The World Health Organization has recommended maftivimab, a component of Regeneron Pharmaceuticals' (NASDAQ: REGN) Ebola treatment Inmazeb, for evaluation in clinical trials to address the current Bundibugyo ebolavirus outbreak in the Democratic Republic of the Congo and Uganda.

Maftivimab represents the most potent neutralizing antibody in Inmazeb, which was approved by the U.S. Food and Drug Administration in 2020 for treating Zaire ebolavirus infections. Laboratory studies have shown maftivimab demonstrates activity against multiple Ebola species, including Bundibugyo, though it has not been tested as a standalone treatment for this specific virus strain in living subjects.

The WHO declared the current Bundibugyo outbreak a public health emergency of international concern and is coordinating with governments in the affected regions to implement research evaluations of prioritized treatments.

Regeneron has administered Inmazeb to hundreds of patients as part of previous outbreak responses. The company donated 500 doses of Inmazeb to WHO in September 2025 for use by low- and lower-middle income countries at risk for Ebola outbreaks. The company maintains existing supply of both maftivimab and Inmazeb in the Democratic Republic of the Congo.

Inmazeb consists of three monoclonal antibodies designed to neutralize the Ebola virus. Its safety and efficacy were established through the 681-patient PALM Trial conducted during the 2018 DRC outbreak, which was stopped early after interim analysis showed superiority over other investigational treatments.

The company is preparing existing maftivimab supply for potential clinical trials while coordinating response efforts with the U.S. Department of Health and Human Services.