On Apr. 27, 2020, Regeneron and Sanofi announced the primary endpoint of overall survival was met in a Phase 3 trial comparing the PD-1 inhibitor Libtayo (cemiplimab) to platinum-doublet chemotherapy in patients with first-line locally advanced or metastatic non-small cell lung cancer that tested positive for PD-L1 in =50% of tumor cells. Based on a recommendation by the Independent Data Monitoring Committee to stop the trial early, the trial will be modified to allow all patients to receive Libtayo for this investigational use. The data will form the basis of regulatory submissions in the U.S. and EU in 2020.

A protocol-specified interim analysis conducted by the Independent Data Monitoring Committee demonstrated that patients treated with Libtayo monotherapy had a significant increase in OS. Libtayo decreased the risk of death by 32.4% (HR=0.676; CI:0.525-0.870, p=0.002), compared to platinum-doublet chemotherapy, despite a third of patients entering the trial within the past six months and all chemotherapy patients being able to crossover to Libtayo if their disease progressed. No new Libtayo safety signal was identified. Detailed trial data will be presented at a future medical meeting.

“This is the largest clinical trial evaluating a PD-1 inhibitor as a first-line monotherapy in patients with advanced non-small cell lung cancer with high PD-L1 expression. These positive results are extremely encouraging, and we look forward to advancing a potential new treatment option for these patients,” said John Reed, M.D., Ph.D., Global Head of Research and Development at Sanofi. “We are grateful to all of the investigators and patients who participated in the global trial.”

Lung cancer is the leading cause of cancer death worldwide. In 2020, more than 2.2 million new cases are expected to be diagnosed globally, with 228,800 new cases in the U.S. alone. Approximately 85% of all lung cancers are NSCLC, with an estimated 25% to 30% of cases expected to test positive for PD-L1 in ≥50% of tumor cells. While immunotherapies have transformed advanced NSCLC treatment in recent years, there remains an unmet need to optimize the identification and treatment of patients with high PD-L1 expression.

Libtayo is being jointly developed and commercialized by Regeneron and Sanofi under a global collaboration agreement. Libtayo was invented using Regeneron’s proprietary VelocImmune^® technology that utilizes a proprietary genetically-engineered mouse platform endowed with a genetically-humanized immune system to produce optimized fully-human antibodies. VelocImmune technology has been used to create multiple antibodies including Dupixent^® (dupilumab), Praluent^® (alirocumab) and Kevzara^® (sarilumab), which are approved in multiple countries around the world. Regeneron previously used these technologies to rapidly develop a treatment for Ebola virus infection, which is currently under review by the FDA, and is now being used in efforts to create preventative and therapeutic medicines for COVID-19.