Currently Enrolling Trials
Xofluza (baloxavir marboxil) - 2 indications
Scroll down for more information on each indication:
- for the treatment of acute uncomplicated influenza in patients >12 years of age who have been symptomatic for no more than 48 hours; approved October 2018; extended to include patients 5 years of age an older in August of 2022
- for the post-exposure prophylaxis of influenza in patients >12 years of age; approved November 2020; extended to include patients 5 years of age an older in August of 2022
Xofluza (baloxavir marboxil) is a virus polymerase acidic (PA) endonuclease inhibitor.
Xofluza is specifically indicated for the following:
- for the treatment of acute uncomplicated influenza in patients 5 years of age and older who have been symptomatic for no more than 48 hours and who are:
- otherwise healthy, or
- at high risk of developing influenza-related complications.
- post-exposure prophylaxis of influenza in patients 5 years of age and older following contact with an individual who has influenza
Xofluza is supplied as a tablet for oral administration, as well as granules for mixing in water. A single dose of Xofluza should be administered orally within 48 hours of symptom onset with or without food. Avoid co-administration of Xofluza with dairy products, calcium-fortified beverages, polyvalent cation-containing laxatives, antacids, or oral supplements (e.g., calcium, iron, magnesium, selenium, or zinc).
The recommended dosage of Xofluza in patients 12 years of age or older is a single weight-based dose as shown in the tables below.
|Patient Body Weight (kg)||Recommended Single Oral Dose (Tablets)|
|Less than 80 kg||One 40 mg tablet|
|At least 80 kg||One 80 mg tablet|
|Patient Body Weight (kg)||Recommended Single Oral Dose (Suspension)|
|Less than 80 kg||40 mg/20 mL (1 bottle) taken as a single dose|
|At least 80 kg||80 mg/40 mL (2 bottles) taken as a single dose|
Mechanism of Action
Baloxavir marboxil is a prodrug that is converted by hydrolysis to baloxavir, the active form that exerts anti-influenza virus activity. Baloxavir inhibits the endonuclease activity of the polymerase acidic (PA) protein, an influenza virus-specific enzyme in the viral RNA polymerase complex required for viral gene transcription, resulting in inhibition of influenza virus replication.
Adverse effects associated with the use of Xofluza may include, but are not limited to, the following:
Indication 1 - for the treatment of acute uncomplicated influenza in patients >5 years of age who have been symptomatic for no more than 48 hours
approved October 2018
Clinical Trial Results
The FDA approval of Xofluza was based on two randomized controlled clinical trials of 1,832 patients where participants were assigned to receive either Xofluza, a placebo, or another antiviral flu treatment (oseltamivir) within 48 hours of experiencing flu symptoms. The primary endpoint of both trials, time to alleviation of symptoms, was defined as the time when all seven symptoms (cough, sore throat, nasal congestion, headache, feverishness, myalgia, and fatigue) had been assessed by the subject as none or mild for a duration of at least 21.5 hours. In both trials, Xofluza treatment at the recommended dose resulted in a statistically significant shorter time to alleviation of symptoms compared with placebo in the primary efficacy population. In Trial 2, there was no difference in the time to alleviation of symptoms between subjects who received Xofluza (54 hours) and those who received oseltamivir (54 hours). For adolescent subjects (12 to 17 years of age) in Trial 2, the median time to alleviation of symptoms for subjects who received Xofluza was 54 hours compared to 93 hours in the placebo arm.
Indication 2 - for the post-exposure prophylaxis of influenza in patients >5 years of age
approved November 2020
Clinical Trial Results
The FDA approval of Xofluza for post-flu exposure prevention was based on one randomized, double-blind, controlled trial in which 607 subjects, 12 years of age and older who were exposed to a person with influenza in their household, received either a single dose of Xofluza or a single dose of a placebo. Of these 607 subjects, 303 received Xofluza and 304 received the placebo. The trial's primary endpoint was the proportion of subjects who were infected with influenza virus and presented with fever and at least one respiratory symptom from day 1 to day 10. Of those who received Xofluza, 1% of subjects met these criteria, compared to 13% of subjects who received a placebo for the clinical trial.