U.S. DEPARTMENT OF HEALTH AND
HUMAN SERVICES
FOOD AND DRUG
ADMINISTRATION
CENTER FOR DEVICES AND
RADIOLOGICAL HEALTH
MEDICAL DEVICES ADVISORY
COMMITTEE
MEETING OF THE
DENTAL PRODUCTS
PANEL
THURSDAY, MAY 22,
2003
The
meeting was held in the Walker/Whetstone Salons of the Holiday Inn
Gaithersburg, Two Montgomery Village Avenue, Gaithersburg, Maryland, at 9:30
a.m., E. Dianne Rekow, Chairperson, presiding.
PRESENT:
E. DIANNE REKOW, DDS, Ph.D. Chair
MICHAEL E. ADJODHA, M.ChE. Exec. Secretary
RICHARD G. BURTON, DDS Panel Member
DAVID L. COCHRAN, DDS, Ph.D. Panel Member
JULIANNE GLOWACKI, Ph.D. Panel Member
ELIZABETH S. HOWE Panel Member
MARK R. PATTERS, DDS, Ph.D. Panel Member
DANIEL R. SCHECHTER, JD Panel Member
JON B. SUZUKI, DDS, Ph.D. Panel Member
FDA PARTICIPANTS:
M. SUSAN RUNNER, DDS, MA, Captain, USPHS
KEVIN P. MULRY, DDS, MPH
ROBERT S. BETZ, DDS, Captain, USPHS
MARJORIE SHULMAN
SPONSOR PARTICIPANTS:
VINCENT J. MORGAN, DMD
THOMAS DRISKELL
JOHN R. LONG, Ph.D.
AGENDA ITEM PAGE
CALL TO ORDER:
Michael
Adjodha........................... 3
CONFLICT OF INTEREST SURVEY:
Katherine
McComas......................... 7
RECLASSIFICATION OF TCP:
Kevin
Mulry............................... 9
RECLASSIFICATION PETITION
Robert
Betz.............................. 13
Vincent
Morgan........................... 28
Thomas
Driskell.......................... 33
John
Long................................ 46
AMERICAN ACADEMY OF PERIODONTOLOGY:
Mark
Reynolds............................ 58
CURASAN AG CORPORATION
Gunter
Uhr............................... 69
REGULATORY
CONSULTANT FOR CURASAN AG:
Thomas
Arrowsmith-Lowe............. 84
PANEL PRESENTATION/DISCUSSION:
Jon
Suzuki.............................. 121
Julianne
Glowacki....................... 123
CLASSIFICATION QUESTIONNAIRE:
Marjorie
Shulman........................ 153
ACTION TAKEN:
Dianne
Rekow............................ 207
P-R-O-C-E-E-D-I-N-G-S
9:32
a.m.
SECRETARY
ADJODHA: Good morning and welcome to
this meeting of the Dental Products Panel of the CRH Medical Devices Advisory
Committee. My name is Michael Adjodha,
executive secretary of this Panel. This
meeting is called to order.
Allow
me to introduce the members of our Panel.
Please, raise your hand as I call your name. Because of an illness, Dr. Leslie Heffez was unable to attend
this meeting. This meeting will be
chaired by Dr. Dianne Rekow. Chairwoman
Rekow is the director of Translational Research and professor in the Division
of Orthodontics at the New York University College of Dentistry, New York, New
York.
Joining
her as voting members are Dr. David Cochran, professor and chair of the
Department of Periodontics at the University of Texas, Health Science Center,
San Antonio, Texas, and Dr. Jon Suzuki, professor at the University of
Pittsburgh, School of Dental Medicine, Pittsburgh, Pennsylvania.
Joining
the voting members are the following consultants, who have been deputized to
vote: Dr. Richard Burton, graduate
program director of Oral and Maxillofacial Surgery at the University of Iowa at
the Department of Hospital Dentistry, Iowa City, Iowa; Dr. Julianne Glowacki,
senior investigator at Brigham and Women's Hospital, Department of Orthopedic
Surgery, Boston, Massachusetts; and Dr. Mark Patters, chairman of the
University of Tennessee, Department of Periodontology, Memphis, Tennessee. Dr. Edmond Hewlett was invited, but was
unable to attend, because of an illness.
Also
serving on this Panel as non-voting members are industry representative Mr.
Daniel Schechter, general counsel for Parkell, Incorporated, Farmingdale, New
York, and Ms. Elizabeth Howe, outreach coordinator for the National Foundation
for Ectodermal Dysplasias, Auburn, Washington.
Joining
us at the table is Dr. Susan Runner, interim director of FDA's Division of
Anesthesiology, Infection Control in General Hospital and Dental Devices.
I
will now read into the record a memorandum from our center director regarding
the building status of our Panel consultants.
"Pursuant to the authority granted unto the Medical Devices
Advisory Committee Charter, I appoint the following consultants as voting
members for the Dental Products Panel for the meeting to be held on Thursday,
May 22, 2003: Dr. Richard Burton, Dr.
Edmond Hewlett, Dr. Julianne Glowacki and Dr. Mark Patters.
For
the record, these individuals are special Government employees and are
consultants to this Panel under the Medical Advisory Committee. They have undergone customary conflict of
interest review. They have reviewed the
material to be considered for this meeting.
In
addition, I appoint Dr. Dianne Rekow to act as temporary Chairperson for the
duration on this meeting. Signed, Dr.
David Feigal, director of Center for Devices and Radiological Health."
Next,
I'll read into the record the Conflict of Interest statement for this
meeting. "The following
announcement addresses conflict of interest issues associated with this meeting
as made part of the record to preclude even the appearance of impropriety.
The
Conflict of Interest statutes prohibit special Government employees from
participating in matters that could affect their or their employers' financial
interests. To determine if any conflict
existed, the Agency has reviewed the submitted agenda for this meeting and all
financial interests reported by the committee participants.
The
Agency has determined that no conflicts exist.
However, we would like to note for the record that the Agency took into
consideration matters regarding Drs. David Cochran and Julianne Glowacki. These panelists reported past and/or current
financial interests in firms at issue, but in matters not related to today's
agenda. The Agency has determined,
therefore, that they may participate fully in today'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 interest of fairness that all
persons making statements or presentations disclose any current or financial
involvement with any firm whose products they wish to comment upon."
On
a related note, a Conflict of Interest Survey is available for this
meeting. This survey is the result of
an FDA University of Maryland collaborative research effort. Dr. Katherine Mccomas, assistant professor
at the University of Maryland's Department of Communication, is a sponsor of
the survey. I would like to ask Dr.
McComas to come to the microphone to say a few words about the survey that's
been handed out at this meeting.
DR.
MCCOMAS: Thank you and good
morning. My name is Katherine McComas,
and I'm a faculty member at the University of Maryland, and I'm working with
the FDA on a study of public understanding and knowledge of the Conflict of
Interest Procedures that the FDA uses to monitor and manage real or potential
conflicts of interest of its Advisory Committee members. This study is being conducted at multiple
Advisory Committee meetings across multiple centers at the FDA, and I would
like to ask for your assistance.
This
is for non-FDA people to fill out. I'm
responsible for the questionnaires in your chairs. It takes about 15 minutes to fill out. If you have a chance today, there's a box at the registration
desk you can drop it in. Otherwise,
there's a postage paid envelope that you can drop it in and mail it back to
me. I also have distributed a separate
questionnaire for Advisory Committee members, and again I appreciate your time
in filling that out and getting that back to me as soon as you can. The higher the number of responses, the more
reliable the results, and the better we are able to make recommendations to the
FDA about ways that we might improve overall satisfaction with the Advisory
Committee process.
I
will be here today to answer any questions that you may have, and, as is in the
letter, which is included with the surveys, the results of this will be freely
disseminated to anybody who is interested.
Thank you very much for your time.
SECRETARY
ADJODHA: Thank you, Dr. McComas. I'll now turn the meeting over to Chairwoman
Rekow.
CHAIR
REKOW: Good morning. We have before us, of course, the issue of
reclassification of the TCP for dental bone repair, and I believe that we will
begin with the presentation by Dr. Mulry, please.
DR.
MULRY: Good morning and welcome to the
Dental Products Panel meeting. Today we
are asking you, the Panel, to provide a recommendation on a petition to
reclassify Beta Tricalcium Phosphate from Class III to Class II. What I will be discussing is the regulation
of tricalcium phosphate beginning with the current regulation, then looking at
the historical prospective and finally regulation in other parts of CDRH.
Dr.
Betz will present a review of the petition and conclude with a risk and
mitigation table, which we will be requesting Panel input. With regard to adverse events, the Agency
has found one report for tricalcium phosphate, which was not associated with
human use. Dr. Betz will discuss this
adverse event in his presentation.
Today
we will ask you, the Panel, to provide input on a table which lists the risks
to help generally associated with the use of tricalcium phosphate and to
comment on recommended measures to mitigate the identified risks. These risks and mitigations could be
included in a Guidance Document to be developed by the Dental Branch if the
Panel makes a recommendation for reclassification.
Tricalcium
phosphate currently is regulated in the Dental Branch as a Class III device
under 21 Code of Federal Regulations 872.3930, Tricalcium phosphate granules
for dental bone repair, and is identified in the CFR as a device intended to be
implanted into the upper or lower jaw to provide support for prosthetic
devices. This classification regulation
for tricalcium phosphate includes all forms of tricalcium phosphate. A reclassification of this regulation would
include all forms of tricalcium phosphate.
However,
as with any new indication for use, if another form of tricalcium phosphate
other than Beta Tricalcium Phosphate were submitted, appropriate data could be
requested. By policy in the Dental
Branch, bone void fillers that are less than 50 percent of Beta Tricalcium
Phosphate or unclassified devices, and are reviewed under the pre-market
notification or 510(k) process.
So
why this tricalcium phosphate originally classified into Class III? At the time of the enactment of the Medical
Device Amendments in 1976, tricalcium phosphate for dental use was regulated as
a new drug requiring a new drug application or NDA. Under the 1976 amendments, Congress identified transitional
devices, meaning those devices previously regulated as new drugs into Class III
requiring a pre-market approval application or PMA.
The
transitional provisions were designed to assure that devices formally
considered as new drugs continued to be subject to appropriate regulatory
controls. The final regulation for this
device was published on August 12, 1987 and classified tricalcium phosphate
granules for dental bone repair into Class III as a transitional device. The Agency has approved one PMA or
pre-market notification application for Beta Tricalcium Phosphate.
So
how is tricalcium phosphate regulated in other branches in the Center for
Devices and Radiological Health or CDRH?
In the Orthopedic and Restorative Branches within CDRH, tricalcium
phosphate is an unclassified device.
For these branches, the regulatory history is different, in that tricalcium
phosphate was not identified as a new drug at the time of the enactment of the
Medical Device Amendments, and thus was not automatically classified into Class
III as a transitional device. The
transitional list was specific for dental bone repair.
The
Orthopedic and Rehabilitation Panel met in January 1998 and recommended that
calcium sulfate bone void filler be classified into Class II, and on February
7, 2002 a proposed rule was published in the Federal Register proposing
to classify the resorbable calcium salt bone void filler device into Class
II. This included Beta Tricalcium
Phosphate.
Dr.
Betz, who will present next, will provide a review of the petition and present
a table outlining the risks and mitigations for your consideration. Dr. Betz?
DR.
BETZ: Good morning. On November 12, 2002, Dr. Vincent Morgan
submitted a petition for the reclassification of Beta Tricalcium Phosphate or
Beta TCP. A revision of this petition
dated April 5, 2002 was reviewed by the Dental Branch of the Office of Device
Evaluation. On 9 December 2002, the FDA
received a letter from Dr. Morgan requesting that the petition be
modified. The requested modification
was to change the final classification of Beta TCP in the petition from
unclassified to Class II.
The
petition contains 11 sections, including appendices. Section I is the Specifications Section. This section describes Beta TCP, identifying
physical properties, such as formula weight density and melting point, as well
as identifying its Chemical Abstract Service or CAS number as 7758-87-4.
Section
II is the Statement of Action. This is
Dr. Morgan's request to reclassify the Beta TCP. Dr. Morgan's letter of December 9, 2002 modifies this request
changing the final classification to Class II with special controls.
Section
III is an FDA Supplemental Data Sheet, FDA form 3247. Dr. Morgan identified the indication for use as that of a bone
substitute. Risks identified included
infection and pyrogenic response. The
information upon which the request for reclassification is based are that Beta
TCP has been successfully used in medicine and dentistry for over 20 years, and
that its properties are known to be beneficial when used as a bone substitute.
Section
IV is also Appendix II. This section is
the FDA General Device Classification Questionnaire or FDA form 3429. This questionnaire was not updated to
reflect Dr. Morgan's December 9, 2002 request for a change in final
classification. Therefore, there is an
inconsistency between the letter and form 3429. This afternoon you will be asked to complete this form as part of
your discussion and deliberation.
Section
V is the Basis for Disagreement with the present classification. It includes the following: Beta TCP has been successfully marketed for
over 20 years for dental purposes; Beta TCP is presently a Class III device for
dental indications requiring a pre-market approval or PMA. However, it has been cleared for market by
pre-market notification or 510(k) when used for other purposes, such as
orthopedic applications; and finally, no clinical adverse events have been
reported.
Section
VI contains the Reasons for Reclassification, which were a reiteration of
statements made in Section V. Appendix
III includes copies of published articles the petitioner submitted to support
claims of safety and effectiveness for Beta TCP.
In
Section VII, the petition states that there are no known unfavorable clinical
data.
FDA
has found in its databases only one reported adverse event related to calcium
phosphate compounds. When an
unspecified calcium phosphate compound was injected into the vein of a pig,
blood clots formed. This is the only
adverse event within our database. In
this report, a calcium phosphate compound was injected intravascularly rather
than being placed in an intraosseous location.
The
FDA believes that this report has little or no relevance to the use of
tricalcium phosphate in periodontal or craniofacial applications, especially
when placed in humans. Again, there
have been no adverse events reported to FDA.
Section
VIII is a Summary of New Information, which is Appendix IV. This information is from a Medline search of
data three years old or less.
In
Section IX, Dr. Morgan indicated that there were no source documents to be
submitted relevant to this petition.
Appendices III and IV contain information that would normally be
included in the section.
Section
X was the Financial Certification/ Disclosure Statement, which stated that Dr.
Morgan has not received any compensation for any clinical studies associated
with the product. He also stated that
he will not have an equity interest in the product.
Section
XI contains the appendices, which were included and reviewed as Section III,
IV, VI and VIII.
To
summarize, Beta Tricalcium Phosphate is a calcium phosphate salt that has the
same intended uses and is similar to legally marketed dental bone void filler
and grafting materials such as: Plaster
of Paris (like Capset); Hydroxyapatite (like Hapset); Ceramics (like Bio Oss
Ceramic). Beta TCP has been
successfully used in orthopedic applications without reports of adverse
events. Beta TCP is presently
unclassified for orthopedic and general restorative purposes. It has been recommended for placement into
Class II by the Orthopedics Device Panel.
Publication of the Final Federal Register Notice to this effect
is pending. We hoped that would be done
by the Panel today so I didn't have to say that, but that's not true.
Finally,
Beta TCP has been cleared under 510(k) regulation for use in dentistry at
concentrations less than 50 percent for quite some time, again without adverse
events. FDA frequently uses guidance
documents to communicate to sponsors and the general public information that
FDA believes is important in their review of 510(k) submissions. The headings above, on the screen, represent
section headings within guidance documents previously released by FDA.
One
of the sections of FDA's forthcoming bone void filler bone grafting material
guidance document will be a table of risks encountered when bone void filling
or bone grafting materials are placed in oral and craniofacial
applications. Because tricalcium
phosphate bone void fillers are similar to other bone void fillers, presently
cleared under 510(k) regulations, the risk table that FDA is asking you to
review today may also be used within our forthcoming bone void filler or bone
grafting material guidance document.
This
table of risks is proposed for you to discuss and consider in the decision
making process to place Beta tricalcium phosphate into another
classification. Identifying these risks
should help you determine whether general controls or special controls are
needed to assure safe and effective use of tricalcium phosphates or whether
they should remain in Class III.
In
your deliberation, please, feel free to add, delete and modify this risk table
as you see fit. Your recommendation,
whatever it may be, should be based in part on this risk table. The risks include, and this is a two part table: Surgical risks; risks related to bone or
soft tissue infections; adverse tissue reactions; problems associated with bone
formation; failure to osseointegrate; problems associated with device migration
or extrusion; and weakness in newly formed bone.
On
the right, you see the mitigations that we propose for you to consider also to
mitigate these risks. This entire table
will be displayed in its entirety in one piece for your discussion. Now, we get to the Panel questions.
Does
the petition, as filed, adequately describe the risks to health when using the
device and provide appropriate controls for these risks? If yes, you're supposed to proceed to
Question 3. If no, you proceed to
Question 2.
Question
2 is what modifications would you make to the risks to health presented by
these devices? The second part of
Question 2 is what controls for these risks would you recommend to provide a
reasonable assurance of safety and effectiveness? And then you proceed onto 3.
Question
3 is, please, complete the Classification Questionnaire and Supplemental Data
Sheet for the device. Completion of
these forms will provide a formal recommendation for the reclassification of
tricalcium phosphate granules for dental bone repair. Again, 21 CFR 872.3930.
And then to Question 4.
Question
4, given your recommended classification, what changes, if any, would you
recommend be made to the labeling? Your
recommendations could include directions for use, indications for use and
contraindications and anything else that you feel appropriate. Thank you.
CHAIR
REKOW: Does anyone have any questions
for Dr. Betz before he sits down?
DR.
GLOWACKI: I have a question for Dr.
Mulry.
CHAIR
REKOW: Or for Dr. Mulry. Go ahead, please.
DR.
GLOWACKI: Mr. Mulry, do I have control
over turning this on?
CHAIR
REKOW: No, I think it will take care of
it.
DR.
GLOWACKI: It will come on
automatically? Can you set the stage
for the Panel's deliberation, because you've described the existing reg as
including all calcium phosphates, and I heard you say for the support of dental
implants and materials having the composition of 50 percent of TCP on one
hand. And then the petition on the
other hand concerns Beta TCP for a specific application that is distinct from
the current regs. So can you set the
stage on how we're to do the reclassification, because I thought I heard you
say we're going to reclassify the whole thing for dental implants, supporting
the dental implants and with the 50 percent, and that the application, the
petition, is much more confined.
DR.
MULRY: Okay. Let me see if I can answer that.
First of all, let's look at the regulation, the current regulation 21
CFR 872.3930, which is entitled "Tricalcium Phosphate Granules for Dental
Bone Repair." It's identified and
the definition is "A device intended to be implanted into the upper or
lower jaw to provide support for prosthetic devices."
This
discussion today, as to whether it is reclassified from Class III to Class II,
deals with the total regulation, and that regulation includes all forms of
tricalcium phosphate, although, the petition is entitled "Reclassification
of Beta Tricalcium Phosphate." So
what you'll need to decide is in the petition there is additional supporting
information about other forms of tricalcium phosphate, besides Beta Tricalcium
Phosphate. What you need to decide
today is is there sufficient information for you to make a recommendation to
either have the whole regulation moved to Class II, meaning all forms of
tricalcium phosphate, or whether you want to separate out Beta Tricalcium
Phosphate alone to be reclassified into Class II.
DR.
GLOWACKI: Does that also mean all
physical forms like granules, blocks?
DR.
MULRY: Yes. It would include all forms of tricalcium phosphate.
DR.
GLOWACKI: Okay.
DR.
MULRY: The other aspect of your
question was about the Dental Branch's policy decision to regulate bone void
fillers that are less than 50 percent Beta Tricalcium Phosphate as pre-market
notification or they are unclassified and also reviewed under the 510(k)
process. And that was a policy in an
administrative position that was made looking at whether combining tricalcium
phosphate with other bone void fillers would present maybe different questions
or would be more appropriately put in with the other bone void fillers, because
this tricalcium phosphate has been separated out only because of its
transitional device status. All the
other bone void fillers have been grouped together.
So
I think the policy decision related to looking at well, if it's less than 50
percent Beta Tricalcium Phosphate, then it may more appropriately have been
regulated with all the rest of the bone void fillers. And, Dr. Runner, you may have a comment on that.
DR.
RUNNER: I don't know the history of why
that happened, but it happened and we have multiple applications of products
that have HA and Beta TCP in less than 50 percent concentration.
DR.
GLOWACKI: My understanding is that
those are biphasic materials not additives, not added in, manufactured in a way
to render them biphasic, even a solid.
DR.
RUNNER: I believe that's correct.
DR.
MULRY: Yes.
DR.
GLOWACKI: And I mean, that's very
helpful. This goes back to the slide
that Dr. Betz showed about does the petition as filed describe the risks to the
health? So in one hand we're being
asked questions that relate to the petition.
DR.
MULRY: Yes.
DR.
GLOWACKI: And yet we have to answer
questions related to the reg.
DR.
MULRY: Right.
DR.
GLOWACKI: Am I understanding this
correctly?
DR.
MULRY: Yes, you are. And I think in looking at reclassifying the
total reg, as I said in my presentation, I think it needs to be remembered that
if a form of tricalcium phosphate other than Beta Tricalcium Phosphate were to
be submitted to the Agency, we would have the option of asking for data,
supported data, to help us make a decision whether it is Class II or Class III.
DR.
BETZ: I would also like to make a
comment as a periodontist. It would
also include bone grafting materials, as well as bone void fillers, used in
periodontal indications.
DR.
GLOWACKI: Even though --
DR.
BETZ: Craniofacial defects, periodontal
defects and in general.
DR.
