Feasibility, Safety and Efficacy Evaluation of Alpha-Type 1 Dendritic Cell(DC)-Based Vaccines Loaded With Allogeneic Prostate Cell Lines in Combination With Androgen Ablation in Patients With PSA Progression After Local Therapy for Prostate Cancer

This study will evaluate the feasibility, safety, and efficacy of intradermal vaccination of prostate cancer patients with alpha-type-1-polarized dendritic cells (DC1) loaded with apoptotic allogeneic tumor (LNCap). The study will target men with recurrent prostate cancer, who failed local therapy, have no measurable metastasis, but have a rising PSA with a doubling time of less than 10 months. The selection of this study group enables us to evaluate time to PSA progression, a highly relevant, clinical primary endpoint of efficacy in this two arm study. In order to facilitate infiltration of vaccination-induced T cells into tumor site(s) and to reduce tumor-specific tolerance, subjects will receive the vaccine in combination with limited androgen ablation (AA) with a LHRH analogue for 3 months. Subjects will be randomly assigned to one of two cohorts. In cohort A subjects will be first treated with limited AA alone for 3 months, and at the time of PSA relapse (PSA ≥ 1 ng/dL) will receive the DC vaccine in conjunction with AA. In cohort B, the sequence of treatment will be reversed. Efficacy will be estimated as the within-subject difference in time to PSA relapse following the combination treatment as compared to the AA alone, thus, each subject will serve as his own control. All subjects will commence the DC1-based vaccination 2 weeks prior to treatment with the LHRH analogue. Each subject will receive 1 intradermal (i.d.) dose of the vaccine at weeks 1, 5, 9, and 13 for a total of 4 doses. Additional courses of vaccination may be administered to subjects without evidence of disease progression every 3 months (±1 month) for up to 12 months depending on the number of doses originally produced and available after the 4 intended protocol doses. All doses of the vaccine will be administered intradermally (i.d.).