FDA Approves Merck's Zepatier To Treat Chronic Hepatitis C Genotypes 1 And 4

(RTTNews) - Merck (MRK), known as MSD outside the United States and Canada, announced that the U.S. Food and Drug Administration (FDA) has approved ZEPATIER (elbasvir and grazoprevir) for the treatment of adult patients with chronic hepatitis C virus (HCV) genotype (GT) 1 or GT4 infection, with or without ribavirin (RBV), following priority review by the FDA. ZEPATIER (pronounced ZEP-ah-teer) is a once-daily, fixed-dose combination tablet containing the NS5A inhibitor elbasvir (50 mg) and the NS3/4A protease inhibitor grazoprevir (100 mg).

The company anticipates that ZEPATIER will be available for shipping to wholesalers within seven business days.

The FDA previously granted two Breakthrough Therapy designations to ZEPATIER, for the treatment of chronic HCV GT1 infection in patients with end stage renal disease on hemodialysis, and for the treatment of patients with chronic HCV GT4 infection. Breakthrough Therapy designation is given to investigational medicines for serious or life-threatening conditions that may offer substantial improvement over existing therapies.

Across multiple clinical studies, ZEPATIER achieved high rates of sustained virologic response ranging from 94 to 97 percent in GT1-infected patients, and 97 to 100 percent in GT4-infected patients. Sustained virologic response is defined as HCV RNA levels measuring less than the lower limit of quantification at 12 weeks after the cessation of treatment (SVR12), indicating that a patient's HCV infection has been cured.

The company warned that ZEPATIER is not for use in patients with moderate or severe hepatic impairment (Child-Pugh B or C). ZEPATIER also is not for use with organic anion transporting polypeptides 1B1/3 (OATP1B1/3) inhibitors (e.g., atazanavir, darunavir, lopinavir, saquinavir, tipranavir, cyclosporine), strong cytochrome P450 3A (CYP3A) inducers (e.g., carbamazepine, phenytoin, rifampin, St. John's Wort), and efavirenz.

If ZEPATIER is administered with RBV, healthcare professionals should refer to the prescribing information for RBV as the contraindications, warnings and precautions, adverse reactions and dosing for RBV also apply to this combination regimen.