Stereotactic Radiation Therapy and Ipilimumab in Treating Patients With Metastatic Melanoma

PRIMARY OBJECTIVES: I. To determine the progression-free survival of patients with oligometastatic melanoma treated with the combination of stereotactic ablative radiation therapy (SABR) (stereotactic radiosurgery) and ipilimumab in patients with oligometastatic melanoma using modified World Health Organization (mWHO) criteria. SECONDARY OBJECTIVES: I. To evaluate the 6-month progression-free survival of the combination of SABR and 3 mg/kg ipilimumab in patients with oligometastatic melanoma using immune related response criteria (irRC) criteria. II. To evaluate the tolerability and safety of the combination. III. To evaluate the response rate based on mWHO \& irRC criteria. IV. To evaluate the local control rate. V. To evaluate the overall survival rate. TERTIARY OBJECTIVES: I. Evaluate changes in blood and serum markers: absolute lymphocyte count, T-cell activation markers, T-cell suppression markers, T-helper cells and related cytokines, T-regulatory (T-reg) markers, co-stimulatory molecules, and serum cytokines when SABR is added to the ipilimumab regimen. II. Evaluate genomic deoxyribonucleic acid (DNA) mutations in key melanoma genes and their correlation with response, progression-free survival, and overall survival. OUTLINE: Patients receive ipilimumab intravenously (IV) over 90 minutes on day 1 in weeks 1, 4, 7, and 10. Treatment repeats every 3 weeks for up to 4 total doses in the absence of disease progression or unacceptable toxicity. At approximately 5-6 weeks, patients undergo stereotactic radiosurgery over 2-3 days per week. Patients with stable disease or confirmed partial or complete response after completion of ipilimumab therapy at week 12 may receive re-induction ipilimumab at the discretion of the treating physician. After completion of study treatment, patients are followed up at 30 and 90 days, every 3 months for 2 years, every 6 months for 3 years, and then annually for 5 years.