If hormone therapy ultimately fails to slow the growth of the cancer, the next step may be a prostate cancer "vaccine" called Provenge (sipuleucel-T). Most men who take Provenge survive at least two years after starting the treatment. Provenge is a therapy created by taking immune cells from a patient, genetically engineering them to fight prostate cancer, and then putting them back into the patient. It's used for men with few or no symptoms and when advanced prostate cancer no longer responds to hormone therapy.