Cell Genesys reports positive results from Phase III prostate cancer trial

Cell Genesys, a biotechnology company, has announced positive results from further analyses of Vital-1, the company’s recently terminated Phase III clinical trial which compared Gvax immunotherapy for prostate cancer to Taxotere chemotherapy plus prednisone and enrolled 626 advanced prostate cancer patients with asymptomatic castrate-resistant metastatic disease.

Vital-1 was terminated in October 2008 based on the results of a futility analysis conducted at the company’s request by the study’s Independent Data Monitoring Committee which indicated that the trial had less than a 30% chance of meeting its predefined primary endpoint of an improvement in overall survival.

However, the final Kaplan-Meier survival curves for the two treatment arms suggest a late favorable effect of Gvax immunotherapy on patient survival compared to chemotherapy, with the curve for Gvax patients crossing above the chemotherapy curve at approximately the same time median survival was reached in both treatment arms (21 months). Additionally, the data suggest that patients with Halabi predicted survival greater than or equal to 18 months may have a more favorable response to the immunotherapy.

According to the company, treatment with Gvax immunotherapy was generally well-tolerated and had a very favorable side-effect profile compared to Taxotere chemotherapy particularly with respect to a lower frequency of grade 3 or higher toxicity of 9% versus 43%.

Stephen Sherwin, chairman and CEO of Cell Genesys, said: We believe that the further analyses of the Vital-1 trial presented today indicate that Gvax immunotherapy for prostate cancer has clinical activity and a favorable safety profile compared to Taxotere chemotherapy, the standard of care for men with advanced prostate cancer.