Miravirsen, the first microRNA-targeted drug to enter human clinical trials, successfully reduced hepatitis C (HCV) RNA levels in patients with chronic HCV infection in a phase 2a trial, according to results published March 27 in the New England Journal of Medicine. The development opens the door to a potential new treatment for the disease.
“This is particularly exciting for patients with chronic hepatitis infection,” said Gyongyi Szabo, MD, PhD, professor of medicine and a translational scientist studying chronic hepatitis C infection and liver function, who was not involved in the trial. “This may represent a new type of therapy that has the potential for future treatments in patients with the most difficult hepatitis C type to treat—genotype 1. Especially when one considers that current treatments have many side effects and limited efficacy.”
Globally, as many as 170 million people are estimated to suffer from HCV infection. Chronic HCV is a major cause of liver cirrhosis, liver failure, hepatocellular carcinoma and is the leading cause of liver transplants in the United States.
Inside the liver, the hepatitis C virus uses a liver-specific microRNA-122 (miR-122) molecule normally important for cholesterol metabolism to replicate. Miravirsen, developed by Santaris Pharma, works by sequestering and effectively inhibiting miR-122 so the virus can’t use it to propagate.
In the study, a total of 36 patients with chronic HCV genotype 1 received various doses of Miravirsen over a 29-day period. Two weeks after treatment, five patients receiving the two highest doses of the drug showed no observable signs of HCV RNA.
Essential for turning genes on and off, microRNA was discovered in 1993 by Victor R. Ambros, PhD, the Silverman Chair in Natural Sciences and professor of molecular medicine.