PCSK9 inhibitors (Liphorus)

A review.In 2003, the gene encoding proprotein convertase subtilisin/kexin type 9 (PCSK9) was first identified and linked to familial hypercholesterolemia (FH).Subsequent studies revealed that PCSK9 regulated low-d. lipoprotein (LDL) receptor recycling and identified loss-of-function PCSK9 variants that were associated with low circulating levels of LDL cholesterol (LDL-C) and a reduced risk of coronary artery disease.The first large randomized controlled trial that assessed the impact of PCSK9 inhibitors (PCSK9i) on major adverse cardiova scular events (MACE) was FOURIER (Further Cardiovascular Outcomes Research with PCSK9 Inhibition in Subjects with Elevated Risk), which randomized 27,564 subjects with stable atherosclerotic cardiovascular disease (ASCVD) on maximally tolerated statin therapy to either placebo or evolocumab.Novel approaches to inhibit PCSK9 are fast approaching, with the most promising being PCSK9 siRNA therapeutics.By lowering both intracellular and circulating PCSK9, therapies may have different effects on metabolic and immune pathways compared with existing PCSK9 antibody therapeutics and could increase the risk of diabetes secondary to the facilitated entry of LDL into pancreatic beta cells.Addnl., although monoclonal anti-bodies against PCSK9 are used primarily to lower LDL-C, they also possess significant Lp(a) lowering capabilities (a characteristic not associated with most other LDL-C lowering therapies).Finally, although most patients on PCSK9i have a profound reduction in LDL-C, understanding why a subset of patients have a blunted LDL-C response is a critical knowledge gap that must be bridged.

In many patients it is difficult to achieve the current very low target LDL-cholesterol levels, recommended for the prevention of atherosclerotic cardiovascular events. If statin therapy or statins in combination with ezetimibe are not sufficient, addition of PCSK9 inhibitors should be considered. PCSK9 inhibitors reduce LDL-CH by an average of 50-60 % and reduce the risk of atherosclerotic cardiovascular events. They are currently reserved for patients with atherosclerotic cardiovascular disease and for patients with familial hypercholesterolaemia, in whom despite intensive hypolipidemic therapy statins with ezetimibe the target LDL-cholesterol value is not reached. In these patients, PCSK9 inhibitors may also be indicated in case of statin intolerance.