The U.S. Food and Drug Administration approved Zepatier with or without ribavirin for the treatment of chronic hepatitis C virus (HCV) for genotypes 1 and 4 in adults. An estimated 3.5 million people in the United States are infected with chronic HCV and genotype 1 is the most common genotype. 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 overall Sustained Virologic Response (SVR), or cure, rates ranged from 94-97 percent in genotype 1-infected subjects and from 97-100 percent in genotype 4-infected subjects across trials for the approved treatment regimens. Read the news release here.