The U.S. Food and Drug Administration (FDA) has approved Zepatier (elbasvir and grazoprevir) with or without ribavirin for the treatment of adult patients with chronic hepatitis C virus (HCV) genotypes 1 and 4.
HCV infection is often asymptomatic, but chronic infection can lead to scarring of the liver and ultimately cirrhosis. Genotype 1 (GT1) is the most common form of the disease in the U.S. and genotype 4 (GT4) is one of the least common.
“Today’s approval provides another oral treatment option for patients with genotypes 1 and 4 HCV infections without requiring use of interferon,” Edward Cox, MD, director of the Office of Antimicrobial Products in the FDA’s Center for Drug Evaluation and Research, said in a press release.
Zepatier, marketed by Merck & Co., is a fixed-dose combination product containing elbasvir, a hepatitis C virus (HCV) NS5A inhibitor, and grazoprevir, an HCV NS3/4A protease inhibitor.
The efficacy and safety of Zepatier was examined in clinical trials that enrolled 1,373 patients with chronic HCV GT1 and GT4 infections with and without cirrhosis. All patients were treated once per day for a period of 12 or 16 weeks. The studies measured whether HCV was no longer present in a patient’s blood after 12 weeks of treatment (sustained virologic response, SVR). Results revealed that the rate of SVR ranged from 94 percent to 97 percent in patients with GT1 infection, and from 97 percent to 100 percent in patients with GT4.
To maximize SVR rates, Zepatier’s label provides recommendations for healthcare professionals to screen genotype 1a-infected patients for certain viral genetic variations before treatment initiation to determine duration and dosage regimen.
Most common reported adverse reactions of all intensity (greater than or equal to 5 percent in placebo-controlled trials) in patients receiving Zepatier without ribavirin for 12 weeks were fatigue, headache, and nausea. In those receiving Zepatier with ribavirin for 16 weeks, the most common adverse reactions of moderate or severe intensity (greater than or equal to 5 percent) were anemia and headache.
Zepatier carries a warning concerning alanine transaminase (ALT) elevations, because of a rise in liver enzymes was seen in about 1 percent of study participants around or at treatment week eight. Doctors are recommended to request hepatic laboratory testing prior to therapy, and again at certain times during treatment. Zepatier should not be given to patients with moderate or severe liver impairment.
According to the Centers for Disease Control and Prevention, roughly 3 million Americans are infected with HCV.