Inclisiran as a siRNA Inhibitor of Proprotein Convertase Subtilisin/Kexin Type 9 (PCSK9); Past, Present, and Future

Reducing low-density lipoprotein cholesterol (LDL-C) levels has been shown to reduce the risk of developing atherosclerotic cardiovascular disease (ASCVD). Statins are the foundation of LDL-C lowering therapy with other non-statin agents used in circumstances where goal LDL-C levels are not reached or owing to intolerance to adverse effects of statins. In 2003, the discovery of the role of the proprotein convertase subtilisin/kexin type 9 (PCSK9) system in promoting elevated LDL-C levels led to new avenues of drug development to achieve target LDL-C. In 2021, inclisiran, a small interfering ribonucleic acid (siRNA) molecule targeting PCSK9 was approved by the Food and Drug Administration (FDA). Inclisiran has demonstrated effective reductions of LDL-C, such as in the large phase-3 ORION-9, ORION-10, and ORION-11 trials in which it achieved LDL-C reductions of 39.7%, 52.3%, and 49.9%, respectively. This review discusses the current clinical evidence and ongoing clinical studies of inclisiran as well as analyzes other areas of PCSK9 inhibition development.