March 29, 2013
Researchers report success in blocking the hepatitis C virus's ability to colonize liver cells in 18 hepatitis C-infected patients with five weeks of treatment using the antisense oligonucleotide miravirsen. Fourteen weeks after miravirsen injections ended, hepatitis C viral loads were still undetectable in 5 of 18 patients.
Miravirsen binds tightly to messenger proteins of liver cells and blocks the hepatitis C virus from colonizing the proteins, which the virus needs to survive and replicate. Without a foothold in liver cells, the hepatitis C virus does not have the chance to develop resistance to protease inhibitors such as teleprevir and boceprivir. As a result, hepatitis C patients could be able to stop taking interferon and ribavirin, which cause side effects like fatigue, anxiety, depression, flu-like symptoms, nausea, and diarrhea.
Harvard University physician Dr. Judy Lieberman and Stanford University professor Dr. Peter Sarnow cautioned that long-term miravirsen use could be unsafe because it also targets "genetic material that helps suppress the development of fatty liver, liver fibrosis, and liver tumors" -- side effects of hepatitis C. Miravirsen does offer the side benefit of lowering cholesterol; hepatitis C patients taking protease inhibitors cannot take statins that lower cholesterol.
Although miravirsen might not present a safe cure for hepatitis C, Sarnow and Lieberman stated that miravirsen could become part of a drug regimen that can keep hepatitis under control. Worldwide, 170 million people are infected with hepatitis C.
The full study, "Treatment of HCV Infection by Targeting MicroRNA," was published online in the New England Journal of Medicine (2013; doi: 10.1056/NEJMoa1209026).