IMpower010: 5-Year Outcomes of Atezolizumab in Japanese Patients With Resected Stage IB-IIIA Non-Small Cell Lung Cancer.

The global Phase 3 IMpower010 study (NCT02486718) evaluated atezolizumab versus best supportive care (BSC) after complete resection and adjuvant platinum-based chemotherapy in patients with stage IB-IIIA non-small cell lung cancer (NSCLC). We report updated efficacy and safety results from the disease-free survival (DFS) final and overall survival (OS) second interim analyses, with ≥ 5 years of follow-up in Japanese patients. Patients who received 1-4 21-day chemotherapy cycles after surgery were randomized 1:1 to receive atezolizumab 1200 mg every 3 weeks (≤ 16 cycles) or BSC. Of 149 patients enrolled, 117 were randomized to the intention-to-treat (ITT) population (atezolizumab n = 59; BSC n = 58). At data cutoff (January 26, 2024), unstratified hazard ratios (HRs) (95% confidence interval [CI]) for DFS in the atezolizumab versus BSC arms were 0.54 (0.28-1.07) in the stage II-IIIA programmed death-ligand 1 (PD-L1) tumor cell (TC) ≥ 1% (n = 74), 0.64 (0.27-1.52) in the stage II-IIIA PD-L1 TC 1%-49% (n = 34), 0.52 (0.17-1.54) in the stage II-IIIA PD-L1 TC ≥ 50% (n = 40), 0.58 (0.34-1.00) in the stage II-IIIA all-randomized (n = 113), and 0.57 (0.34-0.98) in the ITT populations. OS remained immature; median OS was not reached in both treatment arms for all subgroups. Grade 3/4 adverse events occurred in 15 (26.8%) and 7 patients (12.1%) in the atezolizumab and BSC arms, respectively; no deaths were reported. In this exploratory subgroup analysis, adjuvant atezolizumab demonstrated numerically improved DFS and OS versus BSC in Japanese patients and was well tolerated, similar to the global IMpower010 population. Trial Registration: ClinicalTrials.gov identifier: NCT02486718.