reasons due to the investment environment, the amount of money which
has been spent already on Pivotal Study I, to stop funding clinical
studies. So it was a purely financial
decision. We had not seen any of the
data from PSII at the time that decision had been made. We had seen data from PSI. It was purely financial.
CHAIR
NOLLER: Thank you. We'll break now. We will -- wait a minute, not quite yet. We will convene at exactly 1 o'clock. The panel members, your lunch will be in the
restaurant. Tell the host or hostess
you're a panel member and you'll be directed to our secure site. And panel members, please remember to
refrain from discussing these matters during the break. Thank you.
(Whereupon,
the foregoing matter went off the record at 12:17 p.m. and went back on the
record at 1:05 p.m.).
CHAIR
NOLLER: Okay, I'd like to address the
panel first, please. We will have
questions of the sponsor and FDA now for a few minutes. I do want to focus everybody on what we have
to do. Over the next couple of hours,
our main job is to go over the questions that have been posed by FDA. Remember that our job is to give FDA advice,
and they have asked specifically that we give them advice about nine different
things. You have the questions in front
of you. So that's the main job that we
have this afternoon.
Now,
in trying to be able to answer those questions, if we haven't heard from either
the FDA or the sponsor what we need to be able to answer those questions, we
should address some more questions to FDA or the sponsor. But we also don't want to get into a big
discussion with either the FDA or the sponsor.
We're supposed to be discussing this among ourselves. But I know that there are a few items that
need clarification, and people have suggested to me they would like to ask more
questions. So we want to certainly be
able to ask all clarification questions, I just wanted to make that
distinction. Once we finish with the
questions of FDA and the sponsor, then we will start our own discussion among
ourselves about the questions that FDA has posed.
And
I'd like to open this by asking the sponsor if they have an answer to Dr.
Amir's -- I can't say your last name -- Amir's question of this morning.
DR.
FLEWELLING: Yes, thank you. We do not have a slide on it, but I think
you were asking about the error bars on the spectra that appeared in the
publication. And actually we do have
copies of that if you want to turn to it in your Volume 1 of your
materials. The page number is 4-002 and
4-003. It's the small number in the
right-hand, Volume 1, Section 4, Page 2 and Page 3. And I'll wait for you to get that. The number in the lower right-hand column, the Bates number there
is 4-002. That's correct.
I
apologize to the audience if you don't have those materials, but those are the
spectra. And there on the right you see
the standard error bars are shown.
They're quite small. Those are
the population standard errors. Does
that address your question? Was that
what you were asking about? That's the
fluorescence spectra, and on the following page are the same for the
reflectance spectra. And those are
identical to the spectra that were in the published article. Does that answer your question?
DR.
GANDJBAKHCHE: Yes, this is very --
they're so small that I haven't seen them.
DR.
FLEWELLING: Yes, that's right.
CHAIR
NOLLER: Microphone please.
DR.
GANDJBAKHCHE: And the second question
was the relative changes that you can see.
The numbers, that you can say that it's 20 percent different, 5 percent
different, or?
DR.
FLEWELLING: I'm not sure I'm following
you on that. Could you repeat that?
DR.
GANDJBAKHCHE: If -- depending on the
numbers that you put on a Y axis, you know you can have a 1 percent relative
change, or 200 percent relative change.
DR.
FLEWELLING: Oh, I see. I see what you're saying.
DR.
GANDJBAKHCHE: Yes, I wanted ?.
DR.
FLEWELLING: The reason why, those are
absolute units, but they're in arbitrary counts. They're essentially proportional to counts on the detector. So those are actually in linear absolute
units. So you could add any scale you
want. It's directly proportional to the
counts on the --
DR.
GANDJBAKHCHE: Sorry about that, I don't
buy that. What do you mean? You are showing a Y axis.
DR.
FLEWELLING: Yes.
DR.
GANDJBAKHCHE: And this Y axis is the
number of counts? What are these number
of counts?
DR.
FLEWELLING: Oh, I see. I don't have that number. It's directly --
DR.
GANDJBAKHCHE: Roughly the relative
changes that you see, especially in the second figure, Figure 5.
DR.
FLEWELLING: Yes.
DR.
GANDJBAKHCHE: How much is between, for
example, CIN2/3 and CIN1?
CHAIR
NOLLER: If the Y axis for 1 was from 1
to 100, would those differences be one one-millionth of one, or would it be 40?
DR.
FLEWELLING: Well, on the Figure 5,
which is the reflectance spectra, the scale here would be about zero to 40
percent diffuse reflectance. So the
difference between those two is probably on the order of I would say 2 to 4
percent. The mean differences.
DR.
GANDJBAKHCHE: What is the noise level
of your detectors?
DR.
FLEWELLING: It varies a little bit over
wavelength, but the overall noise level of the system, the signal-to-noise is
about 200 to 1.
CHAIR
NOLLER: Does that answer your question?
DR.
GANDJBAKHCHE: Roughly.
CHAIR
NOLLER: Roughly. Thank you.
What questions do other members of the panel have? I'll start here. Dr. Cedars. By the way,
we no longer -- the panel doesn't have to give their names, just people from
the audience.
DR.
CEDARS: I had a question for the
sponsor, going back to the lack of benefit with the high-grade lesions. And your explanation had to do with the fact
that those frequently have visible lesions and so colposcopy alone was good for
that. Is it also variable based on the
prevalence of the disease in the population?
So in other words, you are going to have a much higher prevalence of
having CIN2/3 in your high-grade Paps versus your ASCUS and your
low-grade. And so if it is related to the
prevalence, and if our screening criteria are going to change with HPV
screening, and you are going to potentially have a population getting colposcopy
that has a higher prevalence of true disease, will that decrease your
incremental performance with the machine?
DR.
WRIGHT: Tom Wright. Two issues there. One is that clearly the prevalence of disease in patients with
HSIL is different than ASCUS and LSIL.
What we found in our studies was that in HSIL Pap, about 50 percent of
patients had a CIN2/3. With an LSIL or
an ASCUS, it was around 10 to 11 percent had a CIN2/3. So prevalence changes dramatically.
One
of the reasons that we feel that colposcopy may perform differently is
expectation of whether or not a high-grade lesion is present. If you are in a clinical setting where you
expect that there's going to be a high-grade lesion, you certainly may look at
little more carefully than you do if there's a lower expectation. And that may explain, in part, why we did
not have as much of an effect as we expected in HSIL, in PSI, because
clinicians expected to find the disease.
So that's certainly one issue.
The
other issue you asked was what would the impact of HPV. And I think the role of HPV, certainly as we
were using it today, in reflex management of patients with ASCUS, is to
identify a subset of patients who have the same risk for having CIN2/3, as do
patients with LSIL. That's what a major
finding of ALTS was, was that by identifying those HPV-positive patients in
ASCUS, they had a similar risk as patient with LSIL for having CIN2/3. In our study, we found that the patients
with ASCUS had a similar risk for CIN2/3 as the patients with LSIL, which is
one of the reasons we felt very comfortable pooling them together into a single
strata. Did that answer your question?
DR.
CEDARS: Yes.
CHAIR
NOLLER: Thank you. Any other questions, Dr. Cedars? I think I'll just go around the table. Dr. Weeks?
Any questions? Dr. Julian? Dr. D'Agostino? Dr. Snyder?
MS.
MOORE: I have one.
CHAIR
NOLLER: Okay.
MS.
MOORE: Given the fact that your
geriatric population is increasing, I was wondering if any attention had been
given to that older patient. I notice
in Pivotal Study II the upper age was 64.
I don't remember what the upper age limit was for Pivotal Study I.
DR.
WALKER: Hi, I'm Joan Walker. There's no question that colposcopy is more
difficult in women who are older. And I
think in fact the LUMA will not perform as well in women who are older
also. And that's unfortunate just
because the transformation zone recedes up into the canal of the cervix with
age. And so it is well known that you
can have an abnormal Pap and not be able to find the lesion in older
women. And that makes them have to go
to cone, or another excisional procedure in order to find the lesion. And we do not expect LUMA to overcome that
basic problem.
CHAIR
NOLLER: Thank you. Ms. George?
MS.
GEORGE: Yes, I actually have two
questions. The first is you identified
your second-most exclusion criteria as device malfunction. And I just wanted to confirm whether you
meant the FDA's definition of malfunction based on the fact that you only had a
very few number of adverse events. So I
wanted to confirm that definition.
DR.
WINGROVE: The definition for a
malfunction --
CHAIR
NOLLER: Name please.
DR.
WINGROVE: Theresa Wingrove. The definition for malfunction was that the
device failed to meet specifications.
For example, in the most common pre-exclusion for device malfunction in
PSI was the device failed to calibrate.
CHAIR
NOLLER: And did you have a second
question?
MS.
GEORGE: Yes, I had one other
question. And this may be my lack of
clinical knowledge on this, but are clinical decisions only made through the
use of the video, or retained version in the video, or is it also something
that would be made on a paper version?
And a second part to that is what is your retention storage factor on
these views and screens?
DR.
WRIGHT: We are telling the clinicians
to do a complete colposcopy, identify sites where they would normally biopsy,
once they have done that to then look at the LUMA image. It is a static image on a computer monitor. And based on that image, select additional
sites for biopsy. We are not expecting
them to go back to a paper copy, or to see any printout there, to do it off the
LCD at the time. In terms of storage,
Ross is going to address what the storage capacities are.
DR.
FLEWELLING: We do not --
CHAIR
NOLLER: Name, please.
DR.
FLEWELLING: Ross Flewelling. We do not at this time provide any output of
the stored data. So that's not
available.
CHAIR
NOLLER: Dr. Sanfilippo?
DR.
SANFILIPPO: Yes, I have a technical
question, and that's related to, as I understood it, the fiberoptic
system. I want to draw an analogy to
fiberoptics in an operating room, where with time, any of these fibers are no
longer viable, et cetera. And I'm
curious to know, (a) are there any long-term studies, and (b) is does the
calibration at the beginning of this compensate if some of these fibers are
broken, not viable, et cetera?
DR.
FLEWELLING: Yes, Ross Flewelling. In terms of the fibers, we have done life
testing on those fibers. I believe it's
something like over 10,000 shots. And
we have shown that it lasts for the lifetime of the product, which is at least
five years.
In
terms of actually monitoring, we have a hierarchy of calibration
standards. Of course we calibrate it
coming out of the factory, but we have a required maintenance at least once per
year where we actually test the system against NIST traceable standards. And then at run time we put the probe into
the calibration port, we go through a series of statistical tests, not only to
calibrate the system, but also to verify that it's within its normal boundaries
of operation. So those are the
different procedures we have for verifying that it's continuing to perform.
DR.
SANFILIPPO: Thank you.
CHAIR
NOLLER: Dr. Gerbie?
DR.
GERBIE: I'd like to -- a couple of
questions, please. Number 1, relating
also to the age at either N, since young women 18 and under were excluded, will
the recommendation for its use not include people in that age group?
DR.
WRIGHT: We are only asking for labeling
in patients who were studied, so the age will be 18 and over.
DR.
GERBIE: The likelihood is that people
are -- I'm sure Dr. Hillard has more to say, but it's kind of difficult
technically to separate 17 -- we probably should be doing less colposcopy on
these young women under any circumstance, but since the findings even with the
ASCUS and low-grade were more prominent in the young woman, now you're
excluding a young age group. Am I not
mistaken?
DR.
WRIGHT: Our indications for use,
Theresa? Could you, just in terms of
the specific wording? The indications
for use actually does not have the specific wording for age cutoff. And typically things are looked at in
studied populations. Certainly I would
think if the panel had a recommendation that you would want to see younger
patients, would be -- there's no reason to expect this device -- we see no
reason to expect this device to perform differently in women of reproductive
ages, whether or not they are 18, 24 or 30.
We've shown in PSII no effect of age.
We've looked at age multiple ways.
Only the Bayesian analysis of the FDA can find an effect of age. When we exclude women under 23, we see the
same absolute gain in true positives in women over 23. So we just don't see an effect of age. And there's no biologic reason to expect
one.
CHAIR
NOLLER: Dr. Gerbie, we have a question
on age too, and I think we definitely want to discuss that as we go on. Did you have another question?
DR.
GERBIE: Let me ask another
question. We know that approximately 50
percent of CIN2's will regress spontaneously.
We know we have a 4.7 percent increase in true positives, of which
significant numbers of those are CIN2, which will regress spontaneously,
particularly in the younger age group.
And that's why I have trouble with Slide Number 75 saying this is a
compelling improvement.
DR.
WRIGHT: The natural history of CIN2 is
that some of the CIN2's regress, we agree.
I think the ALTS data you saw in the presentation this morning clearly
shows that some CIN2's regress.
However, some CIN2's do not regress, and most people believe that good
clinical cutoff for high-grade versus low-grade disease in the U.S. is at the
boundary between 1 and 2. Having said
that, CIN2 per se is a relatively uncommon diagnosis. In the ALTS data, and we have Dr. Stoler here who has done the
pathology for ALTS, and he can address the percent of CIN -- no?
CHAIR
NOLLER: We want to just answer Dr.
Gerbie's question. We don't want a
discussion of CIN2.
DR.
WRIGHT: Okay. Clearly, CIN2 is an uncommon diagnosis, pure 2.
CHAIR
NOLLER: Thank you.
DR.
WRIGHT: Did that address your?
DR.
GERBIE: Thank you.
DR.
WRIGHT: Thank you.
CHAIR
NOLLER: Thank you. Give the sponsor a second.
DR.
COX: Dr. Gerbie, that's a good
question, but when we look at --
CHAIR
NOLLER: Who are you?
DR.
COX: Oh, I'm sorry. Dr. Tom Cox. Dr. Gerbie, when we look at the ALTS data, that 7 percent
increase obviously accounted for some regressed CIN2, which I think was
estimated to be about 40 percent in the ALTS trial, and probably for some new
incident CIN2/3 which we can't really estimate. So I think that when we talk about this 4 versus 7 percent, we're
really dealing with a fluctuating, coming and going disease which we can't
totally account for, but that that's a real gain. I don't think that it's -- because out of that 4 percent, if we
have some that regress, we probably would have had some new incident disease
too.
CHAIR
NOLLER: Thank you. Any other questions, Dr. Gerbie? Dr. Jiang?
Dr. Amir?
DR.
GANDJBAKHCHE: I have two
questions. The first one is your
method, the strength of your method is quantitative. And you claim that there will be no subjectivity of anybody who
will calculate the numbers or the colors that you are putting on the
screen. If you have such a clean
spectra, which they don't overlap, how you claim that you have false
positives? What are the reasons that
you have a false positive? This is the
first question.
The
second question --
CHAIR
NOLLER: Actually, why don't you --
let's do that one, and then the second.
DR.
FLEWELLING: Yes, Ross Flewelling. As you saw those spectra, those were the
standard errors, and so of course the population distributions do overlap. And as with any classification method, there
is a tradeoff between true positives and false positives, between sensitivity
and specificity. So we optimized the
system to have enhanced sensitivity and comparable specificity when compared to
colposcopy.
DR.
GANDJBAKHCHE: Okay. My second question is are you using the
whole wavelengths, or you have principal components, and if so, what are the
choice of your wavelengths?
DR.
FLEWELLING: Yes. We certainly collect the entire visible
spectrum from 360 to 720 nanometers.
However you're absolutely right.
When we go to looking at the principal components or the feature
extraction, we narrow down the wavelength range. The wavelength ranges we actually use are typically between 400
and 600 nanometers for that part of the analysis.
DR.
GANDJBAKHCHE: And why?
DR.
FLEWELLING: Excuse me? And why?
DR.
GANDJBAKHCHE: And why?
DR.
FLEWELLING: Because in the early pilot
development of the algorithm we found that that was the optimal
wavelength. The signal-to-noise falls
off below 400 and above about 600, and we have not found that to be useful in
terms of signal-to-noise and the overlapping of the spectra in that wavelength
range.
DR.
GANDJBAKHCHE: And functionally
speaking, you know you are doing functional image, fluorescence or
reflectance. What are the species that
you are interested in wavelengths, that you think that you are taking out to
discriminate between different tissue types?
DR.
FLEWELLING: Actually, I would not say
we're doing functional imaging. I
believe that what we're doing is we have an image of the cervix, and we're
overlaying a diagnostic evaluation at the 1-millimeter level that's been
smoothed. So we're not necessarily
claiming any -- unless I misunderstand your use of the term
"functional". Anything
further?
DR.
GANDJBAKHCHE: No, thanks.
