Definition

A human immunoglobulin G1 (IgG1) monoclonal antibody directed against human proprotein convertase subtilisin/kexin type 9 (PCSK9), that can be used in the treatment of hypercholesterolemia. Upon administration, alirocumab targets, binds to and inhibits the activity of PCSK9. This prevents the binding of PCSK9 to low-density lipoprotein receptor (LDLR) on hepatocytes and prevents its degradation. This increases LDLR on hepatocytes and increases the liver’s ability to remove LDL cholesterol (LDL-C) from the blood, thereby lowering LDL-C levels. PCSK9 binds to LDLR on the surface of hepatocytes to promote LDLR degradation within the liver.