RUNNER: Well, I think you're talking,
you're discussion indications and we're talking about the regulation of the
product itself. Each individual
application comes in with an indication for use, and then we are charged with
looking at that indication to see if it requires additional clinical data,
etcetera. So the indications need to be
--
DR.
GLOWACKI: So just the title of the reg
saying that it's for support.
DR.
RUNNER: Right.
DR.
GLOWACKI: Prosthetic devices.
DR.
MULRY: Right.
DR.
GLOWACKI: -- is not something that we
take hard and fast.
DR.
RUNNER: Right, exactly.
DR.
GLOWACKI: We're talking about other
indications?
DR.
RUNNER: Correct.
DR.
MULRY: It was a generic term or
definition from 1976. We're a little
bit more sophisticated now, I hope.
DR.
GLOWACKI: That's very helpful. Thank you.
CHAIR
REKOW: Because I was about to make the
same mistake, we need to help for the people that are doing the transcription
when we begin to speak, to identify who we are. So this is Dr. Rekow. And
I have a question for Susan or either of you gentlemen. Something that you said was the petition is
the Beta TCP, we could talk about all TCPs.
Are we talking about all calcium salts of all genres? Are we going to stick to the TCP?
DR.
MULRY: No, specifically, TCP.
CHAIR
REKOW: Okay.
DR.
MULRY: This is regulation, because this
was separated out as the only bone void filler in the dental arena that was
regulated as a new drug prior to the 1976 amendments.
CHAIR
REKOW: Right.
DR.
MULRY: We need to limit this discussion
today just to the regulation of tricalcium phosphate, as defined in the CFR.
CHAIR
REKOW: Thank you.
DR.
MULRY: You're welcome.
CHAIR
REKOW: Are there other questions from
the Panel? Okay. I believe we then go on to the presentation
by the sponsors. Dr. Morgan, are you
taking responsibility?
DR.
MORGAN: If you wish.
CHAIR
REKOW: I suspect you probably are the
best person to represent them.
DR.
MORGAN: Well, I will define that. My name is Vincent Morgan, and we brought
this petition because we deemed the current classification to be an oversight
of the Agency, and I believe logical scientific thought would agree with that
process. Because of the fact that it's
just inconsistent to think that an orthopedic surgeon has the capability of
placing tricalcium phosphate or a maxillofacial surgeon could not, to me,
osteoblast and osteocyte, so the regulation is inconsistent with the reality of
biology.
So
to that end, there's also evidence, historical evidence, that I shall not go
into it, I spoke to Susan about, and that's my position. Just to have you look at it as an oversight
on the regulations. Thomas Driskell is
here to follow this discussion, who, in fact, is the person who developed this
product in the 1970s and is the person who wrote initially a PMA and
subsequently a 510(k) for the Miter Corporation, so he can speak to the history
of it better than all of us. And then
Dr. John Long will be producing the product or has produced it and can address
the scientific aspects of the chemistry.
In
addition to the financial statement, since you made this announcement public, I
have been contacted by two parties. One
is representing a Dr. Lynch in Tennessee who wanted to be included in our
presentation in support of this. I
declined. The other I was contacted by
the Curasan Corporation, a German corporation, and they wanted me to drop my
petition or to consider dropping it, and if I were to drop this petition, they
would offer me the sole distributorship of their product in the United States. So I declined that, as well. If there's any questions, I would be happy
to answer.
CHAIR
REKOW: Yes, Dr. Patters?
DR.
PATTERS: Mark Patters. Dr. Morgan, perhaps you could clear up a
discrepancy here in my papers. It lists
you as president of Bicon, Incorporated.
DR.
MORGAN: That's true.
DR.
PATTERS: Somewhere else it says you
have no financial interest in this product.
DR.
MORGAN: That's true.
DR.
PATTERS: Are both those statements
correct?
DR.
MORGAN: That's true.
DR.
PATTERS: I think that requires some
explanation. How can you be the
president of the company, but no financial interest?
DR.
MORGAN: I think you'll find the
question is do I have any equity interest in the company, and the answer is no.
DR.
PATTERS: So you're just a paid employee
of the company?
DR.
MORGAN: True.
DR.
PATTERS: Okay. I would say that's a financial interest.
DR.
MORGAN: I think the question was equity
interest there.
DR.
PATTERS: Thank you.
DR.
MORGAN: I would be happy to tell you, I
have no equity interest. Equity is a
shareholder. You could be an employee
of IBM and not own a share of it. I do
not own a share of Bicon, so to clarify that.
DR.
PATTERS: I know. But I'm asked as a Panel member do I have
any financial interest that if your petition was granted, that I would benefit
from. That doesn't require that I be an
equity holder.
DR.
MORGAN: Well, I won't debate other than
the fact that we answered the question as stated. So if you want to know, I've so disclosed. But I have no equity interest in Bicon.
CHAIR
REKOW: Dr. Rekow again. You are a paid employee and you stated that
clearly.
DR.
MORGAN: Yes, yes, I have no argument
about that.
CHAIR
REKOW: Okay.
DR.
BURTON: Dr. Burton. Does Bicon then intend -- because it's still
sort of unclear. I think what we're all
getting at is what the benefit of doing this, but is Bicon then intending to
market a product of this type?
DR.
MORGAN: If it were, yes.
DR.
BURTON: If it was reclassified, it
would be offering a product. And I
guess the question that I would assume Dr. Patters was getting at that as
president of the company, the product would have some -- whether you had an
equity stake in the company or not, it would still provide some financial incentive to you to have that approved and
come to market in whatever classification.
DR.
MORGAN: Oh, yes. It would to Bicon. But to me personally, I believe the question, I believe I
answered it correctly, but if you want me to state that Bicon hopes to have an
financial interest, absolutely, but I believe the question that was posed by
the FDA is do I have an equity interest.
And I think a distinction was made on your behalf today that some of you
represent other dental implant manufacturers, other dental implants, but for
this particular product you don't. So
if you were to represent a competitor of Bicon in any fashion, I would also
suggest to you that that's a conflict of interest.
However,
if you can distinguish between having representing or your school representing,
you may not have an interest, but your school may receive a significant grant,
as many do. You don't receive it
directly, but your department receives significant funding, then it may be in
your best interest to vote against Bicon.
So the truth is the truth. The
question should be specific.
DR.
RUNNER: I think that we've developed
the answer to the question, so I don't think we need to continue. You know that Dr. Morgan is financially
enumerated by the company for which the product will be marketed.
CHAIR
REKOW: Thank you.
DR.
MORGAN: Thank you.
CHAIR
REKOW: So, Mr. Driskell, you have a
presentation, please? And would you,
please, sir, and the rest of you as you present, would you disclose whatever
financial, if you have a financial, investment in the company just for clarity,
please.
MR.
DRISKELL: Okay. I didn't want to show you any pictures
particularly, so I don't need that. My
name is Tom Driskell. I did invent this
material back in the very early '70s.
Regarding my association with Bicon, I have no equity interest. I have no salary from them. I do receive a royalty, because they market
products to which I've designed and have patents on, so I do get royalty from
them, which I appreciate very much. I'm
not paid in any way for what I do. It's
just that when it goes on the market, if it makes money, maybe I make some
money. Then I appreciate that, because
I'm supposed to be retired.
I
will make this very concise, but I will be happy to answer questions if you
wish. Materials oriented research
ultimately leading to the development of calcium phosphate structural and void
filling materials, bone implant materials I should say, began at Battelle
Memorial Institute's Columbus Laboratories in 1968. I was principal investigator of the project. Disappointed with the results of earlier
research and development of bio-inert ceramics, which the materials and
coatings which began in 1967 stimulated this departure into bio-active
materials development. I think that was
a new term at the time, but that's what they are is bio-active.
In
fact, I even came up with a term for it, so it's not osteogenic and it is
osteoconductive, but it also will allow bone to grow beyond its normal bounds
if you use it as an augmentation material.
So I came up with the term osteophilic, which bone likes it and it
does. In 1971, three high purity
calcium phosphate compounds were selected for in vivo evaluation in rats and
rabbits. The three compounds were
monocalcium phosphate, dicalcium phosphate and Beta Tricalcium Phosphate.
Initial
in vivo studies were conducted at the U.S. Army Institute of Dental Research at
Walter Reed Army Medical Center. Beta
Tricalcium Phosphate proved to be the most promising compound. It was found to demonstrate excellent
bio-compatibility reserved resorbed while being displaced by rapid bone
ingrowth and as was discovered later in our research could be sintered into a
relatively strong structural form.
Our
original concept was to develop a resorbable bone porous block grafting
material for use as a gap filler in large bony defects and a resorbable
particulate form for smaller contained defects. We were successful in developing these concepts in 1971. In vivo research in various laboratories
continued and the results have been presented and published over the
years. Coatings of these materials were
applied to dental implants and successfully implanted in Rhesus monkeys in
1972. There is a joke that goes along
with that, but I'll dispense with it for now.
These
studies and subsequent work by Hubbard, Jarcho, Kay and numerous other
researchers resulted in the development of additional variations of calcium
phosphate materials and coatings. The
substance of this research is the foundation upon which the field of calcium
phosphate materials technology and hydroxyapatite coatings has developed. Thank you.
Any questions?
CHAIR
REKOW: I suspect there will be some
questions.
MR.
DRISKELL: All right.
CHAIR
REKOW: Do you want to stay for just a
minute, please?
DR.
GLOWACKI: I'm not a chemist, so forgive
me if I don't ask the question, this is Dr. Glowacki, if I don't pose the
question in the precise terms that you are used to. We know that the Beta Tricalcium Phosphate, at least what we read
in the books, is resorbable material and that the hydroxyapatites are dense
ceramics with the different type of crystallinity and are far less resorbable.
My
question is whether there is control over the degree of resorption in the class
that we're calling the Beta Tricalcium Phosphates? What I understand is that after preparing the material that
there's an amount of compression and sintering in order to make it into the
granular form, small granules, large granules or blocks. Do those processes give you a consistent
rate of resorption an how dependent is the rate of resorption on compression
and temperature of sintering?
MR.
DRISKELL: Okay. Well, I think it probably does have quite an
effect. The denser it is, the more
material that's there. It obviously is
going to take longer to resorb. The
largest factor is quite possibly the particular proclivities of the
patient. For example, if you have a
person that is not particularly hale or hearty, I hate to say it but
post-menopausal women, people who have some sort of an ongoing illness or
something that affects their health, the resorption would probably be
slower. That is one of the
inconsistencies of it as you really are not sure how long it will take.
But
I can tell you that in a healthy patient, it heals pretty quickly, anywhere
from within six months to a year. And
as the material does resorb, it is immediately replaced by bone in those areas,
because actually osteocytic -- well, the osteocytes seem to osteoblast, I'm
sorry. Osteoclastic activity seems to
be the major cause of resorption of the material. And it is resorbed and broken down into calcium phosphorous,
which is already in the body, which I think accounts for the lack of side
effects. It's a material that is
basically already there.
DR.
GLOWACKI: So there is patient to
patient variability. But let's talk
about animal studies where there may be more consistency with respect to the
recipient.
MR.
DRISKELL: Yes.
DR.
GLOWACKI: If you put material that came
from one batch of preparation of a Beta Tricalcium Phosphate compared to
another batch in similar types of animals, is there a wide range of
resorbability on the basis of the manufacturing process?
MR.
DRISKELL: Well, presuming that you have
adequate controls over the manufacturer, there shouldn't be any appreciable
differences. Again, with the exception
of the relative hale and heartiness of the critter that you're putting it
in. But really, you have to have a good
manufacturing process. It is not a
simple material to make, and we have been very careful over the years in making
it and being consistent in the process, because things like that can affect the
resorption. No doubt about it.
DR.
GLOWACKI: And -- I'm sorry.
MR.
DRISKELL: Well, as I say, it can vary
from patient to patient. But the thing
to keep in mind is that the structural integrity is still there to a fair
degree, because the bone actually does bond to the material. It is not just a resorption as the material
disappears the bone just fills in. The
bone has already bonded to it. I have
scanning electron microscopy that shows that very nicely.
DR.
GLOWACKI: So with respect to the
careful manufacturing steps then, are there tests that are done at the end of
the manufacturing to say, you know, this is a batch that's going to have the
same physical properties as the previous batch?
MR.
DRISKELL: Well, actually, the way it is
made pretty well controls what it is going to be. And if you follow the parameters of how it should be made, of
course the chemistry of it you can do with x-ray faction patterns and that sort
of thing, but frankly over the years of personally making it, I never really
found any discrepancy, because of the way that we ran the materials. We sieve them. And we have the same particulate size that's used all throughout
the whole process. So the variations in
the manufacturing process are very, very slight, because we just are very
careful with what we do.
CHAIR
REKOW: Can I perhaps ask the question
with a slightly different spin?
MR.
DRISKELL: Okay.
CHAIR
REKOW: For a fixed manufacturing and
sintering regime, can you give us some sense of the range and variation you
would expect in the important parameters?
MR.
DRISKELL: I think I'll let our chemist
answer that.
CHAIR
REKOW: Okay.
MR.
DRISKELL: I think that might be the
person.
CHAIR
REKOW: We'll put that question on hold.
MR.
DRISKELL: If you don't mind?
CHAIR
REKOW: No.
DR.
GLOWACKI: That's fine. I just wanted to give you, you know, coming
from the questions, I can't quite picture in the manufacturing how you get
granules of different sizes.
MR.
DRISKELL: Oh.
DR.
GLOWACKI: You applied just now that you
just sort of pressed them and crushed them and sinter them, and then you sieve
them to separate them.
MR.
DRISKELL: Well, we do do that, and we
sieve them so that we have a certain particle size, both plus and minus, so
that we have a certain particulate that we use, and that is pretty consistent.
DR.
GLOWACKI: Thank you.
MR.
DRISKELL: So we don't have a problem
with that.
CHAIR
REKOW: Jon, did you have a
question? Jon first and then you David,
please.
DR.
COCHRAN: Okay.
DR.
SUZUKI: Okay. Jon Suzuki, FDA Panel member.
You used the word osteophilic to describe and relate to your product.
MR.
DRISKELL: Yes.
DR.
SUZUKI: And could you just
differentiate osteophilic versus osteoconductive and make that definition?
MR.
DRISKELL: Well, the osteophilic
materials are always osteoconductive, but osteoconductive is more of a passive
term. Osteophilic means that it seems
to have -- by the way, we don't claim that.
But we have noticed and I'll give you an example. In some of our orthopedic studies in earlier
years, we put some block form material, this was porus block form, in the
femurs of dogs and these were fairly large.
I can't remember the exact size, but they were probably 25 millimeters
or 30 millimeters in length, maybe even longer than that come to think of it.
But
they stuck above the bone by 10 millimeters, and so only the lower part of that
implant was actually implanted in a cut, a defect that was created in the bone,
and we got bone all the way to the top.
So that's 10 millimeters beyond the normal bounds of a long bone. So I think there is something in there, but
it does not -- we do not claim anything as far as being osteogenic or
anything. I don't think it is. But osteophilic it does seem to be from the
standpoint that it will cause bone to grow into an area that it wouldn't
normally be expected to grow into. Now,
whether that bone would stay over a long period of time, I doubt it, because
there's no reason for it being there.
But it does grow in there.
DR.
SUZUKI: Jon Suzuki again. Just one follow-up question. Then osteophilic to me, at least, implies
there is no adverse reactions like immune rejection or anything like that, but
you're not making that claim?
MR.
DRISKELL: Well, actually, I have never
seen any immune rejection. Honestly, I
have never known anything like that.
The only thing that we have ever seen was an occasional infection, and
those are going to happen I don't care what you use, but that's all I can
say. That this never has any sort of an
immune response or anything like that.
CHAIR
REKOW: Dr. Cochran?
DR.
COCHRAN: David Cochran. My question centers around the indications
for this material. As you have alluded
to, when you put in a bony site you see osteoclastic resorption, macrophage
resorbate, but in many of the indications in the oral cavity that we use today,
and especially the particulate material, sometime it gets fibrous and
capsulated. There's fibrous tissue that
will encapsulate the particles. Can you
tell us how that might be resorbed and is that a slower process or how is that
turned over?
MR.
DRISKELL: It would be, but I would like
to know precisely what you're talking about, because I know, for example, the
hydroxyapatite that's not uncommon. But
if it is actually in contact with fresh bleeding bone, and you know, to a
reasonable degree, I mean, I'm not sure I want to give you the total definition
of that, but if it's just sitting on top of some abraded bone, it might or
might not fill. I do have histology,
though, on say a ridge augmentation which has, as you know, become a very
equivocal thing as to whether you really ought to do that. But I can show you absolutely gorgeous bone
in a year, and there's very little of the tricalcium phosphate left. It's just solid bone. So again, it has to be in contact with fresh
bleeding bone to make it work.
CHAIR
REKOW: Are there any other questions? Thank you, sir.
MR.
DRISKELL: You're welcome.
CHAIR
REKOW: Dr. Long, would you, please,
again identify yourself and your potential conflict of interest?
DR.
LONG: My name is John Long. I'm the director of technology at GFS
Chemicals in Columbus, Ohio. I have no
equity, financial or other personal interest, other than as a supplier, of
tricalcium phosphate to Bicon. We are a
private company. We have been in the
same location in Columbus since 1928.
We're in the third generation of family management. The letters in the company name GFS come
from the professor of analytical chemistry, who founded the company. He was at the University of Illinois. And over the years he developed many
analytical reasons that his colleagues were interested in and eventually formed
the company with his brothers, because he and his graduate students could not
keep up with the bucks.
We
had specialized in high purity and materials for analytical markets over the
years, branched off into some other things as well. In the 1960s when the Apollo Program was in full force and NASA
was looking for high purity acids to use in the analysis of lunar samples, our
company was contacted to produce high purity perchloric acid for the digestion
of those samples. So we have a long
history of working with very high purity materials.
The
Beta Tricalcium Phosphate is made in a dedicated room in our facility. We've got about 15 buildings on our plant
site in Columbus, Ohio. Within one of
those buildings there is a room dedicated to its production as well as
dedicated equipment, ovens, various other parts of the operation are confined
to that one room. We are ISO-9000
certified, which means we have the traceability and accountability with our
computer system to govern the batches of the material that are produced and to
provide whatever information might be needed to look at vendor data, vendor lot
information, our lot information, finished goods information, analytical
information that are connected to a given batch.
The
material is qualified by a number of things.
It requires a very particular calcium phosphorous ratio that is governed
in the manufacturing steps. It also can
be confirmed by analytical methods after it is made. The primary analytical method is x-ray diffraction. It allows you to determine that the proper
phase, the Beta phase of tricalcium phosphate is present, usually to the
exclusion of all other phases. We have
made this material a couple of times.
We
have been visited by a Cincinnati representative of the FDA, who came and
discussed with us what our process was.
He looked at our facility. He
looked at our equipment. And as we get
into the further production of this material, he will be available to oversee
its operation, so we have been in contact with a gentleman named Jeffrey Sincek
at the Cincinnati Office of the EPA. So
we are in the position to produce this material in significant quantities and
are pleased to be able to support Bicon in this petition. I'll be happy to answer any questions that
you might have.
DR.
GLOWACKI: I'll ask you a question
then. This is Dr. Glowacki. Good morning, Dr. Long. Can you paint a picture then of the
differences in the actual crystal structure as one varies the
formulations? I'm talking about making
granules versus, can I use the word, casting a larger block with a particular
shape?
DR.
LONG: Sure.
DR.
GLOWACKI: Does the casting or does the,
I'm calling it compression, you'll give me the correct technical words,
compression and sintering to make different forms of it give you materials with
100 percent similar x-ray diffractions or is there some modification due to the
preparation of different forms?
DR.
LONG: The x-ray part of diffraction
defines the microscopic property of the material. It's based upon the repeating array of unit cells in the solid. This could occur with particles of various
sizes. It's not a function of particle
size, but you do have to grind the material to get a powder to be able to do
the x-ray effectively. So if you have
carried out your synthetic process properly, regardless of the number of times
or the nature of the compression of the material, when you grind it to get the
x-ray powder pattern, it will tell you whether you have the Beta phase or if
you have mixed phases.
It
requires a very particular temperature in order to achieve the Beta phase. If you miss that temperature, the x-ray will
show you that you have impurities present and the product is not properly
qualified. This is done after all the
processing, after the compression, after the grinding, so in that sense the
x-ray testing is independent of all of that until you get it ground and you can
put it on the machine and look at it.
DR.
GLOWACKI: Thank you. Now, with respect to the point about the
rate of resorption, because people are always asking in journal articles and
reviewing articles in presentations, you know, what about the rate of
resorption? In your view, does the rate
of resorption in an animal model where there is consistency in the recipient
tissue, are there differences in the rates that are due to casting the blocks
or making or getting granules that have been ground up to greater or lesser
degrees that can influence the rate of resorption because of something that can
be measured, because of some physical property?
DR.
LONG: My opinion, which is not
necessarily an expert opinion in your area, but my opinion is that you're
talking about a microscopic property, especially the ability of blood to flow
through the microcrystalline structure of the material. And do me, that is independent of most
aspects of the processing that we do.
Once the material is cast and there is pressure applied, you produce a
bulk material and you grind that material into the final form.
Once
you produce that material, you have created a microcrystalline property that is
identifiable by x-ray in the Beta form, which according to what Mr. Driskell
says in all the studies that have been done, allow this porosity, blood flow,
this clinical action that enables it to perform as it does. I don't see that variations leading up to
the final step would significantly change the property of the material, as long
as you fire it to the right temperature and get the Beta phase, that's the key
aspect. If you have different phases in
there, the microcrystalline property is changed and it will effect the blood
flow in the resorbability of the material.
DR.
GLOWACKI: Thank you.
CHAIR
REKOW: Okay.
