Adjuvant atezolizumab in surgically resected NSCLC patients with PD-L1 expression ≥ 50%: real-world data from the Italian ATLAS registry

Background: This study describes clinical characteristics, treatment patterns as well as safety outcomes of NSCLC patients harboring PD-L1 ≥ 50% who received adjuvant atezolizumab within the Italian real-world scenario. Methods: Patients with surgically resected NSCLC harboring EGFR/ALK wild type disease and PD-L1 TPS ≥ 50%, who received at least one cycle of adjuvant atezolizumab were included. Clinical-pathological and molecular data, safety and efficacy outcomes were collected from the Italian ATLAS real-world registry. Results: A total of 132 patients were included across 45 Italian centers between July 2022 and August 2024. Lobectomy was performed in 81.1% of cases, with 8.3% pathological stage IIA, 40.2% stage IIB, 43.9% stage IIIA, and 7.6% stage IIIB, according to the eighth TNM staging edition. The median number of atezolizumab cycles was 12.5 (range: 1-20). Treatment related adverse events (TRAEs) during atezolizumab were reported in 44 patients (33.3%), including 11 (8.3%) who experienced multiple TRAEs. Grade ≥ 3 TRAEs were reported in 21 cases (15.9%), leading to treatment discontinuation in 18 (13.6%). The median time to the first onset of TRAEs was 89 days (range: 3-390 days). 15 patients experienced a disease recurrence, including 6 locoregional-only and 9 distant relapses, with a median time since surgery of 13.3 months. Conclusion: This study showed that the safety profile of adjuvant atezolizumab outside of a clinical trial context was comparable to the IMPower-010 study, highlighting the value of the Italian ATLAS registry as source of real-word evidence to optimize the clinical management of NSCLC patients.