Race Begins to Trial Experimental Ebola Drugs Amid Bundibugyo Outbreak

The World Health Organization (WHO) declared an outbreak of Ebola in the Democratic Republic of the Congo (DRC) a public health emergency of international concern on May 17. This declaration comes as scientists intensify their efforts to trial experimental treatments and potentially vaccines against a rare and dangerous species of Ebola, the Bundibugyo virus, which is currently spreading across the DRC and Uganda. With no approved treatments or vaccines specifically for Ebola Bundibugyo, the urgency is palpable, especially given the grim statistics: 336 suspected cases and 88 deaths reported as of May 17, according to data from the US Centers for Disease Control and Prevention. In a significant development, Nature has learned that a WHO-sponsored clinical trial for two experimental treatments targeting Ebola Bundibugyo virus disease is actively being prepared. This crucial initiative awaits final approval from the governments of both the DRC and Uganda, highlighting the collaborative international effort required to combat such outbreaks. Furthermore, health officials are also exploring the possibility of trialling an already approved vaccine, originally developed for a different species of Ebola virus, to assess its efficacy against the current Bundibugyo strain. Amanda Rojek, a clinical researcher at the University of Oxford and a key member of the treatments trial, expressed optimism, stating, "I think we’re in a really strong position to quickly launch trials. We’re working day and night at the moment." The upcoming trial will focus on two promising therapies. The first is remdesivir, a broad-acting antiviral medication manufactured by Gilead Sciences in Foster City, California. Remdesivir gained prominence for its use during the COVID-19 pandemic and has been previously tested against other filoviruses. The second treatment is MBP134, a sophisticated mixture of two antibodies designed to recognize diverse Ebola viruses, developed by Mapp Biopharmaceuticals in San Diego, California. These two candidates represent the forefront of therapeutic innovation in the fight against Ebola. Remdesivir's history includes its trial during the 2018–19 Ebola outbreak in the DRC, which involved the Zaire species of the virus. It was also extensively trialled against SARS-CoV-2 during the global pandemic, where its efficacy was noted to be modest. This prior experience provides valuable data and insights into its potential effectiveness and safety profile, although its specific impact on the Bundibugyo strain remains to be determined through the upcoming trials. MBP134, on the other hand, was administered during a 2022 outbreak of the Sudan species of Ebola in Uganda. However, this was conducted outside the structured environment of a clinical trial, under 'compassionate use' protocols, which allow patients with life-threatening diseases access to investigational therapies. Consequently, it was not possible to definitively determine whether the drug was effective in that context. The planned WHO trial will provide the rigorous scientific framework needed to assess the true potential of MBP134 against the Bundibugyo virus, offering a glimmer of hope amidst the ongoing public health crisis.