Updated analysis of nivolumab and ipilimumab combination therapy in Japanese patients with advanced melanoma

The efficacy and safety of nivolumab and ipilimumab (N + I) combination therapy for Japanese patients with advanced unresectable melanoma was re-evaluated in clinical practice. One hundred Japanese patients with advanced melanoma were included. The overall response rate was 24%; complete response (CR), 6%; partial response, 18%. The response rates were 33.3% in the systemic therapynaive and 15.4% in the prior-treatment groups, and 16.1% for patients who were treated with first-line anti-programmed death 1 antibody monotherapy followed by second-line N + I therapy after progression of the disease. The response rate for cutaneous melanoma was 32.7%, and 47.8% in the naive group. Response rates for non-acral, acral, and mucosal melanoma were 34.9%, 25%, and 16.7%, respectively. The median progression-free survival (PFS) for all patients was 3.25 months (6.5 and 2.5 months in the naive and prior-treatment groups, respectively). Median overall survival (OS) was 14.5 months (25.25 and 7.5 months in the naive and prior-treatment groups, respectively). There were no significant differences in PFS or OS for patients with non-acral, acral, or mucosal melanoma. The 3-year PFS and OS were both 100% in patients who achieved CR with combination therapy. Adverse events occurred in 89% and were grade three or higher in 56% of cases. Although direct comparisons cannot be made due to different patient backgrounds, N + I combination therapy in Japanese patients in clinical practice tended to be inferior when compared to global study and non-Asian patients in clinical practice. The highest response rate was in the cutaneous melanoma therapy-naive group. The best tumor response was associated with survival outcome, and the PFS and OS were good in cases where CR was obtained. The proportion of grade three and four adverse events was as high as that in the global study.