The results came from 88% of patients alive at five years, compared to 73% in a phase 3 trial called Adaura which showed treatment with the adjuvant reduced the risk of deaths by more than half.
The researchers said Tagrisso demonstrated a statistically significant and clinically meaningful improvement in overall survival (OS) compared to placebo in patients at stage 1b, 2 and 3a EGFRm non-small cell lung cancer (NSCLC) after complete tumor resection with curative intent.
These results were presented in an oral presentation at the 2023 American Society of Clinical Oncology (ASCO) annual meeting.
The trial found Tagrisso reduced the risk of death by 51% compared to placebo in both the primary analysis population (stages 2-3a) and in the overall trial population (stages 1b-3a).
NCSLC is the most common type of lung cancer. Like all cancers, NSCLC begins at the cellular level and causes abnormal cells in the lungs to reproduce rapidly and out of control. NSCLCs are carcinomas, which are cancers of the cells lining the surface of the lung airways. These include the bronchi, bronchioles, and alveoli.
Research has concluded that the leading risk for developing NSCLC is smoking cigarettes. |It is well-known that the more you smoke and the earlier in life you begin smoking, the greater your risk for developing NSCLC. Other risk factors include second-hand smoke, exposure to workplace carcinogens, radiation exposure, environmental pollution, family history of lung cancer and previous infection of HIV.
Roy Herbst is deputy director and chief of medical oncology at Yale Cancer Center and Smilow Cancer Hospital, Connecticut, and principal investigator in the trial.
He said: “These highly anticipated overall survival results, with 88% of patients alive at five years, are a momentous achievement in the treatment of early-stage EGFR-mutated lung cancer. These data underscore that adjuvant treatment with osimertinib provides patients with the best chance of long-term survival.”
Tagrisso - the backbone treatment
For superiority trials, the intent-to-treat population (ITT) is considered the primary analysis population because it tends to avoid the over-optimistic estimates of efficacy that results from a per-protocol (PP) population.
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 Tagrisso as a subsequent treatment.
Susan Galbraith, executive vice president, oncology R&D, at AstraZeneca, said: “Tagrisso cut the risk of death by more than half in the adjuvant setting, further establishing this transformative medicine as the backbone treatment for EGFR-mutated lung cancer. These results emphasize the importance of diagnosing patients with lung cancer early, testing for EGFR mutations and treating all those with an EGFR mutation with Tagrisso.”
At the previously reported disease-free survival analysis, all patients had completed or discontinued treatment. The safety and tolerability of Tagrisso 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 Tagrisso arm versus 14% in the placebo arm.