Drugs for hypercholesterolaemia – from statins to pro-protein convertase subtilisin kexin 9 (PCSK9) inhibition

Cardiovascular disease (CVD) remains one of the commonest sources of morbidity and mortality in the world. Lipids and especially low density lipoprotein cholesterol (LDL-C) contribute to the risk of CVD events. Statins are the primary therapy for hypercholesterolaemia and recent evidence supports the use of ezetimibe as a second-line agent. Pro-protein convertase subtilisin kexin 9 (PCSK9) is a regulator of LDL receptor expression. Activating mutations in PCSK9 give rise to a form of familial hypercholesterolaemia, while inactivating mutations lead to lower LDL-C levels and fewer CVD events. Therapies to inhibit PCSK9 are in development and two antibody-based therapies - alirocumab and evolocumab - have recently been licensed. This article reviews the actions of PCSK9, the novel therapeutics targeted on this molecule and how they are likely to be used in clinical practice until large scale CVD outcome studies with PCSK9 inhibitors are published.