Positive results from the ADAURA phase III trial showed osimertinib (Tagrisso) demonstrated a statistically significant and clinically meaningful improvement in overall survival (OS), compared to placebo in the adjuvant treatment of patients with early-stage (IB, II and IIIA) epidermal growth factor receptor-mutated (EGFRm) non-small cell lung cancer (NSCLC) after complete tumour resection with curative intent. 

These results were presented on in a late breaking oral presentation during the plenary session at the American Society of Clinical Oncology (ASCO) Annual Meeting in Chicago last month, and published simultaneously in the New England Journal of Medicine.

Osimertinib reduced the risk of death by 51% compared to placebo in both the primary analysis population (stages II-IIIA) (21% data maturity, OS hazard ratio [HR] of 0.49; 95.03% confidence interval [CI] 0.33 to 0.73; p = 0.0004), and in the overall trial population (stages IB[1]IIIA) (18% data maturity, OS HR of 0.49; 95.03% CI 0.34 to 0.70; p < 0.0001).

In the primary analysis population, an estimated 85% of patients treated with osimertinib were alive at five years compared to 73% on placebo. In the overall trial population, an estimated 88% of patients treated with osimertinib were alive at five years compared to 78% on placebo. Median OS was not yet reached in either population or treatment group. Patients on placebo that recurred with metastatic disease had the opportunity to receive osimertinib as a subsequent treatment if indicated. 

At the previously reported disease-free survival analysis, all patients had completed or discontinued treatment. The safety and tolerability of osimertinib with extended follow-up were consistent with its established profile and previous analyses with no new safety concerns reported. Adverse events at Grade 3 or higher from all causes occurred in 23% of patients in the osimertinib arm versus 14% in the placebo arm.