The U.S. Food and Drug Administration has approved Zepatier (elbasvir and grazoprevir) with or without ribavirin for the treatment of chronic hepatitis C virus genotypes 1 and 4 infections in adults.
Zepatier, marketed by Merck, was granted breakthrough therapy designation for the treatment of chronic HCV genotype 1 infection in patients with end stage renal disease on hemodialysis and for the treatment of chronic HCV genotype 4 infection. Breakthrough therapy designation is a program designed to expedite the development and review of drugs that are intended to treat a serious condition and preliminary clinical evidence indicates that the drug may demonstrate substantial improvement over available therapy on a clinically significant endpoint.
“Today’s approval provides another oral treatment option for patients with genotypes 1 and 4 HCV infections without requiring use of interferon,” said Dr. Edward Cox, director of the Office of Antimicrobial Products in the FDA’s Center for Drug Evaluation and Research in a statement.
The safety and efficacy of Zepatier with or without ribavirin was evaluated in clinical trials of 1,373 participants with chronic HCV genotype 1 or 4 infections with and without cirrhosis. The participants received Zepatier with or without ribavirin once daily for 12 or 16 weeks. The studies were designed to measure whether a participant’s hepatitis C virus was no longer detected in the blood 12 weeks after finishing treatment (sustained virologic response), suggesting a participant’s infection had been cured.
The overall sustained virologic response rates ranged from 94% to 97% in genotype 1–infected subjects and from 97% to 100% in genotype 4–infected subjects across trials for the approved treatment regimens.
The FDA recommends clinicians screen genotype 1a–infected patients for certain viral genetic variations prior to starting treatment with Zepatier to determine dosage regimen and duration. Zepatier 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. The FDA says liver-related blood tests should be performed prior to starting therapy and at certain times during treatment.
Zepatier is not intended for patients with moderate or severe liver impairment.
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