BETHESDA, MD 29 Jan 2016—FDA on January 28 approved the marketing of elbasvir–grazoprevir oral tablets for the treatment of chronic hepatitis C virus (HCV) genotype 1 and 4 infection in adults.
Merck & Company is marketing the combination product as Zepatier.
According to the labeling (PDF) for the combination product, each tablet contains 50 mg of the HCV NS5A inhibitor elbasvir and 100 mg of grazoprevir, an HCV NS3/4A protease inhibitor.
Zepatier may be used with or without ribavirin, according to the labeling.
The recommended dosage of Zepatier is one tablet taken once daily with or without food for 12 or 16 weeks, depending on the viral genotype and the patient's previous use of medications for the treatment of HCV infection.
In clinical trials, up to 97% of patients infected with genotype 1 HCV and up to 100% of patients infected with genotype 4 HCV had a sustained virological response 24 weeks after completing therapy, which is considered a cure.
Before initiating therapy, patients should be tested to determine whether they are infected with HCV that exhibits NS5A resistance-associated polymorphisms, according to the labeling for Zepatier.
The labeling also states that liver-function tests should be administered before initiating therapy and periodically during treatment. Zepatier is contraindicated in patients with moderate or severe liver impairment.
Once treatment is initiated, if alanine transaminase levels persistently exceed 10 times the upper limit of the normal range, discontination of therapy should be considered.
Zepatier is also contraindicated in patients treated with organic anion transporting polypeptide 1B1/3 inhibitors, strong inducers of cytochrome P-450 isozyme 3A, and efavirenz.
Zepatier tablets are available in cartons of 28 tablets packaged in two child-resistant packs containing 14 tablets each. The product should be kept in the original blister packages and stored at controlled room temperature until use.
In clinical trials, the most frequently reported adverse events associated with the use of Zepatier were fatigue, headache, and nausea. Anemia and headache were the most frequently reported adverse events among patients treated with Zepatier and ribavirin.