CHAIR
NOLLER: Dr. Miller, any questions?
DR.
MILLER: I had asked a question earlier
about whether or not there was any comparative evaluation in the Pivotal Study
I of the colpo only arm for the patients who had a LUMA scan, but there was no
mention of how that LUMA scan might or might not have been used. And that question wasn't answered.
DR.
WINGROVE: This is Theresa Wingrove, and
we did not use that LUMA scan. We had it
stored, but we didn't use it. It would
have been useful if you can locate the biopsy to that scan then it would have
had some limited use, but we didn't do any analysis with that data.
DR.
MILLER: Was there another? The other question I had was what do you
anticipate the extent of training that will be required to educate a clinician
that's not apprised of this trial to be up and running? How will that take place?
DR.
WRIGHT: There are going to be two
components to our training program as envisioned. One will be onsite training at the time of device installation,
and there will also be a hands-on interactive looking at pictures, et cetera,
in order to interpret the displays.
What we found was that this was very effective with our
investigators. They were able to learn
to use this device in a short period of time.
And we also looked at learning curve.
Was there a difference between the first 10 patients and additional
patients with investigators as far as their detections. And we found no learning curve after
this. So we believe this training
program will be effective. It's really
reasonably simple. You have blue dots. There are a few areas you want to
exclude. Other than that, it's pretty
simple.
CHAIR
NOLLER: Dr. Hillard?
DR.
HILLARD: I have a question about age
and a comment that, first of all, that one of the things that has changed since
the initiation of these studies is the guidelines for initiation of cervical
cytology screening. So my question is
do you have any information at all about the percentage of adolescents in
particular who would have met the newer screening guidelines recommendations
for initiation of cervical cytology screening three years after first
intercourse after coitarche. Do you
have that information?
DR.
WRIGHT: We know the age range in
Pivotal Study I was 15 to in the 70s. I
showed you the prevalence curve. The
big increase in patients is around age 18.
There are very few 15- and 16-year-old patients.
DR.
HILLARD: So you don't specifically have
that information?
DR.
WRIGHT: We don't have analysis done
specifically for women under the age of 18.
You've sent the under 21 analysis.
We also showed you the under 23 analysis. In terms of time since having first intercourse, we did not get
that information and did not analyze it.
DR.
HILLARD: Thank you.
CHAIR
NOLLER: Thank you. Any final questions to the sponsor? If not, our job now is to discuss the
questions that were raised by FDA. And
you will notice that the first seven questions deal with safety and
effectiveness, 8 and 9 deal with label and training, and 10 post approval
study. And you all have these in front
of you, so I'm not going to read them in their totality. I'll try to paraphrase them so we can move
on and discuss them.
Question
1 deals with -- 1(a) really -- deals with the Pivotal Study I. And the entire population, not just the
ASCUS/LSIL population. And the question
here, or what we're asked to do is discuss the strength of the findings of this
study relative to the proposed indication.
And the proposed indication, let's remember, is as an adjunct to
colposcopy for ASCUS and LSIL Pap smears only.
They're not asking for a statement concerning its use in HSIL
patients. Dr. Gerbie, do you have any
thoughts?
DR.
GERBIE: The numbers are given in
absolute and then in relative improvement in the true positives. But it seems counterintuitive that when you
have two techniques, and the second technique is supposed to add to the
improvement, when you look at them individually the first technique is
better. In other words, the colposcopy
alone figures, the true positives were higher numbers than the LUMA
addition. And I know you're not
proposing that they be done together, but from the way I reviewed this in PSI,
the figures were better in true positives.
And along with that you had, again, the relative improvement of about
20-some percent of true positives as compared to the true for actual 4.7. But I don't see the same comparison with the
false positives. The false positives
are given as an absolute number, and not as a relative number.
CHAIR
NOLLER: Any panel, more discussion on
1(a), thoughts about it? Yes.
DR.
D'AGOSTINO: We're talking about 1(a)
and looking at this particular?
CHAIR
NOLLER: Yes.
DR.
D'AGOSTINO: Where does the colpo look
better in the true positive. There is a
slight increase in the LUMA. Am I
missing something? It's not
statistically significant.
DR.
GERBIE: No here, the LUMA plus
colpo. But in the --
DR.
D'AGOSTINO: Oh, the LUMA alone.
DR.
GERBIE: Yes, when looking at the two
individuals.
DR.
D'AGOSTINO: Yes. I found it hard that they could really sort
out that information the way they ran the studies also.
CHAIR
NOLLER: The other thing is too when you
use two tests, even if it's the same test, if you use it twice in a row, you
know, the second time you'll pick up some more. If you do Pap smears 10 minutes apart, the second one will pick
up a couple that the first didn't. So
anything you add will add some, as long as it has some relevance to the disease
under study.
DR.
GERBIE: I think also an important point
here is that the true positive is not statistically significant. I mean, it just can't.
CHAIR
NOLLER: I have some trouble with the
original population, even discussing at all. Since that isn't the indication
that's being asked for, it seems to me to focus not the ASCUS/LSIL results
really are the ones that we should look at.
If they're asking for indication for everybody, then the original
population would be fine, but it seems like it's the subgroup that's the one to
focus on.
DR.
D'AGOSTINO: But this is what the study
-- it's a good question, but this is what the study was designed to look at.
CHAIR
NOLLER: That's right, it was.
DR.
D'AGOSTINO: It is a post hoc. So by moving, as you're suggesting, it moves
us from the original protocol and we're now ready to say we're willing to have
flexibility in terms of discarding somewhat the original protocol.
CHAIR
NOLLER: (b) sort of follows on this, too. Really a question about whether it's
clinically relevant to focus on the ASCUS and LSIL.
DR.
MILLER: It seems to me, I mean, based
on the comments that have just been made, that the issue at stake here is in
this relatively low-risk population for which we know that there is maybe 30
percent or so that are missed, would another directed biopsy by a skilled
colposcopist be more likely or less likely to yield a positive result versus a
LUMA-directed biopsy for that third or so.
When they looked at the number of biopsies, about -- the LUMA group got
about a third more biopsies. So for the
colposcopist, is the colposcopist going to do a better job, or is the
colposcopist going to do a better job with the LUMA at his or her side
collecting that second biopsy. And
that's probably a question to direct to the colposcopists on the panel.
CHAIR
NOLLER: Dr. Gerbie?
DR.
GERBIE: In looking at some of the CDs
at the various examples given, I came to the same question. If I had a concept of just taking another
biopsy from an area that with a low-grade ASCUS Pap smear I may take only one
or two biopsies. Now I'm saying I don't
have a LUMA, but I'm going to take an additional biopsy. I'm going to take it from another area that
probably wasn't as significant to me. I
must say that looking at the areas in the annotated pictures with the LUMA
addition, they would frequently be from areas that it would not have
taken. So it's more than a random
biopsy, but it may or may not hit the area that the LUMA suggested.
CHAIR
NOLLER: Amir?
DR.
GANDJBAKHCHE: I'm not an MD, but by
looking at the number of false positives for colpo and LUMA, it seems that the
doctors are aggressive to do a lot biopsies, and they get a lot of false
positives. By looking at that, if there
is an area that is not picked up by colpo, and can be picked up by LUMA plus
colpo, although I don't understand the science behind it a little bit, but
that's a plus, I think, knowing that you are doing a lot of biopsies. Why not do another one that can help the
patient?
DR.
D'AGOSTINO: But doesn't the data say
that they're getting more false positives but they're not increasing the true
positives, in this ALTS data?
DR.
GANDJBAKHCHE: I don't know. These numbers, 2 percent, 3 percent, 8
percent, I am not a physician. But as
long as I see that it's the patient is there, they are doing the biopsy, and
they see some other places that can be disease, you know, I'd say okay let's do
it. If you look at the mean number of
the biopsies, you know, it was around 1.03 or 1.9, and I don't talk about the
cost, I don't know about it, but doing another biopsy in the region that the
colposcopy hasn't seen, that's I think a plus.
DR.
D'AGOSTINO: But wouldn't you want their
data to show that by doing that extra they improved the true positives?
DR.
GANDJBAKHCHE: The true positive for me
is an absolute number. It's three
women, it's five women, it's 10 women that maybe they will be saved from
getting cancer. This is my view. I am not a statistician, I don't like too
much statistics in this way, but these are my views by looking at the things.
DR.
D'AGOSTINO: I mean, you know, but if
the data doesn't show that by taking extra -- more declarations of positive
that you're producing more true positives, I think we're hardbound to argue
that the extra is helping.
CHAIR
NOLLER: I'm a little bit blind, so if
you'd raise your hand and I'll try to take Julian and Miller and then Snyder,
looks like.
DR.
JULIAN: Well, this morning --
CHAIR
NOLLER: In the microphone, please, Tom.
DR.
JULIAN: I believe it was Dr. Huh from
the University of Alabama presented these examples of areas that colposcopists
didn't biopsy. And I believe they're
the same slides that appear in the information here. I would have biopsied those areas because you have an abnormal
Pap smear, and you have acetowhite epithelium.
The supposedly expert looked at this and said this isn't worth
biopsying. That's not what colposcopy
was designed to do. You don't predict
CIN1, 2 or 3 from the colposcopy. What
you do is it's an adjunct to biopsy.
Colposcopy is an adjunct to biopsy.
If you do not biopsy abnormal areas you will miss disease. And the false impression that you're an
expert and can tell this is just that, a false impression. And these slides, if you show them again, I
will show you. You can blind me and I
will show you were we will have biopsied, and on at least two out of three of
them there was acetowhite epithelium that did not get biopsied. They just chose not do a biopsy on the basis
of colposcopy. That's a little
concerning. So I think this, if
nothing, it forces you to do a biopsy instead of relying on your opinion which
was wrong.
CHAIR
NOLLER: Dr. Miller?
DR.
MILLER: I was just going to -- I think
the comment was made that there was no benefit. And you know, again, I grant you that they came to this
conclusion late, but they've now decided that this technology best serves the
ASCUS and LSIL group. In that group
there was a benefit, there was a 3 percent benefit of true positives for those
additional biopsies that were taken.
DR.
D'AGOSTINO: But it's still not
significant. It's still not
statistically significant. I mean,
numerically. You see, my concern is
that once you shift these subpopulations and so forth, clinically they may make
a lot of sense, but we wouldn't be talking about it unless the data did show
that it looks like it's in right direction.
And so what we're doing is taking a post hoc analysis, a post hoc look
that came out in the direction and now is being presented to us. We have no real way of judging from a
statistical point of view, and you can discard statistics if one likes, but we
have no real way of judging from a statistics point of view that what we're
seeing is real or just a random fluctuation.
And so you have to be very much driven on somehow or other clinical
intuition and clinical expertise, and then also that the non-significant
results they have here from a statistics point of view is somehow or other
irrelevant to our discussion.
DR.
MILLER: But, I mean, you're the
statistician in the group, but the boundary of 5 percent is just a
boundary. And this, you know, yes it
doesn't achieve the boundary, but their point was that that in combination with
the second pivotal study both lead in the direction that there is some additive
value. The question is is the additive
value this technology, or is the additive value just that the technology -- the
additive value is that the technology spurred the clinician to do a second biopsy,
and that that biopsy.
DR.
D'AGOSTINO: But the second study showed
an additive benefit if you're willing to change the target from 2 percent to
1.5 percent, and willing to change the definition of the group you should be
looking at. I mean, it's a very
uncomfortable route that we have to take.
DR.
MILLER: Okay.
DR.
JULIAN: Just to reinforce one thing, it
doesn't necessarily spur the clinician to do a second biopsy. Not all these were second biopsies. Sometimes they chose not to do a biopsy and
were wrong. Because they're not all
second biopsies.
CHAIR
NOLLER: I have Dr. Snyder, Dr. Jiang,
and then Dr. Gerbie.
DR.
SNYDER: In response to I think Amir's
question about there's some incremental improvement, but it's not reaching
statistical significance. From a
clinical standpoint this is not the last opportunity to pick up somebody's
disease. In other words, these patients
got here because of the screening test, and that's the cervical cytology. And then they are subjected to another screening
test, and that's what colposcopy is.
And we're looking at the addition of a third layer of screening test,
which is the LUMA. These patients, and
we know that the tried and true Pap and colposcopy are going to miss some
patients. But these patients are going
to continue in a more heightened surveillance scheme with at a minimum repeat
cervical cytologies. And the time
course for a lesion to progress from CIN1 to cancer or CIN2 to cancer is years
and years. So I do think we should hold
to the science, that there should be a statistically significant increase if
we're going to add a third screening test, knowing that we're still going to
have opportunity to pick up disease in these patients. Am I making myself clear?
CHAIR
NOLLER: Let me suggest, let's have the
two other people I've already noted, and let's sort of think about (b) and (c)
a little bit and move on a little. Dr.
Jiang?
DR.
JIANG: I guess one of my comments has
to do with increase of sensitivity -- sorry, increase of the true positive
rate. I understand it is short of
significance, but it's very close, so in my mind it's very close to make
it. But then related to that, the flip
side of that, I have a question to the clinicians. It seems clear to me there's an increase in false positive
rate. Clinically, whether that's
significant. I came from a background
in mammography. In that area, false
positive is an issue. Whether it's an
issue here that I need to consider.
CHAIR
NOLLER: Mel, you want to address that,
plus your comment? You're a clinician.
DR.
GERBIE: No, I can't answer that
question. My mind is thinking about
what I wanted to ask.
CHAIR
NOLLER: What was your comment?
DR.
GERBIE: Well, it goes along with Dr.
Julian and Dr. Gandjbakhche, the false negatives. And maybe Dr. Wright and Dr. Cox as clinicians, and Dr. Huh. If one is going to continue to do colposcopy
without changing the paradigm of deciding what should be biopsied by colposcopy
and adding the LUMA, then one would biopsy the white epithelium, the
abnormality that you see. I know that
when I do a biopsy and I get a false positive, if I biopsied and I get nothing
to me that was a false positive reading of colposcopy. But if I get -- if I think this is
low-grade, the Pap smear's low-grade, I think colposcopically it's low-grade,
and I biopsy it and it comes back as low-grade, to me and to most people that
is not a false positive. And I think
this is a statistical difference. And
I'm not sure you're suggesting, I don't hear you suggesting that you change
that idea, saying you don't need to biopsy what you see on colposcopy, just
biopsy what the blue dots say. I don't
think you're saying that. So therefore,
you're still going to be biopsying the low-grades because some significant
numbers of those were higher grade. And
you're happy to say, `Mrs. Jones this is a low-grade lesion, this is likely to
go away.' Or it didn't show anything,
which I told you ahead of time it might not.
But these are not true false positives anymore, when you really look at
what the real world says.
CHAIR
NOLLER: Let me make a comment about
your question about the biopsies. It's
very different from mammography because the morbidity of a needle biopsy or
some sort of guided biopsy in mammography is much more morbid. The cervical biopsies fortunately really
carry virtually zero morbidity once the speculum's already in place, you're
doing a colposcopy already in the office.
To do a second biopsy is minimally uncomfortable, and really has no sort
of problem with care. So whether you do
one or two biopsies is immaterial, really.
It's like getting stuck, apparently, stuck for a blood draw extra. So it's not, if you will, a big deal, I
think even to the people there, once they're in the office and having this
done, if they have two biopsies instead of one.
DR.
JIANG: What about no biopsy versus one
biopsy?
CHAIR
NOLLER: I think the big inconvenience
it seems is having to come to the office and have the exam, the colposcopic
exam. The biopsy, fortunately, if you
keep your instrument sharp isn't terribly uncomfortable. Do other people agree with that? I have never had one.
(Laughter)
DR.
GERBIE: It's still easier and more
pleasant for a patient to say you didn't need any biopsy.
CHAIR
NOLLER: Right. That's right. And the anxiety of waiting for the biopsy to come back, of
course.
DR.
GANDJBAKHCHE: May I say something? I think the good thing about this system,
the thing that I like about it, is it's adding another kind of imaging to the
eye. The eye also is one of the best
imaging systems, it's a log system, and you can look, you guys all, they can
look, and try to identify things. If
the system that they are claiming is quantitative, and using some other feature
of light, I think this is an -- and I think this will be the trend soon. In this sense, it's two imaging systems that
they come together with two imaging methods, one the eye of the physician and
the second one is a quantitative method.
CHAIR
NOLLER: Let me move us on a little
bit. We've spent half an hour on (a) of
the first of 10 questions. But I think
this discussion is the thread that runs through here. (b) and (c) really deal with is the ASCUS/LSIL the right
population for this technique to be used in.
