Prognostic and predictive value of AJCC-8 staging in the phase III EORTC1325/KEYNOTE-054 trial of pembrolizumab vs placebo in resected high-risk stage III melanoma

Abstract Background The American Joint Committee on Cancer-8 (AJCC) classification of melanoma was implemented in January 2018. It was based on data gathered when checkpoint inhibitors were not used as adjuvant therapy in stage III melanoma. The European Organization for Research and Treatment of Cancer (EORTC) 1325/KEYNOTE-054 double-blind phase III trial evaluated pembrolizumab vs placebo in AJCC-7 stage IIIA (excluding lymph node metastasis ≤1 mm), IIIB or IIIC (without in-transit metastasis) patients after complete lymphadenectomy. Patients, methods and results Patients (n = 1019) were randomised 1:1 to pembrolizumab 200 mg or placebo every 3 weeks (total of 18 doses, ∼1 year). At 1.25-year median follow-up, pembrolizumab prolonged relapse-free survival (RFS) in the total population (1-year RFS rate: 75.4% vs 61.0%; hazard ratio [HR] 0.57; logrank P  Conclusions AJCC-8 staging had a strong prognostic importance for RFS but no predictive importance: the RFS benefit of pembrolizumab was observed across AJCC-8 subgroups in resected high-risk stage III melanoma patients.