DEPARTMENT OF HEALTH AND HUMAN SERVICES
TELECONFERENCE MEMORANDUM Public Health Service
Food and Drug Administration
Center for Biologics Evaluation and Research
Date\Time: April 4, 2007
CBER Representatives: Peter Bross
Sponsor’s Representative: Helen Kim
STN : 125197/0
Subject: Clinical Questions
- Please confirm whether the revised D9902B (SPA) protocol contained in amendment 198 (serial number 198) was the most recent protocol (submission date 11-OCT-2005). Please e-mail an electronic copy of the most recent protocol to us including the SAP.
DNDN Response: Yes.
- Please confirm whether the revised IDMC charter contained in amendment 200 (serial number 200) was the most recent one (submission date 11-OCT-2005). Please send an electronic copy of the most recent IDMC charter to us.
DNDN Response: Yes.
- Please update the D9902B enrollment status (blinded information of course) as soon as possible:
- Number of subjects enrolled
DNDN Response: As of April 1, 2007, a total of 403 subject have been randomized.
- Percentage of African-American subjects enrolled
DNDN Response: As of April 1, 2007, 4.1% of African American subjects have enrolled.
- Updated death events after last annual report (26-MAR-07).
DNDN Response: As of April 1, 2007, there are a total 80 death events. This represents 22% (80/360) of the targeted number of death events.
- Please also send an electronic copy of the most recent annual report since the file in EDR is not accessible at this time.
DNDN Response: Per this afternoon's teleconference, please let us know if you will still require an electronic version of the most recent BB-IND 6933 Annual Report.
- In your briefing document (p56) you stated that "Balance between treatment arms for baseline prognostic factors was assessed using an independently validated model (Halabi, 2003)..... Results of the analysis demonstrate that the treatment arms were well-balanced. The median of the estimated survival times for the patients in the sipuleucel-T and the placebo arms were highly comparable, at 20.1 and 19.9 months, respectively. Is there somewhere in the BLA an analysis of the estimated survivals in trials 9901 and 9902A by the Halabi model? If not could you please ask your statistician to do this analysis for the two arms separately and for the whole population of 9902A and share the results with us? We would like to try to understand why the survivals are so different between 9901 and 9902A.
Please note that the additional analyses contained in our response are based upon data included in the initial BLA submission (submitted 21 August 2006). Specifically:
- For Survival Data: refer to BLA ITEM 8, Section 184.108.40.206, Study CSR-D9901, Post-Text Listing 220.127.116.11, page 2390 of 5814.
- For the Immune Response Data: refer to BLA ITEM 8, Section 18.104.22.168, Study CSR-D9901, Post-Text Listing 22.214.171.124, page 2445 of 5814.