Adjuvant nivolumab (NIVO) in resected esophageal or gastroesophageal junction cancer (EC/GEJC) following neoadjuvant chemoradiotherapy (CRT): Expanded efficacy and safety analyses from CheckMate 577.

4003 Background: In CheckMate 577 (NCT02743494), NIVO demonstrated a significant and clinically meaningful improvement in disease-free survival (DFS; primary endpoint) vs placebo (PBO) and was well tolerated in patients (pts) with resected (R0) stage II/III EC/GEJC who received neoadjuvant CRT and had residual pathologic disease. Median DFS doubled with NIVO vs PBO (22.4 vs 11.0 months; HR 0.69; 96.4% CI 0.56–0.86; P = 0.0003). Serious treatment-related adverse events (TRAEs) and TRAEs leading to discontinuation were reported for < 10% of pts with NIVO and 3% with PBO. Methods: Pts were randomized 2:1 to NIVO 240 mg or PBO Q2W for 16 weeks, followed by NIVO 480 mg or PBO Q4W. Here, we p…