DR.
BURTON: You spoke of your plant in
Columbus. Do you currently manufacture
this product for other companies, other than Bicon? You know, you said you had a dedicated facility for this. I mean, it must be going somewhere.
DR.
LONG: We have only manufactured this up
to this time for Bicon. We have had
discussions with a couple of other companies about calcium phosphates of
various types. We are interested in the
Beta phase and we have had contact with other companies about the Alpha phase
and about hydroxyapatite. To this
point, we have not made any of those phases. We have made no commitment with any other companies about any of
those materials. We have only made the
Beta phase for Bicon.
DR.
BURTON: Okay. So we've mentioned the fact that there are dental products that
contain less than 50 percent, and those are manufactured by some other
companies then?
DR.
LONG: To my knowledge, yes. The material that we have produced has shown
well over 95 percent Beta phase. In
fact, the x-ray that we have seen has shown no contamination. It would lead me to believe it's 98 to 99
percent. The more pure it is, the more
efficient it is going to be in its function.
DR.
BURTON: Yes.
DR.
LONG: I think it would still function
below 95 percent, but the specification will be a very, very clean x-ray.
DR.
BURTON: Okay.
CHAIR
REKOW: Jon?
DR.
SUZUKI: Jon Suzuki, Panel member. Just for my own edification, I'm not a
chemist. Can you just highlight the
differences between Beta and the other forms of TCP?
DR.
LONG: Okay. Hydroxyapatite is not a strictly a calcium phosphate. You're looking at a formula of CA3 PO4 taken
twice for tricalcium phosphate. The
hydroxyapatite has hydroxyl groups on it, as the name applies, and it is not a
pure phase, single phase TCP. The Alpha
and the Beta forms are distinguished simply by the difference in temperature to
which they are taken in their final step.
A
few dozen degrees too high or too low in this step, you will not have pure Beta
phase. You will either have a mixture
of Alpha and Beta or you could revert to Alpha, and that simply represents the
three dimensional array in which all the phosphates and all the calciums align
themselves. They can be aligned in more
than one way. And the temperature
allows you to fix the way in which all the elements that are present are
aligned. So that's the primary
difference between the two is the temperature to which it is taken and its
final sintering step.
DR.
SUZUKI: Thank you.
CHAIR
REKOW: Can I ask one more? Dianne Rekow, I'm sorry. Can I ask one more question? You have some quality assurance
specifications. Can you give us some
sense of the percentage of tolerance control you are able to get? I don't think you need to disclose what you
are measuring, but are you holding things to 1 percent, 20 percent, you know,
200 percent? I'm being facetious
clearly.
DR.
LONG: We would be very comfortable
talking about a percent purity in the high 90s. Now, you're talking -- there's various ways of defining chemical
purity.
CHAIR
REKOW: Let me interrupt.
DR.
LONG: Yes.
CHAIR
REKOW: I'm asking more about any
physical properties you might measure, rather than the purities.
DR.
LONG: There are density
specifications. There is a particle
science specification. There is a
calcium phosphorous ratio, which can be a specification, and that can be
managed by careful blending of the starting materials. Then there is the x-ray, which is the
primary specification. We use an
independent laboratory to provide that information.
CHAIR
REKOW: Okay.
DR.
LONG: The other testing we can do on
site. We do not have x-ray diffraction
on our site, so we usually use the Ohio State facility in Columbus. So there is a distinct set of parameters
that are set up in our computer for qualifying the material.
CHAIR
REKOW: Okay.
DR.
LONG: And we also qualify starting
materials, as well.
CHAIR
REKOW: Okay. Susan?
DR.
RUNNER: Just a comment that when we do
get applications on these types of materials that is the sort of information
that we request.
CHAIR
REKOW: Okay. Thanks.
DR.
GLOWACKI: I have one question, too.
CHAIR
REKOW: Yes?
DR.
GLOWACKI: This is Dr. Glowacki. Do you provide sterile product to Bicon?
DR.
LONG: Which product, ma'am?
DR.
GLOWACKI: Sterile.
DR.
LONG: Sterile products, no. At this point, the product that we provide
was not sterile. We can develop those
capabilities if that turns out to be part of what Bicon would desire. To this point, we have not.
DR.
GLOWACKI: Thank you.
CHAIR
REKOW: Thank you.
DR.
LONG: Yes.
CHAIR
REKOW: Are there other questions for
any of the three company representatives?
I'm told that Dr. Morgan has to leave by noon, so perhaps we can
continue if there's no more questions right this minute, but keep in mind that
we have a time issue that we'll need to make sure that we pick his brain
sufficiently before he disappears.
Shall
we take a five minute break, maybe six minutes?
(Whereupon,
at 10:38 a.m. off the record until 10:50 a.m.)
CHAIR
REKOW: If we could, please,
reconvene? I understand that Dr. Boyan
is unable to attend today. She was
going to make a presentation on behalf of the American Academy of Dental
Research. The next speaker who has
agreed to provide some information is Dr. Mark Reynolds, who is speaking on
behalf of the American Academy of Periodontology and I will let him introduce
his academic credentials and his potential conflicts of interest. Please, Mark, good morning.
DR.
REYNOLDS: Good morning. Thank you very much for this opportunity to
address the Panel. I am an associate
professor and director of the Post-Doctoral Residency and Periodontist at the
University of Maryland. To my
knowledge, I have no conflicts of interest or vested interest in Bicon or any
other manufacturers related to this issue.
On
behalf of the American Academy of Periodontology, I would like to make several
statements regarding the position of the academy with respect to this issue of
reclassification. Following this
presentation, at the request of the Panel, the AAP will be delighted to provide
additional and specific scientific documentation to support any of the points
that I raise this morning.
We
speak in support of the reclassification of Beta Tricalcium Phosphate as a
Class II device based on both scientific and clinical considerations. Clearly there are numerous publications that
document both the clinical effectiveness and safety of Beta TCP granules that
we use as a bone substitute in periodontal applications.
Moreover,
there is emerging literature from outside the United States that continues to
provide additional information on the safety and clinical efficacy in use of
Beta Tricalcium Phosphate and other applications including sinus
augmentation. These observations and
documentation coupled with similarities and clinical and safety profiles that
have already been established for other legally marketed ceramic bone grafting
materials argue strongly for reconsideration of the current classification of
tricalcium phosphate.
We
feel that the reclassification of TCP should result in greater public access to
this bone replacement material.
Although there are other materials such as allogeneic bone replacement
grafts, there are considerations that limit their use and acceptance by the
public. Furthermore, the clinical
characteristics of other alloplastic and grafting materials also place limitations on the clinical indication and
use within the community.
Although
Beta Tricalcium Phosphate shares similar physical and chemical characteristics
and properties with other marketed dental grafting materials, we feel that the
inherent properties, both handling and otherwise, may afford clinicians with a
broader range of bone replacement materials for use in clinical practice. It appears that in the axis of a 510(k)
mechanism, cost-benefit considerations will continue to deter manufacturers
from bringing this device to market, ultimately impairing practitioner and
patient accessibility to this technology.
Finally,
there is increasing recognition that future advances and repair to medicine including
periodontal and alveolar regeneration will require the adjunctive use of
biologic mediators. Beta Tricalcium
Phosphate offers great potential as a graft material for the delivery of such
adjunctive mediators. These include
platelet-rich plasma. The adjunctive
biologic mediator such as platelet-rich plasma are already cleared for market
via 510(k), and as such the reclassification of TCP will recognize the current
clinical practice and bring about a consistency in this regulation. Thank you.
CHAIR
REKOW: Does the Panel have any
questions for Dr. Reynolds? Yes,
Elizabeth?
MS.
HOWE: Elizabeth Howe, consumer
representative. I have a question about
the comparison of using this product in orthopedic versus oral implication, and
I'm wondering about the reference that it's soluble in mineral acids and how
that would differ in using this product for oral implications?
DR.
REYNOLDS: If I may ask, please, a
question?
MS.
HOWE: In using this product for oral
use, the fact that it is soluble in mineral acids, would that be different
because of infection in the mouth that might be present? Is there some indication that we need to be
aware of?
DR.
REYNOLDS: If I understand your question
correctly, would there be clinical characteristics of the wound orally that
would make the material behave differently?
For example, the presence of acid secondary bacterial colonization?
MS.
HOWE: Right.
DR.
REYNOLDS: I would argue that there
probably are instances in which oral wounds do differ from orthopedic
applications. However, all of these
environments become contaminated in the surgical process. What makes some applications, particularly
periodontal applications, different is that we have a delay in closure of the
wound. However, there is a long history
of use of bone replacement materials in that environment and almost, you know,
uniformally meet with varying degrees of success. So I don't know if that answers your question directly.
MS.
HOWE: Would there be a concern then in
closing the wound directives that would be given on problems for follow-up that
they need to be aware of?
DR.
REYNOLDS: I would anticipate that there
would be no difference in clinical practice from use of any other bone
replacement material, and those would include appropriate patient management
and post-operative follow-up. One
should not, based on material, anticipate any difference in clinical
behavior. In fact, if anything, there
is properties that might suggest that it may behave more favorably.
MS.
HOWE: Thank you.
DR.
GLOWACKI: This is Dr. Glowacki. One of the comments in the orthopedic
directives mentioned a voidance of its use, Beta TCP, in patients who have
problems with calcium homeostasis. Are
you aware of any experience in the periodontal field using this material inside
patients? For example, what type of
calcium malignancy or patients with renal diseases?
DR.
REYNOLDS: No, I'm not. If I might add, though, when we look at
periodontal applications versus orthopedic indications, there are a considerable
difference in the volumes of material that are used generally, and I would
suspect that that would also be a consideration and concerns regarding
that. There may be potential issues in
the patient populations.
DR.
GLOWACKI: And you talked about your
constituency use in periodontal and alveolar reconstruction, and it's my
understanding that in the orthopedic applications use is restricted to
metaphyseal defects. In other words,
not in cortical bone or bone that is really supporting structure. But with respect to the alveolar ideas and
possibly an association with dental implants, do you have an opinion about
whether there is sufficient experience in the use of Beta TCP and periodontal
disorders for construction of -- for replacement of cortical bone? Let me put it that way.
DR.
REYNOLDS: Excellent question, and I can
only offer my opinion, and that is to say that I believe it will depend in
large measure on the form of the TCP on its placement and whether other
mechanisms are provided to stabilize and support the graft material. Particular material tends to move and that's
a dilemma that we're confronted with with, essentially, all the material,
particularly bone replacement materials that we use in those types of
applications. But we don't have any in
general indications that would require structural support. More often than not it's all tissue support
to the wound healing process.
DR.
GLOWACKI: Thank you.
CHAIR
REKOW: Mark?
DR.
PATTERS: Mark Patters. Dr. Reynolds, in your opinion, given the
existing data, what indications do you think that this product should be
labeled for in treatment of periodontal defects?
DR.
REYNOLDS: Well, at this time,
recognizing that there is variability in clinical outcome in this material, but
others of similar characteristics, currently intrabonal defects, furcation
defects, both associated with dentition and for bonal defects associated with
implants and very likely there will be other augmentation as well as sinus
augmentation. There's very scant
literature though currently on the latter applications, and so there's no
reason that I would expect that the clinical outcome or histologic outcome
would differ appreciably from the use of other ceramics.
DR.
PATTERS: Do you believe that there is
existing data to support the use of furcation defects?
DR.
REYNOLDS: Point well taken. I would argue that currently the literature
suggests that there is no single modality that is appropriate for this
successful management and predictable management furcations if we taken a
spaced approach. In fact, we probably
should revisit a number of materials and approach it that way.
DR.
PATTERS: Thank you.
DR.
BURTON: Richard Burton. Two questions. You had said that, you know, reclassifying this product would
expand. My understanding was that there
are some products of lower percentage on the market. Is there not one that is currently a 3, but that are not marketed
now? Is that correct or not? I mean, what's available right now in the
periodontal area in terms of existing products?
DR.
REYNOLDS: Well, in terms of alveolar?
DR.
BURTON: No, of this particular
material, the other one.
DR.
REYNOLDS: To my knowledge right now,
there is no currently marketed TCP.
DR.
BURTON: Okay.
DR.
REYNOLDS: A centigraph was
available. I believe that is no longer
available in the United States. Please,
correct me if I'm wrong.
DR.
BURTON: No, you alluded earlier that
there was some things on the horizon as well.
I would assume you are planning that this would have the potential then
to act as some kind of a scaffold. You
mentioned PRP as one alternative, but also obviously plans looking at
potentially BMP as a delivery system for that as well.
DR.
REYNOLDS: I would say yes. I did not mention I served frequently as a
reviewer on OPM II and on Reparative Study Section, an area of keen interest. Clearly, the use of biologic mediators will
be in our future and are here now to one extent. Scaffolding remains the one frontier, too, that we need to address. So opportunities to identify material that
might need specific clinical indications are extremely important.
DR.
BURTON: Yes, thank you.
CHAIR
REKOW: This is Dianne Rekow again. I'm assuming you people of the FDA, please,
confirm or correct me, that we're talking about this in its pure form not in
its mixture with all the primordial soup options, right? We're not talking about the BMPs and the
gross factors and the various other stuff that could be added?
DR.
RUNNER: That's correct. Any addition of those types of factors would
push that into a PMA Class III type of device.
CHAIR
REKOW: I share your enthusiasm for
that, but I just want to be clear that what we're addressing here is simply the
material as a material.
DR.
REYNOLDS: Yes.
DR.
RUNNER: And I also wanted to make the
comment that there were a lot of specific questions from the Panel about the
manufacturing of this particular company of the product. You should be thinking of it as a broad
reclassification not of the specific company.
CHAIR
REKOW: Thank you. Are there any other questions for Dr.
Reynolds?
DR.
REYNOLDS: Thank you very much.
CHAIR
REKOW: Thank you. Both Dr. Gunter Uhr and Dr. Thomas
Arrowsmith-Lowe from Curasan, if that's not the proper pronunciation, I'm
sorry, are here. How would you
gentlemen like to proceed, and would you, please, identify yourselves and your
interests?
DR.
UHR: Thank you. Thank you very much.
CHAIR
REKOW: Can you use the microphone,
please, because it needs to be public information?
DR.
UHR: Okay. Thank you.
CHAIR
REKOW: We need as a society to come up
with some comfortable segway from getting computers up and running. You know, there's got to be something we
have to learn to do to take care of that pause.
DR.
UHR: Okay. Thank you for the possibility that I'm here, and that I have you
to give me the chance to make a small presentation. My person, I'm Gunter Uhr from the Curasan. I'm the head of the Clinic of Research, and
the Curasan also purchased the PMA from Miter and intended to bring the product
here in America on the market.
My
intention is to show you that we not agree with reclassification from III to
Class II. Why? You see on the left side is the
skeleton. You'll see the skull, and
what I intend to show is that we have two bones. Bone is not bone. And
bone and wound healing of the skull differ from those in the skeletal
system. This concerns the
histogenesis. This concerns the
function and the healing process. And
the etiology of maxillofacial defects is also different.
And
to take an inference on the wound healing, for example, and therefore we need
material which has a special feature.
We need a material that's as pure, that means more than 99 percent, and
you must have a special shape of the material, the granule form, the size and
the porosity, because all these four features will affect safety and the
effectiveness.
Now,
I structured this presentation in two parts.
One part is a biological one and the second is material. Now, at first to the histogenesis. The skull we have an intramembranous bone
formation. What does it mean? We have small cells, that's this one, this
aggregate, the mesenchymal stem cells, you know, and they differ into
osteoblast and they form at different location simultaneously bone. That's typical for the skull, especially,
you see here the child at nine weeks, and you see the maxillar mandibula and
the frontal bone is formed at nine weeks.
The
blue color it's cartilage. This is
typical for the skull. The next bone is
enchondral bone formation, and this is a typical bone formation for the
skeleton. And what is the
difference? Here the green color it's
cartilage, and cartilage is replaced to bone, and this is here shown. And what is the function? Both bone types have different
function. Here the skeleton has to carry
the load, has to bear the weight, and the function probably here of the
mandible or the maxilla is to carry this, and the load is periodically, not
continuously. And also, the bone
quality is different. The modeling, for
example, you have a higher remodeling rate in this skeleton system than here in
the skull.
Now,
we come to the etiology of the bone defects, and most of the bone defects in
the skeleton have a systemic origin.
There are no contaminations with microorganisms, bacteria, viruses, and
each orthopedic surgeon fears the bacteria invasion. Then you got problems in bone.
If you have a bacteria invasion, you know, the osteomyelitis. This occurs in long bones. What is the situation, the region of the
mouth?
Now,
we are speaking about, you know, the periodontosis. The periodontosis is a chronicle infection with bacteria. It's a completely different situation. And, for example, the apicoectomy, you get
an invasion of bacterial through the root canal in the apex. Here we have an invasion with bacteria. The next point, filling of tooth
sockets. You extract the tooth not just
for fun. And it burns when you have an
invasion there of bacteria, and also if you make a sinus for elevation or
augmentation, lateral or horizontal augmentation, you are working in the field
of contamination with bacteria and microorganisms. And also, in large defects, for example, in tumors. If you have contact with vestibulum, you
have the problem of the infection.
And
now, we look at the time frame. This
infection also has an effect on the time of healing. Here we have typical defects, for example, in long bone. We take this from the hand, because here we
have comparable volumes to defects in the mouth region. Here we have a broken finger. You see the surgery. You see the osteosynthesis, microplate to
stabilize the bone, and you see here the Beta Tricalcium Phosphate. It's completely resolved at six months. It's a marvelous result.
Here
below, that's the young girl. Of
course, we have influences on bone regeneration. You know the age is important, also if their system make
diseases. But here, we see it was a
horse bite. The joint was
destroyed. And the surgeon made a
chiroplasty and filled it with Cerasorb.
You see at two and a half months you take a biopsy to look what has
happened in the defect. And this is a
biopsy, and we can enlarge it, and what you see is that the Cerasorb, the
granules were totally disappeared. They
are dissolved. And we have a very
smooth, smooth transition from the cartilage here, the joint to the bone. If you use a higher magnification, you will
see some rests here of Cerasorb, but only some rests. Cerasorb is the better TCP.
Now,
what will happen in our maxillofacial region and the dental region? Here we have the Beta TCP in the sinus for
elevation situation. And what you see
is, at first, we have separated the regeneration phase into -- we have
separated the regeneration into four phases.
The first phase is the stability of the bone regeneration material
during the acute inflammatory reaction.
That's the first phase in wound healing, and it's very important. Just a minute ago here there was a question
about the acidity, the pH and I will speak a little bit later and come to this
point. It's very important for the
material.
The
next point is, at first, we have the fibrin network, coming from blood, and
this fibrin network is replaced by the collagenous fibers network and then at
about three months, here at this side, the woven bone formation begins into the
inter-granular spaces, and at about six or eight months here, we have the
transition of the maturation into lamellar bone at eight months. And finally, we need 12 to 24 months for the
remodeling, the remodeling starts and the total appears in the material. This is longer than in long bones.
Now,
we go into detail. What happened? What has occurred in the wound? Probably have a broken bone here. What you see is that's the bone line, the
osteoblast. We have at the broken side,
we have to relieve the growth factors, BMPs, for example. We have the clotted blood vessels here in
the bone marrow. Now, the space here is
filled with blood and you put in some granules, Beta TCP granules. The activation of platelets occurs
immediately. They release growth
factors, and then we see here the fibrin network and the cell tied, but first
which come in from the clotted blood vessel, this is the granule side. Here clears the region, but at 12 to 48
hours, they will disappear. They will
disappear, but will be phagocytized.
They make their drop and then they disappear.
And
now the next cell come on the plan and this is a macrophage. And a macrophage is as a central role in
this period. It organizes the whole
wound healing process. The macrophage
and we have seen, here on the top, we had a pH of 4 to 6 until the fibroblast
formed the collagenous fibrin network.
They replace the fibrin network, and then the blood vessels move
in. And this is a point that the pH now
goes to a normal physiological level of 7.4.
But
here we have two important functions concentrated in the macrophage, and the
macrophage will attack, at first, now that's a biological principle, you
know. At first the antigen, the
bacteria, they will clean the region.
Also they phagocytize the microorganisms, and they do it together with
the T lymphocytes. And when this
process comes to an end, then the regeneration begins.
So
if there is a stimulation for the macrophages, the phase of defense will
extend, and they phagocytize not only the bacteria, but they phagocytize
everything which is smaller than 10 H to 10 microns. So if you have a material here, the Beta TCP granules, which are
not stable and they disintegrate, you know, we have an acid situation. And if this acid situation links to
disintegration of a particle, then this particle below 10 microns will
phagocytize by the macrophages. And it
comes to a shrinkage of the defect, of the filling of the defect.
CHAIR
REKOW: Can I interrupt for just one
second, please?
DR.
UHR: Yes.
CHAIR
REKOW: These are fascinating
slides. There's no question about it,
but I need to remind you that almost everyone in this Panel is a clinician and
trained in dentistry and bone regeneration, so maybe we could have a slightly
shorter version of some of the basic concepts.
DR.
UHR: Okay.
CHAIR
REKOW: I don't want you to miss your
main points, by any stretch of the imagination.
DR.
UHR: Okay.
CHAIR
REKOW: Thank you.
DR.
UHR: Now, to the material, and the
material, here we have four features, which are necessary, which are very
important. It's purity, the shape, the
size and the porosity. This effects the
safety and effectiveness. Now, a very
important point is that the Beta Tricalcium Phosphate in Europe was on the
market since 1970, and we see here some publications, also here from the
U.S. And this material disappeared in
1980, roundabout in the '80s, from the market, because no one wants to use any
more the Beta TCP.
