News from Hepatitis Week of April 20, 2003 / Vol. 3 No. 16

Study: Protease Inhibitors Effective Against Hepatitis C

Protease inhibitors can restore the immune response blocked by the hepatitis C virus and reduce the virus to nearly undetectable levels in a matter of days, according to a study reported in the April 17 issue of Science Express.

The findings of this study suggest that protease inhibitors may become an important addition to existing interferon treatments for hepatitis C, potentially impacting it in the way they have revolutionized the treatment of the HIV virus.

Researchers from Texas wanted to determine why the hepatitis C virus is so persistent in human cells and why so many of those who suffer from the disease are unresponsive to treatment.

Senior study author Dr. Michael Gale, assistant professor of microbiology at University of Texas Southwestern Medical Center, and his colleagues discovered that the virus persists, in part, because it blocks the innate immune response of infected cells.

The researchers also found that the new protease inhibitors could actually prevent the virus from blocking this immune response and basically restore the innate antiviral response in human cells.

"If you block the protease, it neutralizes the virus and restores the host response to infection, allowing the cell to clear the virus naturally," said Gale. "That type of mechanism of the drug was completely unexpected."

Two different protease inhibitor drugs are in different stages of clinical trials, and Gale expects them to be evaluated in more detail considering the findings. "As opposed to just studying how much the drug knocks down the virus, now we will evaluate how the drug impacts the host cell's response to the infection," he said.

Other sources: University of Texas Southwestern Medical Center at Dallas