Biotech Values

[rancherho]

Walldiver:

You are right about there being no GVAX randomized trial data yet, pending results from CEGE's Vital 1 and Vital 2 Ph 3 trials. However, their Ph2 dosing studies did compare lower doses vs. high dose GVAX and Dr. Small compared the entire GVAX radiologic group to a Halabi nomogram predicted median survival, much as he did for showing that the actual survival of Provenge 9901 ITT patients exceeded Halabi nomogram predicted median survival by 5.8 months. The median survival of the GVAX high dose followed by chemo (primarily docetaxel)subgroup exceeded 35.2 months as of the last Ph2 study revision in April and reportedly had still not been reached in September. Even given the small subgroup and the Halabi nomogram estimated accuracy of 69%, a suggested benefit in median survival of over 20 months is impressive. IMO, the sometimes expressed theory that only the healthier patients would select docetaxel afer Provenge or GVAX is dubious, especially where Drs. Petrylak and Small both use Halabi as a standard reference. A relevant quote from the GVAX Ph2 study:

>>Survival. In the radiologic group, the overall median survival after initiation of treatment was 26.2 months (95% CI, 17,36), including 24.0 months in the low dose (95%CI, 11, 35) and 34.9 months in the high dose (95% 8, 57). Based on a pretreatment nomogram established by Halabi et al (20), an expected median survival time of 19.5 months was estimated for the 34 patients in the radiologic group. At the end of the study 13 of 34 patients in the radiologic group received subsequent chemotherapy (taxane in 9/13); their median survival was more than 35.2 months (95%CI, 29, 44). The median survival of the non-chemotherapy treated patients was 17.2 months (95% CI, 9, 32).<<
Granulocyte Macrophage Colony-Stimulating Factor�Secreting Allogeneic Cellular Immunotherapy for Hormone-Refractory Prostate Cancer
Eric J. Small 1, Natalie Sacks2, John Nemunaitis3, Walter J. Urba4, Eugene Dula5, Arthur S. Centeno6, William G. Nelson7, Dale Ando2, Catherine Howard2, Flavia Borellini2, Minh Nguyen2, Kristen Hege2 and Jonathan W. Simons Clinical Cancer Research 13, 3883-3891, July 1, 2007. doi: 10.1158/1078-0432.CCR-06-2937 http://clincancerres.aacrjournals.org/cgi/content/abstract/13/13/3883