Efficacy and safety of nivolumab in combination with ipilimumab in Japanese patients with advanced melanoma: An open-label, single-arm, multicentre phase II study

Aim: The aim of the study was to evaluate the efficacy and safety of nivolumab combined with ipilimumab in treatment-naïve Japanese patients with advanced melanoma. Methods: In this multicentre, single-arm study, treatment-naïve Japanese patients with unresectable stage III/IV or recurrent melanoma received nivolumab (1 mg/kg) plus ipilimumab (3 mg/kg) every 3 weeks for four doses, followed by biweekly doses of nivolumab (3 mg/kg). The primary end-point was centrally assessed objective response rate (ORR). Secondary end-points included overall survival (OS), progression-free survival (PFS), disease control rate and safety. Results: The subtypes of the thirty patients enrolled were: 12, mucosal; eight, non-acral cutaneous; seven, acral; two, uveal and one, unknown primary melanoma. The ORR was 43.3% (95% confidence interval [CI]: 25.5, 62.6) with central and local assessment. The centrally and locally assessed disease control rate (95% CI) were 73.3% (54.1, 87.7) and 86.7% (69.3, 96.2), respectively. At the median follow-up period of 14.1 months (range 5.2–27.7), median OS and centrally assessed PFS were not reached. OS (95% CI) at 6, 12, 18 and 24 months was 93.3% (75.9, 98.3), 83.3% (64.5, 92.7), 72.9% (50.0, 86.5) and 65.6% (40.4, 82.2), respectively. Treatment-related adverse events (AEs) occurred in all patients. Grade III–IV and serious AEs occurred, mostly during the combination phase, in 23 (76.7%) and 20 (66.7%) patients, respectively. No treatment-related deaths occurred. Conclusions: This study confirmed the efficacy and safety of nivolumab plus ipilimumab in treatment-naïve Japanese patients with advanced melanoma including rare subtypes. Incidence rates for grade III–IV AEs were high but manageable with appropriate medical attention and treatment. Trial registration: JapicCTI-152869.