Nivolumab or Expectant Observation Following Ipilimumab, Nivolumab, and Surgery in Treating Patients With High Risk Localized, Locoregionally Advanced, or Recurrent Mucosal Melanoma

This randomized phase II trial studies how well nivolumab or expectant observation following ipilimumab, nivolumab, and surgery work in treating patients with high-risk mucosal melanoma that is restricted to the site of origin without evidence of spread, has spread to a local and regional area of the body, or has come back. Monoclonal antibodies, such as nivolumab and ipilimumab, may interfere with the ability of tumor cells to grow and spread. Sometimes the mucosal melanoma may not need more treatment until it progresses. In this case, observation may be sufficient. It is not known if nivolumab or expectant observation following ipilimumab, nivolumab, and surgery may be better in treating patients with mucosal melanoma.