Dr. Cedars?
DR.
CEDARS: I guess I still want to go back
to the prevalence issue, particularly because of the statistical significance
is close but not quite, and we keep getting to a smaller and smaller select
subgroup. It makes me a bit
uncomfortable. And given whatever you
want to say about the age distribution, but given the presentation by the FDA
in terms of the age, and that almost all if not all of your true positive
increase was in the very young population, and if we're going to be changing
our criteria in terms of screening. And
it seems as though the sort of lower risk population you go into, you get away
from the high-grade into the ASCUS, you get away from the older women and into
the younger women, the more benefit you derive from your additional screening
tool, then I wonder as we start to not screen some of these younger women, as
Dr. Hillard was saying, will that have an impact on the incremental
benefit? And since you're so
statistically marginal looking at all of the patients, if you screen less
younger women, will you have even less significance? That concerns me.
CHAIR
NOLLER: Comments on that? Any other comments about the
ASCUS/LSIL? Is this the right group?
DR.
MILLER: Yes, I mean I actually -- my
question would be, on the dark side of the force. Is there any likelihood or propensity for the clinician to become
lazy in the implementation of this technology, and just basically look at the
blue dots, and forget about the careful colposcopic exam upon which this was
all predicated.
CHAIR
NOLLER: Can we hold that till a later
question? That's a very pertinent
comment, but I think we'll get to that a bit later. Let's don't forget that, that's important.
What
about the age, Question 2, the observed age difference in PSI. Again, we're still in PSI. True positives was observed primarily among
the patients less than 21. Clinical
implications of this finding. Does it
matter what age? Yes.
DR.
D'AGOSTINO: Could you remind us, the
sponsor remind us, was the age cutoffs part of the stratification at the
beginning of the study? I got lost in
whether the 21 came completely post hoc or if it was a stratification.
CHAIR
NOLLER: They were stratified in PSI but
not PSII as I remember, and Dr. Wright, can you answer that in a sentence?
DR.
WRIGHT: Age was not part of the
stratification. The 21 came from a --
we stated we would do an analysis based on tertiles, and 21 was the expected
tertile pre-study.
DR.
D'AGOSTINO: So it was really post hoc.
CHAIR
NOLLER: Thank you. Other comments about age? Dr. Hillard?
DR.
HILLARD: My concern about age is that
we do have some evidence that lesions are more likely to regress among
adolescents. And so picking up more
lesions isn't necessarily a good thing among adolescents if they are more
likely to regress. And we do have data
that suggests that that is true. So I
am concerned about the age issue overall.
CHAIR
NOLLER: Yes.
DR.
SANFILIPPO: I would share the concern
just by history. I mean, with the
changes in the Bethesda classification in adolescents specifically, it's my
observation that the number of LEEPs in other procedures has markedly
decreased. And then by adding this
parameter and finding that many more CIN2's, et cetera, theoretically we could
be back to Square One again, where I know Paula and I have kind of worked at
that goal to try to have longer follow-up and less invasive procedures. So I think that that has to be
clarified. And maybe we need studies,
very simply, that focus on patients who are 18 and younger, to address that
question.
CHAIR
NOLLER: One of the things we can
consider is a recommendation around age, be it on either end. And I don't know if anyone wants to think
about that, consider that. When we get
to the end that might come up.
DR.
GERBIE: I can't imagine somebody having
this instrument, knows that it might be a benefit, and saying I've got a cervix
here, I'm going to use it. I see a
potential problem in the older person. I
don't know how old that is anymore, but it's older than me.
(Laughter)
DR.
GERBIE: Where it's almost certain
colposcopy will be unsatisfactory. And
the fact that colposcopy is unsatisfactory, and that nothing is shown on the
LUMA process still means that the normal procedure needs to be done in that
patient, whether it's an endocervical evaluation, or some kind of endocervical
evaluation, or even conization still has to be done. It can't be ignored. I
think we need to make sure that the clinicians understand that.
CHAIR
NOLLER: Ms. George?
MS.
GEORGE: Isn't some of that part of your
basic clinical practice decisions that you guys would be making anyway during
this process, that whether the labeling clearly delineates, any indications for
use clearly delineate that. I think you
started to say it, that if you had a patient that presented themselves that you
felt there would be value in using this, that you would end up going for that,
whether they were 21 or 15 or 75.
DR.
GERBIE: Well, I would -- it would be
unlikely for me to say no I'm not going to use that for you, it was only tested
in women of such and such an age.
There's the possibility, why not.
Since it is non-invasive, since I've -- there's no downside to it, then
I would most likely use it. I'm
concerned that people will totally come to rely on it as "colposcopy
lite".
CHAIR
NOLLER: Let's look at Question 3,
because let's move on to Pivotal Study II.
And to begin with, for the entire study population, the true positive
endpoint was met but the false positive endpoint was not met. And we're asked to discuss the strength of
these findings relative to the proposed indication as an adjunct to colposcopy
for patients with ASCUS and LSIL. Part
(b), then of course deals with the subpopulation. But let's think about Pivotal Study II. Any comments that are different from those that we just discussed
in Pivotal Study I? Yes, Doctor.
DR.
D'AGOSTINO: Just that, you know, here
they pulled out of the air the number 2 percent that somehow or other added the
increment should be greater than 2. And
I'm uncomfortable in what sense, what does 2 mean. And if you look at the confidence intervals, we saw the reverse
of what we saw before. Here we have on
the 3(a) that we have statistical significance but it hovers. Instead of being 2 it's 2.2. And so I think should we have a discussion,
or is there a need for discussion on what the 2 percent means?
CHAIR
NOLLER: Let me. The 2 percent and the 15 percent were agreed
upon between the sponsor and FDA as the criteria, through a long discussion and
so forth. And I think that we could
discuss whether or not they're appropriate.
Maybe they were, maybe they weren't.
But that was the standard to which the sponsor was to be held.
DR.
D'AGOSTINO: That's fine if we take that
posture, I have no problem with that.
Then the sponsor later on wanted to switch to 1.5.
CHAIR
NOLLER: That's our next question. That's 4.
DR.
MILLER: But wasn't that agreement in
conjunction with a different sample size agreement? And to what degree do we need to look at that agreement when, you
know, for whatever reason, in this case a financial decision, the sample size
was altered.
DR.
D'AGOSTINO: It's interesting that they
changed the sample size but didn't change the margin that they were looking
at. I don't want to open up as a big discussion
for us, but in terms of making sense out of this, in terms of what we call
statistical significance or not, these issues do sort of roam around here.
CHAIR
NOLLER: Other comments?
DR.
GERBIE: Once again you have a 4.7
percent chance of finding something that the colposcopy didn't show versus the
18 percent. But looking at the number
of patients, nine and 35, and taking individual patient, you have to tell her
that I've got four times the chance of not finding anything extra by doing
these additional biopsies.
DR.
CEDARS: Well and also I don't think
it's legitimate in PSII to go back to the original population if you've already
sort of changed your criteria, and you're looking primarily at the ASCUS and
the LSIL. Then you've got to go down
and look at the secondary, you've got to go to 3(b) where it wasn't significant
even by the 1.5 percent. You really
can't, I don't think, look at the total population because you've changed your
indication.
CHAIR
NOLLER: Other comments? Looking at (b) also, as we just started to,
that subpopulation again is the indication they're asking for. Any discussion on that before we go to the
changes in the true positive? Dr.
Snyder, then Dr. D'Agostino.
DR.
SNYDER: Let me just make sure I'm at
the same point. This gets back to the
question, I didn't comment on it earlier, when you asked is this subset the
appropriate set to be looking at. And
from a clinical standpoint I think it is, because for the high-grade lesions,
on a clinical standpoint, if we can't explain where a high-grade lesion is
coming from, then we're going to do further evaluation of some kind. So the population that altruistically we
would like to not miss a CIN3 lesion is this population. And then when we look at it, when they went
specifically at this population, we didn't meet statistical significance either
in the true positive or the false positive.
But I think it is the right group that we would like to be targeting if
we're going to add in another screening tool, another layer of screening.
DR.
D'AGOSTINO: I was just going to say
when we move to this, we have to then look at two no's, true positive and false
positive. Both say no.
CHAIR
NOLLER: Ms. George?
MS.
GEORGE: If I remember correctly,
looking at the slide set, the subset of indication for use was only decided
more recently, that it was not the subset originally when they first started
both of the two studies. It seems like
that the indication for use, that that subset was not made until June of 2004,
which would have been after the studies.
So I think looking at both sets of data is why it's included. But again, it's the more narrow focus of the
indication for use is really a more recent decisionmaking.
CHAIR
NOLLER: And clinically, when you think
about it, if it's high-grade, if you don't see something, you have to go on and
do something more. If you do see
something, you have to go on and do something more. So the one that gives us trouble are the ASCUS and LSIL. So that indication seems to me to make more
sense than the whole spectrum. Anybody
else have a problem and think it should be the whole spectrum? I see a lot of -- I guess we're pretty well
agreed on that, that the LSIL/ASCUS is the right one.
Question
4. The sponsor proposed two changes in
the analysis of the true positives for PSII compared to the original
protocol. The first was reducing the
increments needed for success. This is
where we go from the 2.0 to the 1.5.
And assigning success criteria to each Pap substrata, and reducing the
denominator for calculating the true positive rate increment by excluding true
positive patients who were identified by colposcopy. And when you make these changes, the study does meet the revised
TP requirements for ASCUS/LSIL, but it doesn't for the FP requirement. What do we think about that? Perhaps our statistician could address that
first.
DR.
D'AGOSTINO: Well, if I look long enough
I can make anything positive. What is
the a justification for switching to the 1.5.
What is the justification for the denominator. I mean, there's an on the face argument that the denominator
should change, that you should remove those that you've already sort of
clarified. But it wasn't done before,
and my concern is that when you're doing everything post hoc, the only reason
we see it before us is because it happened to turn out in the direction that
the sponsor would like. We don't really
have a way of judging how significant this is.
It's just a set of data that sits before us.
CHAIR
NOLLER: Other comments?
DR.
SNYDER: I'll go back. You said we would discuss this again
later. But I do think there may be some
tendency, like in the Pivotal Study II that as a colposcopist we all like to
think that we're perfect. But we really
know we're not. But if as a
colposcopist I'm challenged to pick the one single most abnormal appearing area
out, I'm going to do that. And if I
know that I've got now LUMA, you know, that's going to add to my ability to do
that second biopsy, which I may have done, knowing that I wasn't going to put
another diagnostic tool in front of me.
When I teach colposcopy, I just stress the fact that it's a screening
tool, and if you've got a 360 degree lesion, that adequate sampling is not
going to be one biopsy. But I do think
there may be a tendency, knowing that now we're going to swing another
instrument in there, that I might be interested in saying, gee, you know, if
found that abnormal area, what's the LUMA going to tell me. And then even if the LUMA doesn't tell me, I
might go biopsy that second area again.
And I might do a third biopsy based on the LUMA.
CHAIR
NOLLER: Actually, that leads right into
5, because then here we talk about -- or the question deals with the false
negative rates. In PSI, the estimated
false negative rate for patients for LUMA is 23 percent if you use colposcopy
as the gold standard, meaning that 23 percent of the CIN2/3 lesions found by
colposcopy were not found by LUMA. In
PSII, 22 percent of the true positive biopsies identified by colposcopy were
not identified by LUMA. This goes onto
the always/never rule we'll talk about in a minute. But there you have the estimated numbers. LUMA isn't perfect. Colposcopy isn't perfect. So the question is is the combination, the
increase, worth the extra biopsies and so forth. More thoughts?
DR.
GANDJBAKHCHE: I can say something.
CHAIR
NOLLER: Amir?
DR.
GANDJBAKHCHE: I think the whole story
is here, you know, the thing that's exciting that there are lesions that were
identified by one and not with the other, and vice versa. It showed that this is really an adjunct.
CHAIR
NOLLER: Complementary.
DR.
GANDJBAKHCHE: Yes. This is the whole story here. And I don't know about 1 percent, 2 percent,
and so on.
CHAIR
NOLLER: Dr. Snyder, then Dr. Julian.
DR.
SNYDER: You know, I'm trying to figure
out, not being a statistician, and I'd like to have somebody really comment on
that. Because your point's very well
taken. You know, again, when we're
talking about screening tools, and we know that the Pap's going to miss
patients, the colpo's going to miss patients, and we know LUMA's going to miss
patients. And so you're right. If we find a third screening tool that's going
to complement all of this, then I would very much welcome that. And if we knew that we were close now to
picking up 100 percent of patients we probably wouldn't even be having this
discussion. If the test was so
complementary that we were in that slide where there's that little tail end of
7 percent. If we were eradicating just
about all of this, we would probably already be on our way home. So I need a statistician to tell me how much
are we obliged to rely on these SAT-defined statistical parameters?
CHAIR
NOLLER: Let's hear from our
statistician, then Dr. Julian, then Dr. Weeks.
DR.
D'AGOSTINO: The point of the fact is
that the statistical significance isn't there.
And so the only way you get a comforting situation is by redefining
targets, and redefining your denominator.
So it's not -- I have to throw back to the panel, it's not really
statistics anymore. Statistics said you
should've stopped in the previous question.
And
again, just to carry this one bit further, when you look at these intervals, we
were saying before that it's almost statistically significant. If you look at the true positives, for
example, the criteria for deciding that there's an additional yield with the
LUMA was 1.5. The confidence interval
starts at 1.6. The confidence interval
is not very comforting in terms of have we even done a good job with the 1.5
percent. So the statistics would just
put an end to the business. I feel the
statistics would say you don't have right for that comfort.
CHAIR
NOLLER: Dr. Julian?
DR.
JULIAN: I've been trying to look at the
numbers for this, and I think that at least from my perspective we might be
losing the big picture here. The
screening for this cervical disease is actually an attempt to detect, prevent,
or treat early cancer, not CIN2/3 in reality.
That's what Pap smears are for, and Pap smears have done that with a 70
percent efficiency in the last century.
Now, Dr. Cox said I believe there are about six million abnormal Pap
smears. If we say that 15 percent of
those are CIN2/3, you're talking about a group of about 900,000 people. Now, you could get rid of one-third of those
with HPV testing, right? Okay. And that would leave you about 200,000
people. So if you look at the cervical
cancer statistics, there aren't 200,000 people a year, you know, of these
200,000 missed CIN2/3's that get cancer of the cervix. There's about 10,000 right now, about 10,000
on the latest statistics. Of the 10,000
that go on to get cervical cancer, half of those had never been screened with
anything in their life. Nothing,
zero. So that leaves you a group of
about 5,000 people that are getting screened.
Now of these, two-thirds are going to survive because of the treatments
we have that exist today. Taking the
number down lower, that you benefit maybe 2,000 people. Of those 2,000 people, another 5 or 10
percent of those have adenocarcinomas, or if they're very young they have such
aggressive lesions they can't be treated at all. And if you assume the machine increases the pickup by 2 to 5
percent, you're talking about somewhere between 25 and 100 lives, from the
whole process. Are you going to screen
900,000 people to save 25? I don't
know. But cancer death is the
reality. It's not really CIN2/3.
CHAIR
NOLLER: Thank you for that
perspective. That's interesting. Dr. Weeks?
DR.
WEEKS: Again, I'm a maternal-fetal
medicine person, so I don't do colpos anymore.
But my concern with this is certainly the statistics don't look
compelling. And against the background
of Dr. Julian's excellent sort of broad view, my concern is will there be a
tendency to swing in the LUMA. Really
over time will colposcopists lean more and more on LUMA rather than really
being diligent in their colposcopy. And
as a stand-alone test, colposcopy we see is better than LUMA alone. So the combination of the statistics being
less than compelling, and the whole question of how important it is to pick up
in CIN2 in young women, some of the other issues we've addressed. And I think the tendency, and we're hearing
that these colposcopists were very, very skilled, this technology to be
introduced into an environment where there won't be as much diligence. I just am very concerned about the
risk-benefit ratio.
CHAIR
NOLLER: Dr. Hillard?
DR.
HILLARD: I was actually going to say
something very similar, which is I'm concerned about the psychology of being a
colposcopist who will then have the tendency potentially to rely on LUMA and
recognizing that LUMA is going to miss this 22 percent. So I do have concerns, and concerns about
actual use, and what this scenario would play out.
CHAIR
NOLLER: Dr. Cedars?
DR.
