PR4 + ledipasvir + sofosbuvir + asunaprevir

This is a combination regimen consisting of four agents: - **PR4** (identity unclear from available data; may refer to peginterferon alfa and ribavirin in some hepatitis C literature) - **Ledipasvir** (an HCV NS5A inhibitor that blocks viral replication and assembly) - **Sofosbuvir** (a nucleotide analog inhibitor of HCV NS5B RNA-dependent RNA polymerase, essential for viral replication) - **Asunaprevir** (an HCV NS3/4A protease inhibitor that prevents viral polyprotein processing) These drugs are all direct-acting antivirals targeting different steps in the hepatitis C virus life cycle. Ledipasvir and sofosbuvir are commonly co-formulated as Harvoni for the treatment of chronic hepatitis C infection[1][2][7]. Asunaprevir is used in some regimens for patients with specific genotypes or prior treatment failures. The addition of PR4 suggests a multi-drug approach possibly intended for difficult-to-treat or previously treated patients.

Brand names

Harvoni