Why? They got here from Holland published that
Beta TCP disintegrates very rapidly into particles that can be found in the
neighboring lymph nodes. And that means
the end for this product. And then this
guy here, this Dr. Heide, he was convinced that Beta TCP is a good
material. But he says it is good if it
is pure and is pure higher than 99 percent.
And here we have a lot of publications which show that this material
works.
Now,
I will show you what happens in the body if you have an impure material. It's a competitive material in Germany. It comes on the market and it disappears
very rapidly, because you see here it corrects, it's covered by am impure phase
and it is very instable material. And
if you test or will test -- if a material is, I'm looking for it, suitable for
the defect to use it, you can move it between your fingers. And if you use this granule and move between
your fingers, and you put it back, and you blow, you have no abrasion, and also
you can also eat them, because there is just like to drink a glass of milk.
But
we go back to impure material and I can show you what will happen. These are all immunohistological figures and
this is a result. And what you see is
after 11 months, you'll see the persistence of lymphoid cells together with
macrophages. And you will see like
stars in the night sky, you'll see the small particles of this Beta TCP
distributed in the tissue. And up to
now, there is no regeneration of material of bone.
So
to sum up, impurities impair the results and process. Impurities less resorbable than Beta TCP. These particles migrate to lymph nodes, De
Groot. Especially, we have talked also
about the Alpha TCP, and it is know that Alpha TCP converts into hydroxyapatite
in the biological system. And the
impurity is more soluble than Beta TCP.
You have retarded bone formation.
Now,
important for the material is the size, the size and the micro-porosity. Here we see the movie and the spherical
shape is important, because you need the intragranular spaces. We have spoken about osteoconductivity. You need the intragranular spaces for the
invasion of blood vessels. And
additionally, the spherical size is necessary.
Most of these indications where you can use this material in dental
field is to fill the sinus. You have to
push the Schneider's membrane. Then you
have to put these granules below. If
you have a material which is broken and has edges, there is a danger to hurt
this membrane. Especially, if you use
the Summers method.
The
next point, you need a well-defined micro-porous structure, because we don't --
we also need the movement of blood vessels and fibrins. It's a street for the cells. The first streets and highways for the cells
into the granule. And so we have a
porosity of 1 to 20 microns, and it's a lower limit for small blood vessels
are, you know, 5 microns.
The
next point is you need a product which is very strong sintered. With this table, you'll see here the cubic
sugar. This will happen with a
material, which is not stable. And you
will get particles which will be phagocytized.
What you need is a solvent from the surface, a continuous solvent from
the surface, and this prevents the particle decomposition and genus solubility,
we call it halisteresis. And there is
no degradation by osteoblast that came there, and the question is the
degradation by the osteoblast plausible?
We
know that for the degradation of osteoblast you need two informations. We need the bio-contact with osteoblast and
we need the membrane of the osteoblast, we need bio-receptors information from
the bone matrix proteins. So in a
acidic material we never have this information.
And
finally, this granule is built up of particles, of primary particles, and these
have a size of 50 percent larger than 10 microns, that's another point. So I want to summary it. Bone and wound healing, I think, I have
shown it in a very short time, so it differs.
We have a different histogenesis.
We have a different function. We
have a different healing process. And
the etiology of the maxillofacial defects differs from the skeletal defects.
Therefore,
you need a material which -- and this is a point, the human body sets the
limits not the material, and therefore we need a purity, a shape, a size and a
special porosity. Thank you. That's the end.
CHAIR
REKOW: Thank you. Are there questions for Dr. Uhr? Yes, Mark?
DR.
PATTERS: Mark Patters. Dr. Uhr, it's a very pretty presentation,
but what I didn't get from it was why you oppose the petition? The petition says nothing about purity, only
reclassification of not just their product, but all tricalcium phosphates that
are intended for use in oral cavity, so why do you oppose that?
DR.
UHR: As a purity.
DR.
PATTERS: The petition, as I read it,
does not address purity.
DR.
UHR: Yes, but may I explain why it is
important that you have such a high purity?
For example, these granules consist of primary particles, batch primary
particles and during a sintering process, these particles are recrystallized,
and you get -- between these particles you get sintering next that means from
both primary particles the crystals move to each other, they bridge, and the
impureness, for example, hydroxyapatite, for example, calcium phosphate, other
phosphates move in front.
Now,
this material gets contact. At this
bridge you have the impureness, and if it is more soluble, the material breaks
down. Especially in the acid condition,
in the acute inflammatory reaction. And
then there's a possibility that these particles below 10 are phagocytized by
the macrophage. Then you will stimulate
the new reaction.
DR.
PATTERS: Now, I understand that, but
the purity issue can be covered in the guidance document with special controls
if this is reclassified. Are you saying
that highly purified Beta TCPs should be reclassified, but impure ones should
not be?
DR.
UHR: Yes, I think it's -- so I'm a
scientist. I would say the purer the
material is, if you have a high pure material, it is -- whether it is to
control, you want to control the purity.
Of course you can make batch controls.
You can make batch controls with diffracture meters, yes?
DR.
PATTERS: Maybe the FDA process is not
completely clear to you. I've been on
the panel for more than 10 years and it's not completely clear to me. But my understanding, however, is that the
guidance documents and the special controls can deal with issues of
purity. What we're looking at, the
Panel is being asked to look at a much more generic issue.
CHAIR
REKOW: Thank you. Dr. Arrowsmith?
DR.
ARROWSMITH-LOWE: Yes, I think I'll be
addressing more of the regulatory aspect of this.
DR.
UHR: Yes, okay.
CHAIR
REKOW: Could you introduce yourself,
please?
DR.
ARROWSMITH-LOWE: Yes, I'm Tom
Arrowsmith-Lowe. I'm a regulatory
consultant, Curasan AG is one of my clients.
I am compensated by Curasan AG for consulting services that I provide to
them, including my presentation. I am a
retired FDAer. I'm a retired public
health service captain and served in the FDA until my retirement. I was a deputy office director in the Center
for Devices and was director of the Human Tissue Program in the Center for
Biologics prior to my retirement from the Agency, and hopefully I can work
this.
CHAIR
REKOW: Just for the record, Dr. Uhr,
I'm sure, will have some more questions for you, but perhaps we can finish the
other presentations and then combine them.
DR.
ARROWSMITH-LOWE: As has previously been
stated Curasan AG is speaking in opposition to the proposal to reclassify Beta
TCP from Class III to Class II. As we
reviewed the reclassification petition it distilled down essentially in making
two points. One that there was no
difference between skeletal and maxillofacial bone, essentially saying that the
use is the same whether it is used maxillofacially a Beta TCP for an implant or
whether it is used in skeletal bone, and the second point being that there were
no reported problems.
We
would like to respond to those two statements.
Dr. Uhr has fairly clearly shown that there are some differences between
the two bones, that bone is not just bone, that there is a difference between
skeletal bone and maxillofacial bone.
He has pointed out that the origin of the bones, the histogenesis of the
two types of bones is different. He has
also shown a difference in function with the maxillofacial bone existing for
support of the dentition for use in mastication and other uses speaking as
well, and has also shown in that that the pressures that are generated in the
function of the two different types of bone are different as well. That there's a different function, one being
for skeletal musculoskeletal support and the other for support of dentition.
And
has then also shown that there is a difference between the stresses that are
applied to the two bones with periodic stresses being the case for the bone
that is supported of dentition with much more constant stresses being applied
to the musculoskeletal system bone. In
addition, he pointed out that there is a difference in the healing process
between the two bones when Beta TCP is used for treatment of a defect, that the
post-operative healing process is a longer process in the maxillofacial bone
than the process that occurs in long bone.
As
well, he has also pointed out a difference in the etiology of the bony defects
in the two types of bones, pointing out that principally the main etiology for
defects that develop in musculoskeletal bone tend to be defects that are
systemic defects. Whereas, the main
etiology for defects that occur in the bone supporting the dentition is
primarily of an infectious origin.
And
so we do support the idea that there really are differences between the two
bones. There are differences not only
in how those bones function, but also differences in their origin and
differences in the etiology of the defects that occur in those bones. So I think the point can be made that we
really can't say that bone is bone in this case. That there are differences that are easily demonstrated here.
In
addition to that, the second point that was made in the petition is a point
about, essentially, there have been no problems reported. One of the points that Dr. Uhr mentioned
having to do with the growth article that was published in the 1980s was that
there actually was a product removal that occurred and Beta TCP was unavailable
for a period of approximately 10 years for dental use in Europe, and that
really primarily related to the fact that the TCP that was being marketed
initially in the 1970s had problems of purity that very definitely effected the
safety and effectiveness of that product.
And so the clinical community stopped purchasing the product, and the
product, essentially, was removed from the market by the manufacturer of that
product. Dr. --
CHAIR
REKOW: Could I --
DR.
ARROWSMITH-LOWE: Yes.
CHAIR
REKOW: Oh, I'm sorry. Actually, I'll wait.
DR.
ARROWSMITH-LOWE: Okay.
CHAIR
REKOW: Sorry.
DR.
ARROWSMITH-LOWE: Dr. Uhr also talked
about other issues that we feel are fairly essential parts of making a
determination of safety and effectiveness.
That variations in the purity of the product, variations in porosity and
particle shape and in particle size can very definitely have an effect on the
product itself and make that product less safe and less effective. This is an issue that is of concern to us,
and we feel it should be a concern to the Panel and to the clinical community
as well.
Because
it is our feeling that the most appropriate way to try to make an assessment
that a product truly is safe and effective and to include in that determination
of safety and effectiveness is looking at how purity, porosity, particle shape
and particle size actually affect the performance of that product in a clinical
setting. So actual review of data as
opposed to just making a comparison between two products, looking at physical
properties, such as purity, porosity, particle shape and particle size.
And
so our recommendation is against reclassification as I have already said, and
for reasons that we feel that the petition has not adequately established those
two primary points about the similarity of bone being bone, and the point that
the product actually has had no problems associated with it throughout its
period of use. And so as I said, we're
recommending against reclassification.
If, however, reclassification were to occur, we would like to make two
recommendations to the Panel and to the Agency about how they would make a
determination of substantial equivalence using a 510(k) process.
One,
we feel that a predicate product, to which substantial equivalence would need
to be established, has to be a current generation Beta TCP. A purer product than the sort of product
that was initially manufactured back at the point when the first PMA was
cleared for Beta TCP. As was mentioned,
Curasan AG now is the owner of the original PMA and, as the Panel may be aware,
there is a submission that has come in from Curasan AG, a supplement, to that
original PMA to, essentially, change the product into a form that is a purer
product form that addresses issues having to do with the size of the particles
and also with porosity and with particle shape as well.
And
so we feel that to have an adequate determination of substantial equivalence if
the 510(k) process is used, that there really must be a comparison made and a
determination that the product that has submitted to pre-market notification
does favorably compare with the current generation of Beta TCP when looking at
a product or particle size, particle porosity, looking at particle shape and
looking at the overall purity of the product.
And we feel that if the 510(k) process were applied, that it would need
to include a determination of substantial equivalence looking at these factors. Thank you.
CHAIR
REKOW: Thank you. Dr. Patters, does that answer your question
or would you like to restate it?
DR.
PATTERS: Well, Mark Patters. My understanding is then that you feel that
this product should come to market through the PMA route, and you already have
a PMA, which I was unaware. I think the
Panel is not aware.
DR.
ARROWSMITH-LOWE: Okay.
DR.
PATTERS: As you thought they were. We're not.
DR.
ARROWSMITH-LOWE: Oh, okay. I thought the Panel was aware. Yes, we feel that --
DR.
PATTERS: PMAs are a closely guarded secret,
I believe, by FDA and they do not share that.
DR.
ARROWSMITH-LOWE: Well, we feel that the
PMA process provides a better opportunity for making a determination of the
safety and effectiveness of the product, rather than just making a comparison
with a predicate product. One of the
things that we want to make certain of is that given the advancement of this
product over the last several decades, and given the improvement in clinical
utility and the decrease in incidences with the purer product and with a
product that addresses some of the other issues as well, that we do have a
level of safety now and a level of product effectiveness.
That
is really a standard with the newer Beta TCP.
And it would be a concern that we would have that using a comparison
method in establishing substantial equivalent might not necessarily provide
sufficient information to really make a determination that this implantable
product really is safe and effective.
DR.
PATTERS: So if I could summarize then
what I understand you to be saying is you do not believe that, at the present
time, there is adequate data in the literature to support
reclassification? And you believe that
new clinical trials and new -- not just clinical trials, but new data need to
be presented?
DR.
ARROWSMITH-LOWE: Well, I believe that
the presentation of new data would go toward establishing safety and
effectiveness of any new product that would come on the market, as opposed to
just merely doing a comparison to a predicate product, yes.
DR.
PATTERS: Thank you.
CHAIR
REKOW: Dr. Cochran?
DR.
COCHRAN: David Cochran. You mentioned four different aspects: The purity,
porosity, shape and size, and you are implying that one would receive
one set of outcomes in testing if you reach some point. Say purity was 99 percent, I think you
mentioned, but maybe at 96 percent it would not. In other words, for each of these issues, these four issues, that
you've mentioned here, you are implying that there is data to say that there is
going to be a difference in performance at some cutoff value. Can you provide any data that would suggest
that that's true?
DR.
ARROWSMITH-LOWE: Well, part of the
reason some of the data, the basic science data, that was presented already
goes to establishing the significance of determining each of those.
DR.
COCHRAN: Well, that was one study or
publication.
DR.
ARROWSMITH-LOWE: Well, no. Actually, the De Groot study basically was
looking at what was wrong, why the product was, essentially, not being an
effective product, and the dental community turned against the use of the
product. And principally, that was
really looking at only one of these issues, looking at the purity issue. Because what was determined was that when
you had purities that were, say only at a 95 or 96 percent range, that you were
going to get a change in the healing process.
What
we've further found beyond that was some of the work that Dr. Uhr was talking
about is the presence of impurities also can effect particle size, because the
success of the sintering, which brings the impurities to the surface when two
of the primary particles join in the sintering process, because the impurities
are brought to the surface through the heating process, the point of juncture
actually is the point of impurity between those two primary particles, and that
increases the likelihood of that particle, primary particles, that have been
sintered and joined of those breaking apart.
Then
what is more likely to happen when you have those smaller particles is that you
are going to get a greater likelihood of having a response on the part of the
body that the macrophages will come in and will consume the smaller particles
and you are actually going to have a slowing of the overall healing process,
because you are having particle disintegration occurring more rapidly.
DR.
COCHRAN: Yes, but what I'm asking for
is do you have data that says that 96 is not good, but 98 is good or you think
99 is good? I mean, if you're going to
make this recommendation, it would be nice to see data that suggests that there
is a cutoff area.
DR.
ARROWSMITH-LOWE: Yes.
DR.
COCHRAN: Or that one is better or
not. Otherwise, we're doing the same
thing, because the Panel has got to make decisions as to what it would
recommend.
DR.
ARROWSMITH-LOWE: Right.
DR.
COCHRAN: Without the data to support
it, it's tough for us to do that.
DR.
UHR: Sorry, I can answer. We, in our company, tested -- our company
tested not for its own, but we test the material. We give it to a nurturer institute, another university, sorry,
and there we tested the material. And
so you can see in a different meter whether there is impure or not impureness.
CHAIR
REKOW: Has that been published yet?
DR.
UHR: It will be published, yes, but not
by us, of course.
CHAIR
REKOW: Yes.
DR.
UHR: It's not in press, but it will
come soon. Another point is we have
publications, especially also of Alpha TCP, that's a material which converts
probably into hydroxyapatite and you can see it in the animal model. You can see in the lymph nodes the particles,
the hydroxyapatite. And I think it is
not the target to use a material which normally it has to be solved and it
should be replaced totally by bone. So
we will not find any particles anywhere.
This should be the target.
CHAIR
REKOW: Yes, Dr. Burton?
DR.
BURTON: Richard Burton. Does your company represent currently market
a competing product or is this product that you have now currently marketed?
DR.
ARROWSMITH-LOWE: Curasan AG markets
Beta TCP in Europe and markets Beta TCP in the United States for orthopedic,
for non-dental use in the United States.
As I also mentioned, they are the holder of what was originally Miter's
PMA and have intentions if the --
DR.
BURTON: And I assume then it's under
that PMA without a reclassification they could market it?
DR.
ARROWSMITH-LOWE: They could basically
market under that PMA the product that was described in the original PMA.
DR.
BURTON: Which was inferior product.
DR.
ARROWSMITH-LOWE: Which is a product
that does not meet Miter standards of production, yes.
DR.
BURTON: Okay.
CHAIR
REKOW: Jon?
DR.
SUZUKI: Jon Suzuki, Panel member. Just this is a question to Dr. Gunter Uhr.
DR.
UHR: Yes.
DR.
SUZUKI: It's a point and then a
question. First, you mentioned that
neutrophilic PMM leukocytes both disappear from the scene and that's not
exactly true. They are always
indeciduous and connected, even in the subsequent stages of wound healing, so
just for the point.
DR.
UHR: I'm sorry. I didn't understand you. Speak a little louder.
DR.
SUZUKI: The PMM neutrophilic leukocytes
--
DR.
UHR: Okay, yes, yes. Okay.
DR.
SUZUKI: -- appear and that's not
exactly correct, to my knowledge, but that's a minor point. The question really deals with macrophage
and your indication that they begin to engulf particles of 10 microns or
less. Are you indicating that this is
harmful because of a potential foreign body reaction or are you saying that the
macrophage is interfered with in terms of their molecular quarterbacking?
DR.
UHR: I think you have to look what they
are phagocytized, of course. But the
phagocytosis process is a stimulation of the activity of the macrophage. And we know that the activated macrophage
released growth factors or signals proteins to attract more and more
macrophages into the region. They leave
the peripheral blood vessels, yes. So
you get a higher concentration of macrophages.
You ultimately activate more and more the acute inflammation reaction.
But
of course, if they phagocytize the material, which is resorbable in the user
zones, it will disappear. But if it is
an impure material, hydroxyapatite, it will not be resorbable. So on the market now it's the tendency, you
know, no particles for a bone regeneration material, and these particles, of
course, are phagocytized by the macrophages, but there is no chance, because
these particles is hydroxyapatite.
DR.
SUZUKI: Jon Suzuki again. Just a follow-up question. Sir, the macrophage is then when they begin
the phagocytosis of the particles that are 10 microns or less. They are impeded in their
"regulation." Is that what
you are implying?
DR.
UHR: Yes.
DR.
SUZUKI: Or if you're not familiar with
the macrophage, they are sometimes considered the field generals or the sponsor
or the host.
DR.
UHR: Yes, yes.
DR.
SUZUKI: And sometimes referred to as
the quarterback.
DR.
UHR: Yes.
DR.
SUZUKI: And where they came from.
DR.
UHR: Okay, right.
DR.
SUZUKI: So this is impeding?
DR.
UHR: Yes.
DR.
ARROWSMITH-LOWE: And in addition to
that, you are having a loss of material as well, and so instead of the material
being able to do its initial function, if the particle size is too small, then
it is not able to do its intended use, because the particles are phagocytized
by the macrophages and you are actually losing some of the material that would
have been maintained as a part of the graft for the reparative process. And so there's the downside of it not being
able to actually meet its intended use, because the particle size being
somewhat say below 8 microns actually.
DR.
UHR: And the other point is you extend
the phase of low pH.
DR.
ARROWSMITH-LOWE: Right.
DR.
UHR: And we know Beta Tricalcium
Phosphate dissolved very quickly in a low pH in an acid environment.
DR.
SUZUKI: Jon Suzuki. And you also indicated that some of these
particles are seen histopathologically in sites in the lymphoid tissue of lymph
glands.
DR.
UHR: Yes.
DR.
SUZUKI: It's not the macrophages that
have carried this product, but it is rather the lymphoid cells. Is that my understanding?
DR.
UHR: No, no, the macrophages runs part
of it.
DR.
SUZUKI: And what are the lymphoid cells
doing there?
DR.
UHR: The T lymphocytes, for example,
they stimulate the fever of the fiber, and the fever is the temperature, yes,
and they release interleukines, for example, you know, to attract the
interleukines. Probably they are
transported to the liver, yes. You
know, they induce release of factors.
You know it, certainly, there is an interconnection between the T
lymphocytes and the macrophage.
DR.
SUZUKI: One last question, Madam
Chair. The T lymphocytes that you just
mentioned are frequently associated with a delayed hypersensitivity or allergic
type or rejection reactions. Are you
suggesting that that might be a parameter, too, that we need to consider?
DR.
UHR: I think so, so that's in the
histological figure. At 11 weeks, we
see a reaction to this small particles distributed in still connective tissue. It's not a bone formation there, yes, and at
this time, the women have a bone regeneration.
That's the point.
CHAIR
REKOW: Daniel?
MR.
SCHECHTER: Dan Schechter. Taking for argument's sake that all of the
biological information you have given is true and that these various factors
are important to the product and to the safety and effectiveness of the
product, these parameters could be spelled out in special controls in a Class
II product, and my question is are you saying that the parameters are not known
in the literature, and the only way that an application could be properly
reviewed would be with data, since there is nothing to compare it to, as I
suppose your company has done, or is it that it just needs to be spelled out,
because it's known? The purity is
known. The particle size that is needed
is known in the literature that we, as a Panel, could recommend it be put into
special controls, because then you are not just comparing to another product,
you're comparing to a standard, but that can be done with a reclassification?
DR.
ARROWSMITH-LOWE: No, that's exactly
right. It could be done with a
reclassification, and so what -- that's why the final slide was there, that if
the reclassification occurs, you know, we feel that it's absolutely essential
that those parameters be assessed as a part of a determination of substantial
equivalents. There is a good bit that
is known, at least a good bit based on work that has been done either in
Curasan AG or by independent researches that Curasan AG has been collaborating
with to make a determination about what is an acceptable level of purity.
