Overall survival with adjuvant atezolizumab after chemotherapy in resected stage II-IIIA non-small cell lung cancer (IMpower010): a randomised, multicentre, open-label, phase 3 trial.

Abstract

IMpower010 (NCT02486718) demonstrated significantly improved disease-free survival (DFS) with adjuvant atezolizumab vs best supportive care (BSC) following platinum-based chemotherapy in the PD-L1-positive and all stage II-IIIA non-small cell lung cancer (NSCLC) populations, at the DFS interim analysis. Results of the first interim analysis of overall survival (OS) are here reported. The design, participants, and primary-endpoint DFS outcomes have been reported for this phase 3, open-label, 1:1 randomised study of atezolizumab (1200 mg q3w; 16 cycles) vs BSC after adjuvant platinum-based chemotherapy (1-4 cycles) in adults with completely resected stage IB (≥4 cm)-IIIA NSCLC. Key secondary endpoints included OS in the stage IB-IIIA intent-to-treat (ITT) population and safety in randomised treated patients. The first pre-specified interim analysis of OS was conducted after 251 deaths in the ITT population. Exploratory analyses included OS by baseline PD-L1 expression level (SP263 assay). At a median 45.3 months' follow-up on April 18, 2022, 127 of 507 patients (25%) in the atezolizumab arm and 124 of 498 (24.9%) in the BSC arm had died. The median OS in the ITT population was not estimable; the stratified HR was 0.995 (95% CI 0.78-1.28). The stratified OS HRs (95% CI) were 0.95 (0.74-1.24) in the stage II-IIIA (n=882), 0.71 (0.49-1.03) in the stage II-IIIA PD-L1 TC ≥1% (n=476), and 0.43 (95% CI 0.24-0.78) in the stage II-IIIA PD-L1 TC ≥50% (n=229) populations. Atezolizumab-related adverse event incidences remained unchanged since the previous analysis (grade 3/4 in 53 [10.7%] and grade 5 in 4 [0.8%] of 495 patients, respectively). Although OS remains immature for the ITT population, these data indicate a positive trend favouring atezolizumab in PD-L1 subgroup analyses, primarily driven by the PD-L1 TC ≥50% stage II-IIIA subgroup. No new safety signals were observed after 13 months' additional follow-up. Together, these findings support the positive benefit-risk profile of adjuvant atezolizumab in this setting.