The Provenge given after crossover is frozen Provenge, with less than half the potency of the fresh Provenge given to the treatment arm.
If this is the case, then how is it ethical to put anyone in the placebo arm when the best they can hope for is crossing over to half-strength Provenge? I thought one of the big issues supposedly vexing the FDA was "how would you ever complete enrollment/finish the trial of 9902B if Provenge is approved, as it would be unethical to put anyone in the placebo arm"?
So now the FDA sends a CR, saying they need more proof of efficacy, effectively accomplishing the same thing: putting patients in a placebo arm when deep inside, they must know Provenge is at least somewhat effective (other than Aschoff, does anyone really believe that Provenge is no better than water?)
I'm such a novice to biotech and biostatistics, that my suggestion is probably laughable, but here goes:
Considering the already available data from 9901 and 9902a, wouldn't the most ethical thing be to run a 250 patient trial with all 250 on Provenge, then simply compare the survival time to the Halabi nomogram? 250 would seem strongly enough powered that if the median survival was well over 19 months, Provenge clearly works? No placebos, no crossovers.
Best regards,
Geoff