CTLA4 and metastatic melanoma: CheckMate 037 was a phase III trial on patients with metastatic melanoma who progressed on or after anti-CTLA-4 therapy and a BRAF inhibitor (if BRAF V600 mutation positive) which demonstrated the efficacy of nivolumab compared to the investigator’s choice of chemotherapy, with an overall response rate (ORR) of 32 vs. 11% [68].