PDCD1 and melanoma: For example, in the CheckMate 067 study, melanoma patients receiving combined anti–PD-1 and anti–CTLA-4 therapy led to 52% 5-year overall survival (OS) in the entire cohort, 44% in the nivolumab group, and 26% in the ipilimumab group, but 96% of patients had an associated irAE, including 59% with grade 3–4 irAEs [4].