Real-world efficacy and safety data of nivolumab and ipilimumab combination therapy in Japanese patients with advanced melanoma.

The efficacy and safety of nivolumab + ipilimumab combination therapy were retrospectively examined in Japanese patients with unresectable advanced melanoma in clinical practice. Fifty-seven patients with advanced melanoma received the nivolumab + ipilimumab combination therapy. The primary site was cutaneous, mucosal, uveal and unknown in 35, 16, two and four patients, respectively. The overall response rate was 26.3%, with complete response observed in two (3.5%) patients, partial response in 13 (22.8%), stable disease in 12 (21.1%) and progressive disease in 30 (52.6%). The response rate in the treatment-naive and prior systemic therapy group was 40.7% and 13.3%, respectively. For those treated with a single immune checkpoint inhibitor followed by the nivolumab + ipilimumab combination therapy as second-line therapy after disease progression, the response rate was 18.8%. Median progression-free survival (PFS) and overall survival (OS) in all patients was 3.3 and 14 months, respectively. Median PFS in the treatment-naive and prior systemic therapy groups was 13 and 2 months, respectively. Median OS was unreached in the treatment-naive group and was 6.3 months in prior systemic therapy groups. There was no significant difference in PFS and OS for non-acral, acral and mucosal melanoma. Adverse events occurred in 86% of patients; 56.1% were grade 3 or worse. The response rate in an actual clinical setting, including the prior systemic therapy group, was lower than that in the global study and the Japanese phase II study. However, in the treatment-naive group, the rate was equivalent to that in the Japanese phase II study. PFS and OS in the treatment-naive group were comparable with those in the global study and Japanese phase II study, suggesting that the treatment was effective. The proportion of grade 3 and 4 immune-related adverse events was as high as that in the global study and Japanese phase II study.