BACKGROUND: Programmed cell death protein-1 (PD1) antibodies are currently the standard treatment for resected high-risk melanoma, yet recurrence rate remains high. OBJECTIVES: This real-life observational study aimed to describe the outcomes of patients with resected high-risk melanoma following adjuvant anti-PD1 immunotherapy and identify factors associated with recurrence risk. MATERIALS AND METHODS: A total of 235 patients with resected stage III/IV melanoma treated with adjuvant nivolumab or pembrolizumab were included. Imaging scans and cerebral imaging were performed every 12 weeks to detect recurrences. Adverse events were collected. Univariate and multivariate analyses were performed to identify predictive factors of recurrence. Overall survival (OS) and recurrence-free survival (RFS) were estimated. RESULTS: Among the 235 patients, 103 experienced at least one recurrence (43%); first recurrences were predominantly locoregional (47%). The predictive factor for recurrence identified by multivariate analysis was ulceration (RR 2,03, 95% CI [1,20; 2,86]). RFS was estimated at 75% [70-81] at 12 months and at 64% [58-71] at 24 months. RFS at 12 months was significantly lower in patients with ulcerations (RFS at 83%) compared to those without ulceration (RFS at 66%), p < 0.01. Overall survival (OS) was estimated at 91% [87%-94%] at 12 months and 84% [79%-89%] at 24 months. The OS after a first recurrence was estimated at 69% [60%-80%] at 12 months and decreased to 43% [32%-57%] at 24 months. After a first locoregional recurrence, surgery with a year of adjuvant immunotherapy (40%) was the favoured therapeutic approach. For distant recurrences, clinical trial enrolment was preferred (21%). Double curative immunotherapy was the preferred strategy for cerebral recurrences (30%). CONCLUSIONS: In this cohort, nearly half of the patients underwent recurrences and RFS at 24 months was 64%. The RFS and OS data were comparable o those reported in the pivotal study Ulceration was the only significant predictive factor for recurrence, associated with decreased RFS at 24 months.
