LBA47 Osimertinib as adjuvant therapy in patients (pts) with resected EGFR-mutated (EGFRm) stage IB-IIIA non-small cell lung cancer (NSCLC): Updated results from ADAURA

Abstract

Osimertinib is a third-generation EGFR-tyrosine kinase inhibitor (EGFR-TKI) that potently and selectively inhibits EGFR-TKI sensitising and EGFR T790M resistance mutations. It has efficacy in EGFRm NSCLC, including in central nervous system (CNS) metastases. In the Phase III ADAURA (NCT02511106) primary analysis adjuvant osimertinib showed a significant and clinically meaningful disease-free survival (DFS) benefit vs placebo (PBO) in pts with completely resected EGFRm (ex19del/L858R) NSCLC, ± adjuvant chemotherapy (CT): stage IIꟷIIIA DFS HR, 0.17; 99.06% CI, 0.11, 0.26; p<0.0001; stage IBꟷIIIA DFS HR, 0.20; 99.12% CI 0.14, 0.30; p<0.0001. We report updated exploratory analyses of DFS and recurrence patterns after 2 yrs added follow up. Eligible pts (aged ≥18 yrs [≥20 in Japan/Taiwan], WHO PS 0/1, completely resected EGFRm stage IBꟷIIIA [AJCC 7th edition] NSCLC; adjuvant CT allowed) were randomised 1:1 to osimertinib 80 mg once daily or PBO for up to 3 yrs. Primary endpoint: investigator-assessed DFS in stage IIꟷIIIA. Secondary endpoints: DFS in stage IBꟷIIIA, overall survival and safety. Patterns of recurrence and CNS DFS were pre-specified exploratory endpoints. Data cut-off: 11 April 2022. Globally, 682 pts were randomised; osimertinib n=339, PBO n=343. In this updated analysis, in pts with stage IIꟷIIIA disease DFS HR was 0.23 (95% CI 0.18, 0.30; 242/470 events; 51% maturity); 3-yr DFS rate was 84% with osimertinib vs 34% with PBO. In the overall population (stage IBꟷIIIA) DFS HR was 0.27 (95% CI 0.21, 0.34; 305/682 events); 3-yr DFS rate was 85% with osimertinib vs 44% with PBO. In the osimertinib arm, fewer pts experienced local/regional and distant recurrence vs PBO. CNS DFS HR was 0.24 (95% CI 0.14, 0.42; 63/470 events) in stage IIꟷIIIA. The long-term safety profile remains consistent with the known profile of osimertinib. With 2 yrs further follow-up, a continued DFS benefit was sustained with osimertinib vs PBO, consistent with the primary analysis. These mature data reinforce adjuvant osimertinib as standard of care for pts with EGFRm stage IB–‍IIIA NSCLC after complete tumour resection and adjuvant CT, when indicated.