9902B Q & A:
Q: What factors led to the relatively poor results of 9902A?
A: Main reason was strong # of bone metastases factor favoring the placebo arm...secondary reason was smaller trial size.
Q: Why should the results of 9902B look much more like 9901 than 9902A at the interim and final?
A: One of the stratification factors in 9902B will be # of bone metastases...this and the much larger size of the trial should help balance out the likelihood of a higher % of placebo crossovers.
Q: Could the results of a few patients sway the results one way or the other if we roughly mirrored the combined 9901 and 9902A results?
A: This would be more possible at the interim look, which probably will occur around the 180-death point...and yes, there is a possibility of this happening if the results of the Provenge arm are moderately successful.
Q: How might the relatively sicker patient population affect the results?
A: It's hard to say...I think a bigger factor could be how balanced the followup Taxotere usage is.
Q: How might slow ramp up on enrollment of 9902B affect the results at the interim and final for an event given trial?
A: There will be a greater effect at the interim look. There will be a lot more censored patients who are more recent enrollees, and this will be a confounding factor.
Q: How do long-term survivors factor into the results of an event driven trial?
A: This is one of the most promising factors for the Provenge arm. In 9901/9902A, the 36-month survivors had to be censored at the 36-month point. In other words, the Provenge arm got no p-value bonus beyond 36 months for Mr. Garcia, who is a 7-year survivor. In 9901, we know that 28/82 survived 36 months, and that eight more deaths were reported in the BLA for those 36-month survivors. Does that mean that 20/82 were alive at the time of the panel meeting? Possibly, but it may just mean that we lost contact with the other 19 besides Mr. Garcia.
