Pibrentasvir – NS5A Inhibitor for Hepatitis C Treatment
Pibrentasvir is an innovative direct-acting antiviral agent, serving as a highly effective pangenotypic inhibitor of the hepatitis C virus (HCV) NS5A protein. The NS5A protein plays a critical role at several stages of the viral life cycle, including RNA replication and the assembly of new viral particles. By blocking this protein, pibrentasvir deprives the virus of the ability to replicate its genetic material, leading to a rapid decrease in viral load and the complete cure of the patient.
The mechanism of action of pibrentasvir is based on selective binding to domain I of the non-structural protein NS5A. A unique feature of this substance is its extremely high barrier to the development of resistance: the molecule remains active even against viral strains carrying amino acid substitutions that typically render other NS5A inhibitors ineffective. Pibrentasvir is active against all major HCV genotypes (1–6), making it a universal component of modern therapy. The drug has a long half-life, allowing for stable plasma concentrations with once-daily dosing. The substance is primarily excreted via the biliary tract, making it safe for patients with severe renal impairment.
The drug is always used in a fixed-dose combination with glecaprevir, providing a comprehensive suppression of the virus at different levels.
Indications
Pibrentasvir is indicated for the treatment of chronic hepatitis C in adults and children over 3 years of age in the following clinical situations:
- Pangenotypic Therapy (genotypes 1–6): treatment of patients without evidence of cirrhosis or with compensated cirrhosis (Child-Pugh Class A).
- Severe Renal Disease: therapy for patients at any stage of renal failure, including end-stage renal disease and dialysis.
- Retreatment: therapy for patients in whom previous courses based on interferons or sofosbuvir were unsuccessful.
- HIV Co-infection: treatment of patients with concurrent HIV infection, provided compatibility with antiretroviral therapy.
Dosage and administration
The dosing regimen for pibrentasvir (as part of a fixed combination) requires strict adherence to ensure a successful cure.
- Standard Dose: daily intake of three combination tablets (each containing 40 mg of pibrentasvir and 100 mg of glecaprevir).
- Administration Method: tablets must be taken once daily with food. Food intake is critically important for the proper absorption of the drug.
- Treatment Duration: for most patients, the course is 8 weeks; in complex clinical cases, the duration may be extended to 12 or 16 weeks.
- Tablet Integrity: tablets should be swallowed whole. Breaking or chewing them is not recommended.
- Missed Dose: if the delay is less than 18 hours, the dose should be taken. If more than 18 hours, wait for the next scheduled dose.
