Long-term safety and effectiveness of alirocumab and evolocumab in familial hypercholesterolemia (FH) in Belgium

Background: In 2019, the European Atherosclerosis Society (EAS) published updated guidelines, recommending even lower blood cholesterol targets than previously. In patients with familial hypercholesterolaemia (FH), who have very elevated blood cholesterol levels and are at ('Very') 'High risk' of atherosclerotic cardiovascular disease (ASCVD), this represents a real challenge. Anti-Proprotein convertase subtilisin/kexin type 9 monoclonal antibody (anti-PCSK9 mAb) has been commercially available for FH in Belgium since 2015. Our study aims to investigate the real-life efficacy of anti-PCSK9 mAb in FH patients. Method: We sourced patients from the EAS FH Studies Collaboration database (an international database on FH in which Belgium participates). We only retained patients using anti-PCSK9 mAb and followed at our Lipid Clinic. Results: Of the 239 subjects included in this study (mean age: 56 years), 85% were considered at 'Very High Risk' (56% with a history of ASCVD), the remaining 15% were at 'High Risk'. The PCSK9 mAb treatment reduced LDL-C levels by 54% within the first year. This reduction was maintained over the follow-up (FU) period (3.0 ± 1.8 years). The EAS targets were reached in 50% of the subjects, 93% of whom were also treated with statins. The treatment was very well tolerated. At the end of the observation period, 96% patients continued receiving PCSK9 mAb. Conclusions: Anti-PCSK9 mAb are a safe and effective therapeutic option for lowering LDL-C levels in FH patients. It allowed a significant portion of our FH patients to reach their lipid targets, mainly in those with combined therapy with statin and/or ezetimibe.