Characteristics and outcomes of advanced melanoma patients with complete response and elective discontinuation of first‐line anti‐programmed death‐1 monotherapy: A real‐world multicentre observational cohort study

Abstract

Anti‐programmed death‐1 (anti‐PD1) treatment has significantly improved outcomes of advanced melanoma with a considerable percentage of patients achieving complete response (CR). This real‐world study analyzed the feasibility of elective anti‐PD1 discontinuation in advanced melanoma patients with CR and evaluated factors related to sustained response. Thirty‐five patients with advanced cutaneous or primary unknown melanoma with CR to nivolumab or pembrolizumab from 11 centers were included. Mean age was 66.5 years, and 97.1% had ECOG PS 0–1. 28.6% had ≥3 metastatic sites with 58.8% having M1a‐M1b disease; 8.6% had liver and 5.7% had brain metastases. At baseline, 80% had normal LDH, and 85.7% had a neutrophil‐to‐lymphocyte ratio ≤3. 74.3% of patients had CR confirmed in PET‐CT. Median duration of anti‐PD1 was 23.4 months (range 1.3–50.5). 24 months after therapy discontinuation, 91.9% of patients were progression‐free. Estimated PFS and OS at 36, 48, and 60 months from the start of anti‐PD1 were 94.2%, 89.9%, 84.3%, and 97.1%, 93.3%, 93.3%, respectively. Antibiotics use after anti‐PD1 discontinuation increased the odds of progression (OR 16.53 [95% CI 1.7, 226.03]). The study confirms the feasibility of elective anti‐PD1 discontinuation in advanced melanoma patients with CR and favorable prognostic factors at baseline.