Medication Monitor

Generic Name (Trade Name—Company)
February 1, 2016

Elbasvir and grazoprevir

(Zepatier—Merck & Co.)
FDA approves new combination oral treatment for chronic HCV genotypes 1 and 4

FDA has approved elbasvir and grazoprevir with or without ribavirin for the treatment of chronic hepatitis C virus (HCV) genotypes 1 and 4 infections in adult patients.

Safety and efficacy of elbasvir and grazoprevir with or without ribavirin were evaluated in clinical trials of 1,373 participants with chronic HCV genotype 1 or 4 infections with and without cirrhosis. The participants received the combination drug with or without ribavirin once daily for 12 or 16 weeks. The studies were designed to measure whether a participant’s HCV was no longer detected in the blood 12 weeks after finishing treatment (sustained virologic response [SVR]), suggesting a participant’s infection had been cured.

The overall SVR rates ranged from 94% to 97% in participants infected with genotype 1 and from 97% to 100% in participants infected with genotype 4 across trials for the approved treatment regimens. To maximize SVR rates for patients, the product label provides recommendations on length of treatment with or without ribavirin specifically tailored to the characteristics of the patient and his or her virus. Health professionals should screen genotype 1a–infected patients for certain viral genetic variations before starting treatment with elbasvir and grazoprevir to determine dosage regimen and duration.

The most common adverse effects of elbasvir and grazoprevir without ribavirin were fatigue, headache, and nausea. The most common adverse effects with ribavirin were anemia and headache.

The product carries a warning alerting patients and health care providers that elevations of liver enzymes to greater than five times the upper limit of normal occurred in approximately 1% of clinical trial participants, generally at or after treatment week 8. Liver-related blood tests should be performed before starting therapy and at certain times during treatment. The agent should not be given to patients with moderate or severe liver impairment.