A long-awaited clinical study to evaluate two potential Ebola treatments officially got underway Thursday in the Democratic Republic of the Congo, with the World Health Organization (WHO) confirming the enrollment of the trial’s first participant. The launch comes as a still-expanding outbreak of the rare Bundibugyo strain of Ebola continues to devastate eastern regions of the country, leaving global and local health officials scrambling for targeted solutions.
Unlike the more widespread Zaire strain of Ebola, the Bundibugyo variant has no approved, specific vaccines or treatment protocols available for use today. As of Thursday, WHO Director-General Tedros Adhanom Ghebreyesus reported that the outbreak has already infected more than 1,400 people and claimed 438 lives. While basic supportive care – when administered early in the course of infection – can improve patient outcomes, with more than 200 people having recovered so far, public health leaders emphasize that more effective interventions are desperately needed to curb the outbreak’s growth.
In his official statement marking the trial’s launch, Tedros framed the research initiative as a critical source of optimism for affected communities, noting that it “offers real hope that we can deliver concrete results for – and with – the communities at the heart of the outbreak.”
The trial will compare the survival outcomes of patients receiving two experimental antiviral therapies against current standard care. The first candidate, remdesivir, is a broad-spectrum antiviral already approved for the treatment of COVID-19, manufactured by Gilead Sciences. Preliminary laboratory testing has already yielded early signs that the drug may be active against the Bundibugyo strain now spreading in Congo. The second candidate, MBP134, is an experimental monoclonal antibody treatment developed by Mapp Biopharmaceutical, engineered specifically to bind to and neutralize multiple strains of Ebola, including Bundibugyo.
Dr. Vasee Moorthy, a research adviser at the WHO, explained the trial’s methodology: all enrolled participants will receive the current best available standard care, then be randomly assigned to one of four groups: remdesivir alone, MBP134 alone, a combination of both drugs, or no additional experimental treatment. Researchers will track patient survival rates for 28 days after the initiation of treatment.
Moorthy cautioned that clear, definitive results will not come quickly. The study may require several months of data collection and up to 1,000 total participants to confirm whether either treatment improves survival. He added, however, that if one of the candidates proves to be highly effective, researchers could reach a conclusion sooner with a smaller patient pool.
At present, the trial is only open to patients at a single Ebola treatment center located in Congo’s Ituri province, a region that has been severely impacted by ongoing armed violence. Targeted attacks against healthcare workers responding to the outbreak have made operating in much of the region unsafe, so officials plan to expand the trial to additional treatment sites only once security conditions improve to allow safe operations.
According to Moorthy, pharmaceutical developers and government partners have already donated a sufficient supply of both experimental drugs to complete the trial. Gilead has donated its supply of remdesivir, while the U.S. government – which funded MBP134 development and owns the trial doses – has contributed the supply of the antibody treatment. If either candidate is found to be effective, stakeholders will immediately move to expand access to the treatment for all patients affected by the outbreak, not just those enrolled in the clinical study.
The WHO-backed trial is the product of a global collaborative effort, bringing together Congo’s national biomedical research institute INRB, the University of Oxford in the United Kingdom, the Institute of Tropical Medicine in Antwerp, and multiple other international public health organizations.
This reporting is part of coverage from The Associated Press Health and Science Department, which receives grant support from the Howard Hughes Medical Institute’s Department of Science Education and the Robert Wood Johnson Foundation. The AP maintains full editorial control over all published content.









