Novel compound protects monkeys from Ebola: study

A new antiviral compound that blocks Ebola's ability to replicate has been found to provide complete protection to monkeys against the deadly virus when treated three days after infection, scientists say.
The findings suggest that the compound, known as GS-5734, should be further developed as a potential treatment.
Researchers from US Army Medical Research Institute of Infectious Diseases (USAMRIID) used cell culture and animal models to demonstrate the compound's antiviral activity against several pathogens, including Ebola virus.
In animal studies, treatment initiated on day 3 post-infection with Ebola virus resulted in 100 per cent survival of the rhesus monkeys.
The animals also exhibited a substantial reduction in viral load and a marked decrease in the physical signs of disease, researchers said.

"GS-5734 is a novel nucleotide analog prodrug. It inhibits Ebola virus by blocking the virus's ability to replicate its own genetic material," said Travis Warren from 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," said Warren.
In cell culture studies, GS-5734 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.

"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," said Sina Bavari from USAMRIID.
"It shows substantive post-exposure protection against Ebola virus in nonhuman primates, even when treatments were started after virus had spread to the blood in some animals," said Bavari.
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, researchers said.

The findings were published in the journal Nature.