CEDARS: I have another statistical
question for our statistician, which gets back to Question 4 in whether or not
the two changes are valid. The change
to 1.5 I think is fairly arbitrary. But
reducing the denominator with the true positive increments on one level, if
what you want to know is incrementally how many more true positives do you get,
then I think it's legitimate, I would think, to take the true positives from
colpo out, except for the fact that if people start to use LUMA as a
stand-alone, or if the colposcopic skills decline, you're missing some true
positives with your LUMA alone, and so they really do belong in the
denominator. So I could sort of
statistically, I guess, slash clinically make an argument either way. And I don't know which would be stronger.
DR.
D'AGOSTINO: Well, I agree with
everything you've said. And I think
that, you know, the protocol said we're going to have the denominator as
everyone. And once you start changing
that, there was a discomfort on my part, and a discomfort on the FDA's
part. And I think the discomfort comes
in the issues that you're raising, is how then solid is the denominator. If the denominator is everybody, then
there's no question. Once you start
removing some subjects, then you really aren't being able to follow. And the point you raised, that if the
strategy for using the test changes, then the analysis we're looking at
basically has very little help to us, even if it was the pre-designed
analysis. So I'm very concerned that we
get the results that one would like to see by these changes which are not
pre-specified and do have the implications that you're describing.
CHAIR
NOLLER: Let's take this a little
farther down in Question 5 with the always/never rule. It's always to be used with colposcopy, you
never eliminate a colposcopically directed biopsy. If you think you should biopsy something you still do, even if
the machine says not to. And do we
believe that the clinical impact of the false negative is adequately mitigated
by the indication statement, which says you use it as an adjunct to colposcopy.
I
will interject here something. As I
read through the sponsor's material, it said that, but I didn't see any clear
statement `Thou shalt not use this stand-alone.' And when we get to labeling, we might want to consider something
stronger in their wording if we do vote for approval. But what does everybody think about to continue this false
negative? Is it covered in the
indication where it says it's to be used always with colposcopy? Tom?
DR.
JULIAN: If it doesn't find abnormal
vessels, and it probably won't tell you when you have a verrucous carcinoma
with keratin from, you know, the reason for the acetowhite versus leukoplakia. It won't tell you about gross lesions. I think that yes, I mean you'd have to use
it as an adjunct rather than a primary evaluation tool.
DR.
SNYDER: It's also not going to assess
adequacy, you know, of ability to be sure you've seen the entire squamocolumnar
junction, nor is it going to tell you anything about lesions extending into the
canal. Can't use it with an
endocervical speculum.
CHAIR
NOLLER: Certainly the colposcopists
will have to decide whether it's satisfactory or not, yes. Other points about that?
DR.
JULIAN: Cervicography, which has the
same sensitivity, doesn't evaluate the canal at all.
CHAIR
NOLLER: Number 6.
DR.
D'AGOSTINO: Can I just add?
CHAIR
NOLLER: Oh, yes.
DR.
D'AGOSTINO: I'm not sure where it was
supposed to come up and so I may be saying something out of order, but back to
the comment, the question that was made about the changing of the denominator. I haven't really had a comforting discussion
about the expertise of the people who were in the study. I think the sponsor said that these were
really super experts. I always, you
know, one of the things when I designed these two studies, is the protocols
look very much alike but one group is really expert and the other is more like
the group that may in fact run the procedure, and so forth. And as you start asking the question what do
these numbers mean, and moving things out of the denominator and the
always/never, I think they become much more compelling, much more important, as
we talk about the expertise of these individuals, and how do we generalize
these studies that are before us. And I
don't know where that's going to come in, but I think that's going to be -- it
should be an important consideration.
CHAIR
NOLLER: Yes, Dr. Sanfilippo, then Dr.
Gerbie.
DR.
SANFILIPPO: Apropos to that comment,
just drawing an analogy to the ALTS trial where there was an education curve of
testing, and then basically I feel comfortable with that, seeing that there was
some level of education. I didn't hear
that similarly with this product, that there was either -- not necessarily a
testing per se, but some signoff where each of the investigators were
demonstrating a particular level of competence.
CHAIR
NOLLER: Dr. Gerbie?
DR.
GERBIE: Well, I think that Dr. Huh's
discussion as to the level of colposcopists in this group showed a fairly wide
range, all, though, with experience and I would think above average knowledge
of the average clinician. But I would
think that this process should only help the less expert person. They still have to follow their rules, and
they may not have followed them yesterday, and they may not follow them
tomorrow. But if they don't follow the
rules, they're going to get in trouble.
CHAIR
NOLLER: Other comments? Do we think this -- yes?
DR.
JULIAN: I have to disagree in that I
think the experts are less likely to follow the rules, make up their own --
It's true in colposcopy, they do less biopsies. And as Dr. Huh showed on these slides here, they skip lesions
they should have biopsied, because they knew what it was. Whereas the basic tenets of colposcopy says
you never know what it is by just looking at it. Is that true?
CHAIR
NOLLER: Maybe you don't.
(Laughter)
DR.
JULIAN: They brought me here because
I'm not an expert.
CHAIR
NOLLER: Yes you are, and you're making
some very good points Tom.
DR.
GERBIE: Well, I think you can look at
it both ways. I know the patients that
we see as a referral center, a non-expert referral center, come from patients
who are by and large over treated prior to our seeing them. I think that's the major problem that
referral centers have is over-treating, and all of ours are from non-academic
or large community institutions.
CHAIR
NOLLER: Does that fit in with our
discussion of safety here? I think it's
clear that the machine doesn't electrocute you, or anything like that. We don't have any fear of infection. But as far as safety, is this going to be
used in a way, or potentially easily used in a way that's going to hurt women? If so, then that's important for us to
decide. Russ?
DR.
SNYDER: And tell me if this is not
pertinent, but I totally agree with Dr. Julian's earlier comments, his summary
picture. The only thing that's been
shown to reduce the mortality odds ratio of dying of cervical cancer is the Pap
smear. We don't even have that data for
liquid-based cytology. But we don't
have that data for colposcopy either.
And I think it's pretty much apparent that this machine doesn't have any
safety concerns. I do have some concern
that could the one thing that is a good screen, you know, I shouldn't use that
term. But I would worry that are people
going to be less apt to do appropriate cytology screening with this device. And I don't know if that's appropriate for
this committee to discuss at all.
Certainly -- and it's a mixed bag.
Some people do an immediate repeat Pap prior to the time of colpo, and
some people don't. There's pros and
cons for that. With this machine we are
taking out one other added safety check, if for no other reason screening for
some sort of endocervical atypia to do a repeat Pap. You can't do that with this machine. Are others going to be inclined to want to follow patients with
LUMA? I don't know if that's
appropriate.
CHAIR
NOLLER: Ms. George?
MS.
GEORGE: I think people should revisit
the definition of safety, and it does link back specifically to when
accompanied by adequate directions and warnings against unsafe use. So that I think that we do need to remember
that when we go to the later questions where we specifically talk about the
labeling. Because if we feel that the
device in general is safe, we want to make sure that there's that linkage back
to the labeling.
CHAIR
NOLLER: Dr. Gerbie?
DR.
GERBIE: I know that in the study a Pap
smear would preclude doing the test, but is that going to be a rule, that a Pap
smear cannot be taken at the same time?
CHAIR
NOLLER: Well, it couldn't be taken
before. You could do it after.
DR.
GERBIE: You certainly can't do it after
because you've already done acetic acid.
But can it -- can we ask the sponsor?
It cannot or it was not?
DR.
CEDARS: I thought they said that it
could not because it would stir up bleeding and it would affect the reading.
DR.
SANFILIPPO: And that was the criteria
for the 7-day interval before the procedure was done, for that very reason.
CHAIR
NOLLER: Just the scraping could change
the reflectance.
DR.
GERBIE: That's an elephant feeling
here. We can have an answer yes or no.
CHAIR
NOLLER: Let's ask the sponsor yes or
no? Can a Pap smear be done before it,
or is it a thou shalt not?
DR.
WRIGHT: Tom Wright. Taking a Pap smear immediately before you do
the scan can result in bleeding, and we do not want a Pap smear done
immediately before the scan.
CHAIR
NOLLER: Thank you.
DR.
GERBIE: Kind of a follow-up is that the
objection about bleeding, is heavy bleeding at the time of LUMA. Light bleeding, as with colposcopy, is still
a subjective choice. One might or might
not do it. Is that the same here? Are we worried about actually causing
bleeding from the cervix that would obstruct the --
CHAIR
NOLLER: Wait just a moment. Would you just address the question whether
it can be done if there's any bleeding?
Just that question.
DR.
WALKER: Well, what I wanted to comment
on --
CHAIR
NOLLER: This is Dr. Walker.
DR.
WALKER: -- is that you can assess the
endocervix after you've completed your colposcopy. And many people use a cytobrush in the endocervix in order to
assess the endocervix. And that can be
done after the LUMA's been utilized.
CHAIR
NOLLER: Can LUMA be used if there is
any bleeding?
DR.
WALKER: Only if you can clear it
off. So you have to use vinegar to
clear it off. In some patients you can,
in some patients it keeps re-bleeding.
CHAIR
NOLLER: Thank you. Okay.
Should we move on a bit? We have
a few more things to cover. Number 7,
did the planned and unplanned analyses of PSI and II demonstrate the safety and
effectiveness of this device for the ASCUS/LSIL population? That is, do the probable benefits to health
from use of the device outweigh any probable risk? We'll talk about that first.
Now we're down to the nitty gritty.
Tom?
DR.
JULIAN: I think one of the things that
is questionable in terms of benefit and risk is that it appears that one of the
groups that was most highly identified were the young patients with CIN2/3
lesions. And what will now happen to
these patients that would have been followed?
CHAIR
NOLLER: Microphone.
DR.
JULIAN: I think they'll get an
excisional procedure once CIN2/3 is found, which is something that -- I mean,
we have two experts in pediatric adolescent gynecology sitting here, and
neither one is me, by the way. And
maybe they could speak to that. But I
think it'll increase the number of LEEPs they get, which indirectly is a safety
issue.
DR.
SANFILIPPO: That was exactly my concern
before, and I felt that at minimum to conduct the studies, and perhaps to
identify that in the conditions of labeling.
Because I share your exact concern, and there's history to support your
statement. And with the change in the
Bethesda classification, we have markedly decreased the aggressive, LEEP, and
other procedures, and that was my point.
I don't want to go back to that.
CHAIR
NOLLER: Dr. Hillard?
DR.
HILLARD: Well, clearly the rationale
behind changing the guidelines about initiation of cytology screening was
related in part to the concern about overly aggressive evaluation, management,
and treatment. And patients getting
LEEP'd and re-LEEP'd and overly problematic procedures. So that is a part. The other aspect of that is of course the fact that -- two
things. One is that these lesions are
more likely to regress in adolescents, and so that certainly is a concern. I am very concerned about this population,
given what I am seeing right now. Those
guidelines are not even now being followed, so I am seeing many patients who
are having Pap smears done at a time prior to -- and of course the clinician
should be allowed to use his or her judgment as to whether it's appropriate to
do an initial screening. But I think
that you start down that path, and you have an abnormal result, and you then
follow it up with colposcopy, and then you get led down the path. And I believe that you're correct. I'm very concerned that this would lead to
more procedures that do have the potential for harm in the future in terms of
possible risk of pre-term delivery, et cetera.
So I'm concerned where we may be led more down the path.
CHAIR
NOLLER: Dr. Snyder?
DR.
SNYDER: I not only share Joe's and
Paula's concerns, but I'm petrified of them.
And that is where we don't -- we don't want to find disease we don't
need to treat in that age group. But I
ask -- I didn't comment earlier on the age effect. Where I'm seeing this is we've got sparing statisticians. We've got, you know, this one model from the
FDA and we've got the sponsor's model.
And I don't, you know, we have to put that in perspective because from
an actual clinician's standpoint, I don't see why if both techniques use acetic
acid, why there should be any difference in our ability. from a colposcopic standpoint it doesn't
matter. So why with this reflectance
and fluorescence would there by really any difference in somebody less than 21
versus somebody that's 25 or 35.
But
so then I get down, if we really don't know which side is correct, maybe the
problem is we don't have enough numbers, and we don't have enough information
like among these really young women with the high-grade lesions, what percent
of them are CIN2, what percent are CIN3.
I mean, nothing here stratified patients by that classification. And I see why they didn't. The reason we have low-grade/high-grade is
treat and not treat. But now as we're
understanding more of this CIN2 is going to regress, more of the higher grade
lesions in younger women are going to regress, more HPV is going to regresses
in the younger women, maybe it is pertinent to have some more data.
CHAIR
NOLLER: Dr. Gerbie wants to make a
comment. Let me just mention that we
can later on decide as we're thinking about conditions, we can think about
age. And perhaps something, you know,
we can think about whether or not it should be used under age 18, or not under
age 18 pending more data, or postmarket analysis and so forth. We can address issues of age in our
deliberations because I think it's clear that we have very little information
in women under age 18 from these studies.
Dr. Gerbie?
DR.
GERBIE: Well, we really should be discussing
the cytologic management, not the histologic or colposcopic management. The thrust should be in not doing cytology
on these young people.
Secondly,
once colposcopy is chosen, then I think you're obligated to make a decision how
far do you want to go to make the diagnosis.
Some people kill the patient to save their life. I think we can go back a few steps. From hysterectomy, back to cone, to LEEP, et
cetera. But if you decide to take a
biopsy, and even if you get a biopsy of CIN2 or CIN3 in a young person, you
still have the choice of how you're going to manage that patient. And how you're going to follow the patient
if you choose a conservative management.
You're going to put a better follow-up on that patient. It doesn't automatically say that yes, she
has a CIN2/3, that now you need treatment.
So there's an education thing. I
don't think we can stick everything into one sock here.
CHAIR
NOLLER: Amir?
DR.
GANDJBAKHCHE: This question is for the
chairman. Could you suggest to change
their data analysis to get more effective?
CHAIR
NOLLER: Can we suggest to change the
data analysis? Certainly we can suggest
that, but it won't be done today of course.
But it would be one of the things that we could talk about. Actually, I don't really want to address
that now because what I would say in response to that might prejudice our
deliberations later, but we might talk about that later. But I'll try to remember that. If I don't, remind me. Dr. Cedars?
DR.
CEDARS: Well, I have two comments. One is that I think it'll be very difficult,
and I realize this isn't really the sponsor's responsibility, but it gets back
to Dr. Miller's dark side. I think it's
going to be very hard to say you have this machine in your office, but if
somebody's under a certain age you can't use it. I just don't see that that's reality. That's not what's going to happen.
The
second issue I have is while I agree with Dr. Gerbie that your choice of what
to do once you have even a histologic finding is dependent upon you, except
that now you have a young woman who thinks she has something really bad. And so you're also going to be driven by
what she thinks she needs, and she wants this bad stuff gone. And so even though your advice might be to
be conservative, and to watch this, and to follow it, the acceptance of someone
who thinks they have a cancer, or pre-cancer, or some bad thing is to cut it
out, get rid of it. And so I still
think you're going to expose a lot of young women to procedures that they might
not need.
CHAIR
NOLLER: Dr. Gerbie?
DR.
GERBIE: Well, I just feel that sticking
your head in the sand is never the right thing to do, and never to presuppose
what a patient wants. And I've gotten
in lots of trouble over the years doing that.
And we see patients on both sides, patients who insist on being treated
for low-grade lesions, and patients who insist on not being treated for
high-grade lesions when I really want to treat them. So the younger person, she gets a vote. And I've been surprised sometimes, but if it is a higher grade
lesion, she, and if there's a parent around, has to be made to understand that
the recommended treatment for a high-grade lesion is to be treated. We can watch this if this is what you want,
but we have to watch it closer, and you have potential for going in either
direction.
CHAIR
NOLLER: Let's -- we've talked about
(a), 7(a) quite a lot. 7(b), though, is
a little different. It says, "Will
use of the device provide clinically significant results." I.e., does it really matter if we pick up a
few more. And we sort of talked about
that. Does anybody have a comment
specifically about that? And clinically
significant results could be, as Tom Julian talked about, how many deaths from
cancer will be prevented, if any, or it could be on the other side, you know,
how may CIN1 lesions are gone. I don't
know, what do people think? Yes.
DR.
D'AGOSTINO: Quite often in these
discussions you like to say we have statistically significant results. Now we want to interpret the confidence
intervals, or the point estimates. We
have to remember in this discussion we don't have statistically significant
result. So you're pushing aside, which
I'm not saying we shouldn't do, but we're pushing aside the statistical
significance and focusing on these numbers, which may not have really sort of
scientific validity in terms of a statistical interpretation.
