Novel compound protects monkeys from Ebola virus

In an advance towards an effective treatment against the deadly Ebola virus disease, researchers have found that an antiviral compound that blocks the virus's ability to replicate can fully protect monkeys when treated three days after infection.

The findings, published in the journal Nature, suggest that the compound, known as GS-5734, should be further developed as a potential treatment.

"It inhibits Ebola virus by blocking the virus's ability to replicate its own genetic material," said study first author Travis Warren, principal investigator at the US Army Medical Research Institute of Infectious Diseases (USAMRIID).

"With this process inhibited, the virus can't make copies of itself. Additionally, we saw no evidence from genetic sequence analyses that the virus was able to generate resistance to GS-5734," Warren noted.

In animal studies, treatment initiated on day three post-infection with Ebola virus resulted in 100 percent survival of the monkeys. The animals also exhibited a substantial reduction in viral load and a marked decrease in the physical signs of disease.

"GS-5734 has several favourable characteristics for potential treatment of Ebola virus disease in humans. It is made using well controlled chemical synthesis procedures, is stable, and can be made on a large scale," senior author on the study Sina Bavari, science director, USAMRIID.

"It shows substantive post-exposure protection against Ebola virus in non-human primates, even when treatments were started after virus had spread to the blood in some animals," Bavari noted.

Taken together, the robust therapeutic efficacy observed in primates, the favourable drug-like properties, and the potential for broad-spectrum antiviral activity suggest that further development of GS-5734 for the treatment of Ebola virus and other viral infections is warranted, Bavari said.

In cell culture studies, the compound was active against a broad spectrum of viral pathogens.

These included Middle East Respiratory Syndrome (MERS) virus, Marburg virus, and multiple variants of Ebola virus, including the Makona strain causing the most recent outbreak in Western Africa, the researchers said.