Osimertinib Keeps Paying Off at 8 Years in Resected EGFR-Mutant NSCLC

Eight-year follow-up from the phase 3 ADAURA trial (NCT02511106) shows that adjuvant osimertinib (Tagrisso; AstraZeneca) continues to extend survival in patients with resected, EGFR-mutated (EGFRm) non–small cell lung cancer (NSCLC), giving pharmacists further reason to keep molecular testing and treatment persistence at the center of postsurgical care for this population.

A Long-Awaited Long-Term Look

The exploratory long-term analysis was presented during the Presidential Symposium at the International Association for the Study of Lung Cancer's 2026 World Conference on Lung Cancer (WCLC) in Seoul, South Korea, and published simultaneously in the Journal of Thoracic Oncology.¹ Principal investigator Roy S. Herbst, MD, of Dartmouth Cancer Center, said the findings reinforce adjuvant osimertinib as the standard of care for patients with resected, stage IB to IIIA EGFRm NSCLC.¹

The ADAURA trial enrolled 682 patients with completely resected, stage IB, II, or IIIA EGFRm NSCLC, randomly assigned 1:1 to once-daily osimertinib 80 mg or placebo for up to 3 years, with adjuvant chemotherapy permitted at the treating physician’s discretion. All patients had the opportunity to complete the full 3-year treatment course before this analysis.¹

What the 8-Year Numbers Show

In the primary population (stage II to IIIA), osimertinib reduced the risk of death by 47% compared with placebo (HR, 0.53; 95% CI, 0.38-0.75), with an estimated 8-year overall survival (OS) rate of 74% versus 58%, a 16-percentage-point difference.¹ In the overall stage IB to IIIA population, osimertinib reduced the risk of death by 48% (HR, 0.52; 95% CI, 0.39-0.71), with 8-year OS rates of 79% and 64%, respectively.²

Investigators noted that crossover to osimertinib among some placebo patients after recurrence may have narrowed the observed difference between arms, meaning the true treatment effect could be larger than what these data capture. No new safety signals were identified relative to osimertinib’s established profile. In the primary population (patients with stage II to IIIA disease), osimertinib reduced the risk of death by 47% compared with placebo (HR, 0.53; 95% CI, 0.38-0.75), with an estimated 8-year OS rate of 74% compared with 58%, a 16-percentage-point difference.¹

The Adherence Question

For pharmacists, the more actionable finding may come from a separate real-world analysis presented at the same meeting. Among US patients with stage I to IIIA EGFR-mutated NSCLC receiving adjuvant osimertinib, those who discontinued before completing the established 3-year course had more than twice the risk of disease recurrence or death compared with patients who completed treatment.² That analysis was retrospective and cannot establish causality, but it puts a number behind something pharmacists are well positioned to influence: whether patients actually finish 3 years of therapy.

That framing matters because osimertinib’s tolerability profile, while generally manageable, is not free of the adverse effects (AEs) that erode adherence over a multiyear course. Common AEs with the treatment include diarrhea, paronychia, rash, and stomatitis.¹

What This Means for Pharmacists

Pharmacists working with this population have several concrete levers: Confirming EGFR mutation status is documented and communicated before adjuvant therapy decisions are finalized, building proactive AE monitoring into follow-up rather than waiting for patients to report problems, screening for drug interactions given osimertinib's cytochrome P450 3A4 metabolism, and checking in specifically around the points in a 3-year course where patients are most likely to quiet down about side effects rather than raise them.

The ADAURA update does not change practice on its own—3 years of adjuvant osimertinib is already the established standard in this setting. What it adds is longer-term evidence that the benefit holds up, and a real-world data point suggesting that the difference between an adequate outcome and a durable one may come down to whether a patient stays on therapy long enough to get there.

REFERENCES

1. Herbst RS, Majem M, John T, et al. Eight-year overall survival update from the ADAURA trial of adjuvant osimertinib in resected EGFR-mutated stage IB-IIIA NSCLC. Presented at: IASLC 2026 World Conference on Lung Cancer; September 2026; Seoul, South Korea. Abstract PL03.01.

2. TAGRISSO (osimertinib) demonstrated unprecedented eight-year landmark survival in early-stage EGFR-mutated lung cancer in ADAURA phase 3 trial. News release. AstraZeneca. September 14, 2026. Accessed September 15, 2026. https://www.astrazeneca.com/media-centre/press-releases/2026/tagrisso-demonstrated-eight-year-landmark-survival-in-adaura-phase-iii-trial.html