194 A multicenter characterization of chronic toxicities following adjuvant anti-PD-1 therapy for high risk resected melanoma

Background Anti-programmed death-1 (anti-PD-1) therapies have improved long-term survival across many advanced cancers. However, chronic immune-related adverse events (irAEs) are not well-defined. We sought to determine the incidence, time-course, spectrum, and predictors of chronic irAEs arising from adjuvant anti-PD-1. Methods In this retrospective cohort, we analyzed patients from 8 academic medical centers with stage III-IV melanoma treated with anti-PD-1 in the adjuvant setting. Acute and chronic (persisting at least 3 months after therapy cessation) irAEs were characterized by type, time-course, management, and incidence. Results Among 387 patients, most were male (60.7%) with a median age of 63 years, had cutaneous primaries (85.8%), BRAF/NRAS WT (51.2%), and resected stage IIIb (33.1%) or IIIc (39.5%) melanomas. Median overall survival and relapse-free survival (RFS) were not reached. 359 patients (93.0%) were alive at median follow-up of 529 days. Patients with acute (p Conclusions Chronic irAEs to anti-PD-1 were more common than previously recognized and frequently persisted even with prolonged follow-up, although most were low-grade. The risks of chronic toxic effects should be integrated into treatment decision making. Ethics Approval This study was approved by the Vanderbilt Institutional Review Board