Hepatitis C Achilles Heel Found
Drugs Now In Pipeline May Shorten, Ease Hepatitis C Treatment
"We found that SCH6 not only inhibits hepatitis C protease, but also allows restoration of this cellular immune response," Gale says. "We could restore the ability of infected cells to respond to the virus, and naturally clear the virus on its own."
There's more good news. Gale's lab worked with genotype 1. It's the most common type of hepatitis C in the U.S. -- and the hardest kind to treat. Yet the protease inhibitor knocked it out.
By attacking the virus and also turning on antiviral immunity, hepatitis C protease inhibitors would have a dual action. And there's likely a third kind of action. Protease inhibitors likely would make current interferon treatments work better, at lower and less toxic doses. That's an exciting idea to Leslye Johnson, PhD, chief of the enteric and hepatic diseases branch at the National Institute of Allergy and Infectious Diseases.
"If a compound like this goes forward into clinical trials, it has the potential for dual activities and may work better than what's out there now," Johnson tells WebMD. "It might also allow people to use decreased doses of interferon. This finding opens new possibilities that are important for drug development. What it says for patients is that a hepatitis C protease inhibitor, as long as it is safe and everything else, could have multiple ways of getting rid of the virus. That is really the bottom line."
At least three drug companies are working on hepatitis C protease inhibitors. Farthest along appears to be BILN 2061 from Boehringer Ingelheim Pharma. It's already being tested in humans. The Schering-Plough product is not yet ready for human tests, says Schering spokesman Robert Consalvo.
Gale's findings appear in the April 17 issue of the online journal Sciencexpress. Also appearing in the same issue is an article by Hiscott's lab, offering new insights into how viruses trigger a cells antiviral immune response. That finding may lead to drugs effective not only against hepatitis C, but all viruses.