Minority pat ients who meet entry criteria will be actively recruited, although the trial is not designed to measure differences in outcomes between ethnic groups. The estimated breakdown o f the target population by race and ethnicity is: 80% white/Caucasian, 15% black/African American, and 5% comprised of other ethnic minorities. 3.5 Prohibited Concomitant Me dications Concurrent use of other anticancer agents or therapies including other experimental treatments is not permitted. Patients may not currently be taking any other form of androgen deprivation therapy, antiandrogens, 5α-reductase inhibitors, chemothe rapy, radiation therapy, biologic therapy , immunosuppressive medications, or systemic corticosteroids . Within 30 days of administration of study drug(s) , patients should ideally not receive other cancer immunotherapies or vaccines including but not limited to the live rotavirus vaccine, the live BCG (bacillus Calmette -Guerin ) vaccine, the live influenza vaccine, the live measles vaccine, the live mumps vaccine, the live poliovirus vaccine, the live rubella vaccine, the smallpox vaccine, the typhoid vaccine, the varicella vaccine, and the yellow fever vaccine. The following list of medications should generally be taken with caution by patients on chronic cyclophosphamide: allopurinol, cyclosporine, etanercept, hydrochlorothiazide, nevirapine, ondansetron, pen tostatin, St John’s wort, tamoxifen, trastuzumab, and warfarin . In the present study, because only a single low -dose administration of cyclophosphamide will be given ( in treatment arm B), these medications are not prohibited. However, the principal investi gator must be notified if a patient is taking any of the se listed agents. Androgen suppression with prostate GVAX and cyclophosphamide J1265 Johns Hopkins University 22 of 68 J1265 PROT (Vers) 1.4 113012 Because of the potential for unknown drug -drug interaction s, concurrent use of all other agents , over -the-counter medications, herbal remedies, vitamins/minerals, and alternative therapies must be documented on the case report form ( CRF) . 4.