Single-Dose XOFLUZA Was as Safe and as Well Tolerated as Placebo1*

Single-dose XOFLUZA had a similar adverse event (AE) rate as placebo—including in patients at high risk of developing complications from the flu.1

The below table shows AEs that occurred in at least 1% of patients (aged ≥12 years) receiving either XOFLUZA or placebo in acute uncomplicated influenza in Trials 1-3.1

Adverse Event XOFLUZA (n=1440) Placebo (n=1136)
Diarrhea 3% 4%
Bronchitis 3% 4%
Nausea 2% 3%
Sinusitis 2% 3%
Headache 1% 1%

*Based on combined data from 3 trials, a total of 1640 subjects received XOFLUZA: 1334 (81%) were adults (18-64 years of age), 209 (13%) were adults 65 years of age or older, and 97 (6%) were adolescents (12-17 years of age). Of these, 1440 subjects received XOFLUZA at the recommended dose.1

A Safe Antiviral Flu Rx for Post-Exposure Prophylaxis1

The safety of XOFLUZA in adult and adolescent patients is based on data from one placebo-controlled clinical study in which 374 patients received XOFLUZA, of which 303 were adult and adolescent patients aged ≥12 years: eight patients (3%) were adults 65 years of age or older, and 12 patients (4%) were adolescents 12 to 17 years of age.1,13

The most frequently reported AEs in the total study population of Trial 4:

Adverse Event XOFLUZA (n=374) Placebo (n=375)
Nasopharyngitis 6% 7%

No serious treatment-related adverse events were reported.1,13

XOFLUZA® (baloxavir marboxil) Household Members

Single-dose XOFLUZA helps protect people who’ve been exposed to the flu by reducing their risk of infection.1

In Trial 4, conducted in Japan, 607 subjects (XOFLUZA n=303, placebo n=304) ≥12 years of age were randomized to receive a single oral dose of XOFLUZA, based on body weight and age, or placebo. In total, 374 subjects were treated with XOFLUZA and 375 with placebo. Subjects aged ≥12 years received 40 mg or 80 mg of XOFLUZA according to body weight. Subjects aged <12 years were dosed according to body weight. Subjects were household members of influenza-infected index patients and were required to have lived with the influenza-infected index patient for ≥48 hours. Index patients were required to have onset of symptoms for ≤48 hours. The primary efficacy endpoint was the proportion of household subjects who were infected with influenza virus and presented with fever and ≥1 respiratory symptom (cough or nasal discharge/nasal congestion assessed by the subject as moderate or severe) from day 1 to day 10. The proportion of subjects ≥12 years of age who met the primary endpoint was 1% (95% CI: 0.4, 3.3) in the XOFLUZA group and 13% (95% CI: 9.6, 17.5) in the placebo group, corresponding to an estimated adjusted risk ratio of 0.10 (95% CI: 0.04, 0.28), based on randomization factors.1,13

XOFLUZA® (baloxavir marboxil) Clipboard Icon

Treats the Flu

See the clinical efficacy for single-dose XOFLUZA.1

XOFLUZA® (baloxavir marboxil) Stop Replication Icon

Stops Viral Replication

Single-dose XOFLUZA works differently by targeting the flu at its source to stop viral replication.1


XOFLUZA is an influenza virus polymerase acidic (PA) endonuclease inhibitor indicated for the treatment of acute uncomplicated influenza in patients 12 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

XOFLUZA is also indicated for post-exposure prophylaxis (PEP) of influenza in patients 12 years of age and older following contact with an individual who has influenza.


Limitations of Use
Influenza viruses change over time, and factors such as the virus type or subtype, emergence of resistance, or changes in viral virulence could diminish the clinical benefit of antiviral drugs. Consider available information on drug susceptibility patterns for circulating influenza virus strains when deciding whether to use XOFLUZA.

Important Safety Information

XOFLUZA is contraindicated in patients with a history of hypersensitivity to baloxavir marboxil or any of its ingredients. Serious allergic reactions have included anaphylaxis, angioedema, urticaria, and erythema multiforme.


Warnings and Precautions

 Cases of anaphylaxis, urticaria, angioedema, and erythema multiforme have been reported in postmarketing experience with XOFLUZA.  Appropriate treatment should be instituted if an allergic-like reaction occurs or is suspected.


Risk of bacterial Infections: There is no evidence of the efficacy of XOFLUZA in any illness caused by pathogens other than influenza viruses. Serious bacterial infections may begin with influenza-like symptoms or may coexist with, or occur as, a complication of influenza. XOFLUZA has not been shown to prevent such complications. Prescribers should be alert to potential secondary bacterial infections and treat them as appropriate.

Adverse Reactions
The most common adverse reactions (≥1%) in clinical studies for acute uncomplicated influenza were diarrhea (3%), bronchitis (3%), nausea (2%), sinusitis (2%), and headache (1%).

The most common adverse reaction in a clinical study for post-exposure prophylaxis (PEP) was nasopharyngitis (6%).


Drug Interactions

Polyvalent cations:
 Coadministration with polyvalent cation-containing products may decrease plasma concentrations of baloxavir, which may reduce XOFLUZA efficacy. Avoid coadministration of XOFLUZA with dairy products, calcium-fortified beverages, polyvalent cation-containing laxatives, antacids, or oral supplements (e.g., calcium, iron, magnesium, selenium, or zinc).


Vaccines: The concurrent use of XOFLUZA with intranasal live attenuated influenza vaccine (LAIV) has not been evaluated. Concurrent administration of antiviral drugs may inhibit viral replication of LAIV and, thereby, decrease the effectiveness of LAIV vaccination. Interactions between inactivated influenza vaccines and XOFLUZA have not been evaluated.

For additional important safety information, please see the XOFLUZA full Prescribing Information.

You are encouraged to report side effects to Genentech by calling 1-888-835-2555 or to the FDA by visiting or calling 1-800-FDA-1088.