More than 50 days have passed since the Ebola outbreak started in the Democratic Republic of Congo and Uganda. Clinicians are striving to care for patients, but they’re missing essential treatments needed for the specific strain of Ebola currently spreading.
“There’s an urgent need for treatments effective against Bundibugyo virus disease,” mentions Amanda Rojek, a physician scientist at the University of Oxford. This strain is less common than the heavily studied Zaire strain that has played a role in previous outbreaks.
Because it’s rarer, there aren’t any specific treatments available for patients, nor drugs that could help shield those exposed to the virus from becoming ill.
However, the situation is changing as clinical trials are either underway or will soon commence to test new treatments that health officials hope could reverse the course of an outbreak that has claimed over 500 lives and infected more than 1,560 people—raising concerns that it could be the largest Ebola outbreak recorded.
Recently, the World Health Organization announced the enrollment of the first patients in a clinical trial focusing on two drugs targeting Bundibugyo. Additionally, researchers are expected to begin investigating whether another drug can protect individuals who have been exposed to the virus.
“One significant takeaway from past outbreaks is that research must occur alongside the response efforts,” Rojek points out, who is also playing a role in coordinating the treatment trials.
These three trials represent a joint effort involving WHO, Africa CDC, various universities, and non-profit organizations. The objective is to test existing drugs against Bundibugyo.
“Starting everything from scratch can take years,” explains Salim Abdool Karim, who directs the Centre for the AIDS Programme of Research in South Africa and is part of the Africa CDC emergency committee monitoring the outbreak. “Hence, we utilize current medications to determine if they can be repurposed.”
“This will take some time”
In terms of treatment, researchers are looking at two drugs: the antiviral remdesivir from Gilead Sciences, and a monoclonal antibody called MBP-134, developed by Mapp Biopharmaceutical. Both are administered intravenously.
Remdesivir gained attention during the COVID-19 pandemic, although it was used with varying effectiveness for hospitalized patients. Originally designed to target various viruses—including Ebola—it went through testing amid the 2018 Ebola incident in the Democratic Republic of Congo but was found to be relatively ineffective against the Zaire strain.
MBP-134 aims to replicate the immune response against the virus, consisting of two monoclonal antibodies sourced from a survivor of the 2014-2016 West African Ebola outbreak, which was caused by the Zaire strain. Lab results suggest it might be effective against Bundibugyo.
The Biomedical Advanced Research and Development Authority (BARDA) significantly funded research for MBP-134 and controls the doses. According to WHO’s Vasee Moorthy, the U.S. government has donated the necessary doses for the clinical trials.
Each drug will be evaluated independently and in combination with existing supportive therapy, which focuses on fluid replacement and pain management. Only one clinic in the DRC is currently participating in the trial, but there are plans for expansion soon, Moorthy noted at a press conference last Thursday.
Researchers will watch if these drugs enhance survival rates. The timeline for results depends on several factors, as stated by Moorthy.
“This is going to take some time, possibly several months, and might carry over into next year. We may require over 1,000 patients to get a conclusive answer,” he said. If either treatment is highly effective, the timeline may shorten, he added.
Treatments aren’t enough
Beyond just treatments, health officials are clear that prevention is key to managing the epidemic, which shows no sign of abating. Yazdan Yazdanpanah, an infectious disease expert in France, emphasized the need for a vaccine, although none is currently available, and testing potential candidates will take months. Meanwhile, administering an antiviral shortly after exposure could help prevent illness and might work faster than a vaccine.
That’s where the third trial comes into play, expected to start soon, according to Yazdanpanah. His team will explore whether taking obeldesivir pills—another antiviral from Gilead—might prevent close contacts of Ebola patients from contracting the virus, a method known as post-exposure prophylaxis.
This study hinges on quick identification of anyone who may have been exposed to an Ebola patient. Research staff will visit participants twice daily to administer the drug and monitor any symptoms.
If obeldesivir shows effectiveness, it could become a critical tool in combating the outbreak, according to Yazdanpanah. It may also encourage more contacts to step forward, as health officials would have something to offer besides quarantine advice.
Challenges ahead
Ensuring the success of these trials depends on smooth operations, which can be tricky during outbreaks—especially in regions facing ongoing conflict.
Additionally, health centers have experienced violence, with several attacks likely fueled by mistrust. Many community members feel uneasy about health workers arriving clad in protective gear, leading to rumors suggesting that humanitarian groups may be causing harm or withholding aid.
Interestingly, WHO officials have chosen not to disclose the clinic’s precise location engaging patients in trials to safeguard its staff.
“There’s a significant trust deficit,” Yazdanpanah commented. Building community trust is essential for executing effective and ethical trials. WHO hopes that increased community advisory meetings—with input from healthcare providers and faith leaders—will help.
“Engagement with the community is critical,” stated Moorthy. “We’re keeping clear communication channels open between the trial team and the community to prioritize their interests.”
