British study discovers flu virus capable of developing resistance to pandemic drug

A drug currently under development for use against flu pandemics is at risk of being outpaced by the virus it is meant to prevent, according to researchers at Imperial College London and Public Health England.

In a study, the organizations found that two genetic mutations could bring the flu virus down a path of drug resistance to favipiravir, an experimental antiviral developed in Japan. While not currently licensed in the United Kingdom, the drug has proven effective in clinical trials. Researchers warn the virus has been shown to develop resistance to it in lab studies, despite original hopes that influenza virus could not overcome the drug. Whether the virus could manage the same in the midst of a pandemic, however, remains uncertain.

“Favipiravir is still an important drug and should be in the pipeline to be used in the event we need it, but we now know that viruses can develop resistance to it,” said research lead Wendy Barclay, a professor in the Department of Medicine and Action Medical Research Chair in Virology at Imperial. “We need to look out for these mutations and monitor for them, particularly if we are using this drug in outbreak situations and in patients that might have prolonged disease, as those are conditions where you might see resistance emerging.”

Despite its potential roadblocks, favipiravir has also been tested against other RNA virus like Ebola and chikungunya and shown promise therein. Unfortunately, other research groups have shown that similar ability to mutate and block favipiravir has been detected in chikungunya as well.