A new oral treatment for Ebola has successfully cured infected monkeys, offering hope for a more practical and accessible human treatment. The experimental drug, obeldesivir, demonstrated remarkable effectiveness in preclinical trials, protecting the majority of treated primates from a lethal infection. If shown to be safe and effective in humans, this pill has the potential to transform Ebola treatment by overcoming the logistical hurdles of existing methods.
A More Practical Solution to Ebola Treatment
Ebola virus disease is among the deadliest infections, with some outbreaks reaching mortality rates as high as 90%. Initial symptoms include fever, fatigue, muscle pain, and headaches, but the condition can quickly worsen, leading to organ failure, severe bleeding, and a high risk of death.
Until recently, treatment options were extremely limited. For years, only supportive care was available, focusing on symptom relief rather than eliminating the virus. More recently, two FDA-approved monoclonal antibody treatments—Inmazeb and Ebanga—have provided effective options against Zaire ebolavirus strains. However, these drugs require administration via intravenous infusion, limiting their use in outbreak situations, especially in remote areas. Similarly, vaccines such as Ervebo and the two-dose combination Zabdeno-Mvabea offer protection but are not always useful in responding to active outbreaks.
Obeldesivir offers a critical advantage over existing therapies. Unlike monoclonal antibodies, which are expensive to produce and require careful storage, this new pill is more cost-effective and easier to distribute. The drug works similarly to remdesivir, a widely used antiviral for COVID-19, by blocking viral replication through enzyme inhibition.
Encouraging Results from Animal Trials
In a recent study, scientists tested obeldesivir in cynomolgus and rhesus macaques—two monkey species frequently used in medical research because their genetic makeup closely resembles that of humans. The animals were given a high dose of the Makona strain of the Ebola virus, known for its lethal effects.
Treatment began 24 hours after exposure, with infected monkeys receiving a daily pill for 10 days. The results were highly promising: 80% of the cynomolgus macaques and 100% of the rhesus macaques survived. In addition to preventing death, the drug triggered an immune response, suggesting it could provide broader protection beyond just treating active infections. Given that rhesus macaques are genetically closer to humans, these findings strengthen the case for further clinical development.
A Potential Game-Changer for Outbreak Response
Treating Ebola outbreaks has long been complicated by logistical and cultural barriers. During the largest recorded outbreak from 2014 to 2016, which spread across Guinea, Sierra Leone, and Liberia, fear and mistrust made it difficult to contain the virus. Many people resisted hospitalization, fearing isolation from their families. The ability to provide an effective treatment in pill form, without requiring hospital stays or IV infusions, could make a significant difference in outbreak control.
Although obeldesivir has only been tested in monkeys so far, further research will determine its potential in human patients. If successful, this breakthrough could make Ebola treatment more accessible, reducing the spread and fatality of one of the world’s deadliest diseases.