Uncomplicated influenza is an illness characterized by the sudden onset of respiratory tract signs and symptoms, like fever, chills, headache, cough, and sore throat. Baloxavir marboxil inhibits influenza cap-dependent endonuclease and may be used in treating uncomplicated influenza. This study aims to evaluate the efficacy of baloxavir marboxil in the treatment of acute uncomplicated influenza. 

This study is a combination of two randomized, double-blind, controlled trials involving 1,064 healthy outpatients with acute uncomplicated influenza. After a 10-40 mg placebo-controlled trial, the participants were assigned to a placebo- and oseltamivir-controlled trial of single, weight-based doses of baloxavir (40/80mg) in patients aged 12-64 years. The primary outcome of the study was the decline in the symptoms of influenza. 

With baloxavir marboxil treatment, the median time for the alleviation of symptoms was 53.7 hours, compared with 80.2 hours with placebo. The time to alleviation of symptoms was similar in oseltamivir and oseltamivir. However, baloxavir was associated with greater reductions in the viral load one day after the initiation of the regimen than oseltamivir or placebo. 

The research concluded that single-dose baloxavir was superior to both oseltamivir and placebo in alleviating symptoms and viral load of acute uncomplicated influenza. Baloxavir was also found to be safer than oseltamivir and placebo.

Ref: https://www.nejm.org/doi/full/10.1056/NEJMoa1716197