An experimental antiviral agent called boceprevir doubled the cure rate for hepatitis C in a small phase 2 clinical trial designed to show efficacy, researchers reported Sunday. The drug will now be submitted to the larger Phase 3 trial required for approval of the drug by the Food and Drug Administration.
Hepatitis C is a chronic viral infection that affects an estimated 170 million people worldwide, leading eventually to cirrhosis and liver cancer if not controlled. The standard treatment now is a 48-week regimen of pegylated interferon, which boosts the immune system, and the antiviral agent ribavirin, which is a general-purpose antiviral agent. But the combination cures less than half of those who receive it and, for reasons that are not clear, is even less effective in African Americans. The most difficult strain to treat is the so-called genotype 1, which is the strain infecting about 70% of Americans.
Boceprevir, originally developed by Schering-Plough, which was recently purchased by Merck, is designed to attack the protease enzyme used by the hepatitis C virus to replicate. In that sense, it is analogous to the protease inhibitors, such as saquinavir and ritonavir, that revolutionized HIV treatment when used in conjunction with other AIDS drugs.
