A groundbreaking study by researchers at the University of Texas Medical Branch is shedding light on a promising development in the battle against highly fatal hemorrhagic diseases caused by orthoebolaviruses, including the notorious Ebola virus.
Published in Science, the research highlights the strong protective efficacy demonstrated by Obeldesivir when administered orally, providing solutions to challenges faced in treating these viruses, particularly in resource-poor areas where intravenous therapies can pose significant logistical hurdles.
“People are also much more likely to take a pill than come to a clinic for IV treatments,” said Dr. Thomas Geisbert, senior author and professor of Microbiology and Immunology at UTMB. “Unlike most filovirus treatments requiring intravenous administration, the oral form provides a more accessible and scalable solution. The convenience of oral antivirals could expedite the treatment of contacts and contacts of contacts, crucial in breaking the chain of virus transmission during outbreaks.”
In the study, researchers focused on the development and efficacy of Obeldesivir (ODV), an oral antiviral drug of the parent nucleoside of remdesivir (RDV) and is presently in phase 3 trials for COVID-19 treatment. Laboratory tests revealed ODV's effectiveness against Ebola, Sudan virus, and Marburg virus. Subsequent experiments on nonhuman primates infected with Sudan virus demonstrated that once-daily oral ODV treatment, for 10 days, starting one day after exposure, provided complete protection against lethal infection. The drug not only delayed the onset of inflammation but also correlated with the activation of the immune system.
“This can be a significant step forward in outbreak response,” said Dr. Robert Cross, coauthor and faculty at UTMB. “We can start early treatment to close contacts of those sick with the virus, similar to how we now give antivirals to potential exposures of influenza or COVID for high-risk individuals.”
The findings highlight the prophylactic potential of oral antivirals, as showcased by Obeldesivir, and offer immediate protection for first responders. This contrasts with traditional vaccines, which may take time to trigger a protective immune response.
Filovirus outbreaks usually occur in resource-poor areas where disease control and treatments can face a substantial logistical challenge. The research further supports the development of Obeldesivir as both post-exposure protection and treatment for filovirus infections, especially when the oral administration of Obeldesivir shows significant advantages in outbreak management, offering simplified supply, storage and distribution.
“This study is the result of brilliant minds coming together in a collaboration using the mighty capabilities of our BSL4 Galveston National Laboratory at UTMB,” said Dr. Jochen Reiser, resident of UTMB and CEO of the UTMB Health System. “The anti-Ebola Virus pill could stall outbreaks and spreading much faster than the current standard of care and could save lives.”
“Obeldesivir has the potential to be a game changer in the way that filovirus outbreaks are managed in the future,” said Geisbert. “We thank our corporate partner Gilead and the NIAID for their support in advancing the development of this promising treatment for Ebola and Marburg virus infections.”
*This study was supported by the Department of Health and Human Services, National Institutes of Health grants U19AI142785 to Dr. Thomas Geisbert and UC7AI094660 for BSL-4 operations support of the Galveston National Laboratory.