This multicentre, double-blind, randomised, controlled, phase 3 trial was done in 130 academic centres, community hospitals, and cancer centres across 25 countries….4-year overall survival was 77·9% (95% CI 73·7-81·5) with nivolumab and 76·6% (72·2-80·3) with ipilimumab (HR 0·87 [95% CI 0·66-1·14]; p=0·31)....At a minimum of 4 years' follow-up, nivolumab demonstrated sustained recurrence-free survival benefit versus ipilimumab in resected stage IIIB-C or IV melanoma indicating a long-term treatment benefit with nivolumab.