Two-Arm Study of a DNA Vaccine Encoding Prostatic Acid Phosphatase (PAP) in Patients With Non-Metastatic Castrate-Resistant Prostate Cancer

A Pilot Randomized Two-Arm Study of a DNA Vaccine Encoding Prostatic Acid Phosphatase (PAP) in Patients With Non-Metastatic Castrate-Resistant Prostate Cancer

The investigators are trying to find new methods to treat prostate cancer. The approach is to try to enhance patients' own immune response against the cancer. In this study, the investigators will be testing the safety of a vaccine that may be able to help the body fight prostate cancer.

The vaccine, called pTVG-HP, is a piece of DNA genetic material that contains genetic code for a protein that is made by the prostate gland, called prostatic acid phosphatase (PAP). The vaccine will be given together with a substance called an adjuvant. Adjuvants are typically given with vaccines and can improve the effect of the vaccine. The adjuvant that will be used in this study is called granulocyte-macrophage colony-stimulating factor (GM-CSF).

The main purpose of this study is to find out whether the vaccine generates long-lived immune responses, and whether a better schedule of vaccination can be found by doing frequent laboratory testing for immune responses. The investigators also want to see if the vaccine stimulates any immune reaction against cancer cells.

Inclusion Criteria:

• Diagnosis of Prostate Cancer
• Castrate Resistant Disease with rising PSA despite continuous treatment with orchiectomy or a LHRH agonist
• Rising PSA after treatment and withdrawal of anti-androgen
• Serum Testosterone <50ng/mL
• Normal organ function per laboratory tests

Exclusion Criteria:

• No evidence of immunosuppression or on treatment with immunosuppressive agents
• Cannot have discontinued LHRH agonist treatment (if not previously treated by orchiectomy) within 6 months prior to study entry
• Must not be concurrently taking other medications or supplements with known hormonal effects (other than the LHRH agonist noted above).
• Cannot have any evidence for metastatic disease on bone or CT scan
• Unable or unwilling to undergo two leukapheresis procedure