Novel compound found effective against H5N1 avian influenza virus

A new study shows that a novel antiviral compound is effective against the highly pathogenic H5N1 avian influenza virus, including oseltamivir (Tamiflu)-resistant strains, according to scientists from Japan, Vietnam, Indonesia, and the University of Wisconsin-Madison. The research, published February 26 in the open-access journal PLoS Pathogens, suggests that the prodrug CS-8958 is a promising alternative antiviral for prevention and treatment of H5N1 influenza. Antiviral drugs are a primary countermeasure against human influenza viruses, including H5N1 avian influenza virus ("bird flu"). Emerging strains resistant to existing drugs, particularly oseltamivir, pose a threat and make the development of alternate antivirals a pressing public health issue. The novel neuraminidase inhibitor R-125489 and its prodrug CS-8958 have previously demonstrated potent activity against seasonal influenza viruses in animal studies.

Working with mice, the researchers found that a single intranasal dose of CS-8958 given two hours after infection with H5N1 influenza virus resulted in a higher survival rate and lower virus levels than a standard five-day course of oseltamivir. CS-8958 was also effective against highly pathogenic and oseltamivir-resistant strains of H5N1 virus. In addition to its therapeutic benefit, CS-8958 also protected mice against lethal H5N1 infection when given seven days before infection with the virus.

While follow-up studies will be needed to confirm the applicability of the findings to humans, the authors conclude that "CS-8958 is highly effective for the treatment and prophylaxis of infection with H5N1 influenza viruses, including oseltamivir-resistant mutants."

Source: Public Library of Science