Xofluza is the first antiviral for the treatment of influenza symptoms to be approved by the FDA in nearly 20 years.

During the 2017–2018 flu season, more than 49 million flu cases were reported in the United States, according to the Centers for Disease Control and Prevention (CDC), and flu vaccines reduced the risk of flu-related doctor visits by just 40%. For most people with uncomplicated flu, symptoms generally last for three to seven days, but coughs can be an issue for an additional two weeks, according to the CDC.

Existing antiviral drugs, such as Tamiflu, treat flu symptoms, but because they have been around for many years, flu viruses have had time to mutate and develop resistance.

A new antiviral from Genentech –– Xofluza –– specifically inhibits a protein essential for virus replication that is found within two strains of the flu virus (A and B). These two strains (out of four total) are the ones that cause flu epidemics, according to the CDC.

The U.S. Food and Drug Administration recently approved Xofluza. The drug has Priority Review status and was evaluated by the agency in just six months so that it would be available for the 2018–2019 flu season. It is indicated for patients 12 years and older diagnosed with acute uncomplicated flu who are within two days of symptom onset. The approval was based on the results of two clinical trials, which showed that the single-dose oral treatment reduces the intensity and duration of flu symptoms.