375O - Final efficacy results from IMpower132: First-line atezolizumab + chemotherapy in patients with stage IV non-squamous NSCLC
Publication Title
ESMO Asia Virtual Congress 2020
Document Type
Presentation
Publication Date
11-22-2020
Abstract
Background
The Phase III IMpower132 study, evaluating first line pemetrexed plus carboplatin/cisplatin with or without atezolizumab in Stage IV non-squamous NSCLC without EGFR or ALK driver mutations, has met its PFS endpoint with an HR of 0.60 (95% CI: 0.49, 0.72; P < 0.0001; Papadimitrakopoulou, WCLC 2018). Here we present the final OS and safety results.
Methods
Patients were randomised 1:1 to 4 or 6 cycles of carboplatin AUC 6 mg/mL/min or cisplatin 75 mg/m2 + pemetrexed 500 mg/m2 Q3W alone (arm PP) or with atezolizumab 1200 mg Q3W (arm APP), followed by pemetrexed (PP) or atezolizumab + pemetrexed (APP) maintenance. Investigator-assessed PFS and OS were co-primary endpoints. Efficacy by PD-L1 status was an exploratory endpoint.
Results
At data cutoff (18 July 2019), 292 patients in arm APP and 286 patients in arm PP had a median follow-up of 28.4 mo. Updated median PFS was 7.7 months (APP) vs 5.2 months (PP); HR, 0.56 (95% CI: 0.47, 0.67). Final OS data are in the table. 38.7% (APP) vs 57.3% (PP) of patients received subsequent anti-cancer therapy, including immunotherapy in 5.5% vs 45.8%. Grade ≥ 3 treatment-related adverse events (AEs) occurred in 58.4% (APP) vs 43.1% (PP) of patients, including immune-mediated AEs in 6.9% (APP) vs 4.7% (PP) of patients. Table: 375O APP PP ITT n = 292 n = 286 mOS (95% CI), mo 17.5 (13.2, 19.6) 13.6 (11.0, 15.7) HRa (95% CI; P value) 0.86 (0.71, 1.06; P = 0.155) 12-Month OS 59.7% 55.0% 24-Month OS 39.1% 34.0% PD-L1–highb n = 25 n = 20 mOS (95% CI), mo NE (22.4, NE) 26.9 (4.7, NE) HR (95% CI) 0.73 (0.31, 1.73) PD-L1–lowb n = 63 n = 73 mOS (95% CI), mo 12.7 (8.7, 18.2) 16.2 (9.6, 22.6) HR (95% CI) 1.18 (0.80, 1.76) PD-L1–negativeb n = 88 n = 75 mOS (95% CI), mo 15.9 (11.6, 22.6) 10.5 (8.1, 13.5) HR (95% CI) 0.67 (0.46, 0.96)
NE, not estimable. a Stratified. b PD-L1 status available in 60% of pts. PD-L1–high: ≥ 50% TC or ≥ 10% IC; PD-L1–low: ≥ 1% and < 50% TC or ≥ 1% and < 10% IC; PD-L1–negative: < 1% TC and < 1% IC.
.
Conclusions
IMpower132 had met its co-primary PFS endpoint at the primary analysis but did not meet its co-primary OS endpoint in this final analysis. Atezolizumab + carboplatin/cisplatin + pemetrexed was well tolerated, and no new safety signals were identified.
Clinical trial identification
NCT02657434.
Clinical Institute
Cancer
Specialty/Research Institute
Earle A. Chiles Research Institute
