Baloxavir

Baloxavir marboxil is an antiviral drug with activity against influenza virus [see Microbiology (12.4) ].

• XOFLUZA is an influenza virus polymerase acidic (PA) endonuclease inhibitor indicated for: 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 . ( 1.1 ) Post-exposure prophylaxis of influenza in patients 5 years of age and older following contact with an individual who has influenza.ICD-10: J11.1

• 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 [see Warnings and Precautions (5.1) ].contraindicated

Treatment and Post-Exposure Prophylaxis of Influenza Take XOFLUZA as a single dose as soon as possible and within 48 hours of influenza symptom onset for treatment of acute uncomplicated influenza or following contact with an individual who has influenza. XOFLUZA may be taken with or without food. ( 2.1 , 2.2 ) Patient Body Weight Recommended Single Oral Dose in Patients 5 Years of Age and Older (Tablets) 20 kg to less than 80 kg One 40 mg tablet (blister card contains one 40 mg tablet) At least 80 kg One 80 mg tablet (blister card contains one 80 mg tablet) Patient Body Weight Recommended Single Oral Dose in Patients 5 Years of Age and Older For Oral Suspension (Packets) 15 kg to less than 20 kg One 30 mg packet 20 kg to less than 80 kg One 40 mg packet At least 80 kg 80 mg (two 40 mg packets) Patient Body Weight Recommended Single Oral Dose in Patients 5 Years of Age and Older For Oral Suspension (Bottles) Less than 20 kg 2 mg/kg 20 kg to less than 80 kg 40 mg (20 mL) At least 80 kg 80 mg (40 mL) Refer to the Full Prescribing Information for additional information on the recommended dosage and preparation of XOFLUZA for oral suspension (bottles) or for oral suspension (packets) for both for oral or enteral use in patients 5 years of age and older. ( 2.2 , 2.3 ) 2.1 Dosage and Administration Overview XOFLUZA is available in two dosage forms: XOFLUZA tablets (40 mg and 80 mg). XOFLUZA for oral suspension is available in two different presentations: packets (30 mg and 40 mg) and bottles (2 mg/mL).

Hypersensitivity such as anaphylaxis, angioedema, urticaria, and erythema multiforme: Initiate appropriate treatment if an allergic-like reaction occurs or is suspected. ( 5.1 ) Increased incidence of Treatment-Emergent Resistance in Patients Less Than 5 Years of Age: XOFLUZA is not indicated in patients less than 5 years of age due to increased incidence of treatment-emergent resistance in this age group . In clinical trials, incidence of virus with treatment-emergent substitutions associated with reduced susceptibility to baloxavir (resistance) was higher in pediatric subjects younger than 5 years of age than older subjects. ( 5.2 ) Risk of bacterial infection: 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. ( 5.3 ) 5.1 Hypersensitivity 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. The use of XOFLUZA is contraindicated in patients with known hypersensitivity to XOFLUZA [see Contraindications (4) and Adverse Reactions (6.2) ].

Adverse events reported in at least 1% of adult and adolescent influenza subjects treated with XOFLUZA included diarrhea (3%), bronchitis (3%), nausea (2%), sinusitis (2%), and headache (1%). ( 6.1 ) Adverse events reported in at least 5% of pediatric subjects (5 to < 12 years) treated with XOFLUZA included vomiting (5%) and diarrhea (5%). To report SUSPECTED ADVERSE REACTIONS, contact Genentech at 1-888-835-2555 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch . 6.1 Clinical Trials Experience Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice. The overall safety profile of XOFLUZA is based on data from 2,079 subjects, 5 years of age and older in 5 controlled clinical trials who received XOFLUZA. Of these subjects, 1,943 were adults and adolescents (≥ 12 years of age) and 136 were in the pediatric age group (5 to < 12 years of age) [see Clinical Studies (14) ] . Treatment of Acute Uncomplicated Influenza Adult and Adolescent Subjects (≥ 12 Years of Age): The safety of XOFLUZA in adult and adolescent subjects is based on data from 3 placebo-controlled trials in which a total of 1,640 subjects received XOFLUZA: 1,334 (81%) subjects were 18 to 64 years of age, 209 (13%) subjects were adults 65 years of age or older, and 97 (6%) subjects were adolescents 12 to 17 years of age.

8.1 Pregnancy Risk Summary There are no adequate and well-controlled studies with XOFLUZA in pregnant women to inform a drug-associated risk of adverse developmental outcomes. There are risks to the mother and fetus associated with influenza virus infection in pregnancy (see Clinical Considerations ). In animal reproduction studies, no adverse developmental effects were observed in rats or rabbits with oral administration of baloxavir marboxil at exposures approximately 5 (rats) and 7 (rabbits) times the systemic baloxavir exposure at the maximum recommended human dose (MRHD) (see Data ) . The estimated background risk of major birth defects and miscarriage for the indicated population is unknown. All pregnancies have a background risk of birth defects, loss, or other adverse outcomes. In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2%–4% and 15%–20%, respectively. Clinical Considerations Disease-Associated Maternal and/or Embryo/Fetal Risk Pregnant women are at higher risk of severe complications from influenza, which may lead to adverse pregnancy and/or fetal outcomes, including maternal death, stillbirth, birth defects, preterm delivery, low birth weight, and small for gestational age.

