Vaccine Therapy Plus Sargramostim and Interleukin-2 Compared With Nilutamide Alone in Treating Patients With Prostate Cancer

RATIONALE: Vaccines made from prostate cancer cells may make the body build an immune response to kill tumor cells. Colony-stimulating factors such as sargramostim may increase the number of immune cells found in bone marrow or peripheral blood. Interleukin-2 may stimulate a person's white blood cells to kill prostate cancer cells. Androgens can stimulate the growth of prostate cancer cells. Hormone therapy using nilutamide may fight prostate cancer by reducing the production of androgens. It is not yet known which treatment regimen is more effective for treating prostate cancer. PURPOSE: Randomized phase II trial to compare the effectiveness of vaccine therapy plus sargramostim and interleukin-2 with that of nilutamide alone in treating patients who have prostate cancer that has not responded to hormone therapy.

OBJECTIVES: * Compare the difference in time to radiographic evidence of disease progression at 6 months in patients with hormone-refractory prostate cancer when treated with vaccine containing recombinant vaccinia-prostate-specific antigen (PSA) admixed with rV-B7.1 plus recombinant fowlpox-PSA vaccine, sargramostim (GM-CSF), and interleukin-2 vs nilutamide alone. * Evaluate the vaccination therapy in relation to the change in T-cell precursor frequency and to the rise of serum PSA in this patient population. OUTLINE: This is a randomized study. Patients are stratified according to HLA-A2 typing (positive vs negative). Patients are randomized to one of two treatment arms. * Arm I: Patients receive vaccine containing recombinant vaccinia-prostate-specific antigen (PSA) and rV-B7.1 subcutaneously (SC) on day 2 only. Beginning on day 30, patients receive recombinant fowlpox-PSA vaccine SC every 4 weeks for 12 vaccinations and then every 12 weeks thereafter. Patients also receive sargramostim (GM-CSF) SC daily on days 1-4 and interleukin-2 SC daily on days 8-12 with each vaccination. Patients without disease progression after 12 courses receive the vaccine regimen every 12 weeks. * Arm II: Patients receive oral nilutamide daily. Treatment continues in both arms for at least 6 months in the absence of disease progression or unacceptable toxicity. After 6 months of therapy, patients with a rising PSA and no radiographic evidence of disease progression may receive therapy in the other arm in addition to the therapy to which they were randomized. Patients are followed monthly for 6 months and then every 2 months thereafter. PROJECTED ACCRUAL: A total of 56-78 patients (28-39 per treatment arm) will be accrued for this study within 1.5-2 years.