Pembrolizumab is significantly better than ipilimumab in terms of progression-free survival, overall survival, and the proportion of patients achieving an overall response for treat ment of advanced melanoma, according to a new study. The randomised phase 3 trial compared ipilimumab with pembrolizumab given every 2 weeks or every 3 weeks. 834 patients with un resectable stage III or IV melanoma were evenly assigned to one of the three groups. Median estimates of progression-free survival were 5· 5 months (95% CI 3· 4–6· 9) for patients receiving pembrolizumab every 2 weeks, 4· 1 months (2· 9–6· 9) for those receiving pembrolizumab every 3 weeks, and 2· 8 months (2· 8–2· 9) for those receiving ipilimumab. Hazard ratios for disease progression for pembrolizumab versus ipilimumab were 0· 58 (95% CI 0· 46–0· 72; p< 0· 001) for the 2-week regimen and 0· 58