And,
you know, I have to say that the acceptable level of purity that Curasan
supports is a higher acceptable level of purity than the ASTM standard, for
instance, on this, and that really is based upon the clinical performance of
the product, the fact that you can actually see histologically that you have a
better healing process when you have far fewer impurities, and the same holds
true for the other aspects that we're talking about, as well. For particle shape, that you can see actual
clinical negative occurrences that can happen from particle shape.
In
addition, particle shape may prevent having intragranular spaces that really
are sufficient for blood vessel introduction, you know, from a standpoint of
porosity, that the healing process is going to proceed more appropriately,
because the porosity provides the opportunity for adequate fiber and
attachment, and then that's a pathway that is subsequently used through the
healing process and, ultimately, to the point of creation of new bone there.
And
so each of these actually does have what we feel is some fairly high
significance and yes, one of the ways of approaching that would be to use a
special control to develop a mandatory standard and just say that, you know,
adherence to this mandatory standard is going to be something that would be
required of any product that is regulated, the Beta TCP product, if it were
regulated as a Class II.
CHAIR
REKOW: Just as a point of
clarification, Dianne Rekow again, I would like a simple yes or no if it's
possible. Is --
DR.
ARROWSMITH-LOWE: I worked at FDA too
long.
CHAIR
REKOW: Yes.
DR.
ARROWSMITH-LOWE: So there is never a
simple yes or no.
CHAIR
REKOW: Is it your belief that there is
scientific data to support upper and lower thresholds for each of those four
parameters that you specified, the purity, the particle size, the particle
shape and --
DR.
ARROWSMITH-LOWE: Yes, particle shape
and porosity.
CHAIR
REKOW: Porosity, yes, I'm sorry.
DR.
ARROWSMITH-LOWE: Yes.
CHAIR
REKOW: Okay. Thank you.
DR.
ARROWSMITH-LOWE: That was an easy one.
CHAIR
REKOW: Susan, did you have --
DR.
PATTERS: But is that data available?
CHAIR
REKOW: Yes, is that in the open
literature? Is that within the company
study?
DR.
ARROWSMITH-LOWE: Well, some of it is
within the company. Some of it is
published European literature. All of
that we would be able to make available.
CHAIR
REKOW: Okay. Susan?
DR.
RUNNER: But my question for that is is
that, those limits, the standard of care, is that accepted in the clinical
community or is that something that is proprietary to Curasan and you would be
making the standard yourself, as opposed to out in the broad literature? Is it something that FDA or the Panel could
recommend or is this just your opinion based on your product and the clinical
data you have?
DR.
ARROWSMITH-LOWE: It's the latter.
CHAIR
REKOW: I have one other question, if I
may, David, before -- I have heard each of you refer to the fact that
historical material was withdrawn from the marketplace. I don't need to know all the details. I am just curious if it was removed because
of market pressures or if it was removed from requirements from any of the
regulatory agencies.
DR.
ARROWSMITH-LOWE: It was based on market
pressures. It essentially was a
response to the fact that the product was not performing effectively. Clinically, it was not performing.
CHAIR
REKOW: Clinicians were not happy, so
the market --
DR.
ARROWSMITH-LOWE: The clinicians were
not happy and so it ceased to be purchased, and was ultimately removed from the
market.
CHAIR
REKOW: Okay. That's an important point, I think. Dr. Cochran?
DR.
COCHRAN: David Cochran. I guess my question is a little bit of
follow-up the same way. I mean, with
any parameters for a product, there is going to be a range, and clearly it's in
the interest of any company to produce the best product they can, and I think,
you know, the Panel needs to consider that as a Panel making a recommendation
when we think of controls, certainly we're going to probably make
recommendations or when we do, that it's some sort of range, but we don't think
ever an intention is that a company is going to come out with a product that's
not something that's going to be effective.
Otherwise, it's a little silly.
CHAIR
REKOW: Dr. Burton?
DR.
BURTON: Richard Burton. Just to carry on to that, was the product
that was removed from the market the license that you now own?
DR.
ARROWSMITH-LOWE: No.
DR.
BURTON: So it was a different product
than the one that you have purchased the license to?
DR.
ARROWSMITH-LOWE: Yes, that's correct.
DR.
UHR: We have, may I say, some
additional information to that. Curasan
was the first on the market in Europe with a pure Beta Tricalcium Phosphate,
and then other companies recognized this as a very successful material, so they
tried to imitate it, and they go with the material on the market as a CE
certificated product, and then it disappears and you can wait two, three or
probably yes, one year, and they have the result. And, you know, one dentist to try a material and he has a bad
result, he will not use this material anymore, and so we have no negative
publication or a publication about negative results. It's a problem. That
material comes on the market. It is
tested and the human being is the model, and then it disappears. This is the way.
CHAIR
REKOW: Yes.
DR.
ARROWSMITH-LOWE: And I think a part of
what we're saying, if I may follow-up on that, is that in the European
situation, the competing company is able to introduce a less pure product given
the regulatory situation that exists there in Europe, and what then
subsequently happens is the performance --
CHAIR
REKOW: Right.
DR.
ARROWSMITH-LOWE: The effectiveness of
that product is not up to the standard that has been set by Curasan's product,
and so the product ceases to be purchased and to be implanted and to be used,
and it eventually leaves the market.
CHAIR
REKOW: Good five-year market
share. That way, they will gain. I'm teasing.
DR.
GLOWACKI: This is Julie Glowacki. I want to ask the question, Dr. Arrowsmith,
in just a slightly different way, but I think it will be a yes or no answer. To any degree, has your opinion been
informed by an analysis of the guidance document that was generated out of the
orthopedic proposal to reclassify it to Class II?
DR.
ARROWSMITH-LOWE: Yes. Actually, I have read the document. I have had discussions with people in that
branch and they let me know when the document was forthcoming, because again,
Curasan has a product that was cleared from market through the 510(k) process
for orthopedic use, so we have been interacting also with the Orthopedic
Branch, and so we were made aware of this previously, yes.
DR.
GLOWACKI: So you're saying that these
four terms should really just be highlighted in that, being to a greater degree
than it is? I haven't reread it since
your presentation.
DR.
ARROWSMITH-LOWE: Yes.
DR.
GLOWACKI: But to be sure that those
four parameters as far as --
DR.
ARROWSMITH-LOWE: Exactly, and we really
do support the idea of the central nature of assessing those four parameters
and, you know, as Mr. Schechter pointed out, that can be done in several ways. We think probably the most appropriate way
is through establishing the safety and effectiveness, but if there were a
reclassification, then the use of a special control and mandatory standard
would be another way of trying to achieve that, as well.
DR.
GLOWACKI: Thank you very much.
CHAIR
REKOW: Dr. Cochran?
DR.
COCHRAN: I'm a little naive about the
European products over there, but I understand that Ceros is another
product. Is that a product that you
would say is the current type TCP standard or the old type standard?
DR.
UHR: No, sorry. I know the Ceros. We also studied this product, and this material has no
inter-connective porosity.
DR.
COCHRAN: Which means what?
DR.
UHR: Which means you put this material
into the defect, and there is only from the surface the solvent, but there is
no ingrowth into a granule. It's not
possible. It just bubbles, yes, which
make the porosity, but it's not inter-connective, but we need an
inter-connective porosity that is lodged, invades into the granule, and
afterwards --
DR.
COCHRAN: What is the purity of that?
DR.
UHR: It's not larger than 99. It's smaller, and there is an impure phase
in it.
DR.
ARROWSMITH-LOWE: If I may just
follow-up on that. The role of the
micro-porosity is really for fibrin attachment, and it forms a pathway that
ultimately, fibroblast can follow the pathway and there can be an establishment
of connective tissue, and it helps maintain the integrity of the implant
itself. Whereas, if you have something
without adequate micro-porosity, you're going to have a decreased opportunity
for fibrin attachment.
DR.
COCHRAN: The reason I raise that
question is that we were provided documentation from a published manuscript
that indicated that that product was used, and there didn't seem to be any
outstanding problems with that material.
DR.
ARROWSMITH-LOWE: Well, some of that may
have to do with the method of assessment of how they made a determination of
problems or effectiveness. I think we
would think it appropriate to be looking at healing time, to be looking at any
possible other negative things that might occur from differences in the
product. And, again, to me that sort of
argues for the whole option of doing some clinical evaluation, rather than just
strictly making a determination on what are more physical factors.
CHAIR
REKOW: We have a published schedule for
the open hearing, and we're getting close to the end of that time. Perhaps I could ask if there are any other
groups in the audience that would like to make a public presentation.
DR.
UHR: Thank you.
CHAIR
REKOW: And then I would like to have
options for questions to be asked to any of the people. Are there any other groups that would like
to say anything? Okay. Failing to hear that, does the Panel have
any questions for any of the people that have presented or any of the experts
that you know are in the audience?
Mark?
DR.
PATTERS: Mark Patters. I would like to give the petitioners just a
couple of minutes to respond to Curasan's presentation, if that's appropriate,
Madam Chair.
CHAIR
REKOW: I think it is. Thank you.
DR.
MORGAN: Having heard their
presentation, the logic escapes me. The
history is the following. Thomas
Driskell is the person who developed the product under a U.S. Department of
Defense grant, and was the owner of the Miter that initially sold this
product. May I discuss the issue, the
PMA? May I?
CHAIR
REKOW: Go ahead.
DR.
MORGAN: The PMA that they so state that
they have, and that the FDA recognizes that they have, is not, in fact,
reality. The history, and Thomas
Driskell could give it to us, is the following, that he initiated a PMA.
CHAIR
REKOW: Can I interrupt for one
second? It will be fascinating, I'm
sure, to hear that, but unless it addresses some important scientific issues --
DR.
MORGAN: Okay.
CHAIR
REKOW: I think that unless the FDA is
anxious to have it in the public record, I'm not sure that it helps us with our
decision.
DR.
MORGAN: Okay. Then I can bypass that.
CHAIR
REKOW: Thank you.
DR.
MORGAN: Then if what they are saying,
they purchased the Miter PMA, that it was marketed in the United States for
over 20 years without a single dental device report, which is true, so this
product has been continuously marketed until they purchased it, I believe, last
year. Why would they purchase it? It is already on the market in the United
States. Now, they are bringing it back
to Germany and claiming that that product, which they claim the FDA recognizes
as a PMA, is going to be modified to their standards. No American company has the opportunity of conforming to their
standards without a PMA. Am I making
sense?
CHAIR
REKOW: So the point that you're making
is that, from a scientific perspective, if I may, and, please, correct me if
I'm wrong, is that a less than a 100 percent pure Beta TCP has been
successfully used in dental products in the United States for over 20 years?
DR.
MORGAN: Over 20 years.
CHAIR
REKOW: Without an adverse --
DR.
MORGAN: Without a single adverse
report.
CHAIR
REKOW: Without a single adverse report.
DR.
MORGAN: And personally, I have used it.
CHAIR
REKOW: Right. And so yours becomes a counter argument to the need for higher
purity. Is that --
DR.
MORGAN: Well, I'm not adverse to higher
purity.
CHAIR
REKOW: No.
DR.
MORGAN: And I don't --
CHAIR
REKOW: But you're arguing that the
lower purity has been able to perform successfully in the market?
DR.
MORGAN: No, because I don't think you
or I know --
CHAIR
REKOW: Okay.
DR.
MORGAN: -- the exact purity of Miter or
their claim.
CHAIR
REKOW: Fair point.
DR.
MORGAN: So we don't know what the
purity is. I could state Miter is 100
percent pure.
CHAIR
REKOW: Yes.
DR.
MORGAN: I could state the product is
going to -- you know, we don't know.
CHAIR
REKOW: Okay.
DR.
MORGAN: So I think there was a lot of
smoke and mirrors, but logic escapes me.
CHAIR
REKOW: Well, I think that there is a
lot of business issues that are critical for each of your companies to succeed,
but I don't think that this is the forum to have this discussion.
DR.
MORGAN: I agree, I agree.
CHAIR
REKOW: Okay. Thank you.
DR.
MORGAN: But if the argument is that the
bone of the skull is different elsewhere, and if you accept that argument, then
I would suggest the FDA as a unit should go back to their medical counterparts,
their orthopedic counterparts, and restrict the use of that product by any
plastic surgeon or orthopedic surgeon.
That's the argument. I don't
accept the argument that the bone of the skull is different than the bone
elsewhere. I'm sorry. I just don't accept it, and if you do accept
it, then the Orthopedic Branch should restrict the use of all their approved
products to only non-skulls.
CHAIR
REKOW: Clearly, the progenitors are
different.
DR.
MORGAN: Oh, yes.
CHAIR
REKOW: The issue is whether or not the
mature bone is different from immature bone.
DR.
MORGAN: Which is true, yes.
CHAIR
REKOW: Okay.
DR.
MORGAN: I agree with that. So without any questions or --
CHAIR
REKOW: So are there questions for any
of the Panel, any of the presenters, any of the groups? Would anyone else from the audience like to
make any comments or statements? I
appreciate all of what you have done. I
applaud Dr. Uhr for the most remarkable slides we have seen for awhile, and
surely a lot of useful and valuable information has been conveyed this
morning. I thank you for your time and
the considerable energy that went into all of these presentations and the
thoughtfulness, and your helpfulness in providing questions to us. I guess now, we break for lunch and the
Panel discussions will resume around 1:15.
Thank you again.
(Whereupon,
the hearing was recessed at 12:09 p.m. to reconvene at 1:25 p.m. this same
day.)
A-F-T-E-R-N-O-O-N
S-E-S-S-I-O-N
1:25
p.m.
CHAIR
REKOW: We will begin with Jon
Suzuki. First, Dr. Suzuki, are you
going to do it from here or there?
DR.
SUZUKI: It doesn't matter.
CHAIR
REKOW: Wherever you would like, sir,
it's yours.
DR.
SUZUKI: Jon Suzuki. I will try to address the Panel's questions
succinctly, and then we can have a discussion later on if necessary. The Panel questions are not on the board
anymore. They are not on the board
anymore. Does the petition, as found,
adequately describe the risk to the health of the device, and provide
appropriate controls to these risks? I
believe the answer to this question is no, and other guidelines that may need
to be spelled out, especially indications, including matters to OP and
including the possible degradation of the product. And with respect to appropriate controls for these risks, perhaps
the indications and the reeducation of the clinician needs to be at least
identified more specifically.
And
on Question 2, what modifications would you make to the risk to the health
presented by the device with respective modifications and controls perhaps
identifying that the risk of infection needs to be identified, and especially
the sterility of the product and its use in infected sites needs to be further
elaborated, especially in periodontal sites where the infection would be
different than that of skeletal bone sites.
With
respect to the controls, we're looking at the form, the shape, the size and
other parameters I think need to be further identified and defined, and that
probably is going to be left up to other FDA Panel members and other FDA
investigations to determine what that threshold is, a maximum and a minimum
control for the regulation of these particular products.
We
will skip the part of classification questionnaire, but we'll spend more time
on that later, Madam Chairman, I'm assuming, so I'll go onto Question 4. With respect to recommended classification
and changes and, especially recommend to the labeling of these devices once
again to reiterate the importance of considering infections and the possible
acidity of the site, as a role in the degradation and/or signed-ability of the
product, and also the potential risk of infections if it's not already included
on the existing labels needs to be identified.
And that concludes my initial rhetoric, and Dr. Glowacki has some
follow-up comments, too.
DR.
GLOWACKI: Yes. This is Julie Glowacki, and my comments come
from the point of view of not being a clinician, so I'm actually going to be
asking the other Panels for some clinical input down the line. But with respect to whether the petition,
Question 1, adequately describes the risk to health of the device and
appropriate controls for this, I view it as the petition was filed to do one
thing. However, we are here as a Panel
that is voting on a reclassification of the current rule, which includes other
materials, other indications.
So
the petition does not address the issues of the classification, but I think
gives me a way of looking at how much information is available for us to feel
that there are some materials within the current rule that do not pose a Class
III, a continuation of a Class III.
And
so with respect to the description of the device being one of the major issues
here, that I think I will be feeling comfortable on the basis of the
information that we're given and, moreover, solely on the petition that Beta
TCP is really what we ought to be reclassifying, and to that end, a more
precise description of the device needs to be provided, and that concerns a
composition, the form, is it granular, is it in blocks, is it a single phase?
I
think we have not been given enough information to say that biphasic materials
perform with the same degree of fidelity with respect to efficacy as does pure
Beta TCP. I think we can talk about
some of the standards that are out there with respect to elemental analysis,
x-ray diffraction, provide the information about the nature of the material.
I
think we needed more clarity than what was in the petition for the intended use
or indications, and I would feel more comfortable talking about intraosseous
applications of this material. I think
the orthopedic literature, as well as what the experience has been in
oro-periodontal maxillofacial uses of these types of materials is that it
cannot be implied that the material is providing the physical properties of
cortical bone, so that stability needs to be an issue. And I think one doesn't want to give the
clinicians the impression that you can use this in discontinuity defects.
So
I am just talking about some of the applications that everybody is comfortable
with, and I think it's primarily intraosseous.
We were provided some information about untoward results if the material
is inserted into an endosseous defect simultaneously with an endosseous
implant, and that that seems to be something to be avoided, that there is
literature recommending that Beta TCP be used first to promote bone formation
and subsequent insertion of a dental device.
I
think all of these things with respect to intended use, indications and
precautions against potentially very damaging misuse need to be put into
guidance documents. I would hope that
there would be a precaution against the use in infected sites, that there would
be a precaution against overfilling or use in discontinuity defects and
information provided to the clinician about how to remove excess.
One
can imagine a situation where the cortical bone structure might be very, very
weak and if someone were very, very aggressive in implanting this material,
there could be potential fractures to thin walls of bone.
With
respect to whether the material we're considering is in granular or block form,
again, looking at the orthopedic guidance document as a guide here, there ought
to be information provided to the clinician on whether the block can be cut or
trimmed or reshaped or made smaller to fit into a disk, into a particular
defect.
Some
of the other materials that are out there are very, very brittle, provide lots
of debris that is very difficult to get rid of, and I think that information
ought to be in the clinician's insert.
Precaution against concurrent use with implants, information about the
suitability to mix this material with other materials, I think, ought to be
provided. This material's potency as an
osteoconductive material is in large measure due to its rate of resorption, and
if it's mixed with other materials that interfere with that, I would think that
that would be a potential problem. So
adding mixtures I would worry about.
Some
people, I understand, are using Beta TCP or have used it as kind of hamburger
helper, mixed with autogenous bone graft inadequate to fill in the material, so
we think we need to see some information about whether that would be an
indication.
Let's
see. Oh, I think also because of some
of the adverse information that we saw on what happens when this material gets
into the bloodstream, one would want to be sure that there were precautions to
avoid soft tissue nerves, pulp and, again, this idea of overfilling the
material with the potential of it getting into the bloodstream. I think those are things that are different
in the oral dental application than in orthopedic.
I
think that it should be possible, just sort of jumping ahead, that talking
about the risks, which were not really that adequately dealt with, I think, in
the petition, the risk of causing an infection or using the material in an
infected or previously infected site has to be addressed.
In
general, I feel that we may, by the end of the day, consider that Beta TCP is
-- there is enough information about its use and the properties that contribute
to its successful use and to its safety, so that it could be reclassified in
Class II with some special controls.
And
one other thing, back to the question about the clinical input. I would really like to hear the clinicians'
views about who should be able to put this material into people. Is this something that a dental degree would
give enough still to be able to follow those instructions and to use it
safely? Does advanced training come
into the use of this at all?
CHAIR
REKOW: Is that all?
DR.
GLOWACKI: That's all.
CHAIR
REKOW: Well, let's have some
conversation and discussion. It seems
to me, if I can put this into some categories, the questions that are the most
compelling and may form the basis for the conversation is do we look at the
form that the material is presented? Is
it block? Is it granules? Is it both?
Are we looking at all the TCPs?
Are we looking at only the Beta TCP?
What is a list of precautions and indications, and then what is the
level of training to be able to utilize it.
Is
that a fair basis to form the conversation around? Before I start driving any conversation thought, are there
questions and issues that you would like to address? Would some of the clinicians like to address some of the
questions that Julie addressed?
DR.
PATTERS: Mark Patters. Let me say that I don't recall ever being at
another Panel meeting that had such a dearth of scientific data to try to make
a decision with. As far as I'm
concerned, most of the papers that were provided in the petition are case
reports and uncontrolled studies. So
there is really not a lot of scientific data to even say that this material is
safe and effective.
However,
I would say that clinicians generally regard it as safe, but I don't know that
it has been definitively proven as safe through carefully controlled clinical
trials, so I regard it as safe. There
have not been, as we have heard before, adverse reactions reported from the use
of this material. On the other hand, I
don't believe the material is widely used enough to be able to gauge what
adverse reactions might occur. So I
don't see that we have a lot of data here to help us. It's just that, as a clinician, it seems that this material is
regarded as safe, but I have not seen any data demonstrating it.
DR.
GLOWACKI: I, too, was disappointed by
it. Ms. Glowacki again. I was disappointed by the papers that were
provided in the petition, but I did take an opportunity to go onto PubMed and
look up my own references on this, and found that sure, you know, there are a
couple of small studies there that could give this material versus other
materials or that use this material for other studies, adding in platelet-rich
plasma or as a carrier for Beta TCP.
And
with respect to the evidence-based practice of medicine, I think Dr. Patters
makes a very important point. Yet, the
general level of experience, and I think I am understanding him correctly, is
that safety and efficacy can be defined.
Do you disagree with that?
DR.
PATTERS: In general or for this
product?
