Pibrentasvir is a direct acting antiviral agent and Hepatitis C virus (HCV) NS5A inhibitor that targets the the viral RNA replication and viron assembly. NS5A is a phosphoprotein that plays an essential role in replication, assembly and maturation of infectious viral proteins. The basal phosphorylated form of NS5A, which is maintained by C-terminal serine cluster, is key in ensuring its interaction with the viral capsid protein, or the core protein. By blocking this interaction, pibrentasvir inhibits the assembly of proteins and production of mature HCV particles. In the United States and Europe, Pibrentasvir is approved for use with glecaprevir as the combination drug glecaprevir/pibrentasvir (trade name Mavyret in the US and Maviret in the EU) for the treatment of hepatitis C. This fixed-dose combination therapy was FDA-approved in August 2017 to treat adults with chronic hepatitis C virus (HCV) genotypes 1-6 without cirrhosis (liver disease) or with mild cirrhosis, including patients with moderate to severe kidney disease and those who are on dialysis.