PCSK9 proprotein convertase subtilisin/kexin type (PCSK9) protein plays an 
important role in LDL cholesterol (LDL-C) metabolism, due to its role in the 
degradation of the LDL receptor. Preliminary clinical data of PCSK9 inhibition 
are quite promising and indicate that PCSK9 inhibition may be a novel strategy 
for the treatment of dyslipidemia particularly for those with refractory 
hypercholesterolemia, statin intolerance, or an elevated lipoprotein (a) level 
and associated cardiovascular diseases. Furthermore, development of PCSK9 
inhibitor is an excellent example of "bench to bedside" concept where discovery 
of a genetic mutation was translated into a novel therapy to address unmet 
clinical needs. Although several approaches have been attempted to inhibit PCSK9 
activity including small molecules, gene silencing and inhibitory antibodies, 
the most promising approach appears to be the use of monoclonal antibodies with 
a 50 -70% LDL cholesterol reduction on top of maximal doses of statins. In this 
article, we review the pharmacology of PCSK9 and summarize findings from key 
clinical studies using PCSK9 inhibitors.