Updated agreement expands 2020 procurement agreement with BARDA for Regeneron’s first-in-class antibody treatment for Orthoebolavirus zairense, adding value of approximately $270 million
TARRYTOWN, N.Y., Oct. 26, 2026 (GLOBE NEWSWIRE) — Regeneron Pharmaceuticals, Inc. (NASDAQ: REGN) announced today that it has extended its agreement with the Biomedical Advanced Research and Development Authority (BARDA), part of the Administration for Strategic Preparedness and Response (ASPR) within the U.S. Department of Health and Human Services (HHS), to provide additional supply of Inmazeb® (a three-antibody cocktail of atoltivimab, maftivimab, and odesivimab-ebgn) for U.S. preparedness against Ebola disease. Inmazeb was the first Ebola treatment approved by the U.S. Food and Drug Administration (FDA), indicated specifically for infection caused by Orthoebolavirus zairense in adult and pediatric patients, including neonates born to infected mothers, and has been administered to hundreds of patients since 2019. In a clinical trial, Inmazeb reduced mortality by approximately 55 percent compared to an active control treatment in patients with low viral load. This agreement continues a partnership that began with BARDA’s original procurement of the treatment in 2020.
Under the new agreement, Regeneron expects to deliver additional treatment doses of Inmazeb treatment to the U.S. government through 2031 and receive payment of approximately $270 million.
“Maintaining a ready supply of Inmazeb is exactly the kind of preparedness this country needs for the threats we can already see on the horizon,” said Leonard S. Schleifer, M.D., Ph.D., Board Co-Chair, President and Chief Executive Officer of Regeneron. “This extended agreement reflects the strength of our long-standing collaboration with BARDA and our shared commitment to ensuring that at-the-ready medicines are available whenever an Ebola outbreak occurs.”
Maftivimab Development Program
Separately, Regeneron’s investigational maftivimab monotherapy is being added to the PARTNERS trial to assess use as a potential treatment in the current Bundibugyo virus disease outbreak
Maftivimab has demonstrated positive in vitro and non-human primate activity against Bundibugyo; preprint data now available
Separate from the Inmazeb procurement agreement, Regeneron is evaluating maftivimab, the most potent virus-neutralizing component of Inmazeb, as a potential treatment for Ebola disease caused by Bundibugyo virus, the orthoebolavirus driving the current outbreak in the Democratic Republic of the Congo (DRC) and for which there are no currently approved treatment options. Maftivimab has demonstrated strong efficacy against Bundibugyo virus in in vitro and non-human primate (NHP) studies, supporting its continued development as a monotherapy or combination treatment candidate. These data are now available in preprint on BioRxiv.org and pending peer review publication.
“Inmazeb was created by Regeneron scientists in record time using our proprietary VelociSuite® rapid-response technologies,” said George D. Yancopoulos, M.D., Ph.D., Board Co-Chair, President and Chief Scientific Officer of Regeneron. “We are now advancing maftivimab, which has already demonstrated positive results in non-human primates infected with Bundibugyo, so that we can bring another potential Ebola treatment forward as quickly as possible to help in the current outbreak. Regeneron’s continued supply of Inmazeb to the U.S. government, our advancement of maftivimab and our partnerships to support frontline response capacity reflect the Company’s long-term commitment to infectious diseases preparedness, from the laboratory to the communities most affected by outbreaks.”
Based on in vitro and NHP efficacy studies, maftivimab is being added to the PARTNERS (Platform Adaptive Randomised Trial for New and Repurposed Filovirus TreatmentS) clinical trial, which is evaluating potential treatments for Bundibugyo virus disease. PARTNERS is delivered through a global partnership of Ministries of Health, researchers, healthcare workers and international research and non-governmental organizations. The trial has been designed and is coordinated internationally by the Pandemic Sciences Institute, University of Oxford, and is being led nationally in the DRC by the Institut National de Recherche Biomédicale (INRB), supported by the Institute of Tropical Medicine (ITM), Antwerp. The trial is sponsored by the World Health Organization (WHO) and is made possible with the support of Africa CDC.
Regeneron also continues to support Afya Foundation’s emergency response efforts aimed at safeguarding frontline healthcare workers and strengthening healthcare system resilience during the current outbreak.
About Inmazeb
Inmazeb is approved by the U.S. FDA for the treatment of infection caused by Orthoebolavirus zairense (formerly known as Zaire ebolavirus) in adult and pediatric patients, including neonates born to a mother who is RT-PCR positive for Orthoebolavirus zairense infection. Inmazeb was created using Regeneron’s
VelocImmune® platform and associated VelociSuite® technologies. The treatment consists of three monoclonal antibodies that help neutralize the Ebola virus by blocking its ability to invade a patient’s cells and/or enlisting other immune cells to target infected cells and remove them from the body.
The safety and efficacy of Inmazeb was established through the 681-patient PALM Trial, which was independently conducted by the WHO, the U.S. National Institutes of Health and the INRB during the 2018 DRC outbreak of Ebola virus. In 2019, as reported in the New England Journal of Medicine, the PALM Trial was stopped early following a pre-specified interim analysis that showed the superiority of Inmazeb in preventing death versus two other investigational treatments.
