Standard Versus Modified Ipilimumab, in Combination With Nivolumab, in Advanced Renal Cell Carcinoma: A Randomized Phase II Trial (PRISM).

PURPOSE:Ipilimumab (IPI), in combination with nivolumab (NIVO), is an approved frontline treatment option for patients with intermediate- or poor-risk advanced renal cell carcinoma (aRCC). We conducted a randomized phase II trial to evaluate whether administering IPI once every 12 weeks (modified), instead of once every 3 weeks (standard), in combination with NIVO, is associated with a favorable toxicity profile. METHODS:Treatment-naïve patients with clear-cell aRCC were randomly assigned 2:1 to receive four doses of modified or standard IPI, 1 mg/kg, in combination with NIVO (3 mg/kg). The primary end point was the proportion of patients with a grade 3-5 treatment-related adverse event (trAE) among those who received at least one dose of therapy. The key secondary end point was 12-month progression-free survival (PFS) in the modified arm compared with historical sunitinib control. The study was not designed to formally compare arms for efficacy. RESULTS:Between March 2018 and January 2020, 192 patients (69.8% intermediate/poor-risk) were randomly assigned and received at least one dose of study drug. The incidence of grade 3-5 trAEs was significantly lower among participants receiving modified versus standard IPI (32.8% v 53.1%; odds ratio, 0.43 [90% CI, 0.25 to 0.72]; P = .0075). The 12-month PFS (90% CI) using modified IPI was 46.1% (38.6 to 53.2). At a median follow-up of 21 months, the overall response rate was 45.3% versus 35.9% and the median PFS was 10.8 months versus 9.8 months in the modified and standard IPI groups, respectively. CONCLUSION:Rates of grade 3-5 trAEs were significantly lower in patients receiving modified versus standard IPI. Although 12-month PFS did not meet the prespecified efficacy threshold compared with historical control, informal comparison of treatment groups did not suggest any reduction in efficacy with the modified schedule.