XOFLUZA

What it is

Xofluza contains baloxavir marboxil. Baloxavir marboxil is a prodrug that is converted by hydrolysis to its active metabolite, baloxavir, the active form that exerts anti-influenza activity. Baloxavir acts on the cap-dependent endonuclease, an influenza virus-specific enzyme in the polymerase acidic subunit of the viral RNA polymerase complex and thereby inhibits the transcription of influenza virus genomes resulting in inhibition of influenza virus replication. This medicinal product is subject to additional monitoring in Australia, which will allow quick identification of new safety information.

Approved indications

— Treatment of 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 complications. — Post-exposure prophylaxis of influenza in patients aged 12 years of age and older following contact with an individual who has confirmed influenza.

Dosing overview

A single oral dose of Xofluza should be taken within 48 hours of symptom onset for treatment of influenza. For prophylaxis of influenza, a single dose of Xofluza should be taken as soon as possible within 48 hours following close contact with an individual who has confirmed influenza. The recommended dose of Xofluza for treatment or post-exposure prophylaxis in adults and adolescents (≥ 12 years of age) depends on body weight: 40 mg for patients weighing 40 kg to < 80 kg, and 80 mg for patients weighing ≥ 80 kg. Xofluza may be taken with or without food.

Key safety warnings

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 medicines. Prescribers should consider available information on drug susceptibility patterns for circulating influenza virus strains when deciding whether to use Xofluza. Hypersensitivity reactions after use of Xofluza have been reported in post-marketing surveillance. Cases of hypersensitivity including anaphylaxis, facial/throat swelling, skin eruptions and urticaria have been attributed to exposure to baloxavir. Appropriate treatment should be instituted if an allergic-like reaction occurs or is suspected. Xofluza should not be co-administered with calcium-fortified beverages, polyvalent cation-containing laxatives, antacids or oral supplements such as calcium, iron, magnesium, selenium, or zinc. Where possible, avoid co-administration of Xofluza with dairy products.

Contraindications

Xofluza is contraindicated in patients with a known hypersensitivity to baloxavir marboxil or to any of the excipients.

PBS listing

No information regarding PBS listing is available in the provided source documents.

Regulatory history

Xofluza was first approved on 21 February 2020. The 20 mg and 40 mg strengths were listed on the ARTG on 21 February 2020, and the 80 mg strength was listed on 2 May 2023. The TGA approved Xofluza for the treatment of uncomplicated influenza in patients aged 12 years and older who have been symptomatic for no more than 48 hours and who are otherwise healthy or at high risk of developing influenza complications, with the decision made on 21 February 2020.