A Phase 3 trial of Regeneron and Sanofi’s PD-1 inhibitor Libtayo in combination with platinum-doublet chemotherapy was stopped early after meeting its overall survival (OS) primary endpoint in patients with advanced non-small cell lung cancer (NSCLC). Adding Libtayo to chemotherapy significantly improved median overall survival in advanced non-small cell lung cancer (NSCLC) patients from 13 to 22 months, leading to a 29% reduction in the risk of death, compared to chemotherapy alone.

The trial enrolled patients with metastatic or locally advanced disease and tumors with either squamous or non-squamous histology and across all PD-L1 expression levels. These data are planned to form the basis of regulatory submissions in the U.S. and European Union.

“Libtayo in combination with chemotherapy increased median overall survival to 22 months in patients with advanced non-small cell lung cancer, compared to 13 months with chemotherapy alone,” said Miranda Gogishvili, M.D., an oncologist at the High Technology Medical Center, University Clinic, in Tbilisi, Georgia and a trial investigator. “Notably, the Phase 3 trial enrolled patients with a variety of challenging-to-treat disease characteristics, as well as those with locally advanced disease. These data add to the growing body of evidence supporting Libtayo in advanced non-small cell lung cancer, which also include the pivotal results for Libtayo monotherapy in cases of high PD-L1 expression.”

The decision to stop the trial early was based on a recommendation by the Independent Data Monitoring Committee (IDMC) during a protocol-specified interim analysis. In this top-line initial analysis of 466 patients, combining Libtayo with chemotherapy reduced the risk of death by 29% compared to chemotherapy alone (hazard ratio: 0.71; 95% confidence interval [CI]: 0.53-0.93; p=0.014). Median OS was 22 months (95% CI: 16 months to not evaluable) for Libtayo and chemotherapy, and 13 months (95% CI: 12 to 16 months) for chemotherapy alone. No new Libtayo safety signals were identified in the IDMC analysis, and additional detailed efficacy and safety data will be presented at an upcoming medical meeting.

Lung cancer is the leading cause of cancer death worldwide. In 2020, an estimated 2.2 million and 225,000 new cases were diagnosed globally and in the U.S., respectively. Approximately 84% of all lung cancers are NSCLC, with 75% of these cases diagnosed in advanced stages. While PD-1 inhibitor monotherapy has primarily advanced the treatment of NSCLC with ≥50% PD-L1 expression, approximately 70% of all NSCLC cases will have <50% PD-L1 expression, making it the most common treatment setting.

The use of Libtayo in combination with chemotherapy for advanced NSCLC is currently under clinical investigation, and its safety and efficacy have not been fully evaluated by any regulatory authority.