CHAIR
NOLLER: Other comments? If not, let's move on to Number 8, labeling
and training. Does the panel have any
comments on the labeling and instructions for use provided by the sponsor. This is where we talk about things like thou
shalt never use without colposcopy, and age, and so forth. You've all seen the proposed labeling that
was in the sponsor's manual. What
things should be added or subtracted from that? Assuming that it's approved, of course. Then it would -- yes.
DR.
SANFILIPPO: Well, I would clearly state
not for use in patients under 18 years of age, as one of the criteria. And once again, that's prerequisite to
designing the studies and getting that information. So I would personally like to see that.
CHAIR
NOLLER: How do other people feel about
the lower age limit?
DR.
GERBIE: I think it does complement the
recommendations of the cytologic evaluation.
And I think together it gives more strength to not doing the Pap smear,
and not doing the procedure.
CHAIR
NOLLER: Yes, Dr. Weeks.
DR.
WEEKS: I could certainly support an age
limit of less than 18, but I would still have quite a few concerns about the
young women who are evaluated at less than 21 years of age because of the
number that may be exposed to LEEPs, and the impact on future fertility,
childbirth, et cetera. So I think the
study didn't include patients less than 18, clearly labeling should prohibit or
discourage the use of the device in that age group. But I still think there's a great concern up till 21 years of age
at least.
CHAIR
NOLLER: Dr. Hillard, then Dr.
Sanfilippo?
DR.
HILLARD: I would agree with the
concerns about under 21. I certainly
would agree with 18, but under 21 given the questions about the statistical
analyses related to under 21, and in addition the concerns about the practical
utility.
CHAIR
NOLLER: Dr. Sanfilippo?
DR.
SANFILIPPO: The other category that we
have not discussed today is pregnancy, and that was one of the exclusion
criteria. And I think that has to be,
again, clearly stated that there is no data in terms of its efficacy with
pregnancy.
CHAIR
NOLLER: Good point. Dr. Hayes?
Microphone please.
DR.
HAYES: We've discussed the younger
client. I'd like to turn our attention
also to the older client, that the sponsor also spoke with the older people
were not in the study. And there was
indeed an indication about how it really would not be appropriate most likely
for the older client. And I think that
needs to be stated.
CHAIR
NOLLER: Ms. Moore?
MS.
MOORE: I was just going to ask Dr. is
it Gerber?
CHAIR
NOLLER: Gerbie.
DR.
GERBIE: Gerbie.
MS.
MOORE: Gerbie, yes. When you said -- no you weren't the one, I
don't think. Whoever it was who said
that this should -- the label should say not to be used for patients under the
age of 18. Do you use the word
"recommended" so that that would give then the physician who is
working with that young person some kind of wiggle room?
DR.
SANFILIPPO: Again, I would tend to
think that that becomes the FDA's decision.
I would see where you're coming not recommended. My bottom line point is I'd like to not see
it used, period, until we get adequate information. So I suppose if I had one word, it'd be stronger than "not
recommended". Not to be used. That's my personal opinion.
MS.
MOORE: Okay.
CHAIR
NOLLER: Dr. Gerbie?
DR.
GERBIE: Unless you have evidence that
there's a difference in the biological behavior of a CIN2/3 lesion diagnosed
with conventional colposcopy versus LUMA, then I don't see how you can make a
recommendation for the difference in age.
CHAIR
NOLLER: Yes, Ms. George?
MS.
GEORGE: I have two questions on the Pap
smear, and also on colpo. Are there
limitations imposed on those already, and if there are not, what would prevent
a doctor who already has a patient under the one who's 15-years-old to just
not, if they've done it for the last six months on all their other patients, to
just go ahead and do it?
And
then the second thing is that there is the limitation -- it is not listed as a
warning, or caution, or prevention -- in their labeling with regards to
pregnancy. And they have quite a long
list, and that may be what we want to consider is that it's just
limitations. But again, practice of
medicine, whether it's a warning, a caution, unless there is a full stop
prevention ability to prevent you doctors from doing something, you're going to
do whatever the hell you want.
DR.
MILLER: We pretty much do whatever the
hell we want even when there is a warning.
(Laughter)
DR.
MILLER: As terbutaline will attest to,
which is still rampantly used even though the FDA has told us we shouldn't be
using it.
CHAIR
NOLLER: Other comments about this
before we move on? Let's look at Number
9. Does the panel have any concerns
about the training needed to use this device safely and effectively?
DR.
GERBIE: Can I go back to the
instructions again? I'm sorry.
CHAIR
NOLLER: Sure, go ahead.
DR.
GERBIE: I think exclusion/inclusion
criteria for a study are different than inclusion and exclusion for clinical
use. And I think these are probably
more stringent in the study than they would necessarily have to be, some of
them, in actual practice. I mean, many
of them are probably the same, but some of the others don't fit.
CHAIR
NOLLER: How about Number 9,
training. Do you have any comments
about that?
DR.
GERBIE: Yes. It looks like I could learn how to use this.
(Laughter)
DR.
GERBIE: With lots of training.
CHAIR
NOLLER: It looks pretty easy if you're
already a colposcopist. And they
demonstrated no learning curve.
Anybody? Joe, was it you -- who
had the comments about learning before?
DR.
SANFILIPPO: Yes, I did, of the
investigators, i.e., drawing a parallel to the ALTS trial. But I think I'm becoming convinced that the
learning curve is a very short one. So
I don't have a problem with it.
CHAIR
NOLLER: Yes.
DR.
MILLER: I guess I would just go back to
kind of the reverse thinking, which is the training seems straightforward, and
in this day of technological elevation to its heights, again I'm concerned
about the bias that this new technology somehow takes the clinician into the
realm of thinking of this as the gold standard of colposcopy and undermining
their clinical skills and their clinical suspicion that basically no stone
should be overturned; that now if the LUMA says -- I just worry that the false
negative results of the LUMA will get missed in the glamour of this nice big
machine that's got a nice LCD monitor, and you know, basically points you right
to the bad parts.
CHAIR
NOLLER: Let me -- yes. First.
MS.
GEORGE: Just a quick comment on
that. I'm assuming that Pap smears came
out before the colpo.
CHAIR
NOLLER: Yes.
MS.
GEORGE: And so the same type of thing,
that do people not do Pap smears at all and just go right to colpo?
CHAIR
NOLLER: No. Screening is still Pap smear.
DR.
GERBIE: But it certainly happened with
the LEEP procedure, let's excise every patient.
CHAIR
NOLLER: One thing, and I've been
sitting here thinking about whether to -- I think this is an appropriate
comment. In the labeling, there
labeling can have an effect on use in the sense that if it says it's not to be
used under age 18, it's unlikely that there will be any reimbursement for its
use under age 18. So in fact the
labeling can have some effect on clinical practice, whereas if it doesn't say
that, it may very well be used, or not in pregnancy, or over age 70, or
whatever. But reimbursement does
dictate, particularly something where there would be some cost of using the
instrument. We aren't supposed to talk
about cost, but I think it's appropriate in this case probably.
Dr.
Snyder looks skeptical.
DR.
SNYDER: The only thing I thought about,
I think a lot of us in academic centers are all hooked up with digital cameras
hooked up to our colposcopes, and monitors for the patients to look at and
everything. I'm not sure how prevalent
that is on the outside. There may be a
temptation to want, since one part of this is just a plain image of the cervix,
and an easy way to print out something for a chart, that even if it said not
under 18, somebody may want to get a picture for the medical record.
CHAIR
NOLLER: Mel?
DR.
GERBIE: Sort of along the same line,
can this instrument, might it be used as a colposcope itself? Because -- can I ask someone to tell me why
not? I'm looking at a magnifying
system, that acetic acid has been put on the cervix, and it's bright lights,
and I'm getting an image. Why can't I
use that?
CHAIR
NOLLER: In two sentences.
DR.
WRIGHT: In two sentences. Dr. Julian is totally right. The resolution of this device is not
sufficient to allow us to look at atypical vessels, and that is key with
colposcopy.
CHAIR
NOLLER: Let's look at Question 10. Does the panel have concerns about any
issues that should be addressed in the post-approval study. Some of you are new to the panel. This supposes that we recommend that it be
approved, and FDA approves it. And this
would be making suggestions for things that should be followed along
afterwards. Are there things that we
would like the sponsor to keep checking on?
For example, say it gets approved for use over age 18. We might suggest that they start a study in
younger or -- 70 patients, patients over 70.
Are there any sort of those sorts of issues that should come up? This is a little different from conditions
we'll talk about later. Yes.
DR.
GANDJBAKHCHE: I have a question, and
the question is as follows. That if you
approve a PMA, is everything locked, for example the design. They should use the same design, the same
algorithm, and so on and so forth? They
cannot change after the premarket approval the design, the head or
anything? I don't know about that.
CHAIR
NOLLER: Colin? Can you answer that, please? Or Nancy?
MR.
POLLARD: The simple answer is to make
changes like that the company, if the device were to be approved, the company
would need to submit a PMA supplement describing those changes, and providing
the appropriate verification and validation data to support that change.
CHAIR
NOLLER: It appears that we're sort of
out of discussion for awhile. We have a
number of things to do after this, but I think maybe -- let's take our break a
little bit early. It's 2:52. Let's try to be here at 3:00.
(Whereupon,
the foregoing matter went off the record at 2:52 p.m. and went back on the
record at 3:08 p.m.).
CHAIR
NOLLER: Take your seats, please. Close the doors, please. I'm going to look to one of our panel
members to raise two issues, please.
Nancy?
MS.
BROGDON: Thank you. There are two questions that have come in
discussion with FDA staff, and we wanted to ensure that the panel covers these
questions. One is a little bit of
follow-up on the age questions, and Dr. Pennello has something he'd like to
discuss there.
DR.
PENNELLO: Hi, Gene Pennello. We are hearing from your discussions a
suggestion to exclude some of the younger women from the indication. And I just want to remind that, in least in
our analysis of PSI, it seemed like much of the effectiveness was in the young
age group, and so removing that group, you may be removing a lot of the
effectiveness of the device.
CHAIR
NOLLER: Panel open for discussion. Paula?
DR.
HILLARD: I guess I would just say that,
yes, you may be looking at the effectiveness of the device. From your analysis, you're saying that it
was more of a difference among the youngest group. Am I correct in understanding that? And that may well be true in terms of pickup of CIN2/3. CIN2 may be more likely to regress among
that age group. So are you really
having the same degree of benefit by doing that pickup to begin with in that youngest
age group, as opposed to an older age group?
CHAIR
NOLLER: I guess sort of another way to
say it is if you take out under-21, there's so little pickup over 32 that why
would you have the instrument to begin with.
Is that what I'm hearing? Was
that your point?
DR.
PENNELLO: That was basically my
point. You might be in danger of losing
any of the effectiveness that LUMA might have by removing that young age group.
CHAIR
NOLLER: More discussion. Dr. Miller.
DR.
MILLER: Well, I guess in the way I'm
thinking about it it takes us back to another way of looking at the
risk/benefit ratio. We've already, in
looking at the different questions that have been put before us, we've already
raised real question about whether there's any benefit. Certainly there doesn't appear to be a
statistical benefit, and we're pushing that line, saying that there may be some
benefit in the subpopulation. Although
there doesn't seem to be overt risk for using the device, there are adjunctive
risks. In other words, over-utilization
of the technology, over-dependence of the technology, populations that may be
adversely affected. So I'm thinking
about it from a risk/benefit perspective, wondering there's not so much benefit,
and there's ever growing risk. And the
benefit, you know, potentially is going down if we take out the younger
group.
And
although we haven't emphasized it, as the other MFM specialist on the panel
I'll just say that over-utilization of LEEPs in young people who have
reproductive life ahead of them, and have not really exercised their
reproductive life is a real problem.
There are some good technologies available to us to assess that problem,
but the application of those technologies is not clear yet. And certainly we potentially set young
people up for more invasive procedures, and more cumbersome pregnancies.
CHAIR
NOLLER: Yes.
DR.
D'AGOSTINO: Could someone remind me,
the endpoint is CIN1, CIN2/3+, and so forth.
Did the data get collected by that grouping, or was the data actually
collected by the individual categories?
Where I'm heading is if we say what else should be done with this data,
can the sponsor actually go back and sort out the CIN2's versus 3's?
CHAIR
NOLLER: That certainly should be
possible.
DR.
D'AGOSTINO: We have it combined.
CHAIR
NOLLER: Do you want to address that?
DR.
WRIGHT: After much discussion with a
variety of people, we collected data as CIN2/3 in the aggregate. So that is the reference pathology.
CHAIR
NOLLER: Thank you. So it's not possible. Nancy, you had another point you wanted to
bring up?
MS.
BROGDON: Yes, our other question was
whether the panel feels there's been enough discussion about the instructions
given to the investigators during the two studies, based on the colors shown in
the display, and where and whether biopsies were taken.
CHAIR
NOLLER: I had some concerns about that
too. I heard a couple different
things. One was that the -- and maybe I
heard it wrong, but that the investigators were asked to take a biopsy based on
the LUMA image in PSII. So if they
decided to do one for colposcopy, then they had to take another one. I'm not sure that's true, but I'd like to
hear.
The
other thing is that the pictures we saw had nice blue areas, but this is a
continuum yellow to blue, somehow. And
what were the instructions given to the investigators about where they should
biopsy. If there's no blue, were they
still supposed to biopsy a yellow site, or not at all? Dr. Wright, can you address that? Both issues, please.
DR.
WRIGHT: Right. Instructions to the investigators were that
they were to biopsy a blue site, and they were to biopsy yellow sites if
clinically indicated. So if a blue site
was there it was to be biopsied. If it
was yellow and it correlated with something they saw colposcopically, any
degree of acetowhitening, we would expect them to do a biopsy.
One
of the points with respect to the difference between PSII and PSI is that in
PSI they looked at both images, the colposcopy and the LUMA images, and decided
where to biopsy. So if there was an
acetowhite area and they decided to biopsy in the center of it, and it was also
blue but had a periphery of it, that would have been considered meeting the
requirements for having taken a blue target.
In PSII, a large lesion, if they wanted to take a colposcopically
directed biopsy of it, if they could fit in a second biopsy of the blue spot
they were instructed to fit in the second biopsy, which is one of the reasons
there were so many biopsies in PSII.
CHAIR
NOLLER: Thank you.
DR.
WRIGHT: Thank you.
CHAIR
NOLLER: Panel understand that? Anybody have concerns about that? Before we go on to the next section, do
people have clear in their mind whether or not you feel the data support the
use of the instrument? Dr. Gerbie?
DR.
GERBIE: We didn't spend a lot of time,
maybe don't want to, on 7(b), clinically significant results. And this has come up in a lot of lay press
about medications. A new medication
has come out, and yes it's safe, but is it worthwhile. Are we going to be held to the same criteria
when we say clinically significant results.
Statistically we look like we're not making it, statistically, but statistically
and significant. And to an individual
patient, as most of us know, statistics and significance get thrown out. I'm not sure we've discussed this enough.
CHAIR
NOLLER: More discussion.
DR.
D'AGOSTINO: Just to remind, the point I
was making is that the usual discussion is you want to see the statistical
significance before you start talking about the clinical significance. And so we're jumping over the statistics
completely, and that leaves us with being in a very precarious position to even
talk about the data in any meaningful way.
CHAIR
NOLLER: Russ, could you? Tom?
DR.
JULIAN: Talking about the statistics?
CHAIR
NOLLER: No, we're trying to decide
whether use of the device will provide clinically significant results. Will it help women?
DR.
JULIAN: Well, I've been thinking about
this somewhat differently, because to me the study itself and the analysis of
it's kind of like quicksand. If you can
walk on water, going across quicksand is just a stroll. If you can't, which I cannot, I can't really
make heads or tails of it. I think what
this does do is it is an adjunct to colposcopy. And I think that colposcopy is going downhill rapidly because
there are more and more practitioners being trained in it with less and less
cases for practitioners, many of whom have never seen cervical cancer. And this may have some real value for the
under-armed colposcopist, so to speak.
CHAIR
NOLLER: Other comments? Let's move on. We're now at the point where we have our second open public
hearing. We have received a request
from Dr. Mark Spitzer to speak during the hearing. Dr. Spitzer, we'd like to ask you to disclose any commitments you
have, or we encourage you to mention any sponsorships that you have. We have, let's see, we've given you 5 to 6
minutes for your statement.
