Purpose

This randomized phase III trial studies how well pembrolizumab works compared with the current standard of care, physician/patient choice of either high-dose recombinant interferon alfa-2B or ipilimumab, in treating patients with stage III-IV melanoma that has been removed by surgery but is likely to come back or spread. High-dose recombinant interferon alfa-2B may help shrink or slow the growth of melanoma. Immunotherapy with monoclonal antibodies, such as ipilimumab and pembrolizumab, may help the body's immune system attack the cancer, and may interfere with the ability of tumor cells to grow and spread. It is not yet known whether pembrolizumab is more effective than the current standard of care in treating patients with melanoma.