115P Aumolertinib as adjuvant therapy in postoperative EGFR-mutated stage I–III non-small cell lung cancer with high-grade patterns

EGFR-mutated (EGFRm) lung adenocarcinoma patients with high-grade patterns are known to be associated with poor prognosis in early-stage NSCLC. The aim of this study was to evaluate the efficacy of aumolertinib as adjuvant therapy in resected stage I–III NSCLC with high-grade patterns. EGFRm stage I–III NSCLC patients who underwent radical surgery with high-grade patterns (micropapillary, solid component or complex glands) were enrolled. EGFRm patients were assigned into aumolertinib group (group A) receiving aumolertinib (110 mg daily) treatment and observation group (group B). EGFR mutation negative or unknown were assigned into Group C also receiving observation. We evaluated disease-free survival (DFS) and safety. DFS was evaluated based on pathological stage or proportions of high-grade patterns. A total of 136 stage I–III NSCLC patients with high-grade patterns (59 pts in Group A, 25 pts in Group B; 52 pts in Group C) were enrolled. At data cut-off, median follow-up was 15.4 months in Group A,26.5 months in Group B and 30.1 months in Group C. Tumor recurrence occurred in only 1 patient in group A. The 2-year DFS rate was 98% in Group A,73% in Group B and 87% in Group C. For patients with stage, I in Group A, the 2-year DFS rate was 100%. The DFS of Group A was significantly better than that of Group B (P=0.0178). When stratified by stage and the proportion of high-grade patterns, the DFS of Group A with stage I (p=0.0134), stage IB(p=0.0394) or stage IA with no less than 5% of high-grade patterns(p=0.0272) was also significantly better than that of group B. Compared Group B and C, the recurrent rate in EGFRm patients was higher than those with EGFR negative or unknown. No AEs of grade≥3 occurred during aumolertinib treatment. 47.3% (26/55) of patients experienced drug-related adverse reactions, with the most common being pruritus (22.8%), rash (12.3%), and oral ulcer (7.0%). This study is the first to demonstrate that EGFRm stage I–III NSCLC patients with high-grade patterns can benefit from aumolertinib adjuvant therapy. The updated results further demonstrate that patients in stage IA with ≥5% high-grade patterns and IB with high-grade patterns can obtain survival benefit from aumolertinib therapy.