ASCO: Osimertinib Boosts PFS in EGFR-Mutated Lung Cancer

In a pivotal study published on June 2 in the New England Journal of Medicine, researchers have found that osimertinib offers a significant advantage in progression-free survival for patients with unresectable stage III EGFR-mutated non-small cell lung cancer (NSCLC). This research was unveiled to coincide with the American Society of Clinical Oncology’s annual meeting held from May 31 to June 4 in Chicago.

The study was led by Dr. Shun Lu of Shanghai Chest Hospital and involved a double-blind trial including patients whose stage III EGFR-mutated NSCLC had not progressed during or after receiving chemoradiotherapy. The trial enrolled 216 participants who were randomly divided into two groups: 143 patients received osimertinib, while 73 patients were given a placebo. The treatment was continued until disease progression or the regimen was discontinued for other reasons.

The findings revealed that osimertinib significantly extended the median progression-free survival to 39.1 months compared to just 5.6 months for the placebo group. This equates to a hazard ratio for disease progression or death of 0.16, with a 95 percent confidence interval ranging from 0.10 to 0.24, and a P-value of less than 0.001. Notably, at the 12-month mark, 74 percent of patients on osimertinib were alive and free from disease progression, compared to only 22 percent of those on the placebo.

Additionally, interim survival data indicated a 36-month overall survival rate of 84 percent for the osimertinib group, versus 74 percent for the placebo group, though this difference was not statistically significant (hazard ratio for death was 0.81; 95 percent confidence interval, 0.42 to 1.56; P = 0.53). However, the incidence of grade 3 or higher adverse events was higher in the osimertinib group, affecting 35 percent of patients, compared to 12 percent in the placebo group.

The authors of the study concluded that osimertinib, administered following chemoradiotherapy, leads to a substantially longer progression-free survival in patients with unresectable stage III EGFR-mutated NSCLC. These results underscore the potential of osimertinib as a critical component of treatment for this patient population.

It is worth noting that several authors of the study disclosed affiliations with pharmaceutical companies, including AstraZeneca, which produces osimertinib and funded the research.