The U.S. Food and Drug Administration (FDA) authorized a major medical breakthrough this week, approving Regeneron Pharmaceuticals to produce Inmazeb, the first treatment for Ebola virus infections to reach that point.
Inmazeb is a mix of three monoclonal antibodies, which work by targeting the glycoprotein on the Ebola virus’s surface. By binding to this glycoprotein, the antibodies block attachment and entry to cell membranes. Typically, the potentially fatal Ebola virus is passed to humans through direct contact with infected blood, body fluids, tissues, or contaminated surfaces.
“Today’s action demonstrates the FDA’s ongoing commitment to responding to public health threats—both domestically and abroad—on the basis of science and data,” FDA Commissioner Stephen Hahn said. “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.”
Inmazeb was evaluated on 382 adult and pediatric patients previously diagnosed with Ebola. Over the course of a clinical trial — the PALM trial — and an expanded access program conducted in the Democratic Republic of the Congo, the U.S. National Institutes of Health and the DRC’s Institut National de Recherche Biomédicale established the safety and efficacy of the treatment. Another 228 patients were given the treatment through the expanded access program.
Of the 154 patients who received Inmazeb in that trial, approximately one-third died after 28 days, down from the 51 percent of the 153 patients given a control. Side effects typically experienced while taking Inmazeb included fever, chills, quickened heart rates and breathing, and vomiting. Hypersensitivity was also experienced, and treatment is advised to discontinue if the latter is felt.
There is some uncertainty about these side effects, though, as many of the symptoms overlap with those of Ebola itself.