Inmazeb was approved by the FDA in 2020, and in 2022, WHO published its first guidelines for Ebola virus therapeutics, which strongly recommends the use of Inmazeb for treatment of Ebola virus infection and calls on the global community to engage all possible mechanisms to improve access to life-saving Ebola disease medicines. In November 2023, Inmazeb became the first and only Ebola disease treatment to be prequalified by the WHO, certifying that the medicine meets WHO’s standards for quality, safety and efficacy and is considered “essential.”
Since 2018, Inmazeb has been offered by Regeneron at no cost under a compassionate use protocol to infected persons in countries experiencing an Ebola virus disease outbreak caused by Orthoebolavirus zairense, including the DRC and Guinea. In September 2025, the company committed to donate up to 500 doses of Inmazeb to the WHO for exclusive use by governments of low- and lower-middle income countries that are most at-risk for Ebola disease outbreaks.1 In addition, Regeneron has worked with governments in higher- and middle-income countries to establish Inmazeb stockpiles.
This project has been supported in whole or in part with federal funds from the U.S. Department of Health and Human Services; Administration for Strategic Preparedness and Response; Biomedical Advanced Research and Development Authority (BARDA), under contract numbers HHSO100201700016C and HHSO100201500013C. The contract and federal funding are not an endorsement of the product or company.
IMPORTANT SAFETY INFORMATION AND INDICATION WARNINGS AND PRECAUTIONS FOR INMAZEB
Hypersensitivity Reactions Including Infusion-Associated Events: Hypersensitivity reactions including infusion-associated events have been reported during and post-infusion with INMAZEB. These may include acute, life-threatening reactions during and after the infusion. Monitor all patients for signs and symptoms including, but not limited to, hypotension, chills and elevation of fever, during and following INMAZEB infusion. In the case of severe or life-threatening hypersensitivity reactions, discontinue the administration of INMAZEB immediately and administer appropriate emergency care.
Infusion could not be completed in 1% of subjects who received INMAZEB due to infusion-associated adverse events. The rate of infusion of INMAZEB may be slowed or interrupted if the patient develops any signs of infusion-associated events or other adverse events.
ADVERSE REACTIONS: The most common adverse events reported in at least 20% of subjects who received INMAZEB were pyrexia (or elevation in fever), chills, tachycardia, tachypnea and vomiting. The evaluation of adverse events in subjects who received INMAZEB may have been confounded by the signs and symptoms of the underlying Orthoebolavirus zairense infection.
DRUG INTERACTIONS: INMAZEB may reduce the efficacy of live vaccine, therefore, avoid the concurrent administration of a live vaccine during treatment with INMAZEB. The interval between live vaccination following initiation of INMAZEB therapy should be in accordance with current vaccination guidelines. The efficacy of INMAZEB among subjects who reported receipt of a recombinant live vaccine prior to their enrollment in the PALM clinical trial was similar to subjects who did not receive a vaccine.
INDICATION
INMAZEB is indicated for the treatment of infection caused by Orthoebolavirus zairense in adult and pediatric patients, including neonates born to a mother who is RT-PCR positive for Orthoebolavirus zairense infection.
Limitations of Use: The efficacy of INMAZEB has not been established for other species of the Orthoebolavirus and Orthomarburgvirus genera. Orthoebolavirus zairense can change over time, and factors such as emergence of resistance, or changes in viral virulence could diminish the clinical benefit of antiviral drugs. Consider available information on drug susceptibility patterns for circulating Orthoebolavirus zairense strains when deciding to use INMAZEB.
Please see accompanying full Prescribing Information for Inmazeb.
About Regeneron
Regeneron (NASDAQ: REGN) is a leading biotechnology company that invents, develops and commercializes life-transforming medicines for people with serious diseases. Founded and led by physician-scientists, our unique ability to repeatedly and consistently translate science into medicine has led to numerous approved treatments and product candidates in development, most of which were homegrown in our laboratories. Our medicines and pipeline are designed to help patients with eye diseases, allergic and inflammatory diseases, cancer, cardiovascular and metabolic diseases, neurological diseases, hematologic conditions, infectious diseases, and rare diseases.
Regeneron pushes the boundaries of scientific discovery and accelerates drug development using our proprietary technologies, such as VelociSuite®, which produces optimized fully human antibodies and new classes of bispecific antibodies. We are shaping the next frontier of medicine with data-powered insights from the Regeneron Genetics Center® and pioneering genetic medicine platforms, enabling us to identify innovative targets and complementary approaches to potentially treat or cure diseases. For more information, please visit www.Regeneron.com or follow Regeneron on LinkedIn, Instagram, Facebook or X.
