Background The results of phase 1 and phase 2 studies suggest that nivolumab (a PD-1 checkpoint inhibitor) and ipilimumab (a CTLA-4 checkpoint inhibitor) have complementary activity in metastatic melanoma. In this randomized, double-blind, phase 3 study, nivolumab alone or nivolumab combined with ipilimumab versus ipilimumab alone were evaluated in patients with metastatic melanoma. Methods We randomly assigned 945 previously untreated patients with unresectable stage III or IV melanoma, in 1:1:1 ratio, to nivolumab alone (3 mg per kilogram of body weight every 2 weeks), or to nivolumab (at a dose of 1 mg per kilogram) plus ipilimumab (at a dose of 3 mg per kilogram) every 3 weeks for 4 doses followed by nivolumab (3 mg per kilogram every 2 weeks), or to ipilimumab alone (3 mg per kilogram every 3 weeks for 4 doses). Progression-free and overall survival were co-primary end points. Patients continue to be followed for overall survival. Results Median progression-free survival was 11.5 months (95% confidence interval [CI], 8.9 to 16.7) for nivolumab plus ipilimumab as compared with 2.9 months (95% CI, 2.8 to 3.4) for ipilimumab alone (hazard ratio, 0.42; 95% CI, 0.31 to 0.57; P<0.00001), and was 6.9 months (95% CI, 4.3 to 9.5) for nivolumab alone (hazard ratio in the comparison with ipilimumab alone, 0.57; 95% CI, 0.43 to 0.76; P<0.00001). In PD-L1-positive patients, median progression-free survival was 14.0 months in both the nivolumab plus ipilimumab and nivolumab alone groups, but in PD-L1-negative patients, progression-free survival was longer with the combination as compared with nivolumab alone (11.2 months [95% CI, 8.0 to not reached] versus 5.3 months [95% CI, 2.8 to 7.1]). Grade 3–4 drug-related adverse events occurred in 16.3%, 55.0%, and 27.3% of patients in the nivolumab, nivolumab plus ipilimumab, and ipilimumab alone groups, with 1, 0, and 1 drug-related deaths, respectively. Conclusions Nivolumab alone or combined with ipilimumab significantly improved progression-free survival, as compared with ipilimumab, among previously untreated patients with metastatic melanoma. Results with the combination versus either agent alone suggest complementary activity between PD-1 and CTLA-4 blockade, particularly for patients with PD-L1-negative tumors. (Funded by Bristol-Myers Squibb; CheckMate 067, ClinicalTrials.gov number, NCT01844505.)

The anti-PD-1 antibody pembrolizumab prolonged progression-free survival and overall survival and had less high-grade toxicity than did ipilimumab in patients with advanced melanoma. (Funded by Merck Sharp & Dohme; KEYNOTE-006 ClinicalTrials.gov number, NCT01866319.).

BACKGROUND Nivolumab combined with ipilimumab resulted in longer progression-free survival and a higher objective response rate than ipilimumab alone in a phase 3 trial involving patients with advanced melanoma. We now report 3-year overall survival outcomes in this trial. METHODS We randomly assigned, in a 1:1:1 ratio, patients with previously untreated advanced melanoma to receive nivolumab at a dose of 1 mg per kilogram of body weight plus ipilimumab at a dose of 3 mg per kilogram every 3 weeks for four doses, followed by nivolumab at a dose of 3 mg per kilogram every 2 weeks; nivolumab at a dose of 3 mg per kilogram every 2 weeks plus placebo; or ipilimumab at a dose of 3 mg per kilogram every 3 weeks for four doses plus placebo, until progression, the occurrence of unacceptable toxic effects, or withdrawal of consent. Randomization was stratified according to programmed death ligand 1 (PD-L1) status, BRAF mutation status, and metastasis stage. The two primary end points were progression-free survival and overall survival in the nivolumab-plus-ipilimumab group and in the nivolumab group versus the ipilimumab group. RESULTS At a minimum follow-up of 36 months, the median overall survival had not been reached in the nivolumab-plus-ipilimumab group and was 37.6 months in the nivolumab group, as compared with 19.9 months in the ipilimumab group (hazard ratio for death with nivolumab plus ipilimumab vs. ipilimumab, 0.55 [P<0.001]; hazard ratio for death with nivolumab vs. ipilimumab, 0.65 [P<0.001]). The overall survival rate at 3 years was 58% in the nivolumab-plus-ipilimumab group and 52% in the nivolumab group, as compared with 34% in the ipilimumab group. The safety profile was unchanged from the initial report. Treatment-related adverse events of grade 3 or 4 occurred in 59% of the patients in the nivolumab-plus-ipilimumab group, in 21% of those in the nivolumab group, and in 28% of those in the ipilimumab group. CONCLUSIONS Among patients with advanced melanoma, significantly longer overall survival occurred with combination therapy with nivolumab plus ipilimumab or with nivolumab alone than with ipilimumab alone. (Funded by Bristol-Myers Squibb and others; CheckMate 067 ClinicalTrials.gov number, NCT01844505.)