WASHINGTON, Oct. 24 (Xinhua) -- The United States Food and Drug Administration (FDA) on Wednesday approved a new drug for the treatment of influenza.

Xofluza or baloxavir marboxil can be used to treat uncomplicated influenza in patients 12 years of age and older who have been symptomatic for no more than 48 hours, according to the agency.

"This is the first new antiviral flu treatment with a novel mechanism of action approved by the FDA in nearly 20 years," said FDA Commissioner Scott Gottlieb. "This novel drug provides an important, additional treatment option."

"When treatment is started within 48 hours of becoming sick with flu symptoms, antiviral drugs can lessen symptoms and shorten the time patients feel sick," said Debra Birnkrant, director of the Division of Antiviral Products in the FDA's Center for Drug Evaluation and Research.

"Having more treatment options that work in different ways to attack the virus is important because flu viruses can become resistant to antiviral drugs," said Birnkrant.

The safety and efficacy of the antiviral drug taken as a single oral dose was demonstrated in two randomized controlled clinical trials of 1,832 patients.

In both trials, patients treated had a shorter time to alleviation of symptoms compared with patients who took the placebo.

In the second trial, there was no difference in the time to alleviation of symptoms between subjects who received Xofluza and those who received the other flu treatment.