Role of Anti-PCSK9 Antibodies in the Treatment of Patients with Statin Intolerance.

Statin intolerance is usually defined as the inability of a patient to tolerate statintreatment due to muscle-related complaints. While randomised trials show that these complaints occure with similar frequency in patients receiving placebo, namely in up to ~5% of the subjects, and data from registries as well as clinical experience indicate a much higher frequency of up to ~30%. The lack of standard definition or of a diagnostic marker of statin intolerance confounds the problem. The diagnosis remains subjective based on the symptoms the patient reports. Therefore, a large number of patients who need a statin are not receiving it, or receiving only very-low and/or intermittent doses unable to achieve a robust decrease in low-density lipoprotein cholesterol (LDL-C), leaving patients at high or very high risk for cardiovascular events requiring an alternative form of lipid-lowering therapy. Until recently, the only available alternatives were niacin, ezetimibe, bile-acid sequestrants and fibrates that decrease LDL-C concentrations by up to 15-20%. Recently the fully human monoclonal antibodies against proprotein convertase subtilisin/kexin 9 (PCSK9), alirocumab (Praluent®) and evolocumab (Repatha®), which have been shown to decrease LDL-C by up to 70% have been approved in Europe for use in patients with primary hypercholesterolemia not at LDL-C target while on maximally tolerated lipid-lowering therapy and specifically for patients with statin intolerance and in the USA for patients with atherosclerotic cardiovascular disease or familial hypercholesterolemia requiring additional LDL-C lowering. Ongoing large clinical trials with cardiovascular endpoints will provide a definitive answer for the role of anti-PCSK9 antibodies in clinical practice.