DR.
GLOWACKI: For Beta TCP.
DR.
PATTERS: That can be defined, yes, I
agree, but the question is have they been?
DR.
GLOWACKI: Yes.
CHAIR
REKOW: David?
DR.
COCHRAN: I have used this product
myself clinically or not this particular, but a TCP product. We have used it in different clinical
applications. We have used a lot of
other different kinds of bone graft fillers, if you will, or bone replacement
grafts, BRGs is what we tend to call them, and I feel like, Mark, that probably
there is a lot of experience over many years with this material and similar
type materials that I don't think we need to worry so much about the safety of
this material in humans for human use, and so I would agree that, from a
clinical point of view, it can be a useful material.
We
have used it not only intraosseously, but as on-lay type materials with flat
coverage with periosteum and flat mucoperiosteal flaps over it, and there
certainly does not seem to be any adverse reactions. Histologically, we really don't see that either. Clinically, we don't see that as a
problem. We have gone back and placed
endosseous implants in this type of material, and have really not had any
problems with the osseointegration around the implants. So I see it from a safe point of view as not
a problem.
CHAIR
REKOW: This is Dianne Rekow. You're talking about the granular form,
right, not the block form or are you?
DR.
COCHRAN: As regards to the TCP, it's
granular form that we have had experience with.
CHAIR
REKOW: Okay. David? Richard? Sorry.
DR.
BURTON: I would agree. I think that the safety issue is sort of one
side of it, but I am not sure that when I look at this, and certainly in the
case study format that we have here though, that some of the efficacy has been
really established. I mean, I think we
have sort of lumped them together, but in reality, they need to be separated,
as well. I think everybody says well,
gee, this is really, you know, it's a good product. It's not going to hurt anybody.
It doesn't seem to do anything terrible. It doesn't fall out. It
doesn't have marked adverse reactions.
The
real question is also that there is some question of efficacy in terms of being
a reasonable product for that, and then I think it goes back, what was
mentioned earlier also, is going to be the clinical indications for this,
because my experience has been that once you get a material out there, people
end up sticking it just about anyplace you can think of to put it, and then
again whether or not we know now that this particular material needs a certain
amount of either bony contact, you mentioned continuity defects.
Sinus
lift situations, we all know, have very poor vascular supplies to those, and
does it have a sufficient vascular supply to such that it's also conductive
prostheses and actually functions? So,
I mean, I think that yes, I would certainly agree that the safety probably has
been established. I just have some
questions regarding what its efficacy is and then how that translates into what
clinical applications it's appropriate for, given the information we have, at
this point in time.
It
might be, that later on, that those clinical indications might be expanded once
there was further usage and research with it once it was in clinical
applications, but I'm not sure that that's been really defined in anything that
I see that has been presented thus far.
CHAIR
REKOW: Jon, do you want to --
Elizabeth?
MS.
HOWE: Elizabeth Howe. I would just like to make an appeal on
behalf of consumer issues, and make one statement that it is certainly exciting
to have products that are more accessible, certainly a lot cheaper, which would
encourage patients to seek treatment, less invasive, a lot less risk, a lot
less recovery time.
But
given all of that excitement for such a product, some of the concerns would be
having a standard of quality that patients can be assured that they are getting
a quality product, certification for the person that is providing that
treatment to know that it's being handled properly and finally, any
contraindications for patients who have special needs because of a disease
process, if it could be, I think somebody mentioned, somebody who is
post-menopausal, if there are any studies on at what point this product is not
appropriate for certain patients.
CHAIR
REKOW: Do you have anything you would
like to add, Dan?
MR.
SCHECHTER: I guess from an industry
standpoint where, as a whole, we're always interested in the least amount of
obstacles and burdens to bring a product to market, so generally we would
always be in favor of a lower classification, going from III to II. And I guess from a practical standpoint,
this is almost a question for FDA, Susan, perhaps.
Given
that the general feeling is that there is kind of a dearth of scientific
evidence here that we can base maybe specific recommendations on, would it be
appropriate for the Panel to, in general, reclassify, recommend that special
controls for certain parameters exist and then leave it up to FDA to state
those more specifically? I'm just
asking the question. If we can kind of
defer some of the specific issues or is that issue for a further Panel meeting,
which I wouldn't advocate as an industry rep?
DR.
RUNNER: You could certainly. We take all of your comments during the
Panel process into consideration when we're developing the guidance documents,
any labeling recommendations, any contraindications and warnings. So you wouldn't necessarily have to vote on
each and every contraindication and warning, but give us a general feeling as
to what you feel would be appropriate areas for us to address and any guidance
or labeling for this product. Does that
answer your question?
MR.
SCHECHTER: Yes, definitely. That is what I was hoping the answer was,
because it doesn't seem like we're going to get to the point where, you know,
we can say here that it's got to be 97 percent or you can't have more than .5
percent Alpha, etcetera. So, you know,
I would encourage the Panel to go as far as we can with whatever the Panel is comfortable
with.
CHAIR
REKOW: I want to remind everyone, too,
that we can engage the people from the audience that have presented, so if
questions come up that can be clarified by them, we have the opportunity of
calling on them. Yes, Susan?
DR.
RUNNER: The other comment I wanted to
make about indications, you are voting on the indications as stated in the
present regulation and that would be included from the original Miter PMA. Any additional indications that might come
to FDA would, of course, have to be supported with appropriate data. For example, I think, sinus lift you
mentioned, I don't believe that is in any of the-- it's not in the original
classification, per se, and is also not in the original Miter PMA and,
therefore, theoretically, we could request clinical data to support those types
of indications.
DR.
BURTON: Dianne? Richard Burton. I don't think we have the original PMA to know what their
indications were.
CHAIR
REKOW: Well, I can read what this--
DR.
BURTON: Oh, okay. You have it?
CHAIR
REKOW: Michael has got it. He is way ahead of us, and so he just handed
me this. You want to know. This is Paragraph 872.3930, and it's on
tricalcium phosphate granules for dental bone repair. The identification is tricalcium phosphate granules for dental
bone repair is a device intended to be implanted in the upper or lower jaw to
provide support for prosthetic devices, so it's granules, it's TCPs in general.
DR.
BURTON: That's the CFR and not the PMA.
CHAIR
REKOW: Oh, I'm sorry. Yes, this is the CFR.
DR.
RUNNER: I think Dr. Mulry has the
indications from the Miter PMA.
CHAIR
REKOW: So while they are looking that
up, again, the discussion that's in the CFR is granules, all TCPs in the jaws
to support prostheses.
DR.
COCHRAN: Dianne, this is David Cochran.
I would interpret that to include sinus
lift procedures.
DR.
BURTON: Yes, so would I. I mean, you could put that in to be -- I
mean, you could do cleft grafts you know, cleft grafts on kids with this.
CHAIR
REKOW: Yes.
DR.
BURTON: Within and meet those
indications. So, I mean, my problem is
that those are almost so broad that, again, you're sort of opening the door
perhaps to some situations that would not be appropriate, in fact, because you
could be doing that to support a prosthesis and you're taking out, you know,
periodontally infected teeth that you want to preserve the ridge and putting
this material into an infected site, and still would meet those indications.
CHAIR
REKOW: Do you have the PMA?
DR.
RUNNER: The PMA was originally cleared
for periodontal alveolar bony defects.
That's very broad, but this is a very early PMA. It was also indicated for use in fresh tooth
extraction sockets and to provide additional stability to fill bony voids.
DR.
GLOWACKI: Can you repeat the last part,
because I didn't hear you?
DR.
RUNNER: To provide additional stability
and to fill bony voids.
DR.
GLOWACKI: This is Julie Glowacki. That statement, I think, we all can
understand, but the other statement about to support prostheses is an
incompatibility, and I, for one, would like a little bit of help on saying
which are we looking at here?
DR.
RUNNER: Well, unfortunately, the
regulation is what it is and it was written some time ago, and it's very broad
and it's open to a significant amount of interpretation. I can tell you than in the Dental Branch, we
have interpreted that not to include bone filling materials around endosseous
implants and whenever endosseous implant, an indication for use around
endosseous implants have been requested, we have asked for clinical data to
support use around endosseous implants.
DR.
GLOWACKI: Ms. Glowacki. So as a follow-up to that then, is this an
opportunity to help really sharply define what education --
DR.
PATTERS: I don't even want to do that.
DR.
RUNNER: I don't think that we can. The regulation as it stands is as it
stands. I think you can make
recommendations in terms of how you would like the Dental Branch to interpret
that regulation, but I think as it stands, it stands.
DR.
PATTERS: Mark Patters. Susan, does the PMA, which the Panel has not
seen, provide clinical data to show the effectiveness of TCP in periodontal
defects?
DR.
RUNNER: Yes, the original PMA did have
clinical data. I can't -- it was a very
early PMA in the history of FDA, so I can't state that it was to the level of
subsequent PMAs in terms of data, but it did have clinical data.
DR.
PATTERS: To your knowledge, is that
data published?
DR.
RUNNER: I don't think so.
DR.
PATTERS: That's why I don't know it, I
guess.
DR.
COCHRAN: David Cochran. I think just to help explain the clinical
indication is, I think, probably when that was written, it was used
predominantly just to fill extraction sockets to help maintain the ridge to
support complete dentures probably. I
would assume that's when that was done, and the endosseous implants came to
vogue much later than that and probably weren't included early on.
DR.
RUNNER: You know, the original data on
that PMA was in 1980.
CHAIR
REKOW: So if I understand it, we really
have been given some direction in terms of how to focus, and that is on
granules and TCP, because the reg doesn't limit it to Beta TCP. Do you want to, as a Panel, add that
limitation of Beta TCP, as opposed to TCP in general? I'm sorry, yes? Yes,
please.
MR.
DRISKELL: I would like to enlighten a
few people on the Committee.
CHAIR
REKOW: Would you go to the microphone,
please, and identify yourself?
MR.
DRISKELL: I'm Tom Driskell. Well, actually, you might remind me of some
of the things that you asked questions on, but I can speak to the indications
to some degree. First of all, I would
like to point out that any type of a material or a device like this that we
have ever put out, we had a package insert in there that said what it was to be
used for, and it had plenty of contraindications in it, because we don't want
this stuff to fail, and you see that package insert before you ever get -- I
mean, when we apply for a 510(k), we would have a copy of that verbiage that
was on the package insert. It's to
protect us and it's to protect the doctor.
CHAIR
REKOW: Right.
MR.
DRISKELL: And I think it's very
important that you keep that in mind, because you don't really have to cite all
the indications, but I think in the package insert, it's got to say what it's
being used for or if that isn't in the regulations, it ought to be. So then you have a chance to oversee what
the manufacturer wants to do with it, and the original PMA when we did fill two
sockets, what we had particularly in mind, at that point, was third molar
sockets, which often really would benefit from being filled with something, so
you generally get the defect back there that you, otherwise, might likely get. So that was a very good use for it.
In
fact, my daughter was the first one that ever had it used on her, on
anyone. By the way, let me throw this
in. Speaking of sinus lifts, my wife
had some periodontal disease and sinus infections, which she didn't even know
she had for years, but the point is that she ended up with one and a half
millimeters of bone in the maxilla, and we wanted to put implants in
there. We used tricalcium phosphate and
we were able to put in 14 millimeter implants, which we no longer even bother
to sell, because you don't need them that big, but in those days we still
thought we did.
So
anyway, those have been in now for about 12 or 13 years and they still look
like they did within a year of the time it was done. So anyway, if you have some questions like this, I would be happy
to give you my best information on it.
CHAIR
REKOW: Thank you.
MR.
DRISKELL: I don't want to -- well,
excuse me.
CHAIR
REKOW: Thank you. I appreciate that and I think that our
frustration is that there are a great many valuable clinical case studies. The frustration that we're having is well
controlled prospective studies, which of course have a different standard of
information that may or may not be extractable from them, but we won't go into
that category. And it's the issue of
what is the standard against which we're going to make our decisions, that's
our frustration, because, clearly, there is lots of experience in positive
results. Thank you. Susan?
DR.
RUNNER: I just wanted to remind the
Panel, as well, however, that the FDA regulations do state that the levels of
evidence include case studies and all the way from experiential all the way to
well controlled clinical studies.
CHAIR
REKOW: Thank you for that
reminder. So we have focused ourselves
a little bit. We're talking about
granules and we're talking about TCP.
Now, the question, I guess, is maybe the easier way to ask the question
first is can we specify enough precautions or contraindications and not address
what they are yet, but can we specify enough to make the Panel feel comfortable
that the device could be reclassified?
Can I take a vote, David?
DR.
BURTON: Yes.
DR.
PATTERS: Yes.
DR.
GLOWACKI: Glowacki, yes.
DR.
SUZUKI: Suzuki, yes.
CHAIR
REKOW: Well, Elizabeth is not
voting. Are you voting? Okay.
So I don't have to break the tie, but I would say yes, too. So before we go to what those precautions
and indications need to be, I think I would like to take on the last issue of
do you need training beyond that of a dentist to be able to use this stuff or
is that intimately tied with the contraindications and indications? Mark?
DR.
PATTERS: Mark Patters. I certainly don't know every product, but I
know of no product that is specified in its labeling that can only be used by a
specialist. I know of no product that
is labeled that way. I don't think I
would want to start one, do you?
DR.
SUZUKI: Jon Suzuki. I agree with Dr. Patters and, in fact, even
dental implants are not specified just for certain specialties either.
CHAIR
REKOW: Okay.
DR.
BURTON: Richard Burton. I would like to agree. I think that the kinds of indications that I
can see for the product would fall within the realm of the general practitioner
as being appropriate for it. There are
going to be conditions that they are going to be treating, as well as
specialists. So, I mean, I think that
to limit the availability of it in that arena would be inappropriate. Yes, cruel of them to say that. I know you will.
CHAIR
REKOW: I am being suggested that we go
onto the classification questionnaire, because that will answer lots of the
questions that need to be resolved.
Does that also tie in enough with your risk table or do you want us to
address the risk table specifically?
Let's do the questionnaire first and then we can see if we can go back
and redo the -- where is the questionnaire?
SECRETARY
ADJODHA: I believe that would be in the
--
CHAIR
REKOW: It was in your stuff. Okay.
So for the Panel, who also don't remember, it's in the last pieces of
what we were given in Section 7, which is at the very bottom of the pile of the
reading, and the general device questionnaire.
The first question is who is the petitioner, and then this is the one,
right, this one?
SECRETARY
ADJODHA: I think we need to refer to
Marjorie Shulman.
CHAIR
REKOW: Marjorie Shulman.
MS.
SHULMAN: I'm handing out new forms,
too, and we're going to get one up on the overhead.
CHAIR
REKOW: Got it. Good.
It's nice to have somebody keeping us on track properly. Oh, I see.
Got it. So, Mark, let me turn it
over to you, please, to guide the discussion.
While she is getting that set up, are there any compelling things that
any of the Panel would like to say?
Mark?
DR.
PATTERS: Yes, Mark Patters. I would just like to address the petition
from Dr. Morgan where under Number 4 in his petition, indications for use in
the device labeling, and he has his indications as bone substitute material for
dental alveolar procedures. I would
have to say that I personally think that is way too broad, dental alveolar
procedures.
DR.
COCHRAN: This is David Cochran. Just listening to what Mark said, I think
what we're actually doing is reclassifying the original PMA is my
understanding, and the language that's in there is what is going to be what
we're really discussing.
CHAIR
REKOW: What exactly are we
reclassifying, the original PMA?
DR.
RUNNER: The tricalcium phosphate for
dental bone repair with the indications as indicated in the PMA and in the CFR
notes.
CHAIR
REKOW: Both?
DR.
RUNNER: Both. It includes --
CHAIR
REKOW: Okay.
MS.
SHULMAN: My name is Marjorie
Shulman. I work for the Program
Operations Staff, and we'll walk you through the forms.
DR.
GLOWACKI: May I interrupt?
MS.
SHULMAN: Sure.
DR.
GLOWACKI: Just to follow-up on that,
Susan, Ms. Glowacki again, if we do a reclassification of the original PMA and
put the specifications in, so that it only applies, it really only applies to
pure Beta TCP for certain uses, what happens to the other whole field that we
don't talk about here?
DR.
RUNNER: The regulation would be split
such that Beta TCP could potentially be Class II and other forms of tricalcium
phosphate would remain as Class III if that's what you so suggested.
DR.
GLOWACKI: Thank you.
CHAIR
REKOW: So that's part of our charge
today, first to look at the original PMA and then to talk about --
MS.
SHULMAN: Yes, just as a matter of --
CHAIR
REKOW: Okay.
MS.
SHULMAN: Marjorie Shulman. Just as a matter, we're not looking at the
PMA, so to speak, to reclassify. We are
reclassifying looking at the reclassification of the reg in which the PMA was
classified under. So we're looking at
the intended use for that PMA, and any supplements that may have been cleared
under that, because if the vote was to go for reclassification, that would then
become a Class I or a Class II device.
CHAIR
REKOW: Okay.
MS.
SHULMAN: So the first thing we want to
do is agree upon exactly what intended use we're looking at from the intended
use from the reg and the PMA, and you, as a Panel, would have to decide do you
want to split it right off the top and go through the sheets two times and see
where you end up or do you feel comfortable enough to go all as one group?
CHAIR
REKOW: This is Diane Rekow again. My understanding then from what you said is
that the PMA is a subset of the reg, and we should just focus on the reg and by
default, all of the things that we have discussed are included as long as it
applies to the ridge.
DR.
RUNNER: Right. I think you also need to consider, however,
that if you split off Beta TCP, that would mean that other forms of tricalcium
phosphate would come in with the PMA.
CHAIR
REKOW: Yes.
DR.
RUNNER: If that's what you so
desire. You can also realize if you
reclassified the entire group, tricalcium phosphate, FDA would also consider
the other forms, because we don't have any experience within requiring clinical
data in most instances, as well. So
that's --
CHAIR
REKOW: Okay. So --
DR.
PATTERS: Excuse me. Mark Patters. Susan, isn't there an alternative that makers of other forms of
TCP could ask for reclassification, rather than have to come in as a PMA?
CHAIR
REKOW: So we're talking about granules
and we're talking about TCP in general?
All right. Is the Panel willing
to do that as the general group for going through this questionnaire form? Do I hear any objections to doing so?
DR.
BURTON: Could you restate that again?
CHAIR
REKOW: Yes. We're going to keep all the TCPs in their granular form as a
group, and address this questionnaire for that group of products, I guess. Is there an objection to doing so? Hearing none, I'm going to give it back to
you again.
MS.
SHULMAN: Thank you. Marjorie Shulman. We'll start with the form then.
The first part is just housekeeping, the Panel name and petitioner and
everyone is able to fill out their own form, but the Panel Chair will keep the
main form.
The
generic type of the device is the regulation.
Is that what we agreed upon?
SECRETARY
ADJODHA: Yes.
MS.
SHULMAN: Okay. The first question --
SECRETARY
ADJODHA: Marjorie, can you explain to
them what they should put in there for generic type of device?
MS.
SHULMAN: You can just put in the
regulation.
SECRETARY
ADJODHA: Oh, the exact name?
MS.
SHULMAN: Okay.
SECRETARY
ADJODHA: Okay. So the exact name is tricalcium phosphate
granules for dental bone repair.
MS.
SHULMAN: Okay. Question 1, and we can do this, you can go
around and tell us yes, no, and then vote.
Is the device life sustaining or life supporting?
CHAIR
REKOW: David?
DR.
COCHRAN: David Cochran, no.
DR.
BURTON: Richard Burton, no.
DR.
PATTERS: Mark Patters, no.
DR.
GLOWACKI: Julie Glowacki, no.
DR.
SUZUKI: Suzuki, no.
MS.
HOWE: Elizabeth Howe, no.
CHAIR
REKOW: Dianne Rekow, no.
MS.
SHULMAN: Okay. Number 2, is the device for a use, which is
of substantial importance in the preventing impairment of human health?
CHAIR
REKOW: Now, we'll go backwards this
time. Jon?
DR.
SUZUKI: No. Suzuki.
DR.
GLOWACKI: Yes, only because, I mean,
Ms. Glowacki, I thought implanting anything into the body is done for a
substantial clinical reason, but maybe I don't understand these words.
CHAIR
REKOW: Let's finish the vote and see if
we need to have that discussion. Mark?
DR.
PATTERS: Mark Patters, yes.
DR.
BURTON: Richard Burton, no.
DR.
COCHRAN: David Cochran, no.
CHAIR
REKOW: My read would be the same as
Julie's, so I would say yes, which I guess splits it. So could we have some clarification from FDA about what this
means? Mark?
DR.
PATTERS: If we answered no to this
question, and we're sure we answered no to the question after it, this then
could be classified as a Class I device.
I'm not sure this Panel wants to do that.
DR.
BURTON: Well, could we go through the
Question 3, which would sort of, at that point, render that discussion null and
void. Okay. If you split Question 2, if we go to Question 3 and the majority
on Question 3 comes up yes, then we're already, then it would appear to me,
moved over to it being a Class II and then looking at some --
CHAIR
REKOW: Okay.
MS.
SHULMAN: Marjorie Shulman. As a matter of clarification, too, you could
answer no to the first three, get to the question is general controls enough,
say no, and then you get back to 2.
DR.
BURTON: Okay. I would go through Question 3.
CHAIR
REKOW: Excuse me? I'm sorry?
DR.
BURTON: I would move that we go through
Question 3, which I think would --
CHAIR
REKOW: Yes, let's do that, and I have
also had some other clarification, which may resolve this. So let's do Question 3, which is does the
device present a potential unreasonable risk of illness or injury? David?
DR.
COCHRAN: Cochran, no.
DR.
BURTON: Burton, yes.
