Background: NIVO (anti-PD-1) and IPI (anti-CTLA-4), alone and in combination, are approved for the treatment of MEL. Phase II and III trials showed improved efficacy for NIVO+IPI versus IPI alone, but with a higher frequency of adverse events (AEs). In the phase II CheckMate 069 trial, the 2-year OS rate was 63.8% for all patients (pts) in the NIVO+IPI group. We report the first OS analysis, as well as updated safety data, from a North American EAP of NIVO+IPI in pts with MEL (CheckMate 218; NCT02186249). Methods: CheckMate 218 included pts with MEL who could have progressed on other therapies, but were anti-CTLA-4 and anti-PD-1 treatment-naive. Pts received NIVO 1 mg/kg + IPI 3 mg/kg Q3W x 4, followed by NIVO 3 mg/kg Q2W until disease progression or a maximum of 48 weeks from the first monotherapy dose. We assessed OS in the US cohort (n = 580) and safety in all pts (n = 732). Pts were followed for a minimum of 1 year in the USA and 6 months in Canada. Results: Of 732 pts, 43% had a BRAFmutation, 84% stage IV MEL, 51% M1c disease, 31% LDH > ULN (9% LDH > 2x ULN), and 13% received ≥1 prior systemic therapy in the metastatic setting. All pts received a median of 3 doses each for NIVO (range: 1–4) and IPI (range: 0–4) in the induction phase; 34% of pts received at least 1 dose of NIVO maintenance. The 1- and 2-year OS rates were 78.6% (95% CI: 74.2–82.4) and 65.3% (95% CI: 56.1–73.0), respectively. AEs of any grade occurred in 717 pts (98%), with grade 3/4 AEs in 470 pts (64%). Immune-modulating medications were used to manage any grade AEs, including grade 1/2 skin and gastrointestinal AEs, in 538 of 717 pts (75%), and to manage grade 3/4 AEs in 279 of 470 pts (59%). The most common treatment-related AEs of any grade were diarrhea (39%), pruritus (26%), and an increase in aspartate aminotransferase level (23%). Treatment-related deaths in 2 pts were reported as drug-induced liver injury and myocardial infarction. Conclusions: In this EAP, which included pts who had received prior systemic therapies for MEL and pts with poor prognostic factors generally not included in clinical trials, NIVO+IPI treatment demonstrated survival outcomes and a safety profile consistent with clinical trial data. Clinical trial information: NCT02186249