There’s no treatment designed for the Ebola strain ravaging DRC. But now there’s hope : NPR

More than 50 days have passed since the Ebola outbreak was announced in the Democratic Republic of Congo and Uganda. Medical professionals are striving to save patients, but they lack the necessary tools to combat this particular Ebola strain.

“We urgently need treatments that can help people affected by Bundibugyo virus disease,” says Amanda Rojek, a physician scientist at the University of Oxford. This strain is less common than the well-studied Zaire strain responsible for earlier outbreaks.

Due to its rarity, there are no specific treatments for patients, nor are there drugs to protect those exposed to the virus from becoming ill.

This situation is changing as clinical trials are underway, or soon will be, to test new solutions that health officials hope could alter the course of the outbreak, which has already claimed over 500 lives and infected more than 1,560 people. Some experts suggest it could become the largest Ebola outbreak ever recorded.

Last Thursday, the World Health Organization revealed that the first patients had been enrolled in a clinical trial to evaluate two drugs against the Bundibugyo strain. Researchers are also expected to begin assessing whether another drug can protect individuals exposed to the virus.

“One of the key lessons from recent outbreaks is that research needs to happen alongside the response, not after it,” says Rojek, who is helping coordinate the treatment trials.

The three trials are a joint effort involving WHO, Africa CDC, universities, and nonprofits. Each will test existing drugs against Bundibugyo.

“To start from scratch takes years,” says Salim Abdool Karim, director of the Centre for the AIDS Programme of Research in South Africa and a member of the Africa CDC emergency committee monitoring the outbreak. “So we take existing medicines and see whether [they] can be repurposed.”

“This will take some time”

For Ebola treatment, researchers are testing two drugs: the antiviral remdesivir, manufactured by Gilead Sciences, and the monoclonal antibody MBP-134, developed by Mapp Biopharmaceutical. Both are administered intravenously.

Remdesivir gained attention during the COVID-19 pandemic, where it was used with varying success to treat patients in hospitals. However, it was initially developed to target a wide range of viruses, including Ebola. It was tested during the 2018 Ebola outbreak in the Democratic Republic of Congo but proved relatively ineffective against the Zaire species.

MBP-134 is a monoclonal antibody treatment designed to mimic the immune system’s natural defense against the virus. It comprises two monoclonal antibodies, both isolated from a survivor of the 2014-2016 West African Ebola outbreak, which was also caused by the Zaire species. However, lab data suggests it might be effective against Bundibugyo.

The Biomedical Advanced Research and Development Authority (BARDA), a U.S. government agency within the Department of Health and Human Services, played a significant role in funding research for MBP-134 and technically owns the doses. The government has donated the necessary doses for the clinical trial, according to Vasee Moorthy, WHO’s research and development lead for the outbreak.

Each drug will be tested individually and in combination against the current standard of care—supportive therapy that aims to replace lost fluids and manage pain. Currently, only one clinic in the DRC is participating in the trial, but there are plans to expand in the coming weeks, said Moorthy at a press conference last Thursday.

Researchers will monitor if the drugs boost survival, with the timeline depending on various factors, says Moorthy.

“From what we see at the moment, this will take some time,” he noted. “It will take some months. It could go even into next year. It could be that we need over 1,000 patients enrolled in the trial until we get a definitive answer.” If either treatment proves highly effective, that timeline could be shorter, he added.

Treatments aren’t enough

To control the epidemic, which shows no sign of slowing soon, health officials need more than treatments. They need to prevent people from getting sick, says Yazdan Yazdanpanah, an infectious disease physician and epidemiologist at ANRS Emerging infectious diseases, a research agency in France.

A vaccine would be ideal, “but we don’t have a vaccine today,” he notes, and it will be months before testing candidates begins. However, administering an antiviral soon after exposure can help prevent disease and may act faster than a typical vaccine.

This is where the third trial comes in, expected to start sometime this week, says Yazdanpanah. He and his colleagues will be testing whether taking obeldesivir pills, an antiviral also produced by Gilead Sciences, can help prevent close contacts of Ebola cases from contracting the disease, a method known as post-exposure prophylaxis.

The study relies heavily on contact tracers quickly identifying anyone who might have been exposed to an Ebola patient. For contacts who enroll, the research team will visit the participant twice a day to deliver the drug and monitor for symptoms.

If obeldesivir proves effective, it could become a powerful tool for controlling the epidemic, says Yazdanpanah. It could also encourage more contacts to come forward, as health officials would have something to offer them besides instructions to quarantine.

Challenges ahead

Proving the effectiveness of any of these three drugs will depend on the clinical trials running smoothly, which is challenging during an outbreak, especially one complicated by ongoing armed conflict.

There has also been violence directed at health centers, with several attacks occurring since the outbreak began, likely fueled by mistrust. Community members are often suspicious of outside health workers who arrive in full protective gear, and rumors circulate that humanitarian aid groups are either harming people or withholding care.

As a precaution, WHO officials have withheld the exact location of the clinic enrolling patients for the treatment trials to protect its staff.

“There’s a lack of trust,” says Yazdanpanah. Establishing trust within the community is essential for conducting an effective and ethical clinical trial. WHO officials hope to achieve this by organizing numerous community advisory meetings involving healthcare workers and faith groups.

“Discussions with the community are absolutely central,” said Moorthy. “There are open lines of communication to the trial team from the community, so that we can make sure that their interests come first.”