Avasimibe: A novel hepatitis C virus inhibitor that targets the assembly of infectious viral particles

Direct-acting antivirals (DAAs), which target hepatitis C virus (HCV) proteins, have exhibited impressive efficacy in the management of chronic hepatitis C. However, the concerns regarding high costs, drug resistance mutations and subsequent unexpected side effects still call for the development of host-targeting agents (HTAs) that target host factors involved in the viral life cycle and exhibit pan-genotypic antiviral activity. Given the close relationship between lipid metabolism and the HCV life cycle, we investigated the anti-HCV activity of a series of lipid-lowering drugs that have been approved by government administrations or proven safety in clinical trials. Our results showed that avasimibe, an inhibitor of acyl coenzyme A:cholesterol acyltransferase (ACAT), exhibited marked pan-genotypic inhibitory activity and superior inhibition against HCV when combined with DAAs. Moreover, avasimibe significantly impaired the assembly of infectious HCV virions. Mechanistic studies demonstrated that avasimibe induced downregulation of microsomal triglyceride transfer protein expression, resulting in reduced apolipoprotein E and apolipoprotein B secretion. Therefore, the pan-genotypic antiviral activity and clinically proven safety endow avasimibe exceptional potential as a candidate for combination therapy with DAAs. In addition, the discovery of the antiviral properties of ACAT inhibitors also suggests that inhibiting the synthesis of cholesteryl esters might be an additional target for the therapeutic intervention for chronic HCV infection.