Lung Cancer Drug Cuts Risk of Death by 51% in Clinical Trial

Results of a large Phase 3 clinical trial reveal that a targeted cancer drug, osimertinib, cut the risk of death by 51% for patients following surgery to remove non-small cell lung cancers harboring a specific mutation. The research is published in the New England Journal of Medicine.

Improving the outlook for lung cancer

Approximately one in five cancer deaths are due to lung cancer, by far the leading cause of cancer deaths. Lung cancer is split into two broad categories – small cell lung cancer (SCLC) and non-small cell lung cancer (NSCLC).

NSCLC represents around 80–85% of lung cancers. These are typically slow growing but have often already spread (metastasized) to different parts of the body at the time of diagnosis, making treatment particularly difficult.

Surgery to remove the tumor (resection) is an important part of treatment – however, many cancers come back despite surgery and chemotherapy, so more effective therapies are needed for these patients.

One option is through targeted therapies, which home in on specific mutations that drive the growth of the tumor. For NSCLC, some patients’ tumors harbor a mutation in the epidermal growth factor receptor (EGFR) gene, which makes them particularly sensitive to drugs that block this pathway.

In the current AstraZeneca-funded clinical trial, the pharma's new drug osimertinib was found to cut the risk of death by 51% for patients with resected, EGFR-mutated NSCLC.

“In the U.S., 10 to 15% of patients with lung cancer will have mutations in the epidermal growth factor receptor,” said Dr. Roy S. Herbst, deputy director and chief of medical oncology at Yale Cancer Center and principal investigator of the trial. He explained that even after these patients receive the leading therapies available, their tumor often returns. “We’re now adding osimertinib, a pill that targets this specific receptor, and what we’ve found is a significant overall survival benefit for patients who received osimertinib,” Herbst continued.

Cutting the risk of death in half

The study recruited 682 patients to take part in this Phase 3 randomized and placebo-controlled trial. The participants, who had stage IB to IIIA NSCLC (i.e., whose tumors had not yet spread to distant parts of the body), received a daily oral dose of either osimertinib or placebo. The treatment regimen lasted for three years, unless their disease returned or they met criteria to discontinue the trial.

After five years of follow-up, 88% of osimertinib-treated patients were still alive, compared to 78% of patients who received the placebo – a significant 51% reduction in the risk of death.

“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,” said Herbst. “These data underscore that adjuvant treatment with osimertinib provides patients with the best chance of long-term survival.”

Investigation in additional trials

Overall, osimertinib significantly improved the overall survival of the participants in this clinical trial. Additional trials will investigate the drug in patients with NSCLC at earlier stages (stage IA2 to IA3), in patients treated for five years after surgery as well as treating patients before surgery.

Reference: Tsuboi M, Herbst RS, John T, et al. Overall survival with osimertinib in resected EGFR-mutated NSCLC. NEJM. 2023. doi: 10.1056/NEJMoa2304594

This article is a rework of a press release issued by AstraZeneca. Material has been edited for length and content.