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Ebanga
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Ebanga

Ridgeback Biotherapeutics' single-antibody Ebola treatment; FDA-approved 2020 for Zaire only; no Bundibugyo efficacy.

WHO's 17 May 2026 PHEIC briefing for the Bundibugyo outbreak flagged that Ebanga's maker, Ridgeback Biotherapeutics, had published no data on whether the drug, drawn from a 1995 Kikwit Zaire survivor's blood, works against the new species; none has followed since.

Last refreshed: 31 July 2026 · Appears in 1 active topic

Key Question

What is Ebanga and why can't it be used in the 2026 Ebola outbreak?

Timeline for Ebanga

#12 31 Jul

Mentioned in: CEPI puts a Bundibugyo vaccine in trials

Pandemics and Biosecurity
#7 12 Jun

Mentioned in: First Ebola treatment trial goes live

Pandemics and Biosecurity
#5 1 Jun

Licensed Ebola therapeutic targeting only the Zaire species

Pandemics and Biosecurity: Mentioned in: Only Ebola treatment still cannot dose
#6 1 Jun

Mentioned in: $112m for vaccines, none for the wards

Pandemics and Biosecurity
#5 29 May

Mentioned in: Ebola passes 1,000 cases in DRC

Pandemics and Biosecurity
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Background

Ebanga is a single monoclonal antibody, ansuvimab (mAb114), developed by Ridgeback Biotherapeutics and approved by the FDA in December 2020 for Zaire ebolavirus. Unlike Inmazeb's triple-antibody design, it uses one broad-spectrum antibody isolated from the blood of a survivor of the 1995 Kikwit outbreak, targeting a conserved receptor-binding site on the Zaire glycoprotein to block viral attachment.

Evaluated alongside Inmazeb in the PALM trial during the 2018-20 DRC Kivu outbreak, Ebanga produced a similar survival rate and, like Inmazeb, is a WHO-preferred Zaire ebolavirus therapy. Ridgeback also developed molnupiravir, the COVID-19 antiviral later licensed to Merck, and holds a US government supply agreement for Ebanga as a biodefence countermeasure.

The drug's origin gives its 2026 exclusion an added dimension: an antibody derived from a Congolese survivor, trialled in DRC communities, cannot be used for DRC's own Bundibugyo outbreak, because the receptor-binding site it targets has no structural equivalent on the Bundibugyo glycoprotein and no cross-protection data has been established. Existing Ebanga stockpiles built for a 2018-style Zaire response sit unused against the current species.

Common Questions
What is Ebanga and how is it different from Inmazeb?
Ebanga (ansuvimab, mAb114) is a single monoclonal antibody against Zaire ebolavirus, FDA-approved December 2020 and developed by Ridgeback Biotherapeutics. Inmazeb is a triple-antibody cocktail (three components) from Regeneron, approved October 2020. Both target Zaire ebolavirus specifically, performed similarly in the PALM trial, and are inapplicable to Bundibugyo.Source: FDA approvals; PALM trial results
Where did the Ebanga antibody come from?
Ebanga was derived from the blood of a survivor of the 1995 Kikwit Zaire ebolavirus outbreak in DRC. Researchers isolated and characterised the human antibody before manufacturing it at scale. It was trialled in DRC communities during the 2018-20 Kivu Ebola epidemic.Source: FDA approval documentation; PALM trial publications
Why aren't Ebola treatments from 2018 being used in 2026?
Both Ebanga and Inmazeb are FDA-approved for Zaire ebolavirus only. The 2026 outbreak is caused by Bundibugyo ebolavirus, a different species with a different glycoprotein that these antibodies do not effectively bind. No cross-protection data has been established or approved. Clinicians in Ituri can legally and medically only use supportive care.Source: FDA labels; Imperial College London; PMC10032372
Source Material
Therapeutic monoclonal antibodies against Ebola virus species and the filovirus class