DR.
SPITZER: Thank you, Dr. Noller. My name is Mark Spitzer. I am a Professor of Clinical Obstetrics and
Gynecology at the Weill Medical College of Cornell University, and I have been
practicing colposcopy and teaching it on a national and international level for
over 20 years. I have taught on and
behalf of and developed educational material for the American College of
Obstetricians and Gynecologists, and the American Society for Colposcopy and
Cervical Pathology. I am currently the
president-elect of the ASCCP, although I am not here representing them, or any
other organization. I am just
representing myself, and these statements are my own.
As
a matter of financial disclosure, I participated in a mock panel review for
MediSpectra in preparation for this meeting, and I was paid for that
participation, but I have no financial or consulting relationship with the
company, and I am not being paid nor are my expenses being reimbursed for this
meeting. I have also done research for
Polytechnics Corporation, which is developing a competing product.
Briefly,
my message is that we have trained more and more colposcopists over the
years. Each practitioner is doing fewer
and fewer colposcopies, a point that Dr. Julian made just a minute ago. The result is that we have many
inexperienced practitioners whose level of skill is marginal at best. Anything that would assist these novice
colposcopists in identifying significant disease can only be viewed as a
benefit.
Please
allow me to make some specific observations.
Skill in colposcopy and the management of abnormal Pap smears requires
three elements, knowledge of management algorithms, knowledge of the underlying
science, and pattern recognition skills.
The most important way to gain these skills is through clinical
experience. Over the last 20 years, we
have improved our didactic education of colposcopy, and we have also trained
many colposcopists, including gynecologists, family practitioners, nurse practitioners,
et cetera. This was invariably done in
referral centers, where a large number of colposcopies were done. These trainees went on to practice
colposcopy in their communities, and improved their patients' access to care,
and reduced waiting times for examinations and treatment. However, in the process the referral centers
disappeared, and today's trainees often do not have access to such centers, and
so they have only limited clinical experience and continue to have limited
experience in clinical practice. You
would expect that these practitioners would not be very good, and in my
experience they are not.
This
observation is supported by research.
In 2001 we published a survey done on behalf of the American Society for
Colposcopy and Cervical Pathology of residency training directors in OB/GYN and
family practice. Four hundred and
eighty-five program directors responded.
On the basis of their estimates, and the colposcopy experience of
graduating residents is quite limited, especially in family practice. By the time they completed their training,
only 15 percent of family practice residents performed more than 10 evaluations
of high-grade lesions, and only half had evaluated more than 10 low-grade
lesions.
The
estimates for OB/GYN residents were much higher. While there is no data available on how many colposcopies it
takes to develop basic competence in colposcopy, various published estimates
range from 50 to 150 colposcopies, with at least 10 high-grade lesions. In 2004, we presented our experience with an
objective online examination to assess resident skills in colposcopy. In the process, we surveyed both the
residents and their program directors.
While 92 percent of the program directors thought their residents were
adequately trained, only 70 percent of the residents felt adequately
trained. The exam scores correlated
better with the residents' assessment.
In other words, the residents who felt they were poorly trained did
poorly on the exam. I feel that this
supports my conclusion that we are turning out many inadequately trained
colposcopists.
Colposcopy
practice by inexperienced practitioners leads to missed or delayed diagnosis
and treatment. Moreover, inexperienced
colposcopists are also likely to take additional unnecessary biopsies, order
unnecessary tests, or do an unnecessary cone biopsy or LEEP because of a lack
of correlation between their colposcopic impression and the histology resulting
from a failure to perform a biopsy at the appropriate area. The Canadians and British solved this
problem by limiting colposcopy to select numbers of experts. It's not possible in this country.
The
literature shows that about 65 to 70 percent of all CIN2 and 3 originate in
women with ASCUS and LSIL smears.
Current guidelines direct that most of these women would not have LEEPs. As the number of ASCUS and LSIL smears rise,
and the guidelines change to have even fewer of these women have LEEPs, more
CIN2 and 3 will be missed unless we improve the quality of our diagnostic
testing, specifically colposcopy. By
the way, it would not be reasonable to solve the problem by creating algorithms
that manage ASCUS and LSIL more aggressively, because that would just result in
more over-treatment.
The
ALTS data shows that with good colposcopy, and we assume that they have good
colposcopy, about one-third of the CIN2 and 3 lesions were missed at the
initial colposcopy. One can only wonder
what that number would have been with colposcopy as it is practiced in the
general community. The only reason that
we're not seeing a rise in cancers is because we're doing way too many LEEPs
for CIN1, and because the disease takes so long to develop.
With
that background, any technology that would assist the novice colposcopist in
identifying CIN2/3 can only be seen as a benefit. We should not stifle the development of new technology and new
approaches to the diagnosis of this condition.
While I will not comment on the merits of device, I am sure that we can
all remember the initial attempts at the development of HPV-DNA testing. They were not very successful, nor was the
test very useful. However, with time,
improved tests were developed on the foundation of the older ones, and today,
HPV testing is a fundamental part of our management strategy for the diagnosis
of cervical pre-cancer. It's my feeling
that we should give new technologies that are safe and demonstrate reasonable
effectiveness a chance. Thank you for
your attention.
CHAIR
NOLLER: Thank you, Dr. Spitzer. We have one more request to address the
panel, and that's from Dr. Schiffman.
He's been granted two minutes.
Just like Congress, two minutes.
DR.
SCHIFFMAN: I testified against HPV
testing in the mid-`80s. And then it
testified for it when it was ready, years later. I don't understand why we are allowing some pretty pictures of a
couple of anecdotal cases and a trial that fails all of the known requirements
of an FDA panel to go to the point where people are saying that need overwhelms
our data rules. I've spent 20 years
evaluating techniques and technologies that are always pressing forward, and
yes, it's hard to get venture capital money, but there are rules as to when FDA
gives approval. And now I believe
they're being bent past breaking, and it's quite of interest to me, given that
we spent $30 million ALTS, and a lot on others to try to validate when a
technique is really useful for national use, to see that something that really
fails all the different criteria is being evaluated based upon the need for
improving colposcopy. There's a great
need to improve colposcopy. This
technique has not shown in any way that it is better than just forcing
additional biopsies. And by forcing
additional biopsies, more disease is detected, sensitivity increases,
specificity decreases. It's a
no-brainer to me, and I don't understand what's going on.
CHAIR
NOLLER: Thank you. Nancy?
MS.
BROGDON: I suggest you may want to ask
Dr. Schiffman on whose behalf he's speaking.
He spoke on behalf of NIH this morning, and you may want to ask that
now.
DR.
SCHIFFMAN: Those were personal views
based on 20 years of doing this.
CHAIR
NOLLER: Thank you. It's not the official NIH position. Is it correct to comment on those? Yes, it's okay. Yes, comment.
DR.
D'AGOSTINO: I think the open hearing
comments were quite useful. My concern
is we don't have the study to evaluate what was being suggested. The study doesn't have people with poor
training, it has people with extremely good training and so forth. We don't know what LUMA is going to do in
the presence of people who are degrading or have very poor performance. And so to use these studies as a basis for
approval because of this need is even worse than overriding the statistical
lack of significance that we have in the data.
CHAIR
NOLLER: This is part of our panel
discussion. Dr. Cedars?
DR.
CEDARS: Well, I just wanted to agree
with that, and just say that my concern is that if the problem is poor
colposcopic skills, that that's what should be worked on. And even though you may have as best, even
if it were statistically significant a 2 to 5 percent increase in true
positives, you have a 20 percent incidence of false negatives. And so I have a concern saying that this is
going to help people who can't do colposcopy.
CHAIR
NOLLER: Amir?
DR.
GANDJBAKHCHE: Yes, but I think the
point of Dr. Spitzer that I liked was you need another eye, a different
eye. And I think it's different from
the subjective assessment of a physician.
And this is the thing that they claim they are able to do. Do some kind of quantitative measurements.
DR.
D'AGOSTINO: But the study didn't have
people with poor skills.
DR.
GANDJBAKHCHE: I -- sorry? Say it again?
DR.
D'AGOSTINO: The studies we have before
us was not designed to test and to show that the device is useful in the
poor-skilled individuals. I mean, it's
a different --
DR.
GANDJBAKHCHE: I haven't voted yet. I don't know what I will do. But the point I am making is this is two
views for the future of the medicine.
That you have a quantitative way to assess things that you see in the
yellow, or blue, or whatever, and they are based on some spectroscopy. It's not the color. I hope it's not the color, and I will tell
when I will vote how I see the future of this kind of device. But you should have in mind that these are
the major new way to look at things.
These are related to the metabolic activity of the claim, or some
species that are behaving differently in different tissue types.
DR.
MILLER: Yes, I just wanted to, in
listening to some of these latter comments, it occurred to me that if we were
to move forward, and we were to consider labeling, we might want to consider
how this technology would be used in the lesser skilled colposcopist in terms
of faced with the pretty pictures, I in my mind have kind of assumed that the
biopsy sites would be really the blue sites.
But really, one could conceive of someone saying, well you know, you've
got yellow here, and some green there, and some blue there. We'd better nail all of those sites, and now
we're talking about really a very different application than what was studied,
but I think has to be a consideration when this is released to a market of much
more variably skilled colposcopists, who might be prone to biopsy all of the
areas that are illuminated.
CHAIR
NOLLER: Dr. Cedars and then Dr. Weeks.
DR.
CEDARS: Again, I think we're arguing a
different study. I mean, if the
argument is that we need accessory tools like this for the people who are less
skilled, then the study should be LUMA alone to colposcopy alone. And that's not the study. If it's done as an adjunct it's done as an
adjunct to people who have good colposcopic skills. So if you remove the good colposcopic skills, then you're looking
at a totally different tool that wasn't tested.
CHAIR
NOLLER: Dr. Weeks?
DR.
WEEKS: Well, at this point I would just
reiterate probably what everyone else has said. But again, I'm bothered by the fact that we haven't proven
statistically that there is benefit, and I think that's extremely
important. And then we're talking about
putting a tool in the hands of a group of investigators that we haven't studied
at all. Third, we really haven't, I
don't think there's been any consensus that we will really improve the health
of a significant number of women, but there is a very real potential that we're
going to increase the number of procedures that we're performing in these
women, and those procedures could have some adverse health consequences.
CHAIR
NOLLER: Dr. Jiang?
DR.
JIANG: I'm just going to make a
comment, speaking my own mind here. I
think the data presented in front of us are not perfect. I think one reason for that, maybe it's
difficult to do these studies, to get the data that we want. And there's a lot more additional study are
required to answer those questions. But
I think a decision has to be made at some point about that. So I guess I'm saying that we have to make a
judgment based on imperfect data.
CHAIR
NOLLER: Thank you. Mel?
DR.
GERBIE: A few months ago I read about
an FDA-approved device for treating fibroids. The headlines, of course, say FDA approves it, and then halfway
into the article it mentions significant failure rates in a certain period of
time. And I'm saying how can you
approve this and know that it's got a significant failure rate over a period of
time. So I'm not sure what our job is
totally here. I don't know of any
studies or devices in the last X number of years that weren't studied by
authorities, by fetal monitors read by people who have more experience. So everything is done by people who have
more experience, and it goes out into the countryside, and works its way
through, and some continue, whether there's evidence, like a fetal monitor,
that it does anything. I don't think
you're going to teach people how to do mid-forcep rotations today, even though
it's maybe significantly easier than doing the high C-section rate we
have. It just isn't going to be
done.
So
what we're trying to do is see what's going to be best for patients. And maybe the ideal situation is to train
specific number of expert colposcopists, devise referral centers and systems
for that. I don't think that's going to
happen. We train our residents. They get state licenses that says most of
the time they can practice medicine in all its specialties. And the female patient wants the best care
she can get. And I'm not saying this is
a pro or con. I think this is just the
difficulties that I'm having with the decisions.
CHAIR
NOLLER: Thank you. Let me ask if there are any other members of
the public that wish to speak at this time?
Seeing none, the open public hearing part of this meeting will be
closed.
We
will now go to the part of the meeting where both the FDA and the sponsor have
approximately five minutes to make their final comments. During these comments, we will not question
them nor have interaction with either one.
The FDA first.
MS.
BROGDON: FDA staff have no comments.
CHAIR
NOLLER: Thank you. Sponsor?
And as you come up, please introduce yourselves.
DR.
ALVAREZ: My name is Ronald Alvarez. I'm the GYN oncologist division director at
the University of Alabama at Birmingham.
I have no financial interest in MediSpectra but I was a PI for several
studies, and have been provided support to travel to this FDA panel
meeting. I appreciate the opportunity
to make a few closing remarks on behalf of the sponsor.
We've
all spent a considerable amount of time reviewing the intricacies of an
enormous amount of data on a novel optical imaging device to be used as an
adjunct to colposcopy. And I repeat, an
adjunct to colposcopy, not a replacement to colposcopy.
I
hope that we would take a few minutes to just step back and gain some
perspective on what we are trying to accomplish here today. Although we've seen a significant reduction
in the incidence of cervical cancer in the United States since the introduction
of the Pap smear, there are still many areas in this country that harbor high
incidences of cervical cancer, many states like my own. There are a number of different avenues of
research that are involved in improving the prevention of cervical cancer. Clearly, a need for behavior modification,
improving access to care for those, particularly in underserved populations. There's clear need to identify new
biomarkers that could be used in cervical cytology to identify those patients
at highest risk. And we've heard today
how important it is to improve our management guidelines, and to educate
physicians about the implementation of these guidelines, particularly in
adolescent populations.
Likewise,
there is clearly a need to improve upon the current methods of evaluating a
patient with an abnormal Pap smear.
This has really been the primary focus of our discussion today. I'd like to recall that there was a time
when patients with an abnormal Pap smear all underwent conization, or multiple
blinded and random biopsies. Colposcopy
was developed to facilitate the evaluation of these patients, to direct the
clinician to biopsy the areas most likely to harbor disease, and to guide the
physician with respect to further management of the patient. It has remained the gold standard for
evaluating patients with an abnormal Pap smear for over 50 years.
For
so many years, we all believed that colposcopy was a very accurate method to
detect significant cervical dysplasia.
However, we have come to understand from a number of studies, including
the ALTS studies, how poorly accurate this device is, how insensitive it is for
detecting significant disease. As you
heard often today, over 60 percent of patients with CIN2 present with an ASCUS
and LSIL Pap smear, and in the ALTS study, one-third of these patients were
missed for colposcopy. I hate to inform
you that myself and many of the people that are here with us today were those
so-called expert colposcopists that participated in that trial.
Today
we've discussed in detail emerging optical technology that provides us
quantitative information and has been demonstrated to improve upon the
performance of colposcopy when used as an adjunct, once again, and not as a
replacement for colposcopy. We have
reviewed in detail two studies that show a similar and repeatable magnitude of
effect with respect to detecting CIN2/3 in a patient population that this is most
relevant in. These studies included a
large group of institutions and colposcopists, and a large patient population
that was geographically and demographically diverse. Specifically, we've seen an approximately 25 percent increase of
detection of CIN2/3 when LUMA was used as an adjunct to colposcopy compared to
when using colposcopy alone, many that were performed by these so-called
experts.
Were
these studies perfect? The answer to
this questing is clearly no. Who
wouldn't redesign a study, once completed, particularly when the results of
that study come to fruition. I caution
you that we must be able to recognize in any study the potential clinical
significance of an intervention when the results of a study do not meet the
strict preset statistical design placed on the initial protocol. Much like we must recognize whether an
intervention is of no clinical significance in spite of reaching statistical
significance in appropriate design trials.
Hundreds
of studies have demonstrated the potential benefits of spectroscopy in the
context of cervical neoplasia. Most of
these have actually involved very small populations of patients. The studies today presented represent the
largest to date to evaluate this emerging technology in a very clinically
relevant manner. Designing,
implementing, and analyzing the perfect study to evaluate this technology in a
strict ASCUS/LSIL population would require enormous patient and financial
resources that quite frankly not even the federal government could currently
afford. And we'll perhaps miss a
potentially unique opportunity to begin to incorporate this technology to
improve the performance of colposcopy.
