Is There a 'Baloxavir' for Coronavirus?

A new study has found that some influenza antivirals are useful for more than helping sick people get better — they also can prevent hundreds of thousands of virus cases if used in the early stages of infection.

The study from researchers at The University of Texas at Austin (UT-Austin) published in the journal Nature Communications on June 2, 2020, focused on influenza and has implications for the coronavirus that causes COVID-19. 

By modeling the impact of a pair of leading flu drugs, the team found significant differences in effects between oseltamivir, an older antiviral treatment for flu that patients know by the name Tamiflu, and a newer one, baloxavir, which is sold under the brand name Xofluza.

The UT-Austin researchers found that the newer treatment — by effectively and rapidly stopping virus replication — dramatically reduced the length of time that an infected person is contagious and, therefore, better limited the spread of flu.

“We found that treating even 10 percent of infected patients with baloxavir shortly after the onset of their symptoms can indirectly prevent millions of infections and save thousands of lives during a typical influenza season,” said Robert M. Krug, Ph.D., a professor emeritus of molecular biosciences, writing for a blog that accompanied the paper.

This study estimated that about 22 million infections and 6,000 fatalities would have been averted in the 2017–2018 flu season in the USA by administering baloxavir to 30 percent of infected cases within 48 hours after symptom onset. 

Furthermore, starting treatment within 24 hours would almost double the impact.

Early basic research discoveries by Krug informed the development of baloxavir.

Dr. Krug and a UT-Austin team of epidemiological modelers concluded from the study that having a similarly effective antiviral treatment for the coronavirus would help to prevent thousands of infections and deaths. 

Creating such an antiviral would take time and new strategies in public health planning, but the benefits for patients, communities, and healthcare settings could be profound.

To date, most COVID-19 drug research efforts have prioritized existing antivirals that can be deployed quickly to treat the most seriously ill patients coping with life-threatening symptoms. 

The scientists acknowledge it would represent a shift to develop a new antiviral for the coronavirus, to be used early in infection with the aim of curtailing viral replication, just as baloxavir does for flu.

“It may seem counterintuitive to focus on treatments, not for the critically ill patient in need of a life-saving intervention, but rather for the seemingly healthy patient shortly after a COVID-19 positive test.”

“Nonetheless, our analysis shows that the right early-stage antiviral treatment can block transmission to others and, in the long run, may well save more lives,” Dr. Krug concluded.

The research was supported by grants from the National Institutes of Health, including through the Models of Infectious Disease Agent Study program. No conflicts of interest were disclosed.

Precision Vaccinations publishes influenza therapy news.