WHO-Backed Clinical Trial to Test Remdesivir and MBP-134 Against Bundibugyo Ebolavirus in DRC

A clinical trial set to begin next week in the Democratic Republic of the Congo will test Gilead Sciences' antiviral drug remdesivir and MappBio's monoclonal antibody MBP-134 against the Bundibugyo ebolavirus, the World Health Organization announced Wednesday. The trial, prompted by a fast-moving outbreak in Central Africa, will assess each drug separately and examine whether combining them produces stronger results.

What Is Bundibugyo Ebolavirus — and Why the Species Label Matters

Ebola is not a single disease but a family of related viruses, and the specific species driving an outbreak determines which treatments are likely to work. Bundibugyo ebolavirus is a distinct member of that family. A therapy validated against one Ebola species does not automatically carry over to another, which is precisely why a fast-moving Bundibugyo outbreak demands its own clinical evidence rather than reliance on data gathered against different strains.

The Two Drugs Under Evaluation

Remdesivir is an antiviral medicine made by Gilead Sciences. MBP-134, developed by MappBio, is a monoclonal antibody — a laboratory-engineered protein designed to recognize and neutralize a specific pathogen. The DRC trial will test each drug against the Bundibugyo form of Ebola and will also run a combination arm, asking whether using the antiviral alongside the monoclonal antibody outperforms either treatment alone.

That combination question carries weight beyond the clinic. If pairing the two drugs proves more effective, it would shape treatment protocols and procurement decisions for any future Bundibugyo response — determining which products health systems and international bodies would need to stockpile.

Stakes for the Companies and the Outbreak Response

The research will be conducted in the DRC, where the current outbreak is under way. WHO officials did not outline a public timeline for when results might be available.

For Gilead Sciences, a positive outcome would extend remdesivir's track record into a high-profile infectious-disease context. For MappBio, success with MBP-134 would establish the antibody as a validated option against a form of Ebola for which the WHO announcement cites no existing approved therapy. Which institutions — national health ministries, international health bodies, or humanitarian procurement funds — would bear the cost of any eventual treatment at scale remains an open question dependent on how the outbreak unfolds.