236P Adjuvant osimertinib in resected EGFR-mutated NSCLC: A real-world analysis from the Italian ATLAS registry

Background:The phase III ARTS trial established adjuvant aumolertinib as a standard treatment for stage IIA-IIIB EGFR-mutated NSCLC.However, robust real-world evidence regarding its long-term efficacy and safety, particularly in earlier-stage (IA2-IIIA) disease, remains limited.This multicenter analysis evaluated the long-term outcomes of adjuvant aumolertinib in a real-world cohort of patients with completely resected stage IA2-IIIA EGFR-mutated NSCLC.Methods: Patients with radically resected EGFR-mutated (exon 19 deletion or L858R) stage IA2-IIIA NSCLC from four Chinese centers were included.All patients received oral aumolertinib 110 mg once daily, with treatment duration individualized (1-3 years) based on pathological stage and clinician judgment.The primary endpoints were disease-free survival (DFS) and safety.Results: A total of 311 patients were enrolled: stage IA (n=172, 55.3%), IB (n=66, 21.2%), II (n=44, 14.1%), and IIIA (n=29, 9.3%).After a median follow-up of 43.1 months (data cutoff as of December 2025), the 5-year DFS rate for the overall population was 85.0%, with the median DFS not yet reached.7 patients deaths were recorded.Notably, among patients with stages IB to IIIA disease, the median DFS was 66.1 months-a finding comparable to the reported efficacy of adjuvant osimertinib in similar stage populations.Of particular interest, 80.1% (249/311) of stage I patients presented with high-risk pathological factors; nevertheless, this subgroup maintained a high 5-year DFS rate of 89.2%.The CNS protective effect was outstanding: only 4 patients experienced CNS recurrence, yielding a 5-year CNS-DFS rate of 98.0%.AEs were documented in 200 patients, with an incidence of 52.5% (105/200).Events were predominantly grade 1-2, most commonly rash (26.0%), elevated liver enzymes (10.5%), diarrhea (7.5%), and oral ulceration (7.0%).Only one patient (0.5%) experienced a grade 3 TRAE.Conclusions: This extended real-world analysis confirms that adjuvant aumolertinib provides sustained efficacy, exceptional CNS protection, and a superior safety profile.These findings support its routine clinical use in patients with resected EGFRmutated NSCLC across stages IA2-IIIA.