Anti-PD1 checkpoint inhibitor therapy in acral melanoma: a multicenter study of 193 Japanese patients

•Acral melanoma is a distinct entity that is underrepresented in clinical trials on immunotherapy in melanoma.•We retrospectively examined advanced-stage acral melanoma patients treated with an anti-PD-1 antibody.•Anti-PD-1 antibodies have limited efficacy in Japanese acral melanoma patients.•Patients with nail apparatus melanoma had poorer response and survival than patients with palm and sole melanoma. BackgroundAcral melanoma (AM) is an...