Abstract CT200: IMpower130: Progression-free survival (PFS) and safety analysis from a randomized phase 3 study of carboplatin + nab-paclitaxel (CnP) with or without atezolizumab as first-line (1L) therapy in advanced non-squamous NSCLC

Abstract

Abstract Background: Atezolizumab (atezo) (anti-PD-L1) monotherapy improves overall survival (OS) vs docetaxel in 2L+ NSCLC regardless of PD-L1 status; phase 3, 1L studies have shown clinical benefit of atezo plus chemotherapy and atezo in combination with bevacizumab and chemotherapy. IMpower130 (NCT02367781) evaluated atezo + CnP vs CnP in patients (pts) with measurable (RECIST v1.1) stage IV non-squamous NSCLC. Methods: Pts (randomized 2:1) received atezo (1200 mg IV q3w) + CnP (carboplatin: AUC 6 q3w; nab-paclitaxel: 100 mg/m2 IV qw) (Arm A) or CnP (Arm B), for 4 or 6 21-day cycles and maintenance (Arm A: atezo until loss of clinical benefit; Arm B: best supportive care or pemetrexed q3w until disease progression [PD]). Crossover to atezo at PD was initially permitted for Arm B pts. Co-primary endpoints were investigator-assessed PFS and OS (ITT-WT population: EGFR-WT/ALK-negative). Secondary endpoints were OS and PFS (ITT population and by PD-L1 expression), response rate and safety. ITT population could be formally tested for OS/PFS if ITT-WT OS was positive. Results: 723 ITT (679 ITT-WT) pts were enrolled. Statistically significant, clinically meaningful improvements in OS and statistically significant and clinically meaningful improvements in PFS (ITT and ITT-WT) were observed in Arm A vs Arm B (table). PFS and OS benefit was observed in all PD-L1 subgroups, and consistently across all subgroups, except in pts with liver metastases and EGFR/ALK genomic alterations. In treated pts, 73.2% (Arm A) vs 60.3% (Arm B) had grade 3-4 treatment-related adverse events. Conclusions: Overall, IMpower130 showed statistically significant, clinically meaningful improvements in OS and statistically significant improvements in PFS with atezo + CnP, vs CnP, in 1L, stage IV non-squamous NSCLC, in this predominantly ITT-WT population. No new safety signals were identified. Table.IMpower130 Efficacy AnalysesArm A Atezo + CnPArm B CnPITT-WTn = 451n = 228Median OS (95% CI)18.6 mo (16.0-21.2)13.9 mo (12.0-18.7)HR (95% CI; P value)0.79 (0.64-0.98; 0.033)12-mo OS (95% CI)63.1% (58.59-67.66)55.5% (48.89-62.17)Median PFS (95% CI)7.0 mo (6.2-7.3)5.5 mo (4.4-5.9)HR (95% CI; P value)0.64 (0.54-0.77; < 0.0001)12-mo PFS (95% CI)29.1% (24.83-33.44)14.1% (9.37-18.76)n = 447n = 226Confirmed ORR (investigator assessed) (95% CI)49.2% (44.49-53.96)31.9% (25.84-38.36)n = 220n = 72Median DOR (95% CI)8.4 mo (6.9-11.8)6.1 mo (5.5-7.9)PD-L1 highan = 88n = 42Median OS (95% CI)17.4 mo (14.78-NA)16.9 mo (10.94-NA)HR (95% CI)0.84 (0.51-1.39)Median PFS (95% CI)6.4 mo (5.49-9.76)4.6 mo (3.22-7)HR (95% CI)0.51 (0.34-0.77)PD-L1 lowan = 128n = 65Median OS (95% CI)23.7 mo (18.63-NA)15.9 mo (12.32-25.63)HR (95% CI)0.70 (0.45-1.08)Median PFS (95% CI)8.3 mo (7.16-10.35)6.0 mo (5.29-6.93)HR (95% CI)0.61 (0.43-0.85)PD-L1 negativean = 235n = 121Median OS (95% CI)15.2 mo (12.88-19.15)12.0 mo (8.97-17.71)HR (95% CI)0.81 (0.61-1.08)Median PFS (95% CI)6.2 mo (5.52-7.16)4.7 mo (4.11-5.72)HR (95% CI)0.72 (0.56-0.91)ITTn = 483n = 240Median OS (95% CI)18.1 mo (15.3-20.8)13.9 mo (12.0-18.2)HR (95% CI; P value)0.80 (0.65-0.99; 0.039)Median PFS (95% CI)7.0 mo (6.3-7.3)5.6 mo (4.5-5.9)HR (95% CI; P value)0.65 (0.54-0.77; < 0.0001)a PD-L1 high (TC3 or IC3): Patients with PD-L1 expression in ≥ 50% of tumor cells or ≥ 10% of tumor-infiltrating immune cells; PD-L1 low (TC1/2 or IC1/2): Patients with PD-L1 expression in ≥ 1% and < 50% of tumor cells or ≥ 1% and <10% of tumor-infiltrating immune cells; and PD-L1 negative (TC0 and IC0): Patients with PD-L1 expression in <1% of tumor cells and < 1% of tumor-infiltrating immune cells. Data cut-off: 15 March 2018. Minimum follow up: 13 months. NCT02367781.DOR, duration of response; HR, hazard ratio; IC, immune cells; ORR, objective response rate; OS, overall survival; PFS, progression-free survival; TC, tumor cells. Citation Format: Howard L. West, Michael McCleod, Maen Hussein, Alessandro Morabito, Achim Rittmeyer, Henry J. Conter, Hans-Georg Kopp, Davey Daniel, Steven McCune, Tarek Mekhail, Alona Zer, Niels Reinmuth, Ahad Sadiq, Venice Archer, Tania Ochi Lohmann, Helen Jessop, Lijia Wang, Marcin Kowanetz, Alan Sandler, Federico Cappuzzo. IMpower130: Progression-free survival (PFS) and safety analysis from a randomized phase 3 study of carboplatin + nab-paclitaxel (CnP) with or without atezolizumab as first-line (1L) therapy in advanced non-squamous NSCLC [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr CT200.