Used in the treatment of chronic hepatitis C virus (HCV) infection, particularly genotypes 1 and 4. It is combined with sofosbuvir to form a highly effective antiviral regimen that inhibits viral replication by targeting the NS5A protein of HCV. This combination therapy offers high cure rates, shorter treatment duration, and fewer side effects compared to older treatments involving interferon. It is prescribed for adults and some adolescents, including those with liver cirrhosis or co-infection with HIV. The drug plays a key role in reducing liver damage, preventing progression to cirrhosis or liver cancer, and improving overall survival in HCV patients.