FDA Approves First Ebola Virus Treatment

The US Food and Drug Administration (FDA) has approved atoltivimab, maftivimab, and odesivimab-ebgn (Inmazeb) for the treatment of adult and pediatric patients with Zaire ebolavirus (Ebola virus) infection. With the indication, the monoclonal antibody cocktail from Regeneron Pharmaceuticals becomes the first drug approved to treat Ebola virus. The three-drug combination therapy is designed to target the glycoprotein located on the virus' surface, and inhibit its attachment to the cell receptor, stopping the virus from entering cells. Its efficacy and safety was observed the PALM trial, a 382-adult and -pediatric patient assessment led by the US National Institutes of Health (NIH) and DRC's Institut National de Recherche Biomédicale as part of the expanded access program conducted in the Democratic Republic of the Congo (DRC) during an outbreak in 2018-2019. The multi-center, open-label, randomized controlled study compared 154 patients administered 50 mg of each monoclonal antibody in Inmazeb intravenously in a single infusion, versus 168 patients on investigational control therapy. Primary efficacy endpoint was 28-day mortality. One-third (33.8%) of patients treated with Inmazeb died after 28 days, versus 51% of control patients. Investigators provided the therapy to another 228 patients in the expanded access program. The most common symptoms reported among treated patients included fever, chills, tachycardia, tachypnea, and vomiting—symptoms also closely associated with Ebola virus infection. Patients administered Inmazeb are advised by the FDA to avoid concurrent live vaccine administration, due to the therapy's ability to inhibit replication of a live vaccine virus and reduce its efficacy. The FDA previously approved the first vaccine for the prevention of Ebola virus disease in December 2019. Generally famed for a series of international outbreaks over recent decades, Ebola virus is transmitted through direct contact with blood, body fluids and tissues of infected people or wild animals, as well as with contaminated surfaces and materials. Care providers for those with the virus are often at the greatest risk of infection—especially those without appropriate personal protective equipment (PPE). FDA Commissioner Stephen M. Hahn, MD, called the decision a demonstration of the agency's ongoing commitment to public health threat response "on the basis of science and data." "This approval was made possible because of our steadfast dedication to facilitate the development of safe and effective treatments for infectious diseases as part of our vital public health mission," he said in a statement.