Adjuvant Osimertinib in Resected EGFR-Mutated Stage IB–IIIA NSCLC: Exploratory 8-Year Overall Survival Landmark Update from the ADAURA Trial

Introduction: In ADAURA, adjuvant osimertinib improved disease-free survival (DFS) and overall survival (OS) compared with placebo in patients with resected epidermal growth factor receptor (EGFR)-mutated stage IB–IIIA NSCLC. We report a post hoc exploratory analysis of long-term OS after adjuvant treatment completion. Methods: Patients (N = 682) were randomized to osimertinib or placebo until recurrence, treatment completion, or discontinuation. Updated survival data were collected from 431 of 558 patients alive at the planned final OS analysis (data cutoff [DCO], January 27, 2023) through yearly follow-up until the current DCO (May 4, 2026) or from accessible records or information from the last contact date after January 27, 2023. Patients without additional follow-up remained censored, with survival time unchanged from the planned final OS analysis DCO (n = 127). This exploratory long-term OS analysis was conducted in all randomized patients. Results: At the current DCO, in the stage II–IIIA population, the OS hazard ratio (HR) was 0.53 (95% confidence interval [CI]: 0.38–0.75); the 8-year OS rates were 74% (osimertinib) versus 58% (placebo); the median follow-up was 92.0 versus 68.5 months. In the stage IB–IIIA population, the OS HR was 0.52 (95% CI: 0.39–0.71); the 8-year OS rates were 79% (osimertinib) versus 64% (placebo); the median follow-up was 93.3 versus 79.6 months. The OS HRs according to EGFR Ex19del and L858R mutations were 0.45 (95% CI: 0.29–0.68) and 0.72 (95% CI: 0.46–1.11), respectively. An OS benefit with osimertinib was observed across subgroups. Conclusion: With the longest OS from a global phase III adjuvant trial in EGFR-mutated stage IB–IIIA NSCLC, these additional long-term results further characterize the established survival benefit of adjuvant osimertinib. Clinical Trial Information: ADAURA (NCT02511106).