ocyanblue:
1. We can both agree that Ph2 studies are primarily used for dosing and some indication of efficacy and not for extrapolation statistically to Ph3 results.You are among a handful of statisticians on the MB's whose observations are valued, which includes negative as well as positive ones. I am a strong believer in the future role of immunotherapy in cancer and believed that Provenge would be the first on the market. The reason for the post was not to create certainty, but the opposite. As the CCR article described, there may be several viable ways that cancer vaccines will come to be accepted. The two leaders with large randomized PH3 trials are DNDN and CEGE and both have strong proponents.
2. In my book, clear writing sets up the issues; lack of essential known information and the unpredictability of future events creates uncertainty. I will be the first to acknowledge that if I had known about the February Form 483 issued as a result of the FDA preapproval inspection of DNDN's NJ facility, my investment decisions with DNDN would have been dramtically different based on my past experience with the manufacturing problems of developmental biotech companies. So you can add hiding negative results of FDA preapproval inspections from shareholders to all the other risks in biotech investing, but that is one the courts may act to stop.
3.Studies of the different methods of action of the various immunotherapies unlike the black and white statistical results of a Phase 3 trial are being published continually in many medical/scientific journals.A lot of this material can shed light on whether the presumed superiority of maturing a patient's own dendritic cells with a single target antigen as Provenge does is essential or whether the combined antibody / T cell response apparently stimulated by GVAX's vaccine based around two inactivated prostate cancer cell lines or of Onyxax's vaccine based around three PC cell lines is superior. The CCR article raised such issues while leaving answers to such issues to ongoing studies. Theoretically, antibodies stimulate cell destruction by macrophages by phagocytosis, a process which is different than destruction of a cell by a CD8 T cell immune attack and is not deactivated by Tregs. Petrylak's presentation last November to the Chemotherapy Foundation hypothesized that a similar macrophage cancer cell killing process by Taxotere is what substantially increased the efficacy of the Provenge plus Taxotere combination. Thus, there is some scientific basis, although no certainty, that a combined antibody / T cell immune attack may approximate the MofA of Provenge plus Taxotere. JMHO.
