Conditional survival and long‐term efficacy with nivolumab plus ipilimumab versus sunitinib in patients with advanced renal cell carcinoma

BACKGROUND: Conditional survival estimates provide critical prognostic information for patients with advanced renal cell carcinoma (aRCC). Efficacy, safety, and conditional survival outcomes were assessed in CheckMate 214 (ClinicalTrials.gov identifier NCT02231749) with a minimum follow‐up of 5 years. METHODS: Patients with untreated aRCC were randomized to receive nivolumab (NIVO) (3 mg/kg) plus ipilimumab (IPI) (1 mg/kg) every 3 weeks for 4 cycles, then either NIVO monotherapy or sunitinib (SUN) (50 mg) daily (four 6‐week cycles). Efficacy was assessed in intent‐to‐treat, International Metastatic Renal Cell Carcinoma Database Consortium intermediate‐risk/poor‐risk, and favorable‐risk populations. Conditional survival outcomes (the probability of remaining alive, progression free, or in response 2 years beyond a specified landmark) were analyzed. RESULTS: The median follow‐up was 67.7 months; overall survival (median, 55.7 vs 38.4 months; hazard ratio, 0.72), progression‐free survival (median, 12.3 vs 12.3 months; hazard ratio, 0.86), and objective response (39.3% vs 32.4%) benefits were maintained with NIVO+IPI versus SUN, respectively, in intent‐to‐treat patients (N = 550 vs 546). Point estimates for 2‐year conditional overall survival beyond the 3‐year landmark were higher with NIVO+IPI versus SUN (intent‐to‐treat patients, 81% vs 72%; intermediate‐risk/poor‐risk patients, 79% vs 72%; favorable‐risk patients, 85% vs 72%). Conditional progression‐free survival and response point estimates were also higher beyond 3 years with NIVO+IPI. Point estimates for conditional overall survival were higher or remained steady at each subsequent year of survival with NIVO+IPI in patients stratified by tumor programmed death ligand 1 expression, grade ≥3 immune‐mediated adverse event experience, body mass index, and age. CONCLUSIONS: Durable clinical benefits were observed with NIVO+IPI versus SUN at 5 years, the longest phase 3 follow‐up for a first‐line checkpoint inhibitor‐based combination in patients with aRCC. Conditional estimates indicate that most patients who remained alive or in response with NIVO+IPI at 3 years remained so at 5 years.