A Multi-Institutional Phase 2 Study of Nivolumab or Nivolumab in Combination With Ipilimumab in Refractory Metastatic Squamous Cell Carcinoma of the Anal Canal

This phase II trial studies how well nivolumab with or without ipilimumab works in treating patients with anal canal cancer that has not responded to previous treatment (refractory) and has spread to other places in the body (metastatic). Immunotherapy with monoclonal antibodies, such as nivolumab and ipilimumab, may help the body's immune system attack the cancer, and may interfere with the ability of tumor cells to grow and spread.