Baloxavirmarboxil

Products

Baloxavirmarboxil was approved in film-coated tablet form in Japan and the United States in 2018 and in many countries in 2020 (Xofluza).

Structure and properties

Baloxavirmarboxil (C27H23F2N3O7S, Mr = 571.5 g/mol) is a prodrug of baloxavir (synonym: baloxaviric acid). It is converted to the active drug by hydrolysis. It is practically insoluble in water. The drug was developed from and is structurally related to the HIV integrase inhibitor dolutegravir.

Effects

Baloxavir (ATC J05AX25) has antiviral properties against influenza viruses. The effects are due to inhibition of the endonuclease activity of the PA subunit of viral RNA polymerase, which is involved in transcription of viral vRNA to mRNA, replication, and thus viral replication. RNA polymerase is a heterotrimer consisting of the following protein subunits:

  • PB1: Polymerase Basic Protein 1
  • PB2: Polymerase Basic Protein 2
  • PA: Polymerase Acidic Protein

Baloxavir inhibits the formation of mRNA, which is necessary for the formation (translation) of new viral proteins. This blocks viral replication and significantly reduces the duration of disease. The half-life of baloxavir is in the range of 79 hours. As a prodrug, baloxavir is administered to improve absorption and increase bioavailability.

Indications

For the treatment of patients 12 years of age and older with uncomplicated influenza who have been symptomatic for 48 hours or less. The drug is intended for patients who are otherwise healthy or at high risk for complications.

Dosage

According to the SmPC. Therapy should be initiated within 48 hours of the onset of symptoms. A single dose is sufficient for treatment, depending on body weight. This represents an advantage for adherence to therapy. The tablets can be administered independently of meals. However, certain foods and drugs should not be taken at the same time because they may reduce absorption (see below).

Contraindications

  • Hypersensitivity

For complete precautions, see the drug label.

Interactions

Drugs or foods containing multivalent cations such as iron, zinc, selenium, calcium, and magnesium may reduce the plasma concentration of the active ingredient. These include, for example, antacids, mineral supplements, dietary supplements, and milk.

Adverse effects

Possible adverse effects include allergic reactions such as skin reactions and anaphylaxis. The exact incidence is not yet known.