Could
we achieve the same results with additional biopsies? Dr. Solomon and Schiffman have alluded to this fact. However, are multiple biopsies the current
standard of care for patients with ASCUS and LSIL, or should they be
mandated? In fact, in the ALTS trial, a
little over 10 percent of over 5,000 patients entered into this trial had more
than one biopsy obtained. Should more
than two biopsies be mandated in this population to even further increase the
sensitivity for detection of CIN2/3? It
seems to me that this policy is retroactive, is moving the field back to a time
where we did a conization on all patients with an abnormal Pap smear.
What
about the discomfort and other side effects associated with additional
biopsies? We all have done colposcopy
and biopsies. And I'm sure that many of
us have patients that we recognize how uncomfortable this procedure is. Perhaps you can believe that you will
ultimately detect this CIN2/3 in a patient with an ASCUS or LSIL Pap smear the
next time she comes in for an evaluation.
Well
that may indeed be the case if we could be assured that patients were 100
percent compliant with follow-up. This
is far from the case, particularly in patients at highest risk for developing
cervical cancer. Indeed, this was the
case with the ALTS trial, in which compliance was about 85 percent in an
environment that was rich with infrastructure and incentives to ensure
compliance. My colposcopy clinic
patients at UAB are in general from lower socioeconomic groups, have poor
understanding of the importance of cervical cancer screening, and have limited
resources to access cervical cancer clinic facilities.
At
my institution, we schedule 120 patients with an abnormal Pap smear from the
local health departments each week at our colposcopy clinic for either
colposcopic evaluation or a loop procedure.
Over half to these patients fail to keep their appointments each week,
and there are many who are never evaluated or appropriately treated. Thus, relying on patient follow-up to
address deficiencies in colposcopy I think is fraught with false security, and
doesn't directly address the problem of colposcopy.
In
summary, we have demonstrated that the LUMA device when used as an adjunct to
colposcopy is safe, easy to utilize, and improves the detection of CIN2/3 by
nearly 25 percent in the most relevant patient population, namely those with an
ASCUS and LSIL Pap smear. The
information presented represents years of diligent work that only begins the
important research that needs to be done in this area. Is there likely some other method presently
available to address this deficiency in such a forward-thinking manner? There is none to my knowledge. Is there going to be a need for training
physicians in the use of this technology?
Certainly that is the case, and the company is certainly committed to
doing that in the appropriate fashion.
Will there be a need to ensure that we address the issues regarding
management of patients, particularly the younger patients, with respect to once
they have had a diagnosis? Certainly
that is the case. Will there be
improvements upon this technology? We
will certainly see additional enhancements.
My
colleagues and I believe that this will be the first of many innovations that,
consistent with the initiatives within the NIH roadmap, will allow us to
improve upon our ability to image the cervix and diagnose more patients at
highest risk for developing cervical cancer, namely those with ASCUS/LSIL Pap
smears that harbor CIN2/3. With over 2
million women referred with these abnormal Pap smears annually, can we afford
not to adopt this emerging quantitative optical imaging technology that will
provide true health benefits for a significant number of patients at risk for
cancer? Certainly we know that that is
the question that you will have to address today. Remember that approximately 20 percent of patients who develop
cervical cancer do so as a result of failure to follow up, and as a result of
inappropriate management. I thank you
for your time and your attention.
CHAIR
NOLLER: Dr. Wingrove, I am told you can
do this in a minute?
DR.
WINGROVE: That's correct. I just want to echo some of Dr. Alvarez's
thoughts. We do believe we have a study
which has -- two studies which have consistently found the same finding, a 25
percent increase in CIN2/3 detection.
We believe that the medical community should have the opportunity to use
this advice, but we have heard your recommendations. We have heard your concerns regarding training and regarding
labeling, and we would welcome any further recommendations you would have on
how you think that would best improve or address your concerns. We have every intention of working with
medical societies like the ASCCP to ensure that the training is optimized and
consistent with their recommendations.
Thank you.
CHAIR
NOLLER: Thank you. The panel will now proceed to the
deliberations and vote. And as a
prelude to this we'll ask our secretary Dr. Bailey to read the panel options
and the votes. I ask the panel to pay
particular attention to this part.
DR.
BAILEY: The Medical Device Amendments
to the Federal Food, Drug, and Cosmetic Act, as amended by the Safe Medical
Devices Act of 1990, allows the Food and Drug Administration to obtain a
recommendation from an expert advisory panel on designated medical device
premarket approval applications (PMA) that are filed with the agency. The PMA must stand on its own merits, and
your recommendation must be supported by safety and effectiveness data in the
application, or by applicable publicly available information.
The
definitions of "safety", "effectiveness" and "valid
scientific evidence" are as follows.
"Safety" is defined as a reasonable assurance that the device
is safe when it can be determined based upon valid scientific evidence that the
probable benefits to health from use of the device for its intended uses and
conditions of use when accompanied by adequate directions and warnings against
unsafe use outweigh any probable risks.
The definition of "effectiveness" is a reasonable assurance
that a device is effective when it can be determined, based upon valid
scientific evidence, that in a significant portion of the target population the
use of the device for its intended uses and conditions of use when accompanied
by adequate direction for use and warnings against unsafe use will provide
clinically significant results.
"Valid scientific evidence" is defined as valid scientific
evidence from well controlled investigations, partially controlled studies,
studies and objective trials without matched controls, well documented case
histories conducted by qualified experts, and reports of significant human
experience with the marketed device from which it can fairly and responsibly be
concluded by qualified experts that there is a reasonable assurance of the
safety and effectiveness of a device under its conditions of use. Isolated case reports, random experience,
reports lacking sufficient details to permit scientific evaluation, and
unsubstantiated opinions are not regarded as valid scientific evidence to show
safety or effectiveness.
Your
recommendation options for the vote are as follows. One, approval if there are no conditions attached. Two, approvable with conditions. The panel may recommend that the PMA be
found approvable subject to specified conditions, such as physician or patient
education, labeling changes, or a further analysis of existing data. Prior to voting, all of the conditions
should be discussed by the panel. The
third option is not approvable. The
panel may recommend that the PMA is not approvable if the data do not provide a
reasonable assurance that the device is safe, or the data do not provide a
reasonable assurance that the device is effective under the conditions of use
prescribed, recommended, or suggested in the proposed labeling.
Following
the voting, the chair will ask each panel member to present a brief statement
outlaying the reasons for his or her vote.
Dr. Noller?
CHAIR
NOLLER: Thank you. And now as we go through this, the format is
fairly rigid. And I would ask that when
we get to the discussion if you would raise your hand high so I can see you,
and I will try to take you in order as I see you.
The
first think we need to do is to obtain a main motion. And I'm going to ask the group if there is a motion to recommend
approval, approval with conditions, or not approvable.
DR.
GERBIE: Question.
CHAIR
NOLLER: Dr. Gerbie has a question.
DR.
GERBIE: Can you state what are we --
what is the proposal. Excuse me. What exactly is the proposal?
CHAIR
NOLLER: The proposal is to recommend to
the FDA that this device is safe and effective as described, and I guess that's
really it. Is that right? Because ?. Is that right?
DR.
GERBIE: My question is, is this
specifically for ASCUS, ASC-H, low-grade, or not?
CHAIR
NOLLER: That's the -- yes. That's true. That's what the sponsor has asked for. That is the indication, specifically for ASCUS and LSIL. Nancy, is there anything more there I should
say that I messed up on?
MS.
BROGDON: No, I think you got it.
CHAIR
NOLLER: Okay. So I'm looking for a motion to approve, approve with conditions,
or not approve. I can't make the
motion. Dr. Cedars?
DR.
CEDARS: I would put a motion to not
approve.
CHAIR
NOLLER: We have a motion not to
approve. Did I hear a second?
DR.
SNYDER: Second.
CHAIR
NOLLER: Please say your name when you
second.
DR.
SNYDER: Dr. Snyder.
CHAIR
NOLLER: Dr. Snyder seconds. Now we'll have discussion of the
motion. Who would like to speak first? Let me ask Dr. Cedars to speak first since
she made the motion, then Dr. Snyder, and we'll go from there.
DR.
CEDARS: I make the motion number one
because I don't believe that there is scientific evidence to support efficacy,
certainly not statistically significant, and because of concerns specifically
regarding the youngest population in which there appeared to be the greatest
benefit, based on the data that's available.
CHAIR
NOLLER: Dr. Snyder?
DR.
SNYDER: I'd like to start off by saying
I'm really excited about this technology.
I'm optimistic about this technology.
And I just, you know, pray that it's going to get to the point where
it's going to be able to maybe even replace colposcopy. And I will always worry about stifling
ongoing research because of decreased funding.
And that could be construed to not be in the public's best interest, but
I also feel strongly that neither is it in the public's best interest to put a
device out there that doesn't meet the rigors of good clinical evidence, and
science-based evidence. And that
concludes my comments.
CHAIR
NOLLER: Other discussion? Yes.
DR. D'AGOSTINO: Having said so much earlier, I have to say something to repeat
myself. But I don't see the statistical
significance there, and it's very bothersome.
And the more we talked, the issues of the young group being the group
that may in fact have the CIN2's where there's going to be potential
regression, the expertise of the people who are using this when it goes out, if
it does go out to be used. There's just
so many issues about the data, and the implications of this being approved that
I support the non-approvable.
CHAIR
NOLLER: Other discussion? Before we take a vote, I will ask the three
members who have participated in the panel discussion today but who will not
vote to make a statement. Our public
member, please? Into the microphone.
MS.
MOORE: I guess I start with a
question. I wanted to know if -- that I
don't expect you to answer, it's just one of these questions that I have in my
mind. Does statistical significance
override clinical significance. That
was one of the questions that I thought about.
And
then the other comment is if this device is to be used as an adjunct, as we
have been told, it is to me another tool in the diagnostic process which I
think could be of benefit. So as the
consumer representative, it would seem to me that with the suggestions that
have been offered today, that this should be approved with conditions. And if I were a voting member, I think
that's what I would vote for.
CHAIR
NOLLER: Our industry member, please.
MS.
GEORGE: Very similar to what Christine
has just said is that I, having actually sat in their shoes and created many of
these 510(k) PMA's myself, I think they've done an excellent job of clinical
study. They've really taken a significant
amount of time to pull all of the information together. I too would have chosen the approval with
conditions, specifically using some of the discussions of going back and doing
more analysis of data, because I think there is a significant amount of
information and data they have here that could be sliced and diced in many
different ways. I know that the
statisticians say that you can put anything together to make it look good, but
I think that, you know, inversely as well maybe they'd go back and find out
that it wouldn't be as good, and they wouldn't want to put it out there.
And
then secondarily, I think that also as Christine stated, I think that a new
technology, an added technology that doesn't harm the patients, because I think
that there was no evidence here that anyone was getting hurt by anything of
this, that there was really only evidence that it either supported or
potentially assisted in the clinical decision process. So I too would have gone with approval with
conditions.
CHAIR
NOLLER: Third member. Dr. Sanfilippo, do you have any comments?
DR.
SANFILIPPO: I want to just say that
certainly clinical application, and clinical importance is absolutely
paramount. And I am very impressed with
the technological advances bringing us here today, because it represents some
tremendous thought, ingenuity, et cetera.
While I don't have a vote, I do feel this technology one day will
certainly help clinicians. And
personally, I would just like to see some additional data, and I'm hopefully
that perhaps somehow it occurs, because I do think that there is some clinical
application at all age ranges.
Unfortunately, I didn't see that today.
CHAIR
NOLLER: Thank you. It has been moved and seconded that
MediSpectra's premarket approval application P040028 for the LUMA Cervical Imaging
System is not approvable. In a moment I
will ask everyone on the panel for their vote.
You have three options, to vote for the motion of not approvable,
against the motion, or you may abstain.
I will start with Dr. Gerbie.
Dr. Gerbie, how do you vote?
DR.
GERBIE: I vote against the motion.
CHAIR
NOLLER: Against the motion. Dr. Jiang?
DR.
JIANG: I vote for the motion.
CHAIR
NOLLER: Votes for the motion. Amir?
DR.
GANDJBAKHCHE: No, against the motion.
CHAIR
NOLLER: You vote against the
motion. Dr. Miller?
DR.
MILLER: I vote for the motion.
CHAIR
NOLLER: Miller votes for the
motion. Dr. Hillard?
DR.
HILLARD: I vote for the motion.
CHAIR
NOLLER: Dr. Hillard votes for the
motion. Dr. Cedars?
DR.
CEDARS: For the motion.
CHAIR
NOLLER: Dr. Cedars votes for the
motion. Dr. Weeks?
DR.
WEEKS: For the motion.
CHAIR
NOLLER: Dr. Weeks votes for the
motion. Dr. Julian?
DR.
JULIAN: For the motion.
CHAIR
NOLLER: Dr. Julian votes for the
motion. Dr. D'Agostino?
DR. D'AGOSTINO: For the motion.
CHAIR
NOLLER: Vote for the motion. Dr. Snyder?
DR.
SNYDER: For the motion.
CHAIR
NOLLER: Votes for the motion. Dr. Hayes?
DR.
HAYES: For the motion.
CHAIR
NOLLER: Votes for the motion. It's the recommendation of the panel to FDA
that the MediSpectra PMA P040028 for the LUMA Cervical Imaging System be not
approved. The motion carried 9-2, 9-2
with no abstentions.
I'm
now going to ask each panel member the reason for his or her vote, starting
with Dr. Gerbie, and we will go around the table. Following this, we will go around the table a last time, asking
each person to state what the sponsor would need to do to make the PMA
approvable. Dr. Gerbie, why did you
vote as you did?
DR.
GERBIE: I voted against the motion
because I feel that the technology has shown enough promise to get this into
the public arena for further development.
I realize there are shortcomings in the statistical analysis. There are many small points I disagree with
in the presentation, including even the last statistic of the 25 percent
increase, but I feel that for women's health issues, that this is an
appropriate technology, that we should look at the positive aspects of this
rather than the statistical analysis.
CHAIR
NOLLER: Thank you. Dr. Jiang?
DR.
JIANG: I voted for the motion. To me it seemed to be this device can pick
up additional CIN2/3 lesions, but then there's downside. There's additional biopsies of patients who
otherwise would not have biopsy. And
there's potential of over-treatment.
But really, the issue was the motion raised that the biggest benefit is
in younger patients, and there's some argument on that, but the data seems
clear to me. And that caused me to
think the clinical significance is really the problem.
CHAIR
NOLLER: Thank you. Dr. Amir?
DR.
GANDJBAKHCHE: My motion would be
approval with condition. I will explain
why. Because this is maybe the first
device that we see that's quantitative.
And it's very important to assess these needs for physicians. I think the data they provided showed some
promises. But my condition would be
more data analysis. Open their black box
and let FDA and other experts look at this, and see if the way that they are
looking at the data can be improved.
And I'm sure it can be approved.
They were under tight conditions because they were doing the PSI and
PSII. They could not unlock their
algorithms. They can do that, and I am
pretty confident approval with condition, that opening the black box will for
sure bring new sites for this kind of technology.
CHAIR
NOLLER: Thank you. Dr. Miller?
DR.
MILLER: I voted for the motion because
ultimately I wasn't persuaded that this technology, although exciting and also
of interest to me personally, would provide a significant benefit over and
above a skilled colposcopist doing an adequate number of biopsies. So I echo some of the other sentiments
stated before, that I think this is a technology in motion. I recognize the difficulty and the expense
in getting to this point. But I think
there are real risks, and the risks are over-treatment, over-diagnosis, and
also potentially a dumbing down of a skill set that we need to be drumming up.
CHAIR
NOLLER: Thank you. Dr. Hillard?
DR.
HILLARD: I voted for the motion, and
for a number of reasons. I do think
it's an exciting technology. I think it
has potential, and the concept of putting together a more objective evaluation
of colposcopy I think is very exciting.
So I think it is exciting.
I
am concerned, however, because I start from the assessment that the results did
not meet the preset criteria for statistical significance. And there certainly are others on the panel
and in the room who have more expertise in statistics, but I think that I have
to rely on this as a starting point. So
I have those concerns.
I
am concerned about that I'm not sure whether an increase in detection of the
CIN2/3 that is present with the device is that much better than an additional
biopsy. So I have those concerns. I'm concerned about the over-detection of
disease that may not be clinically significant. And so while I'm not concerned about the safety of the device
itself in how it is used, I am concerned about, and I'm concerned that an
increase in false positives can lead to over-treatment that may potentially
harm women. And for all of these
reasons I felt compelled to vote as I did.
CHAIR
NOLLER: Thank you. Dr. Cedars?
DR.
CEDARS: I just want to echo what
everyone else has said. I think this is
very exciting technology. I have
concerns about approving it because it's exciting technology until it is able
to pass the burden of proof. And I feel
like that's what's not yet been done.
