Androgen (a male sex hormone) deprivation is the standard therapy for metastatic prostate cancer and results in regression or control of disease in 80-85% of patients. This hormone therapy results in a progression-free survival of 12-18 months and overall survival of 24-30 months. However, all patients ultimately develop hormone-refractory prostate cancer (HRPC). Management of HRPC patients is a significant challenge for both patient and physician. Neither past nor current chemotherapy regimens have shown curative potential in patients with HRPC. Thus new treatment strategies are a high priority.

A major focus of new treatment strategies is to enlist the aid of the immune system, particularly the development of prostate cancer vaccines. There has been a number of studies using dendritic cell based vaccines and the treatment has been well tolerated. Specific T-cell immune responses have been observed and occasional evidence for tumor regression. A reduction in serum prostate-specific antigen (PSA) has been observed as well. Lengthening the time-to-progression and delays in the onset of bone pain have been observed in subsets of patients with HRPC.

The initial preclinical observations suggesting that a granulocyte-macrophage colony-stimulating factor (GM-CSF) gene transduced allogeneic (GVAX) prostate cancer vaccine may be efficacious in poorly immunogenic cancers were reported.

The objective of this study is to evaluate the safety and immunologic effects of vaccinations with Allogeneic Prostate GVAX® (CG1940 & CG8711) in patients made lymphopenic by treatment with chemotherapy and infused with autologous peripheral blood mononuclear cells (PBMC). Clinical observations and laboratory measurements will be monitored to evaluate safety, toxicity and immune responses. Additionally, the effects of treatment on serum PSA levels and tumor response will be evaluated.