Nivolumab, marketed as Opdivo, is a medication used to treat cancer. It is used as a first line treatment for inoperable or metastatic melanoma in combination with ipilimumab if the cancer does not have a mutation in BRAF, as a second-line treatment following treatment with ipilimumab and if the cancer has a mutation in BRAF, with a BRAF inhibitor, as a second-line treatment for squamous non-small cell lung cancer, and as a second-line treatment for renal cell carcinoma.