Real-world efficacy of anti-PD-1 antibodies in advanced acral melanoma patients: A retrospective, multicenter study (JAMP study).

Abstract

9529 Background: Anti-PD-1 antibodies are used worldwide for patients (pts) with advanced melanoma. Clinical trials have demonstrated its efficacy and safety for nonacral cutaneous melanoma (NACM) in controlled settings. Since acral melanoma (AM) is epidemiologically and molecularly distinct from NACM, data on the real-world efficacy of anti-PD1 antibodies in advanced AM is still lacking. Thus, we aim to analyze the real-world efficacy and safety of anti-PD-1 antibodies in advanced AM. Methods: We retrospectively reviewed clinical records of advanced AM treated in any line with an anti-PD1 antibody at 21 Japanese institutions. Clinical response was assessed by (Response Evaluation Criteria in Solid Tumors) RECIST criteria. Survival was estimated using Kaplan-Meier analysis. Toxicity was assessed according to CTCAE 4.0. Results: A total of 193 pts (median age, 71 years) with advanced AM (subungual, 70; palm and sole, 123) were included in the study. Anti-PD-1 antibody was used as first-line therapy in 143 pts (74.1%). Nivolumab was used in 168 pts and pembrolizumab in 25 pts. Base-line lactate dehydrogenase (LDH) was within normal level in 102 pts (52.8%). The objective response rate (ORR) of all pts was 16.5% (complete response 3.1%, partial response 13.5%), and median overall survival (OS) was 18.1 months. Normal LDH level was significantly associated with better prognosis than abnormal level (median OS 24.9 vs 10.7 months; P < 0.001). Although baseline demographics and characteristics were almost similar between subungual group and palm and sole group, ORR was significantly lower in the subungual group than in palm and sole group (6/70 pts [8.6%] vs 26/123 pts [21.1%]; P = 0.026); median OS was significantly poorer as well (12.8 vs 22.3 months; P = 0.031). Immune-related adverse events of grades 3 to 5 occurred in 27 pts (14.0%). One patient (0.5%) died of grade 5 myasthenia gravis. Conclusions: Real-world efficacy of anti-PD-1 antibodies in AM pts is limited. Notably, pts with subungual melanoma showed poorer response and survival, making them strong candidates for further research of efficacy of anti-CTLA-4 and anti-PD-1 combination therapy.