Overall survival (OS) analysis of IMpower150, a randomized Ph 3 study of atezolizumab (atezo) + chemotherapy (chemo) ± bevacizumab (bev) vs chemo + bev in 1L nonsquamous (NSQ) NSCLC.

Abstract

9002 Background: Atezo (anti–PD-L1) inhibits PD-L1 to restore anticancer immunity; bev may enhance atezo efficacy by inhibiting VEGF immunosuppression and promoting T-cell tumor infiltration. IMpower150 is the first randomized Ph 3 trial evaluating atezo + chemo (carboplatin [C] + paclitaxel [P]) ± bev vs CP + bev in 1L NSQ NSCLC. PFS benefit was observed with atezo + CP + bev vs CP + bev regardless of PD-L1 expression. Here we present the IMpower150 interim OS results. Methods: 1202 patients (pts) received atezo 1200 mg + C AUC 6 + P 200 mg/m2 (Arm A) or atezo + CP + bev 15 mg/kg (Arm B) vs CP + bev (Arm C) IV q3w for 4 or 6 cycles per investigator (INV); then maintenance atezo, atezo + bev, or bev, respectively. Co-primary endpoints were INV-assessed PFS in the ITT-WT (EGFR/ALK WT) and in WT pts with expression of a tumor T-effector gene signature (Teff-high WT) and OS in the ITT-WT. Data cutoff: 1/22/2018. Results: 349, 359, and 337 ITT-WT pts were enrolled in Arms A, B, and C, respectively, with median age 63 y, 62% male, 85% current/previous smokers, and 42% ECOG PS 0. With 13.5 mo min FU, OS was improved in Arm B vs C (HR, 0.78 [95% CI: 0.64, 0.96]; P = 0.016) in the ITT-WT; populations of interest are shown in the Table. Arm A vs C OS HR was 0.88 (95% CI: 0.72, 1.08; P = 0.204). In all treated patients, Gr 3-4 treatment-related AEs occurred in 43%, 57%, and 49% of pts in Arms A, B, and C, respectively. Conclusions: IMpower150 showed a significant OS benefit with atezo + CP + bev vs CP + bev in 1L NSQ NSCLC, and no new safety signals were seen. Clinical trial information: NCT02366143. IC, tumor-infiltrating immune cells; NE, not estimable; TC, tumor cells. a WT excludes pts with EGFR or ALK genomic alterations. b Present at baseline. TC1/2/3 or IC1/2/3 = PD-L1+ ≥ 1% of TC or IC; TC0 and IC0 = PD-L1+ < 1% of TC and IC Arm B vs C OS in populations of interest. Population No. of Pts HR (95% CI) mOS, mo Arm B Arm C ITT-WTa 696 0.78 (0.64, 0.96) 19.2 14.7 ITT 800 0.76 (0.63, 0.93) 19.8 14.9 EGFR/ALK+ 104 0.54 (0.29, 1.03) NE 17.5 Liver metastasesb 94 0.54 (0.33, 0.88) 13.2 9.1 Subgroups in ITT-WT TC1/2/3 or IC1/2/3 357 0.77 (0.58, 1.04) 22.5 16.4 TC0 and IC0 339 0.82 (0.62, 1.08) 17.1 14.1 Teff-high 285 0.83 (0.59, 1.17) 25.0 16.7 Teff-low 377 0.78 (0.60, 1.02) 17.6 14.3