CTLA4 and metastatic melanoma: Ipilimumab, an anti–CTLA-4 antibody, was approved by the FDA in 2011 for metastatic melanoma.12 The approval was based on results of a phase 3 trial involving patients with pretreated metastatic melanoma and showed an overall survival benefit compared with the glycoprotein 100 peptide vaccine (ie, 10.1 months with ipilimumab [3 mg/kg intravenously every 3 weeks] vs 6.4 months with glycoprotein 100; hazard ratio [HR], 0.66; P = .003).12