ADAURA: 8-yr overall survival update

At WCLC 2026, Prof Dr Mariana Brandão discussed the updated eight-year analysis of the phase III ADAURA trial, evaluating three years of adjuvant osimertinib versus placebo following complete tumour resection in patients with EGFR-mutated non-small cell lung cancer (NSCLC). Previous analyses demonstrated improvements in both disease-free survival and overall survival (OS) with osimertinib, which is currently reimbursed as adjuvant treatment in Belgium.

The updated analysis provides further insight into the durability of this benefit eight years after treatment completion. At eight years, 74% of patients were alive with osimertinib compared with 58% with placebo. In the overall stage IB–IIIA population, eight-year OS rates were similarly favourable, at 79% with osimertinib versus 64% with placebo, with a hazard ratio of 0.52. The benefit was more pronounced in patients with EGFR exon 19 deletions than in those with L858R mutations, although these findings should be interpreted in the context of a subgroup analysis.

Importantly, the updated findings demonstrate that the survival benefit persists well beyond the three-year treatment period. Five years after stopping adjuvant osimertinib, a clinically meaningful difference in survival remains evident.

Nevertheless, several questions remain regarding how adjuvant therapy could be further personalised. Some patients still relapse or die after completing three years of osimertinib, raising the question of whether treatment duration should be tailored to individual risk. Minimal residual disease (MRD) could potentially help identify patients who may benefit from continuing or escalating treatment during or after adjuvant osimertinib. Future strategies could include combinations with chemotherapy or other targeted agents, although their role in this setting remains to be established.

Extending the duration of targeted therapy also raises questions about maintaining long-term treatment adherence. Trials investigating longer courses of adjuvant osimertinib, including five years of treatment, are ongoing, although Brandão noted the limitations of evaluating this approach in a single-arm setting.

Overall, the eight-year ADAURA analysis provides evidence of a durable overall survival benefit with three years of adjuvant osimertinib after complete resection of EGFR-mutated NSCLC. While future research may allow treatment duration and intensity to be tailored more precisely, the current results demonstrate that a finite three-year course can translate into survival benefits that persist for several years after treatment discontinuation.