Sanofi and Regeneron have announced positive late-stage results for Libtayo (cemiplimab) plus chemotherapy for the treatment of non-small cell lung cancer (NSCLC) at the 2021 European Society for Medical Oncology (ESMO) virtual congress.

The Phase III trial evaluated the use of PD-1 inhibitor Libtayo plus a physician’s choice of platinum-doublet chemotherapy in patients with locally advanced or metastatic NSCLC across all PD-L1 expression levels, compared to chemotherapy alone.

The trial met its primary overall survival (OS) endpoint and all key secondary endpoints, with Libtayo plus chemotherapy demonstrating a 22-month median OS compared to 13 months for chemotherapy.

This represents a 29% relative reduction in the risk of death, with the 12-month probability of survival being 66% for the Libtayo combination and 56% for chemotherapy.

Patients treated with the Libtayo combination had an eight-month median progression-free survival compared to five months for chemotherapy, representing a 46% relative reduction in the risk of disease progression.

“This Phase III trial was stopped early because Libtayo significantly improved overall survival compared to chemotherapy, a milestone also achieved by our Phase III trial for Libtayo monotherapy as a first-line treatment for advanced non-small-cell lung cancer with high PD-L1 expression,” said Israel Lowy, senior vice president, translational and clinical sciences, oncology at Regeneron.

“Both trials were designed to reflect everyday clinical practice by allowing for the enrolment of patients with difficult-to-treat disease characteristics. And this is the second Libtayo trial to demonstrate significant improvement in its primary and key secondary endpoints for these patient populations, compared to chemotherapy.”