BETHESDA, MD 16 May 2011—FDA on May 13 approved boceprevir oral capsules as part of a combination regimen for the treatment of chronic hepatitis C virus (HCV) infection in adults.
Boceprevir inhibits NS3/4A, an HCV protease that is critical for viral replication. The drug is indicated for the treatment of infections caused by HCV genotype 1 isolates and must be used in combination with peginterferon alfa and ribavirin.
Boceprevir is marketed as Victrelis by Merck and will be shipped to pharmacies within the week, according to the company.
The FDA-approved labeling (PDF) and medication guide (PDF) for boceprevir are available online. There is no risk evaluation and mitigation strategy for the drug.
The medication guide emphasizes that boceprevir can harm or kill a developing fetus. Women who use the drug must take a pregnancy test before initiating boceprevir therapy and periodically thereafter and must use two forms of birth control to prevent conception, according to the document.
The medication guide and labeling list numerous medications that are contraindicated during boceprevir therapy. Also listed are many medications that may interact adversely with the HCV drug.
According to the labeling, boceprevir is indicated for use in patients with compensated liver disease, including cirrhosis, whose infection has not been treated or has not responded to previous treatment with peginterferon alfa and ribavirin.
In clinical trials described in the labeling, about two thirds of the patients who were treated with boceprevir plus peginterferon alfa and ribavirin had no detectable virus in their blood 24 weeks after ending their therapy. FDA stated that this type of sustained virologic response "suggests that the HCV infection has been cured."
Before starting bocepravir therapy, patients must complete four weeks of treatment with peginterferon alfa and ribavirin. Bocepravir is then added to the regimen for an additional number of weeks, depending on the patient's previous treatment history and the virologic response to the regimen.
The recommended bocepravir dosage is four 200-mg capsules taken three times daily—every seven to nine hours—with a meal or a light snack.
The labeling recommends against reducing the boceprevir dosage. But discontinuation of the drug is recommended if HCV RNA levels do not decrease adequately, which indicates that the treatment is not working.
The most common adverse events associated with boceprevir use in clinical trials were fatigue, anemia, nausea, headache, and an altered sense of taste.
The labeling warns that boceprevir treatment increases patients' risk for anemia and neutropenia and recommends periodic blood tests to monitor the development of these conditions.
Bocepravir is supplied as 200-mg capsules packaged 12 per bottle in cartons of 28 bottles each. Each bottle contains a single day's supply of boceprevir. The bottles should be refrigerated at 2–8 degrees C until dispensed. Patients may store the capsules at 25 degrees C for up to three months.