Regeneron scores first FDA approval for Ebola antibody treatment

The US Food and Drug Administration (FDA) has approved Regeneron’s Inmazeb, making it the first FDA-approved treatment for the Ebola virus in adults and children.

Inmazeb (atoltivimab, maftivimab, and odesivimab-ebgn) is a mixture of three monoclonal antibodies which target the glycoprotein on the surface of the Ebola virus.

This glycoprotein attaches to the cell receptor and fuses the viral and host cell membranes together, allowing the virus to enter the cell. Regeneron’s antibody combination binds to this glycoprotein and blocks attachment and entry of the virus into the body’s cells.

The approval is based on results from the PALM trial, which was conducted as part of an expanded access programme in the Democratic Republic of Congo (DRC) during the Ebola virus outbreak in 2018-19.

This study was led by the US National Institutes of Health and the DRC’s Institut National de Recherche Biomédicale, with additional contributions from a number of international organisations and agencies.

In the PALM study, out of 154 patients who received Inmazeb, 33.8% died after 28 days compared to 51% of the 153 patients on the placebo arm.

“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,” said FDA Commissioner Stephen Hahn.

“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 added.

Regeneron is currently developing an antibody treatment for the novel coronavirus disease COVID-19.

The antibody cocktail, REGN-COV2, was recently given to US president Donald Trump after he tested positive for coronavirus earlier this month.

In a descriptive analysis of a large programme evaluating REGN-COV2 in non-hospitalised COVID-19 patients, the treatment demonstrated the ability to reduce viral load and speed up recovery time in non-hospitalised patients.

Regeneron announced earlier this week that it had applied for an emergency use authorisation (EUA) from the FDA for COVID-19 following the positive results.

REGN-COV2 has also recently advanced into a phase 3 trial in the UK, coordinated by researchers from Oxford University. The RECOVERY study is investigating Regeneron’s investigational treatment in patients hospitalised with COVID-19, and is set to compare the effects of adding the cocktail to the usual standard-of-care treatment versus standard-of-care alone.