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.