DR.
PATTERS: Patters, no.
DR.
GLOWACKI: Glowacki, yes.
DR.
SUZUKI: Suzuki, no.
DR.
BURTON: Dianne?
CHAIR
REKOW: So the general vote is no. I'm told I only have to vote if there's a
tie. So if that's the case, does that
resolve Number 2?
DR.
BURTON: No.
CHAIR
REKOW: Let's redo the vote on Question
2, please. Jon?
DR.
SUZUKI: Suzuki, no.
DR.
GLOWACKI: Glowacki, yes.
DR.
PATTERS: Patters, yes.
DR.
BURTON: Burton, yes.
DR.
COCHRAN: Cochran, no.
CHAIR
REKOW: So the answer to that is yes?
MS.
SHULMAN: Correct, Question 2 is yes.
DR.
COCHRAN: Do I have to have my opinion
or their opinion?
CHAIR
REKOW: Okay.
MS.
SHULMAN: Okay. Number 4, did you answer yes to any of the
above questions? The answer is yes.
CHAIR
REKOW: We don't have to vote?
MS.
SHULMAN: If yes, we go to Item 6. Is there sufficient information to establish
special controls, in addition to general controls to provide reasonable
assurance of safety and effectiveness?
CHAIR
REKOW: Okay. And the implications of this, of course, and the comments is that
if you say yes, you can classify it as a Class II and if you say no, it remains
a Class III?
MS.
SHULMAN: Correct.
CHAIR
REKOW: So, Jon, shall we start with
you?
DR.
SUZUKI: Suzuki, yes.
DR.
GLOWACKI: Glowacki, yes.
DR.
PATTERS: Patters, yes.
DR.
BURTON: Burton, yes.
DR.
COCHRAN: Cochran, yes.
CHAIR
REKOW: Okay. Good. So that's
unanimous. So now, we go to Item 7.
MS.
SHULMAN: Number 7, if there is
sufficient information to establish special controls to provide reasonable
assurance of safety and effectiveness, identify the special controls needed to
provide such reasonable assurance for Class II. And the guidance document can include a lot of the discussion
from earlier, so you can say that.
CHAIR
REKOW: Okay. So the choices, of course, are guidance document performance
standards, device tracking or testing guidelines or other things that we may
deem appropriate. Could you, please,
for me, and I apologize if you had this discussion earlier, differentiate the
difference between the content of a guidance document and a performance
standard. Is a performance standard
like an ASTM or an ISO standard?
MS.
SHULMAN: It could be recognized
standards like that. Performance
standards are also recognized by a rule and it goes through a rule making. A guidance document may have standards in it
that you abide by. A company does not
have to go 100 percent to the guidance document. However, they would just have to explain why they deviated, how
they deviated and what they used instead.
CHAIR
REKOW: Okay.
MS.
SHULMAN: So the performance standard is
rule making.
CHAIR
REKOW: Okay. Could we poll the Panel and see if there is substantial places
that we need to do that at, as opposed to initially taking a vote? David, can I put you on the spot and ask you
your preference first?
DR.
COCHRAN: I'm sorry. Repeat your request.
CHAIR
REKOW: Just rather than voting on which
one we need to do first, can we have a discussion by each of you of what your
preference of that ranking should be, and then have an open discussion about
that if it's clear that we need to. I
think it's going to throw out a few options.
DR.
COCHRAN: Okay. This is David Cochran. My feeling is that we want to be least
restrictive if we can, and I think the guidance document, from my
understanding, would do that and it sounds like from what the FDA can do in a
guidance document, they can help direct the issues, which we have concerns
about.
MS.
SHULMAN: If I can just clarify one
thing, too. Dr. Betz just reminded
me. There was the risk table that was
discussed earlier in the presentation.
If you want to refer to that or we could put it back up there. It may help identify the risks or what could
mitigate them.
CHAIR
REKOW: Okay. What is the preference of the Panel? Do you want to do that or you want to try to sort through it
first, and then go back to the risk table?
DR.
BURTON: Keep going, I think.
CHAIR
REKOW: Keep going this way and go back
to the risk table? Make sure to use
that as our backup check. Okay.
MS.
BLACKWELL: Do you want to see the risk
table?
CHAIR
REKOW: No.
DR.
BURTON: No.
CHAIR
REKOW: Not right now. We will go back to it though, because I
think it's a useful piece. Richard?
DR.
BURTON: I would agree with that. I think that in looking at what those
guidelines are, I think that the guidance document, I think, is what people are
really, truly going to look at. I think
that that's really just the way to go, and I think the way we can address that
most effectively.
CHAIR
REKOW: Mark?
DR.
PATTERS: Patters. I think, obviously, the guidance document is
necessary, but I would give some consideration to device tracking if we are not
100 percent satisfied that adequate studies have been done to show safety.
CHAIR
REKOW: Okay.
DR.
GLOWACKI: Glowacki. I think from the general discussion that's
going on, that it should be possible that guidance documents would cover it
all.
CHAIR
REKOW: Jon?
DR.
SUZUKI: Suzuki. I believe I agree with everybody else that
the guidance document is probably -- that that's the way to, at least, approach
this question, and I don't really believe, at this point, that device tracking
is that critical of testing. That's
just my opinion at this point.
CHAIR
REKOW: So clearly, everyone is pretty
comfortable with the guidance document, and we need to probably come back to
whether or not we need some special tracking.
Can we do that as we go back to the risk table or how would you like us
to proceed?
DR.
RUNNER: I would just -- Marjorie, could
you comment on tracking in terms of what kind of devices, at this point in
time, are tracked, as opposed to not?
MS.
SHULMAN: I didn't do my homework. Very few devices are tracked actually.
DR.
RUNNER: I think, in general, tracked
devices actually put quite a burden on the manufacturer in terms of keeping
records of who devices are sold to and who they are they implanted in.
MS.
SHULMAN: Correct.
DR.
RUNNER: And I think that for a device,
usually, for example, TMJ implants, which have had a history of having
significant problems are tracked devices, and there are very few other ones. In my opinion, it would probably be very
unwieldy to track a device, such as this, which may potentially be implanted in
quite a number of patients.
MS.
SHULMAN: Correct.
DR.
BURTON: Burton. I would agree with that, because when I
think of a tracked device, first of all, it would be something that could be
potentially explanted, at some point in time, so that, you know, you could
recover something. Whereas, you know,
hopefully down the road, there is nothing here to explant.
And
again, I think also, you know, if you're looking at this type of product and
the cost factor involved, most of those that have been tracked are, I would
say, expensive devices, but they are also things, which would be an overhead
where the manufacturer could afford to have a tracking system. You know, this is broadly or at least
potentially as broadly as this could be used in terms of the potential
indications would be very, very difficult, because if you were in practice, you
would be tracking, literally, it could be hundreds of patients with this and
probably, I'm not sure what you would really gain from that.
CHAIR
REKOW: Susan?
DR.
RUNNER: I think, in addition, it would
be significantly different from any of the other bone filling materials that
are on the market presently without that requirement.
CHAIR
REKOW: I see that there is also this
check box of other, and to specify either any special things that are done in
the other bone filler materials that we might think of that perhaps address
some of the concerns that Dr. Patters has.
Are they simply included and integrated into the guidance document? Is there a guidance document for the bone
filling materials in general?
DR.
RUNNER: There is not. That's one of the reasons why we gave you
the risk and mitigation table, because that could potentially be used in such a
guidance document. The only guidance
documents that the center has put out so far is the one that you have seen for
orthopedics in terms of bone filling materials.
CHAIR
REKOW: So does it seem that it might be
appropriate for us to go to the risk table now?
DR.
COCHRAN: Dianne, this is David
Cochran. I have a question for maybe
Susan. I think on the market, there are
so-called bio-active classes that are sold.
What are they classified as?
DR.
RUNNER: All of the other dental bone
filling materials are presently unclassified.
MS.
SHULMAN: We could continue on this
sheet, and in the next sheet we get into the risks of health and that way it
would be more helpful.
CHAIR
REKOW: Okay. So can we leave the other for the moment, Mark? Are you comfortable with that, just making
the recommendation at the moment, a guidance document, knowing that we are
likely to come back and revisit at least a part of this?
DR.
PATTERS: Yes, I'm comfortable. My concern was if the Panel had doubts, that
was -- but if you don't, you don't.
CHAIR
REKOW: Okay.
DR.
PATTERS: My personal concern is that
the lack of reports of adverse reactions may just stem from the lack of broad
base use, and once it's in broad base use, we maybe can see them and will we
recognize the problem without any type of control?
CHAIR
REKOW: Okay. Thank you.
MS.
SHULMAN: Number 8 is regarding the
Regulatory Performance Standard, but that was not chosen, so we can skip
that. Number 9 is also a question about
the performance standard, so we can skip that.
Number 10 is a question if it was to be classified or stay in Class III,
which is wasn't, so we can skip that.
So we can go to the next page.
Number
11, identify the needed restrictions.
There are three other restrictions and another. The first one is the basic prescription
labeling, and the other two used only by persons with specific training or
experience in its use and use in only certain facilities adds upon the
prescription labeling. So the first
question is identify the needed restrictions, and the first one is only upon
the written or oral authorization of a practitioner licensed by law to
administer or use the device, and then the other two. We have been on those.
CHAIR
REKOW: Okay. I have forgotten which way we were going. David, do you want to go first?
DR.
SUZUKI: Jon Suzuki. Oh, sorry.
CHAIR
REKOW: Go ahead.
DR.
PATTERS: Jon Suzuki. Answer 1, which is only upon written or oral
authorization of a practitioner licensed by law to administer or use the
device.
DR.
GLOWACKI: Julie Glowacki, yes to the
authorization with the licensed practitioner.
DR.
PATTERS: Patters, I agree with that.
DR.
BURTON: Burton, concur.
DR.
COCHRAN: Cochran, with a question. Does that mean like a licensed dentist or
are we talking about a prescription, per se?
MS.
SHULMAN: A prescription per se.
DR.
COCHRAN: I don't think that's our
understanding on the Panel.
CHAIR
REKOW: No, I don't think so either.
DR.
RUNNER: I think what -- this device
would not be -- you would not write a prescription for this device and give it
to your patient to go get it. In other
words, you wouldn't need a licensed practitioner to obtain the device to
implant it.
CHAIR
REKOW: I think, if I may, rather than
taking another vote, I know I'll be corrected if I'm not correct, that a person
who is a licensed dentist with all of the abilities and assurances that they
can practice dentistry could use this product.
Is that the consensus of the Panel?
So however you have to say that.
MS.
SHULMAN: That would be the first block.
CHAIR
REKOW: That's what we thought.
DR.
COCHRAN: Well, then my answer is
affirmative.
CHAIR
REKOW: Okay. All right.
MS.
SHULMAN: Okay. Now, we can move on to the supplemental data
sheet and the generic types of device, Question 1, was whatever you said. Question 2, the Advisory Panel is the Dental
Products Panel. Question 3, is device
an implant?
CHAIR
REKOW: Can you read us whatever 21 CFR
860.3? I don't know how I survive with
all these numbers. So we have a
definition of an implant. An implant
means a device. For those of you who
have the handouts, that's on page 11.
An implant means a device that is placed into a surgically or a
naturally formed cavity in the human body.
The device is regulated as an implant for the purpose of this part only
if it is intended to remain implanted continuously for a period of 30 days or
more unless the Commissioner determines otherwise in order to protect human
health.
What
does that last phrase mean? Like in an
emergency, something can happen? So if
it's in the body for over 30 days, I guess it's an implant.
DR.
PATTERS: Right. Yes.
MS.
SHULMAN: Correct.
CHAIR
REKOW: So the breakdown products that
we have seen, that's everything is over 30 days, right? I'm getting an affirmative nod from the corporate
people, so I guess that makes it an implant.
MS.
SHULMAN: Number 4, the indications for
use in the device's labeling. We can
fill out what was in the regulation and approved PMA.
DR.
RUNNER: I actually have the actual list
now of what was approved in the PMA, and I could read them for you again if you
would like. The Miter PMA had five
indications, use in defects after extrication of dental alveolar cysts. In periodontics, for filling of two-wall
bone pockets, as well as bifurcations and trifurcations of the teeth. Three, augmentation of the atrophied
alveolar ridge.
CHAIR
REKOW: Say that one again.
DR.
RUNNER: Augmentation of the atrophied
alveolar ridge. Four, defects around an
apicoectomy and five, filling of bone defects after surgical resection of
impacted teeth.
SECRETARY
ADJODHA: Susan, seeing that the Panel
has recommended so far Class II, shouldn't we use the indication for the
intended use in the reg?
DR.
RUNNER: I believe the intended use in
the reg is just a description of the generic class of device.
SECRETARY
ADJODHA: Okay.
DR.
RUNNER: These are the indications that
would be --
MS.
SHULMAN: Right. So it's the intended use of the reg and the
indications that were cleared.
SECRETARY
ADJODHA: Okay. Thank you.
CHAIR
REKOW: So that does not -- does it or
does it not include sinus lifts?
DR.
RUNNER: It does. I will read them once again. Use in defects after extrication of dental
alveolar cysts. In periodontics, for
filling of two-wall bony pockets, as well as bifurcations and trifurcations of
teeth, augmentation of the atrophied alveolar ridge, defects around
apicoectomies and filling of bone defects after surgical resection of impacted
teeth.
CHAIR
REKOW: So to you periodontists, does
augmentation of an atrophied ridge include a sinus lift?
DR.
BURTON: No.
DR.
RUNNER: We have not interpreted it as
such.
CHAIR
REKOW: Thank you.
DR.
BURTON: Burton. I would say that it wouldn't. The other thing is though that that's even
more restrictive than, at least, what I have been hearing at least from
manufacturers, because, I mean, there it limits it down to saying, you know,
surgical extractions of third molars, which would then not make an indication
for use, let's say, in general surgical -- just general extractions for ridge
preservation would not be an indication within what was given there. You know, that's a pretty tight limitation
to say that it has to be surgical extraction of third molar or an impacted
tooth. I mean, that's, you know, an
impacted cuspid.
DR.
RUNNER: But it's also a combination of
the intended use, which sort opens the door wide if you look at the intended
use definition in the CFR, because the intended use in the CFR says tricalcium
phosphate granules for dental bone repair is a device intended to be implanted
into the upper or lower jaws to provide support for prosthetic devices. So our interpretation of that couldn't be --
CHAIR
REKOW: Okay.
DR.
BURTON: But not sinus lifts.
DR.
PATTERS: Patters. I am somewhat disturbed about those
periodontal indications. It's my
understanding that if we include an indication, we are saying that there is
scientific data to support that use, are we not? If there is scientific data that shows any bone filling material
to be effective in the treatment of bifurcations and trifurcations, it has
escaped my notice.
CHAIR
REKOW: Yes.
DR.
COCHRAN: This is Cochran. I'm not sure that probably any device has
scientific data for every particular indication in the world out there that
it's used for, and it sounds like the regulation is to use for dental alveolar
surgery, and I would hope that we would allow the clinician to have some say in
how the product is used if they think it's going to benefit the patient. I favor the regulation.
CHAIR
REKOW: Mark?
DR.
PATTERS: Patters again. I think that if it's labeled for this use,
that that states that there is scientific data to support it. So I am very uncomfortable with filing a
label that says this is useful in periodontal defects and bifurcations and
trifurcations.
DR.
RUNNER: Unfortunately, when this came
and it was approved back in the '80s, I assume it went before a Panel, at that time, it was
determined that there was scientific evidence to support that indication and it
was approved, at that time. We have to
--
DR.
PATTERS: But that's not like getting
the Ten Commandments though, is it? I
mean, just because it was carved in stone in 1980 doesn't mean that the pillars
have not been broken, does it?
MS.
SHULMAN: Those were the approved PMA
indications.
DR.
PATTERS: But further data might show in
the future that those indications were not appropriate. Is that not true or is it like the Ten
Commandments?
DR.
RUNNER: I believe that if we were to
take an indication off, we would probably have to have some evidence of medical
device problems with the issue that would be submitted to the Agency that this
indication should be eliminated, and to date, we don't have that data, so it is
sort of like the Ten Commandments.
DR.
PATTERS: You know, I have no problem
with the clinician making a determination as to how to use the device, but I
have a problem with labeling it. That
is when you label it, you are stating that it has been shown to be effective,
and perhaps there were data in 1980, but it has escaped my notice. That's all I can tell you. Perhaps David could recite it for us.
DR.
COCHRAN: No.
DR.
PATTERS: Or perhaps Dr. Suzuki who is
very familiar with that literature.
MS.
SHULMAN: Marjorie Shulman. Right now, that is an improved indication
that is out. Maybe it's not being
marketed, at this time, but it's an improved indication that is out on the
market.
DR.
SUZUKI: This is Jon Suzuki. I do tend to agree with Dr. Patters'
concerns about the labeling, but I think if we go the route, as already alluded
to by Dr. Cochran, it really is up to the clinician jurisdiction, clinician
judgment, and if he feels he can utilize them in these types of defects like
bifurcations and trifurcations, then more power to him.
But
in their education, they learn the risks and the benefits, and most astute
clinicians would probably go to the literature and know that it doesn't work in
certain situations. So I do see Dr.
Patters' concerns, but I would like to see us accept them the way they are, I
guess.
DR.
PATTERS: Well, again, I would like to
see it say that it can be used in periodontal defects and leave it to the
clinician to decide what type of defects, rather than say that it is labeled
for use and treatment of trifurcation and bifurcation involvements, because
that's very different to me.
DR.
SUZUKI: This is Suzuki. What would it take to add that clause?
MS.
SHULMAN: A more specific indication?
DR.
COCHRAN: I guess, a procedural question
would be are we really -- is this language with those indications, is that
going to be on the labeling of this product or will it just fit into the
regulations as whatever that CFR thing is you're talking about?
MS.
SHULMAN: Marjorie Shulman. It would not only be on the label of a
product if a company came in for that indication for the labeling of their
product.
DR.
PATTERS: But there is nothing to
prevent them from doing so if it's in the labeling. They don't even have to show data, I mean, if it's in the
regulation.
MS.
SHULMAN: Under pre-market notification,
under Class II, we could ask for data.
We could ask for clinical data.
DR.
RUNNER: And you could --
DR.
PATTERS: But if it's already a known
indication, why would you do that?
MS.
SHULMAN: It's a known indication.
DR.
PATTERS: Because, like I say, I'm
uncomfortable with it.
MS.
SHULMAN: It's an improved indication
for the one company who has the approved PMA.
Anyone else who is to introduce this into the market would require a new
510(k) and would require anything that was to be in the guidance document, any
clinical data that we might need, any special labeling, anything like that.
DR.
RUNNER: And I think you could recommend
to us that you feel that it would be important to specifically require data
when they were making a claim for bifurcations and trifurcations, and we could
certainly ask for that.
DR.
PATTERS: You guys always have a way
out.
CHAIR
REKOW: Richard?
DR.
BURTON: Richard Burton. One of the things that has changed in the
world since 1980 though, which concerns me a little about this is we have split
off in so many areas, pediatrics. I do
a lot of pediatric surgery, and my concern is that this also opens -- I mean,
again, I would say it's one thing in adults, but, you know, I would have a lot
of heartburn with people using this type of material in some pediatric
situations that would fall within those accepted guidelines. I mean, is there any way you can add this,
you know, for -- I would say things now oftentimes have a young age limit
sometimes built into it, but, you know.
MS.
SHULMAN: Marjorie Shulman. I would have to look at the labeling that
was actually cleared in that PMA. If it
wasn't cleared for pediatric, pediatric use is a new indication for use. New indications for use require new 510(k)s,
and there would be a new 510(k) and we would get data.
DR.
BURTON: Because again, you could have
-- it might be a fine product if you want to put it in a cyst. I'm not sure you would want to put it into a
cyst in an 8 year-old kid, because I think that, again, you know, they are not
the same use. We didn't split those
things out. It was sort of a little
more across the board, but I don't know whether that could be looked at. At least, I would certainly recommend doing
that.
CHAIR
REKOW: Okay. I guess on the form under indications for use, we say whatever is
in the regulation and the PMA with concerns as noted in the discussion,
especially relating to pediatric and periodontal.
DR.
PATTERS: Treatment of bi and
trifurcations.
CHAIR
REKOW: Okay. Let me write that before I forget.
DR.
BURTON: It would be a lot easier if you
could have just pulled them out and got rid of them, just pull them out and put
it in.
CHAIR
REKOW: Any other things that people
want as noted concerns? Okay.
MS.
SHULMAN: Okay. The identification of any risks to health
presented by the device. Did you have
an overhead for that?
CHAIR
REKOW: Maybe this is when we go to the
risk table.
MS.
SHULMAN: It was on the risk table, but
there's an overhead. We can put it
up. Okay. We can put it up there and then you can vote as is or you can add
or subtract anything that you see fit.
CHAIR
REKOW: Okay. So the first risk is those associated with surgical treatment procedures
and the thought is that the indications for use and labeling would deal with
those. Is that adequate? Yes?
DR.
GLOWACKI: I have a question about the
failure to osseointegrate.
CHAIR
REKOW: Can we go down to the --
DR.
GLOWACKI: Oh, I'm sorry.
CHAIR
REKOW: We'll go one by one.
DR.
GLOWACKI: Oh, I'm sorry.
CHAIR
REKOW: Okay. I'm sorry.
DR.
GLOWACKI: Yes.
CHAIR
REKOW: Infection of the soft tissue
and/or bone, the guidance document could deal with that, as well as the sterility
review question. What is the sterility
review? Is that like a specification?
DR.
RUNNER: It's a guidance document. Well, first of all, we would review all
information about sterility of the device, and guidance on how the company --
CHAIR
REKOW: Okay.
