Evaluation of Two Dosing Regimens for Nivolumab in Combination With Ipilimumab in Patients With Advanced Melanoma: Results From the Phase IIIb/IV CheckMate 511 Trial

Abstract

Purpose: Nivolumab 1 mg/kg plus ipilimumab 3 mg/kg (NIVO1+IPI3) is approved for first-line treatment of patients with advanced melanoma in several countries. We conducted a phase IIIb/IV study (CheckMate 511) to determine if nivolumab 3 mg/kg plus ipilimumab 1 mg/kg (NIVO3+IPI1) improves the safety profile of the combination.

Patients and methods: Patients (N = 360) age 18 years or older with previously untreated, unresectable stage III or IV melanoma were randomly assigned 1:1 to NIVO3+IPI1 or NIVO1+IPI3 once every 3 weeks for four doses. After 6 weeks, all patients received NIVO 480 mg once every 4 weeks until disease progression or unacceptable toxicity. The primary end point was a comparison of the incidence of treatment-related grade 3 to 5 adverse events (AEs) between groups. Secondary end points included descriptive analyses of objective response rate, progression-free survival, and overall survival. The study was not designed to formally demonstrate noninferiority of NIVO3+IPI1 to NIVO1+IPI3 for efficacy end points.

Results: At a minimum follow-up of 12 months, incidence of treatment-related grade 3 to 5 AEs was 34% with NIVO3+IPI1 versus 48% with NIVO1+IPI3 ( P = .006). In descriptive analyses, objective response rate was 45.6% in the NIVO3+IPI1 group and 50.6% in the NIVO1+IPI3 group, with complete responses in 15.0% and 13.5% of patients, respectively. Median progression-free survival was 9.9 months in the NIVO3+IPI1 group and 8.9 months in the NIVO1+IPI3 group. Median overall survival was not reached in either group.

Conclusion: The CheckMate 511 study met its primary end point, demonstrating a significantly lower incidence of treatment-related grade 3-5 AEs with NIVO3+IPI1 versus NIVO1+IPI3. Descriptive analyses showed that there were no meaningful differences between the groups for any efficacy end point, although longer follow up may help to better characterize efficacy outcomes.

Trial registration: ClinicalTrials.gov NCT02714218.

FIG 1.

CONSORT diagram. Patient disposition as of June 1, 2018.

FIG 2.

Kaplan-Meier plot of (A) progression-free survival (PFS) and (B) overall survival (OS) in patients who received NIVO3+IPI1 (nivolumab 3 mg/kg plus ipilimumab 1 mg/kg) or NIVO1+IPI3 (nivolumab 1 mg/kg plus ipilimumab 3 mg/kg). Symbols indicate censored observations. Median PFS was 9.92 months in the NIVO3+IPI1 group and 8.94 months in the NIVO1+IPI3 group (hazard ratio, 1.06; 95% CI, 0.79 to 1.42). Median OS was not reached in either group (hazard ratio, 1.09; 95% CI, 0.73 to 1.62).