TARRYTOWN, N.Y. | May 28, 2026
Regeneron Pharmaceuticals announced that maftivimab, the lead neutralizing antibody within its FDA-approved Ebola therapy Inmazeb®, has been prioritized by the World Health Organization (WHO) Therapeutics Advisory Group for evaluation in clinical studies targeting the ongoing Bundibugyo ebolavirus outbreak in Uganda and the Democratic Republic of the Congo (DRC).
The recommendation follows WHO’s declaration of the outbreak as a public health emergency of international concern and highlights growing interest in leveraging existing Ebola countermeasures against emerging viral threats. Regeneron stated it is actively coordinating with the WHO and the U.S. Department of Health and Human Services (HHS) to support potential clinical evaluations of maftivimab as an investigational treatment during the outbreak response.
Maftivimab Demonstrates Broad Activity Against Multiple Ebola Species
Maftivimab is the most potent virus-neutralizing component of Inmazeb®, a three-antibody cocktail that also includes atoltivimab and odesivimab-ebgn. While Inmazeb is approved for the treatment of infections caused by Orthoebolavirus zairense (Zaire ebolavirus), laboratory studies have demonstrated that maftivimab possesses broad neutralizing activity against multiple Ebola species, including Bundibugyo ebolavirus.
Based on these findings, WHO has recommended evaluating maftivimab as a standalone therapy during the current outbreak. Although the antibody has not yet been tested clinically as a monotherapy for Bundibugyo virus infection, it has already been administered to hundreds of patients as part of the Inmazeb regimen and has established a favorable safety profile.
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Inmazeb Established as a Proven Ebola Treatment
Inmazeb became the first FDA-approved treatment for Ebola virus disease in 2020 following results from the landmark PALM trial, which demonstrated superior survival outcomes compared with other investigational therapies during the 2018 Ebola outbreak in the DRC.
Developed using Regeneron’s proprietary VelocImmune® and VelociSuite® technologies, the therapy combines three monoclonal antibodies that work together to neutralize the virus and help the immune system eliminate infected cells. The treatment later received strong endorsement from WHO and became the first Ebola therapy to achieve WHO prequalification status, validating its quality, safety, and efficacy for global procurement and deployment in outbreak settings.
Global Preparedness Efforts Support Rapid Outbreak Response
Regeneron has continued to strengthen global Ebola preparedness through collaborations with international health agencies and governments. In 2025, the company donated 500 doses of Inmazeb to the WHO for deployment in low- and lower-middle-income countries at risk of Ebola outbreaks and has also supplied stockpiles to the U.S. government through partnerships with BARDA and HHS.
According to the company, existing supplies of Inmazeb are already available in the DRC should immediate treatment be required, while preparations are underway to make maftivimab available for potential clinical studies. The company is also supporting broader outbreak response efforts through partnerships aimed at protecting frontline healthcare workers and strengthening healthcare infrastructure in affected regions.
Source: Regeneron press release
