The identification of the critical role of proprotein convertase 
subtilisin/kexin type 9 (PCSK9) has rapidly led to the development of PCSK9 
inhibition with monoclonal antibodies (mAbs). PCSK9 mAbs are already in limited 
clinical use and are the subject of major cardiovascular outcomes trials, which, 
if universally positive, could see much wider clinical application of these 
agents. Patients with familial hypercholesterolaemia are the most obvious 
candidates for these drugs, but other patients with elevated cardiovascular 
risk, statin intolerance or hyperlipoproteinaemia(a) may also benefit. PCSK9 
mAbs, administered once or twice monthly, reduce LDL cholesterol levels by 50% 
to 70%, and appear to be safe and acceptable to patients over at least 2 years 
of treatment; however, treatment-emergent adverse effects are not always 
identified in clinical trials, as well-evidenced by statin myopathy. Inclisiran 
is a promising RNA-based therapy that promotes the degradation of PCSK9 mRNA 
transcripts and has similar efficacy to mAbs, but with a much longer duration of 
action. The cost-effectiveness and long-term safety of therapies targeted at 
inhibiting PCSK9 remain to be demonstrated if they are to be used widely in 
coronary prevention.