In a dramatic finding, a new drug for hepatitis C virus (HCV) infections that targets liver cells produced a substantial drop in blood levels of the virus in animals and continued to work up to several months after treatment, say scientists at the Southwest Foundation for Biomedical Research (SFBR) in San Antonio.
The drug, SPC3649, was developed by the biopharmaceutical firm Santaris Pharma A/S in Denmark using their proprietary nucleic acid chemistry called "locked nucleic acid" or LNA. SPC3649 is a nucleic acid, or DNA-based drug, that captures a small RNA molecule in the liver, called microRNA122, that is required for HCV replication.
"Our collaboration with Santaris Pharma proved that the drug worked exceptionally well in treating HCV infections in chimpanzees," said SFBR's Robert Lanford, Ph.D., the lead author on the study appearing in the December 3, 2009 issue of Science Express, which provides rapid electronic publication of research papers ahead of print in the journal Science.
SPC3649 also showed a high barrier to resistance, a major problem with therapies that directly target the virus. Moreover, this proof of concept study suggests that the technology might also prove useful in treating many other diseases such as HIV, cancer, and inflammatory diseases.
HCV infections affect 170 million people worldwide and progress over years to end stage liver disease including cirrhosis and liver cancer. In the United States, 4 percent of the adult population is chronically infected with HCV. The only U.S. Food and Drug Administration approved therapy is interferon and ribavirin, which is very toxic, requires 48 weeks of treatment and works in less than half of patients. Scientists believe that a cocktail of three drugs will be needed to prevent antiviral resistance and replace interferon.