Investigators say that a new approach to inhibiting the hepatitis C virus worked amazingly well in a group of four chimpanzees. And now researchers have taken the therapy into the clinic for the first time, testing it in humans in a Phase I trial.
The drug is dubbed SPC3649 and is being developed by Denmark's Santaris Pharma. And it relies on a whole new mechanism of action. The currently used cocktail of interferon and ribavirin directly targets the virus. But SPC3649 binds to microRNA122, which the virus needs in order to replicate, and halts the progression of the disease. At its highest dose, the drug reduced viral loads by a factor of 350.
Significantly, the scientific team studying the therapy said that the drug was not toxic, still worked months after it was given and demonstrated an ability to overcome the body's natural resistance, a problem for patients who often don't respond to the cocktail therapy. This same proof of concept indicates that the therapy has promise as a treatment for HIV, cancer, and inflammatory diseases. Researchers, though, will stay focused on hepatitis C for now.
"This antiviral could be used alone to treat disease progression and there are indications that it can convert interferon non-responders to responders, so that non-responders to the current therapy could be treated with the combination of this drug with interferon," said lead author Robert Lanford of the Southwest Foundation for Biomedical Research.
"If you had asked me five years ago, I would have been very skeptical that this approach would work," microbiologist Peter Sarnow of Stanford University tells the Los Angeles Times. But these new results, he notes, "are very exciting."