Inclisiran

Low-density lipoprotein (LDL) receptors expressed on hepatocytes are responsible for the removal of circulating LDL-C from plasma via receptor-mediated endocytosis. Proprotein convertase subtilisin-kexin type 9 (PCSK9) is a serine protease that is mainly produced by hepatocytes. It binds to LDL receptors and targets them for lysosomal degradation, thereby reducing the levels of LDL receptors, attenuating the recycling of LDL receptors, and elevating the levels of circulating plasma LDL-C.

Inclisiran is conjugated to triantennary N-acetylgalactosamine carbohydrates, which can bind to asialoglycoprotein receptors expressed in the liver. Binding to asialoglycoprotein receptors facilitates the uptake of inclisiran into the hepatocytes. Once inside the hepatocyte, inclisiran binds to the RNA-induced silencing complex (RISC), which is a ribonucleoprotein complex that serves as a template for recognizing the target complementary mRNA, activate RNAse, and cleave the target mRNA. Inclisiran incorporated into the RISC allows the drug to cleave PCSK9 mRNA and prevent PCSK9 translation, thus decreasing hepatic production of PCSK9. Less PCSK9 protein available allows more LDL receptors to be recycled to the hepatic membrane for circulating LDL-C uptake.