BACKGROUND: CheckMate 649 (NCT02872116) is a randomized, open label phase 3 study in first line (1L) GC/GEJC/EAC. Prespecified interim results showed statistically significant improvement in overall survival (OS) and progression-free survival (PFS) for N+C vs. C in all randomized pts and pts whose tumors expressed programmed death-ligand 1 combined positive score (CPS) ≥ 5. We present interim HRQOL results for CPS ≥ 5 pts, included as exploratory in the study.
METHODS: HRQOL was assessed using EQ-5D-3L (EQ-5D) and Functional Assessment of Cancer Therapy–Gastric Cancer (FACT-Ga). Assessments were performed at baseline (BL), every 6 weeks during treatment, and during follow-up. Change from BL EQ-5D Visual Analog Scale (VAS), Utility Index (UI) and FACT-Ga scores were analyzed using mixed models. Time to first symptom deterioration (TTSD), time until definitive deterioration (TuDD), and time to improvement (TTI) were estimated with Kaplan-Meier estimators and stratified Cox models; deterioration/improvement was based on prespecified meaningful change thresholds.
RESULTS: 1,581 pts were randomized to N+C (n = 789) and C (n = 792); of those, 955 pts had CPS ≥ 5 (N+C [n = 473] and C [n = 482]). Among 821 pts with BL and post BL PROs (N+C [n = 421] and C [n = 400]), BL scores for FACT-Ga total were similar for N+C and C. Least-squares mean differences from BL favored N+C at most visits for EQ-5D and FACT-Ga total and GaCS, and were comparable for other FACT subscales (data not shown). TTI largely favored N+C (most hazard ratios (HR) > 1) but was not significantly different between treatments. For TTSD, pts treated with N+C had decreased risk of deterioration (HR < 1) in EQ-5D UI, FACT-Ga total, and GaCS. TuDD showed statistically significant delays in deterioration (HR with confidence intervals [CI] < 1) for all scores.
