84O Neoadjuvant nivolumab (N) + platinum-doublet chemotherapy (C) for resectable NSCLC: 3-y update from CheckMate 816

The phase III CheckMate 816 study demonstrated statistically significant and clinically meaningful improvements in event-free survival (EFS) and pathologic complete response (pCR) with neoadjuvant N + C vs C in patients (pts) with resectable NSCLC. Here, we report 3-y efficacy, safety, and exploratory biomarker analyses from CheckMate 816. Adults with stage IB (tumors ≥4 cm)–IIIA (per AJCC 7th ed) resectable NSCLC, ECOG PS ≤ 1, and no known EGFR/ALK alterations were randomized to N 360 mg + C Q3W or C alone Q3W for 3 cycles followed by surgery. Primary endpoints were EFS and pCR, both per blinded independent review. Exploratory analyses included EFS by surgical approach and extent/completeness of resection, and EFS and pCR by a 4-gene (CD8A, CD274, STAT-1, LAG-3) inflammatory signature score derived from RNA sequencing of baseline (BL) tumor samples. At a median follow-up of 41.4 mo (database lock, Oct 14, 2022), continued EFS benefit was observed with N + C vs C (HR, 0.68; 95% CI, 0.49–0.93); 3-y EFS rates were 57% and 43%, respectively. N + C improved EFS vs C in pts who had surgery, regardless of surgical approach or extent of resection, and in pts with R0 resection (table). Recurrence occurred in 28% and 42% of pts who had surgery in the N + C (n = 149) and C arms (n = 135), respectively. In the N + C arm, BL 4-gene inflammatory signature scores were numerically higher in pts with pCR vs pts without, and EFS was improved in pts with high vs low scores (data to be presented). Grade 3–4 treatment-related and surgery-related adverse events occurred in 36% and 11% of pts in the N + C arm, respectively, vs 38% and 15% in the C arm. Neoadjuvant N + C continues to provide long-term clinical benefit vs C in pts with resectable NSCLC, regardless of surgical approach or extent of resection. Exploratory analyses in pts treated with N + C suggested that high BL tumor inflammation may be associated with improved EFS and pCR.