Eight years out, adjuvant osimertinib (Tagrisso) continues to provide an overall survival advantage to patients with resected EGFR-mutated non-small cell lung cancer (NSCLC), according to a landmark update from the phase 3 ADAURA trial.

Following earlier findings from ADAURA, 3 years of adjuvant osimertinib became standard of care for patients with resected, EGFR-mutated, stage IB-IIIA NSCLC. The trial's final overall survival analysis, published in 2023, found that 5-year overall survival was 85% with the targeted therapy vs 73% with placebo.

The new analysis shows that the survival advantage persists at the 8-year mark, or 5 years post-treatment: 79% of patients who received osimertinib were still alive, compared with 64% of those in the placebo arm (hazard ratio [HR], 0.52; 95% CI, 0.39-0.71).

Among patients with stage II-IIIA disease, specifically, 8-year overall survival was 74% with osimertinib vs 58% with placebo (HR, 0.53; 95% CI, 0.38-0.75), according to results presented at the 2026 World Conference on Lung Cancer in Seoul, South Korea.

Trial investigator Roy Herbst, MD, PhD, of Dartmouth Cancer Center in Lebanon, New Hampshire, called the data "really phenomenal."

"I've been doing this for 30 years, and this has been the goal," he said during his presentation.

Study discussant Antonio Passaro, MD, PhD, of the European Institute of Oncology in Milan, Italy, said the updated data confirm a durable benefit — and a potential cure for some patients.

"We can see that there is no late overall survival convergence," he said. "We are confirming today that osimertinib may do more than delay recurrence. We have a consistent rate of patients [in whom], potentially, we are curing the disease."

The findings were published online in the Journal of Thoracic Oncology to coincide with the conference presentation.

ADAURA was a global, double-blind, randomized trial enrolling 682 patients with completely resected, EGFR-mutated, stage IB-IIIA NSCLC. It began in 2015, with patients receiving once-daily osimertinib 80 mg or placebo for up to 3 years. Adjuvant chemotherapy was permitted at the treating physician's discretion.

Herbst said his team chose to do the 8-year landmark analysis because that time point represented 5 years since the treatment period ended. The analysis included data on 77% of patients, while the remainder had no additional survival data.

The researchers found consistent overall survival benefits across prespecified subgroups, including patients with or without a smoking history, and those who received adjuvant chemotherapy and those who did not.

The analysis, Herbst said, represents the longest overall survival follow-up from any adjuvant phase 3 trial in EGFR-mutated lung cancer. And it underscores the need to ensure patients have timely access to EGFR testing.

"If this works, let's make sure everyone gets EGFR tested," Herbst said. "We have a new paradigm now. We see that throughout this meeting that we're taking our best drugs and we're using them early."

Passaro noted that many treatment discussions center on minimal residual disease — which, in his view, should not determine whether to use a tyrosine kinase inhibitor (TKI) in the first place, but could inform the duration of treatment.

Passaro also highlighted the "four questions that matter now," under investigation in several ongoing trials in earlier-stage EGFR-mutated disease, including ADAURA 2, TARGET, and OCEANiC: Should targeted therapy be given earlier? Should it be given for longer periods? Should it be guided by biology rather than pathological stage? And how well do other TKIs or treatment combinations work?

ADAURA was funded by AstraZeneca. Both Herbst and Passaro reported financial ties to the company.