Metabolism

Baloxavir marboxil is a prodrug that is almost completely converted to its active metabolite, baloxavir, following oral administration. Baloxavir pharmacokinetic parameters are presented for healthy adults and adolescents as the mean [% coefficient of variation (%CV)], unless otherwise specified, in Table 5 .

Treatment of an overdose of XOFLUZA should consist of general supportive measures, including monitoring of vital signs and observation of the clinical status of the patient. There is no specific antidote for overdose with XOFLUZA. Baloxavir is unlikely to be significantly removed by dialysis due to high serum protein binding [see Clinical Pharmacology (12.3) ].

• Oct 24, 2018NDANDA210854Genentech Inc
• Nov 23, 2020NDANDA214410Genentech Inc

1. 1No Adverse Event54024%
2. 2Off Label Use42419%
3. 3Intentional Product Use Issue28313%
4. 4Diarrhoea1345.9%
5. 5Vomiting1285.7%
6. 6Pneumonia1125.0%
7. 7Drug Ineffective904.0%
8. 8Nausea743.3%
9. 9Rash662.9%
10. 10Hyperpyrexia622.7%
11. 11Headache612.7%
12. 12Influenza592.6%
13. 13Colitis Ischaemic562.5%
14. 14Pyrexia552.4%
15. 15Cough452.0%

The 10 most recently updated of 27 ClinicalTrials.gov registrations naming Baloxavir as an intervention. Registration is not evidence of efficacy or safety — reference crosswalk only.

• COmbination Therapy With Baloxavir and Oseltamivir 1 for Hospitalized Patients With Influenza (The COMBO Trial 1)
  Completed · Phase 2 · Phase 3 · Interventional · 15 enrolled · Bassett Healthcare
  NCT04327791updated 2026-05-14
• Efficacy of Baloxavir Against Influenza in Hospitalized Patients: The INFLUENT Study (INpatients inFLUENza Treatment)
  Recruiting · Phase 3 · Interventional · 484 enrolled · Dre Pauline Vetter
  NCT06653569updated 2026-05-01
• A Surveillance Study of Susceptibility to Baloxavir Marboxil in Pediatric Participants With Influenza and Transmission of Influenza to Household Contacts
  Recruiting · Phase 3 · Interventional · 1,100 enrolled · Hoffmann-La Roche
  NCT06094010updated 2026-05-01
• Study to Assess the Safety, Pharmacokinetics, and Efficacy of Baloxavir Marboxil in Chinese Pediatric Participants 1 to <12 Years of Age With Influenza Symptoms
  Completed · Phase 3 · Interventional · 100 enrolled · Hoffmann-La Roche
  NCT06774859updated 2026-04-27
• Randomised Evaluation of COVID-19 Therapy
  Recruiting · Phase 3 · Interventional · 70,000 enrolled · University of Oxford
  NCT04381936updated 2026-04-21
• A Phase 2 Trial Comparing Antiviral Treatments in Early Symptomatic Influenza
  Recruiting · Phase 2 · Interventional · 3,000 enrolled · University of Oxford
  NCT05648448updated 2026-04-14
• Effectiveness of Xuanfei Jiangzhuo Decoction for Influenza-Induced AECOPD
  Not yet recruiting · Observational · 300 enrolled · Tianjin Medical University
  NCT07393685updated 2026-03-12
• A/Texas Flu Challenge
  Recruiting · Phase 1 · Interventional · 50 enrolled · Emory University
  NCT06753474updated 2026-03-03
• Baloxavir and Oseltamivir for the Treatment of Severe Influenza Infection in Immunocompromised Patients
  Recruiting · Phase 2 · Interventional · 60 enrolled · M.D. Anderson Cancer Center
  NCT04712539updated 2026-02-11
• Adaptive Platform Trial of Treatments for Respiratory Infections in Community Settings (TreatResp)
  Not yet recruiting · Phase 3 · Interventional · 264 enrolled · Unity Health Toronto
  NCT07314905updated 2026-01-02

Frequently asked questions

How does Baloxavir work?

Baloxavir marboxil is an antiviral drug with activity against influenza virus [see Microbiology (12.4) ].

What is Baloxavir used for?

According to FDA labeling, Baloxavir carries indications including: XOFLUZA is an influenza virus polymerase acidic (PA) endonuclease inhibitor indicated for: 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 . ( 1.1 ) Post-exposure prophylaxis of influenza in patients 5 years of age and older following contact with an individual who has influenza.. This is a reference summary of labeled uses, not medical advice or a treatment recommendation.

What class of drug is Baloxavir?

Baloxavir is classified as Polymerase Acidic Endonuclease Inhibitor, Chelating Activity, Polymerase Acidic Endonuclease Inhibitors, Decreased RNA Replication.

What are the contraindications for Baloxavir?

Baloxavir labeling lists contraindications including: 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 [see Warnings and Precautions (5.1) ].. Always consult the full prescribing information and a clinician.