Adjuvant nivolumab in resected esophageal or gastroesophageal junction cancer (EC/GEJC) following neoadjuvant chemoradiotherapy (CRT): First results of overall survival (OS) from CheckMate 577.
Ronan J. Kelly, Jaffer A. Ajani, Jarosław Kużdżał, Thomas Zander, Eric Van Cutsem, Guillaume Piessen, Guillermo Méndez, Josephine Feliciano, Satoru Motoyama, Astrid Lièvre, Hope E. Uronis, Elena Elimova, Cecile Grootscholten, Karen Geboes, Jenny Zhang, Stephen McCraith, Beilei He, Ming Lei, James M. Cleary, Markus Moehler
Abstract
4000 Background: At 24.4-month (mo) median follow-up, adjuvant nivolumab demonstrated a statistically significant and clinically meaningful improvement in disease-free survival (DFS) vs placebo with a well-tolerated safety profile in patients (pts) with resected EC/GEJC with residual pathologic disease following neoadjuvant CRT and surgery in the primary analysis from the global, phase 3 CheckMate 577 study (NCT02743494). We report the final analysis of the hierarchically tested secondary endpoint of OS along with longer follow-up of DFS. Methods: Adults with resected (R0) stage II/III EC/GEJC who received neoadjuvant CRT and had residual pathologic disease were randomized 2:1 to nivolumab 240 mg or placebo Q2W for 16 weeks, followed by nivolumab 480 mg or placebo Q4W. Maximum treatment duration was 1 year. The primary endpoint was DFS. OS was a secondary endpoint, and exploratory endpoints included safety, distant metastasis-free survival (DMFS), and progression-free survival on subsequent systemic therapy (PFS2). Results: 794 pts were randomized (nivolumab, n = 532; placebo, n = 262). With a median follow-up of 78.3 (range, 60.1–96.6) mo, adjuvant nivolumab continued to show DFS benefit vs placebo (HR 0.76 [95% CI 0.63–0.91]; Table). Median OS was numerically longer with nivolumab vs placebo (51.7 vs 35.3 mo), although the difference was not statistically significant (HR 0.85 [95.87% CI 0.70–1.04]; P = 0.1064; Table). OS rates at 3 and 5 years with nivolumab vs placebo were 57% vs 50% and 46% vs 41%, respectively. OS subgroup analyses will be presented. Clinically meaningful improvement in DMFS with nivolumab vs placebo was maintained (Table). PFS2 favored nivolumab vs placebo (HR 0.81 [95% CI 0.67–0.98]). In the nivolumab group, 46% of pts received subsequent therapy vs 60% in the placebo group; 5% vs 15% received subsequent immunotherapy. No new safety signals were identified. Conclusions: Adjuvant nivolumab demonstrated sustained long-term DFS benefit and numerical improvement in OS vs placebo in pts with resected EC/GEJC and residual pathologic disease following neoadjuvant CRT. The safety profile of adjuvant nivolumab remained well-tolerated with longer follow-up. These results further support the use of adjuvant nivolumab in this pt population. Clinical trial information: NCT02743494 . Efficacy Nivolumab(n = 532) Placebo(n = 262) Median DFS (95% CI), mo 21.8 (16.6–29.7) 10.8 (8.3–14.3) HR (95% CI) 0.76 (0.63–0.91) Median OS (95% CI), mo 51.7 (41.0–61.6) 35.3 (30.7–48.8) HR (95.87% CI; P value) 0.85 (0.70–1.04; P = 0.1064) Median DMFS (95% CI), mo 27.3 (21.4–36.0) 14.6 (10.9–20.3) HR (95% CI) 0.75 (0.62–0.90) Safety, n (%) n = 532 n = 260 Any-grade/grade 3–4 TRAEs 379 (71)/75 (14) 124 (48)/17 (7) Any-grade/grade 3–4 TRAEs leading to discontinuation 48 (9)/26 (5) 8 (3)/7 (3) TRAE, treatment-related adverse event.