The National Institute of Biomedical Research and Ridgeback Biotherapeutics Respond to 16th Ebola Outbreak in the Democratic Republic of Congo

KINSHASA, Democratic Republic of the Congo and MIAMI, Sept. 12, 2025 /PRNewswire/ -- The Minister of Health from the Democratic Republic of the Congo (DRC) has declared an outbreak of Ebola virus disease (EVD) in Kasai Province after samples tested at the National Institute of Biomedical Research (INRB) in Kinshasa confirmed the cause of the EVD outbreak as Orthoebolavirus zairense (EBOV) (formerly, Zaire ebolavirus). Infection cause by Orthoebolavirus zairense, referred to as Ebola virus disease (EVD), is severe and often fatal with case fatality rates ranging from 25% to 90%, and is transmitted via bodily fluids, zoonotic transmission, or contact with contaminated surfaces.

As of this press release, there have been 25 laboratory-confirmed cases, among them 14 deaths. Patients came from Bulape and Mweka health zones in Kasai Province and presented with symptoms including fever, asthenia, vomiting, and hemorrhage.

The INRB in collaboration with Ridgeback Biotherapeutics ("Ridgeback") announces the deployment of their emergency response team to the Kasai Province to treat individuals with EBOV-infection and those with high-risk exposure to EBOV as post-exposure prophylaxis (PEP) during this 16^th EVD outbreak in DRC. The team is providing EBOV-specific treatment with Ebanga^™ (ansuvimab-zykl), which was approved by the U.S. Food and Drug Administration but not registered in DRC, under an Expanded Access Protocol (EAP).

During the past three EBOV-specific outbreaks, which occurred in the DRC from June 2020 to December 2021, the INRB and Ridgeback were able to collaborate and successfully implement a similar EAP.

For this 16^th EVD Outbreak, the INRB and Ridgeback are working together in coordination with national and international organizations to assist the DRC government in the response efforts to contain this outbreak as soon as possible. Despite logistical challenges, the INRB was able to deploy a medical team within 4 days of the outbreak declaration and to provide Ebanga^™ to EVD confirmed patients who were isolated at Bulape General Hospital. As of the date of this press release, eight patients have been treated with Ebanga^™. Ridgeback receives no compensation in return for supporting these efforts.

"Our collaboration with Ridgeback has allowed us to treat EBOV infected patients quickly after diagnosis. As transmission is ongoing, the number of new cases is likely to increase. While the DRC Ministry of Health and its partners are working to put in place all components of the outbreak response, we aim at providing treatment to EVD cases as faster as possible with drug inventory already stockpiled in the country," said Professor Jean-Jacques Muyembe-Tamfum, Director General of INRB.

Wendy Holman, CEO and co-founder of Ridgeback added, "In this outbreak, as in all other EVD outbreaks, we will work with INRB to support the team of clinicians and pharmacists specialized in the treatment of EVD to ensure patients are treated as quickly as possible."

About Ebanga^™
Ebanga^™ is an Orthoebolavirus zairense glycoprotein (EBOV GP)-directed human monoclonal antibody 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 Ebanga^™ 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 Zaire ebolavirus strains when deciding whether to use Ebanga^™.

Hypersensitivity reactions including infusion-associated events have been reported with Ebanga^™. These may include acute, life-threatening reactions during and after the infusion. Monitor patients and in the case of severe or life-threatening hypersensitivity reactions, discontinue the administration of Ebanga^™ immediately and administer appropriate emergency care. The most frequently reported adverse events (≥ 5%) after administration of Ebanga^™ were pyrexia, tachycardia, diarrhea, vomiting, hypotension, tachypnea, and chills.

Please see Full Prescribing Information for Ebanga^™ (ansuvimab-zykl) here.

Development of Ebanga^™ has been funded in whole or in part with federal funds from the Department of Health and Human Services; Administration for Strategic Preparedness and Response; Biomedical Advanced Research and Development Authority.

About the National Institute of Biomedical Research
The National Institute of Biomedical Research ["Institut National de Recherche Biomedicale (INRB)"], founded in 1984, is a 70,000 Sq. ft. facility that serves as the National Laboratory for Biomedical Research for the Ministry of Health in the Democratic Republic of the Congo (DRC) and is a World Health Organization collaborating center since 2018. It is a multi-disciplinary institute that collectively has several years of experience both in the identification, treatment, and prevention of disease within the DRC. The foundation of which is the performing of medical and biological analysis, applied and translational research, conducting surveillance of communicable diseases, and promoting professional growth and development. The INRB has continually being involved in quality research and public health intervention regarding infectious disease producing exceptional outcomes, most recently the hands-on efforts to the control, prevention and research in Ebola outbreaks. INRB in collaboration with WHO and NIH has conducted the first RCT on Ebola therapeutics in DRC which led to the recognition of ansuvimab as an effective treatment for patients infected with EBOV.

About Ridgeback Biotherapeutics
Headquartered in Miami, Florida, Ridgeback Biotherapeutics LP is a biotechnology company focused on emerging infectious diseases. Ridgeback developed Ebanga^™ for the treatment of Ebola virus disease caused by Orthoebolavirus zairense and now partners with Emergent BioSolutions on the manufacture, commercialization, and distribution of Ebanga^™ across its respective territories. In line with Ridgeback's mission for equitable global access, all Ridgeback's services and treatment for Ebola patients in Africa are delivered free of charge. The team at Ridgeback is dedicated to developing life-saving and life-changing solutions for patients and diseases that need champions as well as providing global access to these medicines.

Ridgeback Biotherapeutics Contacts
For Company Inquires
[email protected]

For Expanded Access Protocol Support
[email protected]

INRB Contacts
Pr. Jean-Jacques MUYEMBE, MD, PhD
INRB Director
[email protected]

SOURCE Ridgeback Biotherapeutics LP