DR.
RUNNER: What about performing those
tests.
CHAIR
REKOW: For adverse tissue reactions,
aside from failure to osseointegrate, which may be a separate issue. The FDA has an ISO standard and there is
biological information of medical devices and evaluation and testing, which is
standard procedures, which would again be in the guidance document, I
assume. Adequate? I'm getting affirmative nods from everybody,
just for the record.
Incomplete
or lack of bone formation, and here the data would be obtained either through
performance testing, animal and/or clinical data, as well as directions for
use. Is that adequate? My, what an accommodating group we have
here.
MR.
SCHECHTER: Dianne?
CHAIR
REKOW: Yes, sir?
MR.
SCHECHTER: This is Dan Schechter. With, I guess, the last four categories on
the risk table, it talks about performance testing. Is it FDA's position that every 510(k) under this category regardless
of indications is going to require clinical data, either animal or human?
DR.
RUNNER: No.
MR.
SCHECHTER: Okay. Just checking.
CHAIR
REKOW: So having said that, can
you --
DR.
RUNNER: I think that would depend on
the indication for use that was proposed by the company.
CHAIR
REKOW: Okay.
DR.
PATTERS: Susan?
CHAIR
REKOW: Yes, Mark?
DR.
PATTERS: Patters. Susan, can the performance testing be put in
the guidance document?
DR.
RUNNER: Yes.
CHAIR
REKOW: Okay. The next one is a failure to -- let me go back and make sure that
we took care of incomplete or lack of bone formation. Everybody is okay with that?
Okay. Failure to osseointegrate,
to be controlled again by performance testing, directions for use in animal
and/or clinical data. Julie had a
question about that.
DR.
GLOWACKI: This is Julie Glowacki. I'm not sure that that concept has any
relevance, osseointegration, if we're talking about resorbable materials. Now, I may in a spiralling argument here
with respect to are we talking about resorbable forms or biphasic and so
forth? So I just wanted to raise that
as a point of clarification.
CHAIR
REKOW: Yes. It's an interesting one.
If it's in for 30 days, but it's going away, does it osseointegrate? Dr. Betz, you have a comment?
DR.
BETZ: This is Dr. Betz. Unfortunately, this is my baby right here
and I stole it from the draft guidance that the orthopedic people did. Failure to osseointegrate maybe doesn't have
anything to do directly with the bone itself, with the grafting material
itself, but my concern in putting in and separating to get out from incomplete
or lack of bone formation was related to the fact that the bone that is
generated therefrom may or may not osseointegrate and, therefore, I threw it in
just to make sure you guys were on your toes and you would want to consider
that as a possibility. It may not apply
in your opinion. That's your choice.
CHAIR
REKOW: Can you help me understand
better the difference between lack of bone developing and lack of
osseointegration?
DR.
BETZ: Well, my concern was that the
bone that is generated may or may not have properties that would permit it to
osseointegrate.
CHAIR
REKOW: Permit what to osseointegrate?
DR.
BETZ: It's a big unknown. We don't know whether bone generated like
this will osseointegrate as such.
CHAIR
REKOW: With the natural bone that is
remaining? Osseointegrate with what?
DR.
BETZ: With the dental implant.
CHAIR
REKOW: Oh.
DR.
BURTON: Burton. I know what Dr. Betz is alluding to. There have been some various studies at
different times looking at both autogenous and allogeneic materials, and
whether the bone that seems to be developed from that doesn't seem to have
quite the same capabilities as some native.
That has been one of the tradeoffs between autogenous bone and various
allogeneic, you know, various allogeneic materials has been -- yes, it sort of
forms bone, but it doesn't seem to function quite as well or whatever as
that. And I think what you're saying is
does the bone -- you know, there's a risk from this that the bone that would be
generated by it may not be of the same quality that would support
osseointegration that native bone would.
DR.
BETZ: This is Betz again. I agree 100 percent. That is also related to weakness, newly
formed bone, you know, at the bottom.
We don't know a lot about the nature of the quality of bone that you
get, and the last thing I would want to do is have somebody and my wife,
especially my wife, sink a brand new implant in some very freshly generated
bone and have to go heck in a hand basket and then have to explain to her why,
my dear, you have to do this again.
CHAIR
REKOW: Julie?
DR.
GLOWACKI: Julie Glowacki. Then I think it's a matter of grammar,
rather than anything else, because the way this table is set up, I think you're
talking about this implant material.
DR.
BETZ: Right.
DR.
GLOWACKI: So could I make a suggestion
to say failure to support osseointegration of devices?
DR.
BETZ: This table is yours to do with as
you see fit. That's fine with me.
DR.
GLOWACKI: Let's make it go back.
DR.
COCHRAN: I would like to make a
comment. This is David Cochran. In a lot of the more recent literature, we
understand that the quality of the bone is fine that's being stimulated, but a
lot of it has to do with the nature of the implant surface itself, and that may
be a lot more overriding a factor whether you actually have osseointegration of
the implant or not. So I am not
sure. I would agree with Julie. I think it's a matter of what we're saying,
because the way it's sort of stated now is like does this new bone integrate in
the old bone? But you mean it to be a
dental implant.
DR.
BETZ: Yes, sir.
DR.
COCHRAN: Yes. And I'm not sure if we should really comment. I mean, I think what you're trying to say is
if you want to use it in support of a dental implant, that you need to have
data that suggests that when you use it, you do enhance osseointegration of the
implant.
CHAIR
REKOW: And you could go one step
further to the last item. It's stiff
enough to do that.
DR.
COCHRAN: I don't know if stiff is the
right word.
CHAIR
REKOW: Right, it isn't.
DR.
COCHRAN: But osseointegration is bone
to implant contact at a light microscopic level, but I think that's a little
different issue. So I would think we
just need to work on the wording of that to get the meaning across of what you
really want to say.
DR.
BETZ: Yes. This is Betz again. I
just want to make sure you guys were awake.
CHAIR
REKOW: While you're standing there, you
want to help us with the last item, because it's going to be the same
issue? When you talk about the weakness
of the newly formed bone, is that also relating to in support of endosseous
implants or are you talking about in general there?
DR.
BETZ: In my opinion, I would consider
it in general.
CHAIR
REKOW: Okay.
DR.
BETZ: But including related to
implants.
CHAIR
REKOW: Okay. Thanks for the clarification.
We'll get there. So if we make
the change to, say, something like failure to support osseointegration of
endosseous implants or something like that to clarify.
DR.
BURTON: It would seem to me that we
could almost take all three of those, the areas incomplete or lack of bone
formation, failure support osseointegration, weakness in newly formed bone are
really all sort of one thing, and they all have the same outcomes across from
there. They all say performance
testing, animal and/or clinical data, that those could be rolled into maybe one
statement, which was just really, you know, incomplete or weak bone formation,
which may fail to support osseointegration, make it into one. I mean, you have just brought out a bunch of
lines.
CHAIR
REKOW: Say incomplete or inadequate
maybe.
DR.
COCHRAN: I would have the opinion that
we ought to get rid of the last one. I
don't think we do any testing for weakness of the bone. I don't think that's the appropriate
language at all there.
DR.
BURTON: Yes. I mean, that's really an orthopedic term, because what it is is
when they used this to deal with a gap issue was whether it was strong enough
to support function. It would appear
that we're really not doing that.
DR.
COCHRAN: We don't do that.
CHAIR
REKOW: Especially with granules.
DR.
COCHRAN: Right.
CHAIR
REKOW: It's a good trick if you can do
that.
DR.
COCHRAN: We would drop that last
one. I don't think that's appropriate.
CHAIR
REKOW: So what if we just made that
heading incomplete or inadequate bone formation?
DR.
COCHRAN: Yes.
CHAIR
REKOW: Because that then gets you to
the applications.
DR.
COCHRAN: Yes.
CHAIR
REKOW: It addresses some of the
alveolar ridge stuff underneath prostheses, and it lets the test be driven by
what the application --
DR.
COCHRAN: In that Number 4 that we have,
the fourth block down.
DR.
BURTON: Yes. But I would say, you know, incomplete or what was the other word
you used?
CHAIR
REKOW: Inadequate.
DR.
BURTON: Inadequate bone formation,
which may not support osseointegration.
CHAIR
REKOW: No, I would actually go back, if
I may, I'm sorry. Sometimes I get too
pushy. Take the first, the second and
the fourth one and collapse them into just saying incomplete or inadequate bone
formation, and let the application drive the decision and the test for what
that needs to be, because if it's inadequate, it can't support the endosseous
implant. If it's too weak, it can't do
the other stuff it's supposed to do.
DR.
COCHRAN: But we don't measure weakness
in bone.
CHAIR
REKOW: No, I know we don't, but that's
why I would just say get rid of the word entirely, and just put all three of
those into one category that says incomplete or inadequate.
DR.
RUNNER: So you're going to get rid of 5
and 7?
CHAIR
REKOW: Oh, I'm sorry. I would like to get rid of -- collapse
together the incomplete, the failure to osseointegrate and the weakness.
DR.
COCHRAN: I would vote against that,
Dianne.
CHAIR
REKOW: Okay.
DR.
COCHRAN: The reason for it is that
Number 4, the incomplete or lack of bone, can apply to other indications in
this material. A lot of times we have
placed in an intraosseous defect without an implant.
CHAIR
REKOW: Right. I agree completely, but the point that I was trying to make is
that if we make it more generic, then it becomes a decision process for every
application, because you need either complete or adequate bone for whatever
application you're thinking about. If
you're going to enhance the ridge, if you're going to do it around an implant,
if you're going to replace a cyst, all those things needed to be adequate and
they needed to be complete.
DR.
COCHRAN: My feeling is, in the
experience I have had, is that we are really looking at very different
indications when we put it around an endosseous implant.
CHAIR
REKOW: I agree.
DR.
COCHRAN: Versus when we use it as a
bone augmentation material in a ridge.
CHAIR
REKOW: Okay.
DR.
COCHRAN: So my preference would be to
keep them separate.
CHAIR
REKOW: Okay.
DR.
COCHRAN: Because I think you're going
to see, the FDA is going to see very different data in the performance testing
in those kinds of things.
CHAIR
REKOW: Okay. We just want it to work.
Any comments, changes, suggestions?
Okay. We have the device
migration or extrusion and there, the answers that are given are the
performance testing, animal and/or clinical data and the directions for
use. I would like to motivate a tiny
bit of conversation about whether or not it's appropriate and needs to be
specified what the breakdown product dynamics are. Dynamics is probably the wrong word, but to be able to
characterize the breakdown products as a function of time. Does that need to be more completely
specified than it is or is it already taken care of in the data that you would
collect under this?
DR.
RUNNER: We typically collect that data
as a part of these applications.
CHAIR
REKOW: Okay. Never mind.
MS.
SHULMAN: That would be under
adverse tissue reaction.
CHAIR
REKOW: Okay. Jon?
DR.
SUZUKI: This is Suzuki. I guess I'm not reading it the same way you
are, Dianne. Device migration or
extrusion to me means lost out of a site or a pocket, as opposed to degradation
of products.
CHAIR
REKOW: Okay. Okay.
DR.
SUZUKI: And I getting mixed up?
CHAIR
REKOW: You are probably right. Okay.
So does that take care of the risks?
SECRETARY
ADJODHA: Well, you need to go through
and list each one. You should agree on
it.
CHAIR
REKOW: Okay. Okay. So will you write
and I'll see if I can summarize them?
So the first one, maybe we can just tie it to Angela's table. The first one is the risk associated with
surgical and treatment procedures and that is as it appears. There were no modifications. Yes, we're talking about Question 5.
MS.
BLACKWELL: Question 5? Okay.
CHAIR
REKOW: The second point -- Angela,
maybe you can number those, so that Michael can --
DR.
RUNNER: Dr. Rekow?
CHAIR
REKOW: Yes, ma'am?
DR.
RUNNER: Maybe we could just say see
table, table of risks.
SECRETARY
ADJODHA: But they modify the tables.
DR.
RUNNER: See table as modified.
CHAIR
REKOW: So maybe we can mark up your
table. The second one is fine. The third one is fine. The fourth one we decided. What did we decide? The incomplete or lack of bone formation, we
said we would leave or did we want lack to be inadequate?
DR.
SUZUKI: Suzuki. Lack to be inadequate, I think, is what we
agreed.
CHAIR
REKOW: Okay. So, Angela?
MS.
BLACKWELL: What does it say?
CHAIR
REKOW: The next one up from where your
finger is. Change lack to inadequate.
MS.
BLACKWELL: Okay.
CHAIR
REKOW: And the next one down, I think
we modified that to say failure to support osseointegration of endosseous
implants.
DR.
BURTON: Endosseous dental.
CHAIR
REKOW: Dental implants?
MS.
BLACKWELL: Yes, we'll use the one from
this.
CHAIR
REKOW: Okay. The next one was fine, and the we were going to eliminate the
last one, the last row, yes. Okay?
DR.
RUNNER: Okay.
SECRETARY
ADJODHA: Okay.
MS.
SHULMAN: Perfect. On the form, we can move to Number 6, the
recommended Advisory Panel classification of priority. Classification is Class II. The priority you would vote on a high,
medium and low, and all that means is how fast would you like us to work on the
regulation reclassifying the device?
CHAIR
REKOW: Yesterday afternoon would have
been good.
MR.
SCHECHTER: This is Dan Schechter. Do we get to ask the petitioner what
priority they like? As industry
representative, I endorse high priority.
CHAIR
REKOW: Do you ever get anything that
isn't high priority?
DR.
BURTON: You could try carbon dating.
CHAIR
REKOW: Excuse me? What did you say, Rick?
DR.
BURTON: I said we could try carbon
dating.
CHAIR
REKOW: Do you ever get anything that
isn't high priority, Susan?
MS.
SHULMAN: I can tell you. Marjorie.
We do get some things that are low priority if they are Class III
already undergoing 510(k), so it's not a change in the regulatory path, PMA
versus 510(k).
MR.
SCHECHTER: This is Dan Schechter. In all seriousness, given that there aren't
many or any, at this point, products in this category on the market and,
although, the studies we have may not be gold standards studies, it does seem
to be a very helpful product. I would
just push for a high priority, so that these products can actually get back out
there on the market.
CHAIR
REKOW: Is there anyone that would argue
otherwise?
SECRETARY
ADJODHA: Did we vote on what
classifications?
CHAIR
REKOW: Oh, I guess Michael has just
brought up that we didn't formally vote on which classification --
MS.
SHULMAN: We'll vote on the sheets when
completely done.
CHAIR
REKOW: Okay. I'm sorry. So I'm hearing
the priority should be high. David?
DR.
COCHRAN: I think medium would work, as
well, for fairness to the FDA, but I don't really care how we go on this one.
MS.
BLACKWELL: We can't go any faster.
DR. BURTON: It's sort of like the mule.
It only has one speed. You can
dangle carrots or a whip.
CHAIR
REKOW: Rather than putting anyone on
the spot, is there anyone who will --
DR.
GLOWACKI: I'll go on the spot.
CHAIR
REKOW: Go ahead.
DR.
GLOWACKI: Julie Glowacki. I think, you know, having made this
recommendation for reclassification is absolutely no reason to suggest any
delay, and I think we ought to say high.
CHAIR
REKOW: Any other comments,
suggestions? All right. I will take that as affirmation.
MS.
SHULMAN: Okay. Number 7, if device is an implant or is life
sustaining or life supporting and has been classified in a category other than
Class III, explain fully the reasons for the lower classification with
supporting documentation and data, and we may say as discussed in the Panel
meeting if you so wish.
CHAIR
REKOW: Is there anyone that would like
to explicitly state all of our things, as opposed to saying as discussed in the
Panel meeting?
MS.
SHULMAN: Okay. Number 8, summary of information, including
clinical experience and judgment upon which classification recommendation is
based. You can also say as discussed in
the Panel meeting.
CHAIR
REKOW: Anyone want to say other than
that? Hearing nothing, we'll go on.
MS.
SHULMAN: Number 9, identification of
any needed restrictions on the use of the device, for example, special
labeling, banning prescription use, anything else besides what has already been
discussed in the risk to health?
DR.
BURTON: Children.
MS.
SHULMAN: Pardon me?
DR.
BURTON: Children, children.
MS.
SHULMAN: Oh, pediatric? All right.
CHAIR
REKOW: Julie brought up a list. I'll have to write and talk at the same
time. That never works. Julie brought up a series of questions. Do we want to go with any of these? If I remember her list, it was not doing
infected sites, being careful about overfilling, discontinuous defects.
DR.
GLOWACKI: Discontinuity.
CHAIR
REKOW: Discontinuity defects, I'm
sorry. I guess now that we have only granules,
we won't worry about the block and the machinability. Concurrent use with implants, I guess we have taken care of
that. One that we haven't addressed is
the suitability of mixing it with other materials, and that might be either
inert materials and/or biologic materials, but I guess under this umbrella, it
would be with other inert materials, perhaps HA, perhaps other forms of the
TCP, and whether or not we need to explicitly say to avoid various tissue
types, including the blood stream, and I think you mentioned soft tissue and
nerves and the dental pulp and those sorts of things.
So
do we need to go with a conversation in any of those? David?
DR.
COCHRAN: This is David Cochran. My comment is even on the pediatric one, we
really don't have any data to say anything about these or any of these, at this
point, and I think we almost have to rely on the FDA that when they get the
applications or the 510(k)s, that the data they get supports whatever
indication you're going to use, and I would just vote that we allow that to
happen.
CHAIR
REKOW: So I guess we don't have a
burden of proof to be able to prove that it is an issue. It's a concern that we have, but there is no
proof and there is plenty of practical usage proof that suggests
otherwise. Do we need to worry at all
about the mixing and combinations or does more than 50 percent --
DR.
PATTERS: The guidance document should
cover that.
CHAIR
REKOW: The guidance document can cover
it?
DR.
RUNNER: The mixing has already occurred
in cleared 510(k)s in terms of --
CHAIR
REKOW: Okay.
DR.
RUNNER: However, if that's something
that you think we should look more into in terms of concerns, you know, the
Panel transcript is reviewed and your concerns are looked at when we do write
the guidance document.
CHAIR
REKOW: Okay. So I guess the answer to Number 9 is nothing other than what has
already been discussed.
MS.
SHULMAN: Perfect.
DR.
GLOWACKI: This is Glowacki. Since pediatric was brought up, I wonder
about the geriatric, extreme geriatric population, where there-- you know, with
the prevalence of diabetes and inadequate healing responses of diabetics and
geriatric patients that we may also want to think about an upper end of the age
or health status just as we begin on the lower level.
CHAIR
REKOW: Mark?
DR.
PATTERS: Mark Patters. I think that's the clinician's judgment
about the surgical risks involved for any given patient, and there is no reason
to believe that in a perfectly healthy 80 year-old patient, this device would
not be helpful, so it has nothing to do with their age. It's just surgical judgment. Some patients are not candidates for
surgery. I'm not sure it's device
related.
CHAIR
REKOW: The same would be true for
biologic, pathologic conditions and various disease states, I think. Okay?
MS.
SHULMAN: Okay. Number 10 we get to skip, because it's not a
Class I device. Number 11, if the
device is recommended for Class II, recommend whether FDA should exempt it from
pre-market notification. That's a yes
and a no. A Class II device can be
exempt from pre-market notification and we would not see, so you would vote yes
or no.
CHAIR
REKOW: Can I have a vote, David?
DR.
COCHRAN: Cochran, no.
DR.
BURTON: Burton, no.
DR.
PATTERS: Patters, no.
DR.
GLOWACKI: Glowacki, B, no.
DR.
SUZUKI: Suzuki, no.
CHAIR
REKOW: You have it.
MS.
SHULMAN: Okay. Number 12, existing standards applicable to
the device of assemblies, components or device materials. We can say what we have discussed earlier,
though it has been presented or if you wanted to add any.
CHAIR
REKOW: Does anybody have any compelling
standards that we have overlooked so far in our conversation?
DR.
SUZUKI: Suzuki, nothing to add.
CHAIR
REKOW: Angela?
MS.
BLACKWELL: I think there is an ASTM
standard that's out there.
CHAIR
REKOW: Can we say this is as discussed?
MS.
SHULMAN: We can, as discussed in the
Panel meeting.
CHAIR
REKOW: Okay. And if there are new ASTM standards and ISO standards, I would
assume that those would be applied as part of the guidance document anyway.
MR.
SNIDER: Those would be reviewed and
applied.
MS.
SHULMAN: Then you will take one final
vote on the forms as filled out and voted upon as a Class II device
reclassification.
CHAIR
REKOW: Okay. So the question is should this be reclassified as a Class II
device. Jon?
DR.
SUZUKI: Suzuki, yes.
DR.
GLOWACKI: Glowacki, yes.
DR.
PATTERS: Patters, yes.
DR.
BURTON: Burton, yes.
DR.
COCHRAN: Cochran, yes.
MS.
SHULMAN: Thank you very much for your
time.
CHAIR
REKOW: Is there any other comments or
statements that anyone has a compelling urge to make? Hearing none, I thank you all, and it has been fun, as always,
Susan.
SECRETARY
ADJODHA: Onto the closed session now.
CHAIR
REKOW: Now, we have a closed
session. Sorry.
DR.
BURTON: Can we take a break first?
DR.
COCHRAN: Take a break.
SECRETARY
ADJODHA: Yes.
CHAIR
REKOW: No.
DR.
BURTON: I'm going to have to take my
own.
DR.
COCHRAN: Yes, me, too.
CHAIR
REKOW: Why don't we take a 10 minute
break, and then we'll come back for a closed session. Thank you all.
(Whereupon,
at 3:04 p.m. a recess until 3:17 p.m., when the Panel resumed in Closed
Session.)