Grazoprevir is a drug[1] approved for the treatment of hepatitis C. It was developed by Merck and completed Phase III trials, used in combination with the NS5A replication complex inhibitor elbasvir under the trade name Zepatier, either with or without ribavirin.[2]
Grazoprevir is a second generation hepatitis C virusprotease inhibitor acting at the NS3/4A protease targets.[3] It has good activity against a range of HCV genotype variants, including some that are resistant to most currently used antiviral medications.[4][5]
Grazoprevir reaches peak plasma concentrations two hours after oral intake together with elbasvir (variation between patients: 30 minutes to three hours). In hepatitis C patients, steady state concentrations are found after about six days. Plasma protein binding is 98.8%, mainly to albumin and alpha-1-acid glycoprotein. Part of the substance is oxidised in the liver, largely by the enzyme CYP3A4. The biological half-life is 31 hours on average. Over 90% are excreted via the faeces, and less than 1% via the urine.[7]
^Lawitz E, Gane E, Pearlman B, Tam E, Ghesquiere W, Guyader D, et al. (March 2015). "Efficacy and safety of 12 weeks versus 18 weeks of treatment with grazoprevir (MK-5172) and elbasvir (MK-8742) with or without ribavirin for hepatitis C virus genotype 1 infection in previously untreated patients with cirrhosis and patients with previous null response with or without cirrhosis (C-WORTHY): a randomised, open-label phase 2 trial". Lancet. 385 (9973): 1075–86. doi:10.1016/S0140-6736(14)61795-5. PMID25467591.
^Gentile I, Buonomo AR, Borgia F, Zappulo E, Castaldo G, Borgia G (May 2014). "MK-5172 : a second-generation protease inhibitor for the treatment of hepatitis C virus infection". Expert Opinion on Investigational Drugs. 23 (5): 719–28. doi:10.1517/13543784.2014.902049. PMID24666106. S2CID207477059.