Ipilimumab and Sargramostim in Treating Patients With Metastatic Prostate Cancer

This phase I trial is studying the side effects and best dose of ipilimumab when given with sargramostim in treating patients with metastatic prostate cancer. Monoclonal antibodies can locate tumor cells and either kill them or deliver tumor-killing substances to them without harming normal cells. Colony-stimulating factors, such as sargramostim, may increase the number of immune cells found in bone marrow or peripheral blood and may help a person's immune system kill more tumor cells.

PRIMARY OBJECTIVES: I. Determine the maximum tolerated dose of anti-cytotoxic T-lymphocyte-associated antigen-4 monoclonal antibody (MDX-010) (ipilimumab) administered with sargramostim (GM-CSF) in patients with metastatic androgen-independent prostate cancer. (Phase I) II. Determine the safety of this regimen in these patients. (Phase I) III. Evaluate the efficacy as measured by reduction in PSA associated with combining GM-CSF with CTLA-4 blockade with ipilimumab at a dosage of 3 mg/kg given monthly x 6 doses (d1 of courses 1-6). (Cohort Expansion) SECONDARY OBJECTIVES: I. Determine the T-cell immunity and T-cell response in patients treated with this regimen. (Phase I) II. Determine the pharmacokinetics of MDX-010 in these patients. (Phase I) III. Determine the prostate-specific antigen and/or objective responses in patients treated with this regimen. (Phase I) IV. Determine the percentages of activated, naive, and memory T-cells. (Cohort Expansion) V. Determine the measurement of T-cell response to describe epitopes from prostate antigens including PSA, PSMA, and PAP. (Cohort Expansion) VI. Quantitate T-cell response to antigens in patients with relevant HLA allele using HLA\*0201 tetramers. (Cohort Expansion) VII. Evaluate the toxicity of this regimen in these patients. (Cohort Expansion) VIII. Determine the initial efficacy as measured by reduction in PSA associated with combining GM-CSF with CTLA-4 blockade with ipilimumab at a dosage of 3 mg/kg given monthly x 6 doses (d1 of courses 1-6). (Cohort Expansion) IX. Determine objective response by post-therapy measurable disease changes using RECIST criteria. (Cohort Expansion) OUTLINE: This is a multicenter, dose-escalation study of ipilimumab. Patients receive ipilimumab intravenously (IV) over 90 minutes on day 1 and sargramostim (GM-CSF) subcutaneously (SC) on days 1-14. Treatment repeats every 28 days for 4-6 courses. GM-CSF continues beyond 4 courses in the absence of disease progression or unacceptable toxicity. Cohorts of 3-6 patients receive escalating doses of ipilimumab until the maximum tolerated dose (MTD) is determined. The MTD is defined as the dose preceding that at which 2 of 3 or 2 of 6 patients experience dose-limiting toxicity. Some patients undergo blood sample collection periodically for laboratory and pharmacokinetic studies. Samples are analyzed for human anti-human antibodies, IgG antibodies to ipilimumab semi-quantitative ELISA assay, and plasma concentrations of ipilimumab via quantitative ELISA assay. Patients are followed at 30 days.