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A Few More CMC Questions - Provenge, May 28, 2010

(System Info - 126202 TULL LORI 04/16/2010 13:09:55 TULL)

From:          Finn, Thomas
Sent:          Wednesday, January 06, 2010 9:45 AM
To:             Smith, Liz
Cc:             Tull, Lori
Subject:       A few more CMC questions
 

Hi Liz,

I know you’re busy over there but I have a few, hopefully quick questions:

  • I noted in some of your lot line listing that the b(4) in the APH ranged from as little
    as b(4). Some times this seems to be attributable to the patient because similar numbers are obtained
    from the same patient for 2 or 3 of the APH, whereas in other cases it varies a lot from the same patient.
    When the percentage is very low do you still follow through with the SOP and perform the b(4)
    I assume the answer is yes, but just wanted to check. With regards
    to the upper end of the spectrum, when the percent b(4) is high can that be attributed to a
    leukapheresis problem or differences in the efficiency of apheresis equipment? Have you noted any
    differences in the APH quality from different apheresis sites over the years?
  • In amendment 33, table 8 “Summary of leukapheresis and Product Infusions, Intent-to-Treat
    Population” you have indicated that for sipuleucel-T treated patients about 1/3 of subjects required a 3rd
    leukapheresis. Was that typically due to complications with the apheresis that required another visit, or were
    there situations where insufficient APH volume was collected or an in-process or final product release
    criterion was not met?
  • In amendment 33 you have listing 16.2.6.13 (begins on page 4890 of 5667) that provides a line
    listing on cell product parameters. It appears that roughly 10% of the time a product lot was not infused. I
    assume most of these were due to medical reasons. Were any of these due to a product not meeting inprocess
    or final product release testing? Were any of them not infused because the shelf life (dating period)
    had expired?
    I don not need answers to these questions immediately (I have plenty to keep me busy), but would
    appreciate some feedback from your end.

    Thanks,
    Tom