PCSK9 inhibition: current concepts and lessons from human genetics

Low-density lipoprotein cholesterol (LDL-C) plays a central role in the pathogenesis of atherosclerotic cardiovascular disease (ASCVD). Statins are the cornerstone of therapy for the treatment of elevated LDL-C and for the primary and secondary prevention of ASCVD. However, some patients are intolerant of statins or are unable to achieve acceptable lipid levels on statin-based regimens alone. Proprotein convertase subtilisin/kexin type 9 (PCSK9) serves as an important regulator of hepatocyte LDL receptor expression and degradation, and recent genetic studies have highlighted the critical role of PCSK9 in human disease. Gain-of-function mutations in PCSK9 are associated with familial hypercholesterolemia, whereas loss-of-function mutations are protective against ASCVD. Therefore, PCSK9 inhibition offers a promising supplement or alternative to statin therapy in the reduction of LDL-C. Numerous phase II and III randomized control trials have demonstrated the tolerability of monoclonal antibodies against PCSK9 and their efficacy in lowering LDL-C by an additional 40-70 %. In this article, we review the growing role of PSCK9 inhibition in LDL-C reduction for diverse patient populations.