Sanofi and Regeneron Pharmaceuticals have started a clinical program evaluating Kevzara (sarilumab) in patients hospitalized with severe COVID-19. Kevzara is a fully-human monoclonal antibody that inhibits the interleukin-6 (IL-6) pathway by binding and blocking the IL-6 receptor. IL-6 may play a role in driving the overactive inflammatory response in the lungs of patients who are severely or critically ill with COVID-19 infection. The role of IL-6 is supported by preliminary data from a single-arm study in China using another IL-6 receptor antibody.
 
This U.S.-based trial will begin at medical centers in New York, one of the epicenters of the U.S. COVID-19 outbreak, and will assess the safety and efficacy of adding Kevzara to usual supportive care, compared to supportive care plus placebo. The multi-center, double-blind, Phase 2/3 trial has an adaptive design with two parts and is anticipated to enroll up to 400 patients. The first part will recruit patients with severe COVID-19 infection across approximately 16 U.S. sites, and will evaluate the impact of Kevzara on fever and patients’ need for supplemental oxygen. The second, larger part of the trial will evaluate the improvement in longer-term outcomes including preventing death and reducing the need for mechanical ventilation, supplemental oxygen and/or hospitalization.
 
Scientists have preliminary evidence that IL-6 may play a key role in driving the inflammatory immune response that causes acute respiratory distress syndrome (ARDS) in patients critically ill from COVID-19. Initial non-peer reviewed results from a single-arm, 21-patient Chinese trial found COVID-19 patients experienced rapidly reduced fevers and 75% of patients (15 out of 20) reduced their need for supplemental oxygen within days of receiving another IL-6 receptor antibody (tocilizumab). Based on these results, China recently updated its COVID-19 treatment guidelines and approved the use of that IL-6 inhibitor to treat patients with severe or critical disease.
 
In late 2019, Regeneron and Sanofi announced their intent to simplify the joint collaboration for Kevzara, which is expected to be finalized in the first-quarter of 2020. The companies will continue to collaborate on COVID-19 and other related ARDS development, with Regeneron leading U.S.-based work and Sanofi leading work outside of the U.S.
 
The use of Kevzara to treat the symptoms of COVID-19 is investigational and has not been fully evaluated by any regulatory authority.