Immunotherapy shown to lower mortality risk in patients with prostate Ca

New explanatory analyses of a phase III study support earlier results observed with treatment using the investigational active cellular immunotherapy sipuleucel-T (Provenge) in men with advanced androgen-independent prostate cancer, researchers reported at the Prostate Cancer Foundation’s annual scientific retreat in Scottsdale, AZ.

According to the analyses presented by Eric Small, MD, of the University of California, San Francisco, the overall survival benefit associated with sipuleucel-T does not appear to be due to any imbalances in the treatment arms or the subsequent use and timing of chemotherapy. As published earlier this year, a phase III study demonstrated a median overall survival of 25.9 months in the sipuleucel-T arm compared with 21.4 months in the placebo arm, or a 4.5-month survival difference (J Clin Oncol 2006; 24:3089-94).

Analysis of prostate-cancer-specific survival showed a median survival of 35.2 months for patients randomized to sipuleucel-T compared with 23.5 months for patients randomized to placebo, a difference of 11.7 months and a 50% reduction in prostate cancer-specific mortality (p=.002).

Dendreon Corp., manufacturer of sipuleucel-T, said it planned to submit a biologic license application to the FDA prior to the end of 2006 to seek market approval for the drug.