CHAIR
NOLLER: Thank you. Dr. Weeks?
DR.
WEEKS: Likewise, I wasn't convinced by
the statistical analysis. I believe
that the statistical analysis was set up in a way to reveal important clinical
changes. The potential for harm, I
think, is significant. While I think
some of the speakers' comments about losing patients to follow-up in some ways
can be compelling, but even if such a technology were used, and we diagnose a
young woman with a CIN2/3, they still have to have follow-up. Unless we're going to embark upon some of
those early treatments that, again, I'm very concerned about.
CHAIR
NOLLER: Thank you. Dr. Julian?
DR.
JULIAN: I have great respect for the
investigator sponsors.
CHAIR
NOLLER: Can't hear you, Tom.
DR.
JULIAN: I have great respect for the
investigator sponsors. I know many of
them. I feel that LUMA may have great
potential. It's an intriguing
device. I don't think there's any doubt
that it's safe. And I think in a
society where we have an everything must be done mentality about public health,
it has much potential. But the
potential is in finding a small number of potentially problematic lesions, but
probably not in preventing cervical cancer, or preventing cervical cancer in
such small numbers as to not be truly beneficial.
I
think the potential that should be studied is the benefit to non-expert
colposcopists, rather than expert colposcopists. If it could be shown that this was effective at improving the
marginal, or the early colposcopist, it would have real value. But the overwhelming data in my opinion
presented by the FDA and two of the three statisticians here convinced me that
it had not met rigid enough criteria to be a benefit.
CHAIR
NOLLER: Thank you very much. Dr. D'Agostino?
DR.
D'AGOSTINO: I also am excited about the
technology. I just wanted to make sure
it's clear that people, or maybe they don't understand, that I spend most of my
research life on the Framingham Study.
It's a cardiovascular study, but we spend lots of time looking at
non-invasive technologies, subclinical markers, and this is exactly, this idea
of new technologies, and discriminate functions, and classification functions
is exactly what I do all the time. That
doesn't mean that we get excited about a technology and therefore say it's
ready for primetime, it's ready for use.
And I think when they went to the studies, and interpreted the studies,
and ran the analysis of the studies, they left some of the statistical
significance issues aside, which I think we correctly picked up in terms of
emphasizing them.
And
also, I think that I was speaking mainly about the statistical significance
during the day, but I think the clinical significance, I'm not overwhelmed by
the notion of these false positives, and also the idea of the regression of the
CIN2 without us really having a clear indication of what's going to happen to
these individuals. And I don't think
the study addressed those issues. So
it's not just the statistical significance that led to my decision.
CHAIR
NOLLER: Thank you. Dr. Snyder?
DR.
SNYDER: I'm going to reiterate also
much of what some others have said. And
first off I too want to say that I have the absolute utmost respect for the
individuals that are involved in this trial, and involved with advising this
company. I think women's health owes
very much to these individuals that have published, that have done research,
and have additionally done teaching to our specialty, and ancillary health care
providers. And we owe a great deal to
them. And I also feel comfortable that
they're going to stay involved in the cutting edge of research, and to how we
can further decrease cervical cancer and mortality. And I want to see them do further development and refinement of
this.
If
I could have recommended approval of this device to stay only in the hands of
the clinical researchers that were doing this, I would have done that. But as I see it, that my job on this panel
is to say whether we are going to recommend that something comes out with FDA
approval or not. And as I see it,
patients regard that in very high esteem.
And if we say this device is ready to carry the seal of the FDA, then
patients are going to go out there, and they're going to hear about it, and
they're going to feel like they are possibly getting inferior care if their
health care provider doesn't have access to this piece of equipment. And then the next thing is that clinicians
are going to be compelled, irrespective of the science, to be able to provide
this technology, because that's what their patients are demanding.
And
I just did not feel like we had met the rigors of science, which we are
supposed to be guarding at this point in time.
I don't think that just another tool is a fix for inadequate training,
and I don't think it's -- well, let me, I think one of the other things you
said I could do is suggest other areas of research. I would love to see this go head to head with colpo. I'd like to see it --
CHAIR
NOLLER: Actually, we may -- let's do
that in the next round.
DR.
SNYDER: Okay.
CHAIR
NOLLER: Thank you. Dr. Hayes?
DR.
HAYES: Yes, I voted for the motion
because I do not believe based on the data that we had that it met the
definitions of safety and effectiveness.
There was not compelling data support.
And that realistically there was a high probability that there would be
potentially over-treatment and inappropriate treatment.
CHAIR
NOLLER: Thank you. Since the panel voted to recommend that the
PMA is not approvable at this time, we must now identify what the panel
believes is needed by the sponsor to make the PMA approvable. We're trying to help both the sponsor and
the FDA. And before I ask the voting
members, let me ask our non-voting members what they think. Ms. Moore?
MS.
MOORE: Well, of course since I
mentioned the labeling regarding -- well, not the labeling. I mentioned the question of age earlier on
in the discussion. And I talked about
the senior citizen, or the geriatric patient, but since then we've brought up
that about the adolescent. So then I
would add that to my comment.
And
then to satisfy the statisticians, I'm not one -- I don't know exactly what to
tell them, but I think that they would have to do something with maybe a
population of people, and then to set their statistical goals, and in some way
meet those goals.
CHAIR
NOLLER: Thank you. Ms. George?
MS.
GEORGE: I think as everybody has said,
focusing on the statistical aspects of it, getting more data, looking at the
data they already have to be able to help support the concerns that everybody
has identified. I think that additional
focus on the training and the labeling.
I think the labeling, one of the things I noted was I had mentioned it
earlier, that there's limitations, but they're not really clear whether they're
things that they should or should not do.
So maybe addressing that a little more clearly.
And
then lastly, the training. I know I had
some -- I did wonder a little bit about the reader variability and I think a
few people have brought it up with the skill level of the people that were
involved, that they may have been very skilled, so maybe there variability is
even more so a risk. I think Dr. Julian
mentioned that, that sometimes the more skilled they are, the more variability
there could be there. So I think that
that needs to be addressed.
CHAIR
NOLLER: Thank you. Dr. Sanfilippo, what should the sponsor do
to make it approvable?
DR.
SANFILIPPO: I would just say personally
witnessing a secretary who works with me, and has worked with me for many
years, and is as we speak dying of cervical cancer, this becomes something very
important to me, and in a sense near and dear to my heart. And my communication is that I just hope you
all will continue with what is very much cutting edge. And if I were to have some communication, it
would be the experimental design going forward. And again, I would strongly encourage you to give due
consideration. I'd like to see studies
in individuals less than 18 years of age.
I'd like to see this in the hands of residents, and I'd like to see this
in the hands of attending physicians who, if you will, are remote from their
educational curve, i.e., residency. And
I'd like to see head to head comparison with colposcopy. And again, to right out of the gate
initially look at the labeling recommendations, restrictions if you will. And in a sense, if those four criteria were
present with appropriate significance, then I think we could move forward.
CHAIR
NOLLER: Dr. Gerbie, you voted against
the motion, but what advice would you give the sponsor?
DR.
GERBIE: I'm afraid I don't have a lot
of advice. And I realized, as did many
of the people who voted the other direction, that there's potential here. I've followed some of this information from
publications in the journals, and from other researchers, and think that we
need somehow to keep the stimulus going.
I think it would be very difficult to devise a different trial that's
better than the trial that was done.
The numbers are -- 4.5 percent is still a relatively small number at
this condition. And to get to a point
that is still treatable in a conservative fashion, with the main argument being
that to avoid loss of patients. Perhaps
the low-grade patient who remains low-grade over a period of time with no
obvious findings is a small subset for this, but it looks like that would be a
lesser market.
CHAIR
NOLLER: Thank you. Dr. Jiang?
DR.
JIANG: I guess two comments. One has to do with technology. It seemed to me the device had some
potential to increase true positive, but that potential is quite small. So from the technology standpoint, if that
can be improved, that would be great.
On the other side, reduce the false positive.
And
the other point I think that's more important is clinically understand the age
effect, whether there is an effect, and whether the device can benefit people
that -- not the younger group.
CHAIR
NOLLER: Thank you. Dr. Amir, you voted against the motion, but
what do you have to suggest?
DR.
GANDJBAKHCHE: I don't think that the
idea to do another clinical trials and so on is right. Because they have done a very good job on
that. It's impossible to get better
than this. However, being in the
biomedical optics maybe for 20 years, the devil is in the algorithm. Because there is a lot of data processing
that should be done to obtain the kind of images that you see there. And I recommend to the company to actually
look at this, go back to their data, and try to re-analyze it in some other
way. Open up the box to the FDA, they
will ask some experts to come and look at it, and I'm pretty sure that these
numbers that you see here in the false positive/true positive will change, I
assure you.
CHAIR
NOLLER: Thank you. Dr. Miller?
DR.
MILLER: Yes, maybe to echo some of
those thoughts. I think fundamentally
the goal should be to enhance that which distinguishes the LUMA assessment from
the colposcopic assessment, so that ideally you increase the true positive and
lower the false positive rate. And some
specific ideas would be to, number one, maybe do some more careful analysis of
what happened in those cases where the LUMA identified a lesion that the
colposcopist didn't think existed. You
know, we had some commentary about, you know, there was some controversy,
difference of opinions, but it was a sense that there were some examples of
patients where the LUMA took the colposcopist to an area of the cervix that
would not have been felt to be suspicious by clinical assessment. So what was it about those cases in your
cohort that maybe could change the algorithm, or enhance the product.
The
second point was I think there was a feeling on the panel, certainly I had a
feeling that because the CIN2 and the CIN3 were lumped together that it diluted
the value of the diagnostic tool; that it would have been of greater value if
the LUMA device had better distinguished between 2 and 3, because we would have
been more persuaded by value in the 3 category. And we were told by Dr. Wright that it wasn't possible, but I
assume that you have these block specimens.
I assume that it might require having a pathologist look at it again,
but my question would be is it possible to separate out the 2's from the
3's? You might have some power
problems, but that might be worthwhile.
And
the third was is it possible to go back to the PSI trial, and again try to look
more carefully at the colpo only group, where the colposcopist was directed by
their own intuition in terms of where to biopsy, but you have the LUMA
assessment, and try to match the scan and where the LUMA scan would direct
someone to biopsy compared to where the colposcopist biopsied.
CHAIR
NOLLER: Dr. Hillard?
DR.
HILLARD: Certainly others have made
some good suggestions, and some good thoughts.
I think that if one were to do additional studies, or even to try to
look at this issue around this device or others in the future, being sure that
you have good data for the youngest age group in collecting the data about age
of coitarche and first intercourse.
Certainly lesions take awhile to develop, and knowing how long it has
been that that lesion has potentially been developing is potentially
important. So collecting that data.
And
then the only other thought I had has already been mentioned, related to CIN2
versus 3, and looking also at that data by age.
CHAIR
NOLLER: Thank you. Dr. Cedars?
DR.
CEDARS: I think that there actually do
have to be other studies that are done, because as we've been discussing, you
can sort of slice and dice the statistics in different ways, but if it's not
statistically significant, in answer to your question in terms of clinical
significance versus statistical significance.
If it's not statistically significant, you can't even say that the
conclusion is valid. And so it doesn't
really matter whether it's clinically significant or not. You can ask the reverse, but I think it's
very hard to try to say something's clinically significant if it's not
statistically significant first because that's whether or not it's valid. And so I think you're going to have trouble
doing that with the data that you have.
And
I particularly think, and Dr. Hillard brought this up earlier, that the
criteria for screening has changed. And
obviously, you can't sort of be penalized for having started the study before
the new criteria. But I think that the
new criteria, having changed, is going to change how people practice, or at
least we hope it's going to change how people practice. And I would think that any new study is
going to have to be based on the new screening criteria. And as your first study showed, you're going
to be looking primarily at your low-grade Paps, your ASCUS and your LSIL, which
is going to take out 50 percent of your patients, which is part of the reason
you probably didn't have power when you started looking at the lower grade
lesions.
So
I think you almost have to do another study, using the new current screening
guidelines, including age, and HPV status, and looking at specifically just
your low-grade Paps. And then you're
going to have to set hard statistical guidelines that you're going to
meet. And I think in terms of opening
up the black box, if you open up the black box and you change the algorithm,
then you've got to do the study all over again anyway. I mean, you can't really -- because you
don't have biopsies.
CHAIR
NOLLER: No discussion, please.
DR.
CEDARS: You don't have biopsies in
those spots. So I think you really are
-- I mean, I think it's very exciting technology, but I really do think that
you're going to have to do another study.
CHAIR
NOLLER: Thank you. Dr. Weeks?
DR.
WEEKS: Well, I don't know how practical
a suggestion this is, but it sounds like a number of panel members think more
study is needed. I'd simply like to see
Pivotal Study II completed, because if it were completed with the N that was
estimated in the beginning, then I think the data, if it holds true, if this
trend holds true, would be much more compelling.
I
agree with Dr. Miller that it'd be interesting both for PSI and II to look back
at the slides and try to separate out CIN2 and 3. For the package material, or teaching material, I think it's an
important question, what are clinicians going to do when CIN2 specimen, or CIN2
is discovered while using LUMA. Perhaps
some of the magnates, or the practitioners and researchers who are in the forefront
can put together some sort of teaching material that could be available to the
clinicians online to hopefully encourage them not to start off on a path of
doing multiple LEEPs and surgical procedures, particularly on young women. And that's the end of my suggestions.
CHAIR
NOLLER: Thank you. Dr. Julian?
DR.
JULIAN: Well, I have to reiterate that
looking at the group of investigator sponsors here, they're among the best in
the specialty, and I'm not really qualified, in my opinion, to tell them how to
do research. If I had to make a single
recommendation, it would be to demonstrate that the LUMA improves outcomes in
non-expert colposcopists, not in expert colposcopists. That is the target group for this
device. Rehashing the information
presented here will bring up the same problems that we had today, I think.
CHAIR
NOLLER: Thank you. Dr. D'Agostino?
DR.
D'AGOSTINO: I think re-analyzing the
data that you have is going to be very important. I think the CIN2's versus CIN3's, if it's possible to make that
sort, and also look at the situation where the LUMA was taken but then not
read, if you can get some data, and whatever else you can do to get data from
the existing studies. I do think you're
going to need another study, and possibly can design the next study on a sort
of smaller population, a target population, some population where you think the
LUMA, from analyzing this past data, where you think the LUMA might actually
make a big contribution so that there's sort of enough evidence for the FDA and
for an advisory committee to say there's something going on here.
I
do think the issues that were just raised, though, will haunt you, and I'm not
sure how you're going to handle that without a really large study. I do think it's expert-driven in this study,
and the open hearing just made me all the more concerned that if the study
looks similar to what you have now, how are you going to generalize it. So I do think you have those issues, but in
terms of getting approval, getting the FDA to be convinced that there's
something going on here, you may be able to, from looking at the past data, get
a well directed new study with clear hypotheses, clear statistical procedures,
and not a huge study to show that there is a benefit, and then you face the
other issues as time goes on.
CHAIR
NOLLER: Thank you. Dr. Snyder?
DR.
SNYDER: Like Dr. Julian, I don't really
feel qualified to be telling them what to do.
I do think that if there's any way to refine the ability of this to
detect abnormality, through different changes in the algorithm, through more
just direct comparison from one biopsy to another biopsy, it would be
wonderful. I'm not sure how to do that.
CHAIR
NOLLER: Thank you. Dr. Hayes?
DR.
HAYES: Well, in appreciation of the
richness of skill on the team and our discussion today, and some of the
recommendations regarding education and labeling, and almost like lessons
learned. And that's a retrospective
look. As we go forward, I do think
there needs to be another study, but operationalizing some of the suggestions I
think will make it ever better, and address the questions would be a good thing
to do, and I would encourage them to do that.
CHAIR
NOLLER: Thank you. One last bit of housekeeping here. Please leave all your materials on the
table. FDA will pick them up. Nancy Brogdon, any final comments for us?
MS.
BROGDON: Only that FDA staff would like
to thank the panel for your time and efforts and your expertise. Thank you.
CHAIR
NOLLER: I would like to thank all the
panel members. I think everyone was
very thoughtful today. They did their
homework, and I greatly appreciate it.
It made my job easier. This 69th
Meeting of the Obstetrics and Gynecology Devices Panel is now adjourned.
(Whereupon,
the foregoing matter was concluded at 4:31 p.m.).