New Hepatitis C Treatment Shows Promise

Dec. 4 -- THURSDAY, Dec. 3 (HealthDay News) -- A new drug to treat hepatitis C has shown promise in a primate study.

The drug, called SPC3649, uses a new strategy to prevent the hepatitis C virus from replicating. Unlike other antivirals that target the virus itself, the new DNA-based drug targets a small RNA molecule in the liver that hepatitis C needs to replicate, the researchers explained.

By inhibiting the molecule, SPC3649 reduced hepatitis C virus levels in the liver and in the bloodstream in chimpanzees that received the highest dose by 350-fold.

Importantly, the virus showed no signs of resistance to SPC3649, developed by the Denmark-based company Santaris Pharma A/S. And levels of the virus remained low several months after the chimps had ended treatment, raising the possibility that the medicine would only need to be taken temporarily, the researchers added.

"It is a conceptually new approach. Instead of directly targeting the virus, the drug targeted a liver-specific molecule necessary for replication," said study author Robert Lanford, a scientist at the Southwest Foundation for Biomedical Research in San Antonio, Texas. "If we take that away from the virus, it can't replicate anymore."

Viruses replicate inside cells. Like small factories, they require all of the "machinery" inside the cell to accomplish this, explained Lanford. "The beauty of this drug is it takes away the host factor that the virus needs to replicate, and the virus cannot gain a mutation that allows it to be resistant to it."

The study appears in the Dec. 3 online edition of Science.

Hepatitis C, which is spread by contact with the blood of someone who is infected, infects the liver. About 70 percent to 80 percent of those with the virus have no symptoms initially, according to the U.S. Centers for Disease Control and Prevention. But over time, between 60 percent and 70 percent will develop chronic liver disease. Eventually, the virus can cause enough damage to the liver to lead to the formation of scar tissue, and eventually cirrhosis. The virus can also cause liver cancer.