WHO Disease Outbreak News 607, published 13 June, reports that a clinical trial of Bundibugyo Ebola treatments is now underway, the first authorised therapeutic intervention in an outbreak that ran for weeks with no drug to offer. The protocol pairs MBP134, a two-antibody cocktail, with REGN3479, a Regeneron monoclonal antibody, for treatment, and adds obeldesivir, an oral antiviral, for post-exposure prophylaxis1. A monoclonal antibody is a laboratory-made protein that locks onto one structure on the virus; obeldesivir is a prodrug, an inactive compound the body converts to the active drug, which lets it be given by mouth to people exposed but not yet infected.
Both REGN3479 and obeldesivir differ from the drugs named in the 28 May expert advisory, which had centred on MBP134 and remdesivir. WHO attributes the trial design to national leadership with community consultation, pending ethics-committee and regulatory review. The change of drug set is the news; the protocol is owned by DRC and Uganda, not handed down by Geneva.
The drug list matters more than it looks, because a trial is also a gate. Whether obeldesivir and REGN3479 reach licensure depends on the data this outbreak generates, and a haemorrhagic-fever trial in an insecure conflict zone produces evidence slowly. After the long stretch when Inmazeb, Ebanga and Ervebo were confirmed useless against this Ebola species, something is finally being dosed, but a drug in trial is not a drug in routine use.
