Real-world effectiveness and safety of adjuvant atezolizumab in pathological stage IIA–IIIB non-small cell lung cancer following curative surgery

Background: Postoperative atezolizumab is approved as adjuvant therapy for programmed death-ligand 1 (PD-L1)-positive non-small cell lung cancer (NSCLC) in Japan, based on the phase III IMpower010 trial. However, real-world data on this therapeutic approach remains limited. This study aimed to evaluate the real-world effectiveness and safety of adjuvant atezolizumab in patients with pathological stage II-III NSCLC. Methods: This single-institution retrospective cohort study included patients with completely resected pathological stage IIA-IIIB [Union for International Cancer Control/American Joint Committee on Cancer (UICC/AJCC) staging system version 8] NSCLC who received at least one cycle of adjuvant atezolizumab after platinum-based chemotherapy between January 2021 and December 2024. Clinical characteristics, treatment completion, disease-free survival (DFS), overall survival (OS), and adverse events (AEs) were evaluated. Survival outcomes were estimated using the Kaplan-Meier method. Results: ≥50%: 57.7%; P=0.37). AEs occurred in 60.0%, including two grade 3 events. No grade 4-5 toxicities or treatment-related deaths were observed. Fifteen patients (60.0%) completed 1 year of treatment. Conclusions: In this real-world cohort, adjuvant atezolizumab demonstrated favorable tolerability and clinically meaningful DFS across PD-L1 expression subgroups, including patients with PD-L1 1-49%. These findings are descriptive in nature and should be interpreted with caution, nevertheless, they provide real-world evidence supporting the potential clinical utility of adjuvant atezolizumab in appropriately selected patients with resected stage II-III NSCLC.