grazoprevir + uprifosbuvir + ruzasvir + ribavirin

This is an investigational **oral combination therapy** consisting of four antiviral agents: **grazoprevir** (a protease inhibitor), **uprifosbuvir** (a nucleotide NS5B polymerase inhibitor), **ruzasvir** (an NS5A inhibitor), and **ribavirin** (a nucleoside analog with broad-spectrum antiviral activity). It targets multiple key viral proteins of the hepatitis C virus (HCV) and is designed to achieve a high barrier to resistance, especially in patients who have previously failed all-oral direct-acting antiviral therapy that included an NS5A inhibitor. Clinical trials have demonstrated that the regimen, given for 16 weeks with ribavirin, achieves high rates of sustained virologic response in HCV-infected patients[3][5]. - **Grazoprevir**: NS3/4A protease inhibitor—blocks viral polyprotein processing. - **Uprifosbuvir**: Nucleotide analog inhibitor of HCV NS5B RNA-dependent RNA polymerase—prevents viral RNA synthesis[7]. - **Ruzasvir**: NS5A inhibitor—blocks viral replication and assembly. - **Ribavirin**: Nucleoside analog—broad, not fully characterized antiviral effects; thought to impair viral replication fidelity and immune modulation[2][6]. The combination has been investigated by Merck (MSD) for the treatment of hepatitis C virus infection in patients with previous treatment failure.

Other names

grazoprevir plus uprifosbuvir plus ruzasvir plus ribavirin