Phase III trial evaluating Libtayo in NSCLC halted because of significant OS improvemen

In Clinical Studies News by Barbara Jacoby


The primary endpoint of overall survival was met in a phase III 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 who tested positive for PD-L1 in ≥50% of tumor cells.

Libtayo is jointly developed and commercialized by Regeneron and Sanofi under a global collaboration agreement.

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 companies said. The data will form the basis of regulatory submissions in the U.S. and European Union  in 2020.

“While demonstrating a survival benefit in first-line NSCLC has been challenging for immunotherapies, the one FDA-approved anti-PD-1 monotherapy has changed the therapeutic paradigm,” George D. Yancopoulos, co-founder, president and chief scientific officer of Regeneron, said in a statement.

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.

“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,” John Reed, global head of Research and Development at Sanofi, said in a statement.

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). Regeneron previously used these technologies to develop a treatment for Ebola virus infection, which is under review by the FDA, and is used in efforts to create preventative and therapeutic medicines for COVID-19.