Osimertinib is routinely used as a standard care therapy for non-small lung cancer (NSCLC) that has been previously untreated and is epidermal growth factor receptor (EGFR) mutation-positive. This study aims to evaluate the safety and efficacy of osimertinib as adjuvant therapy for EGFR-mutated NSCLC.

This double-blind, phase-3 trial included a total of 682 patients with completely resected EGFR mutation-positive NSCLC. The patients were randomly assigned in a 1:1 ratio to receive either osimertinib (n=339) or placebo (n=334) for three years. The primary outcome of the study was disease-free survival, along with overall survival and safety.

At a follow-up of 24 months, 90% of patients in the osimertinib group with stage 2-3a disease and 44% of those in the placebo group achieved disease-free survival. In the case of the overall population, 89% of the patients in the osimertinib group, and 52% of those in the placebo group did not have any central nervous system disease. The overall survival data were not accurate; however, 29 patients died during the treatment. No significant safety concerns were identified.

The research concluded that patients with EGFR-mutated NSCLC of stage 1b-3a experienced a greater overall and disease-free survival when treated with osimertinib.

Ref: nejm.org/doi/full/10.1056/NEJMoa2027071