Clinical outcomes with perioperative nivolumab (NIVO) by nodal status among patients (pts) with stage III resectable NSCLC: Results from the phase 3 CheckMate 77T study.

LBA8007 Background: In CheckMate 77T, perioperative NIVO showed statistically significant EFS improvement vs neoadjuvant (neoadj) chemo followed by adjuvant (adj) placebo (PBO) in pts with stage (stg) II or III resectable NSCLC. We report clinical outcomes by baseline (BL) stg III N2 status, a subgroup with poor historical 5 y survival (26%–36%; Goldstraw J Thorac Oncol 2016). Methods: Adults with resectable stg IIA–IIIB (N2; AJCC v8) NSCLC were randomized to neoadj NIVO 360 mg Q3W + chemo (4 cycles cyc) followed by adj NIVO 480 mg Q4W (13 cyc) or neoadj PBO Q3W + chemo (4 cyc) followed by adj PBO Q4W (13 cyc). Primary endpoint: EFS per BICR. Exploratory analysis: efficacy and safety in pts with BL clinical stg III N2 or non N2 disease (dz). Results: BL characteristics were generally similar between pts with stg III N2 (NIVO, 91; PBO, 90) and non N2 dz (55; 57), and between treatment (tx) arms, except a higher percent of pts with N2 dz had NSQ histology and ECOG PS 0 (both arms). Pts with N2 dz had improved EFS with NIVO vs PBO (HR 0.46; 1 y EFS 70% vs 45%) and higher pCR (22.0% vs 5.6%; median f/u 25.4 mo; Table). Pts with non N2 also had EFS benefit with NIVO vs PBO (HR 0.60; 1 y EFS 74% vs 62%) and higher pCR (25.5% vs 5.3%; Table). Surgical feasibility was similar between pts with N2 and non N2 dz and numerically higher with NIVO vs PBO. Of pts with N2 dz, 77% (NIVO) vs 73% (PBO) had definitive surgery (pneumonectomy 1% vs 14%; R0 resection 86% vs 86%); of pts with non N2 dz, 82% vs 79% had definitive surgery (pneumonectomy 13% vs 9%; R0 resection 84% vs 87%). Tumor downstaging postsurgery was seen in most pts with stg III dz and was deeper with NIVO vs PBO: 61% vs 50% (N2; 33% vs 14% to ypT0), 87% vs 76% (non N2; 27% vs 11% to ypT0). Of all pts with stg III dz, nodal downstaging postsurgery was 52% (NIVO) vs 45% (PBO); 46% vs 36% to ypN0. Grade 3–4 TRAEs occurred in 34% (NIVO) and 26% (PBO) of pts with N2; 29% and 21% of pts with non N2 dz. Conclusions: In this exploratory analysis, perioperative NIVO showed clinical benefit vs PBO in pts with stg III NSCLC, regardless of N2 status. Over half of pts with stg III dz had nodal downstaging with NIVO; majority downstaged to ypN0. This first comprehensive analysis by nodal status among pts with stg III dz from a global phase 3 study of perioperative immunotherapy further supports perioperative NIVO as a tx option for pts with resectable NSCLC. Clinical trial information: NCT04025879 . Table: see text