At present, no curative therapy is available for subjects with advanced or metastatic prostate cancer. Approximately 1 of every 3 men present with advanced or metastatic disease; therefore, current standard therapies are ineffective and new therapeutic approaches are warranted. There is ample evidence that active immunotherapy against cancer is safe and capable of stimulating potentially therapeutic immune responses in the cancer patient. Moreover, several Phase II immunotherapy trials have suggested clinical benefit by reducing the tumor mass or prolonging time to progression in subjects with advanced prostate cancer.