I think Provenge stands a better chance of statistical significance at the final look than Asentar does. It's hard to say which one has a better chance at the interim. Much depends on the allocation of the p values for the interims and final looks of the two trials.
As for approval, and assuming that both treatments attain strong statistical significance of p=0.01 or better for survival, I think the odds of approval will be slightly better for Asentar, although the odds of approval will be high for both. The research/clinical genitourinary oncologists are lined up behind Asentar to a much greater extent than Provenge, since it's being combined with Taxotere chemotherapy.
Even if Provenge hits stat sig in the 9902B trial, there will probably be an element both inside the FDA (OOD/CDER/Pazdur) and in the research/academic genitourinary oncology community that won't want to see it approved, as much of the primary care for HRPC patients will revert back to urologists...but I don't think the patient advocacy groups would let Pazdur get away with blocking it this time.
