Victrelis (Boceprevir) has been approved by the U.S. Food and Drug Administration to treat chronic hepatitis C when used in combination with pegylated interferon alfa and ribavirin.
Victrelis is the first drug in a new class of antiviral protease inhibitors. This drug binds to the Hepatitis C virus to prevent it from multiplying. The safety and effectiveness of Victrelis was evaluated in two phase III clinical trials with 1,500 adult patients. In both of these trials, two-thirds of the patients receiving Victrelis in combination with pegylated interferon and ribavirin experienced a significantly increased sustained virologic response, the hepatitis C virus was no longer detected in the blood 24 weeks after stopping treatment, compared to pegylated interferon and ribavirin alone, which is the current standard of care.
Victrelis is added in the fifth week of treatment therapy with peginterferon alfa and ribavirin. It is added at a dose of 800mg, four 200mg capsules, three times a day. This medication should be given with food.
How it is administered, routes
Victrelis is administered orally, in pill or capsule form. This medication must only be used in combination therapy with peginterferon alfa and ribavirin.
Mechanism of action
Victrelis is primarily metabolized through the aldoketoreductase (AKR)-mediated pathway to ketone-reduced metabolites that are inactive against HCV, it also undergoes oxidative metabolism mediated by CYP3A4/5, to a lesser extent.
Victrelis is a direct acting antiviral drug against the hepatitis C virus. Boceprevir is an inhibitor of the HCV NS3/4A protease that is necessary for the proteolytic cleavage of the HCV encoded polyprotein into mature forms of the NS4A, NS4B, NS5A and NS5B proteins. Boceprevir binds covalently, but reversibly, to the NS3 protease active site serine (S139) through an alpha-ketoamide functional group which inhibits viral replication in HCV-infected host cells. In a biochemical assay, boceprevir inhibited the activity of recombinant HCV genotype 1a and 1b NS3/4A protease enzymes, with Ki values (values of bonding enzymes) of 14 nm for each subtype.
Expected outcomes of effective drug therapy
A sustained virologic response, achieved when the hepatitis C virus is not detected in the blood six months after stopping the three-drug combination treatment, is expected after the 48 week treatment with Victrelis used in combination with peginterferon alfa and ribavirin.
According to the FDA, Victrelis was evaluated in a pair of clinical trials that involved 1,500 adult participants. The infected participants using the three-drug therapy had a higher rate of sustained...