Targeting Host Cell MicroRNA: An Exciting New Approach to HCV Treatment

MicroRNAs (miRNAs) exert a posttranscriptional effect on gene expression by binding to sites within target messenger RNAs. MicroRNA-122 (miR-122), which is expressed in hepatocytes, attaches to a highly conserved region of the hepatitis C virus (HCV) genome and protects it from degradation. An antisense oligonucleotide, miravirsen, binds to miR-122 and prevents it from stabilizing HCV. Now, in a manufacturer-sponsored, phase IIa clinical trial, investigators have assessed the safety and antiviral activity of miravirsen in adults with chronic HCV genotype 1 infection.

Thirty-six patients were randomly assigned to receive five weekly injections of miravirsen (at 3 mg, 5 mg, or 7 mg per kg) or placebo. The mean maximum reduction in HCV RNA leve…