Forward-Looking Statements and Use of Digital Media
This press release includes forward-looking statements that involve risks and uncertainties relating to future events and the future performance of Regeneron Pharmaceuticals, Inc. (“Regeneron” or the “Company”), and actual events or results may differ materially from these forward-looking statements. Words such as “anticipate,” “expect,” “intend,” “plan,” “believe,” “seek,” “estimate,” variations of such words, and similar expressions are intended to identify such forward-looking statements, although not all forward-looking statements contain these identifying words. These statements concern, and these risks and uncertainties include, among others, the nature, timing, and possible success and therapeutic applications of products marketed or otherwise commercialized by Regeneron and/or its collaborators or licensees (collectively, “Regeneron’s Products”) and product candidates being developed by Regeneron and/or its collaborators or licensees (collectively, “Regeneron’s Product Candidates”) and research and clinical programs now underway or planned, including without limitation Inmazeb® (a three-antibody cocktail of atoltivimab, maftivimab, and odesivimab-ebgn) for the treatment of infection caused by Orthoebolavirus zairense (also known as Ebola virus) as well as maftivimab as a potential treatment for Bundibugyo ebolavirus; uncertainty of the utilization, market acceptance, and/or commercial success of Regeneron’s Products (including Inmazeb) and Regeneron’s Product Candidates and the impact of studies (whether conducted by Regeneron or others and whether mandated or voluntary), including the studies discussed or referenced in this press release, on any of the foregoing or any potential regulatory approval of Regeneron’s Products and Regeneron’s Product Candidates (such as maftivimab); the likelihood, timing, and scope of possible regulatory approval and commercial launch of Regeneron’s Product Candidates (such as maftivimab) and new indications for Regeneron’s Products; whether and the extent to which Regeneron will be able to deliver the additional treatment doses of Inmazeb set forth in its agreement with the Biomedical Advanced Research and Development Authority, part of the Administration for Strategic Preparedness and Response within the U.S. Department of Health and Human Services (collectively, the “U.S. Government”) discussed in this press release (the “Supply Agreement”), the amount of payments (if any) Regeneron may receive pursuant to the Supply Agreement, and whether the Supply Agreement is terminated by the U.S. Government or otherwise prior to completion; the extent to which the results from the research and development programs conducted by Regeneron and/or its collaborators or licensees may be replicated in other studies and/or lead to advancement of product candidates to clinical trials, therapeutic applications, or regulatory approval; determinations by regulatory and administrative governmental authorities which may delay or restrict Regeneron’s ability to continue to develop or commercialize Regeneron’s Products and Regeneron’s Product Candidates (such as maftivimab); the impact of public health outbreaks, epidemics, or pandemics on Regeneron’s business; the ability of Regeneron’s collaborators, licensees, suppliers, or other third parties (as applicable) to perform manufacturing, filling, finishing, packaging, labeling, distribution, and other steps related to Regeneron’s Products and Regeneron’s Product Candidates; the ability of Regeneron to manage supply chains for multiple products and product candidates and risks associated with tariffs and other trade restrictions; safety issues resulting from the administration of Regeneron’s Products and Regeneron’s Product Candidates in patients, including serious complications or side effects in connection with the use of Regeneron’s Products and Regeneron’s Product Candidates in clinical trials; ongoing regulatory obligations and oversight impacting Regeneron’s Products, research and clinical programs, and business, including those relating to patient privacy; the availability and extent of reimbursement or copay assistance for Regeneron’s Products from third-party payors and other third parties, including private payor healthcare and insurance programs, health maintenance organizations, pharmacy benefit management companies, and government programs such as Medicare and Medicaid; coverage and reimbursement determinations by such payors and other third parties and new policies and procedures adopted by such payors and other third parties; changes to drug pricing regulations and requirements and Regeneron’s pricing strategy, including in connection with Regeneron’s April 2026 agreements with the U.S. government; other changes in laws, regulations, and policies affecting the healthcare industry; competing products and product candidates (including biosimilar products) that may be superior to, or more cost effective than, Regeneron’s Products and Regeneron’s Product Candidates; unanticipated expenses; the costs of developing, producing, and selling products; the ability of Regeneron to meet any of its financial projections or guidance and changes to the assumptions underlying those projections or guidance; the potential for any license, collaboration, or supply agreement, including Regeneron’s agreements with Sanofi and Bayer (or their respective affiliated companies, as applicable), to be cancelled or terminated; and risks associated with litigation and other proceedings and government investigations relating to the Company and/or its operations (including the pending civil proceedings initiated or joined by the U.S. Department of Justice and the U.S. Attorney’s Office for the District of Massachusetts), risks associated with intellectual property of other parties and pending or future litigation relating thereto (including without limitation the patent litigation and other related proceedings relating to EYLEA® (aflibercept) Injection), the ultimate outcome of any such proceedings and investigations, and the impact any of the foregoing may have on Regeneron’s business, prospects, operating results, and financial condition. A more complete description of these and other material risks can be found in Regeneron’s filings with the U.S. Securities and Exchange Commission, including its Form 10-K for the year ended December 31, 2025, and its Form 10-Q for the quarterly period ended June 30, 2026. Any forward-looking statements are made based on management’s current beliefs and judgment, and the reader is cautioned not to rely on any forward-looking statements made by Regeneron. Regeneron does not undertake any obligation to update (publicly or otherwise) any forward-looking statement, including without limitation any financial projection or guidance, whether as a result of new information, future events, or otherwise.
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1 As defined by the World Bank based on gross national income per capita.
