Real-World Effectiveness of PCSK9 Inhibitors in Reducing LDL-C in Patients With Familial Hypercholesterolemia in Italy: A Retrospective Cohort Study Based on the AIFA Monitoring Registries

: Background Information on the real-world use of proprotein convertase subtilisin kexin 9 inhibitors (PCKS9is) in familial hypercholesterolemia are limited. We evaluated the pattern of prescription and the long-term efficacy of alirocumab and evolocumab in Italian patients with familial hypercholesterolemia in clinical practice. Methods and Results The data set for analysis was extracted from the PCKS9i Italian Medicines Agency (AIFA) registry and included 2484 patients with heterozygous familial hypercholesterolemia (HeFH) and 62 patients with homozygous familial hypercholesterolemia (HoFH) who were prescribed PCKS9is from February 2017 to December 2021. As the follow-up schedules were not prespecified and could vary, persistence and adherence as well as low-density lipoprotein cholesterol (LDL-C) changes during 2 years of treatment were analyzed in a final cohort of 1299 patients with familial hypercholesterolemia. At baseline, 53.8% of patients with HeFH and 69.4% of patients with HoFH were receiving maximally tolerated lipid-lowering therapies, while 45.9% of patients with HeFH and 30.7% of patients with HoFH reported statin intolerance; mean LDL-C was 197.7±52.3 mg/dL in HeFH and 252.0±106.2 mg/dL in HoFH. The 6-month persistence and adherence to therapy were >85%, and LDL-C reduction reached 58.6% (to 79.7 mg/dL) in HeFH and 57.6% (to 95.1 mg/dL) in HoFH after 24 months of treatment. The European Atherosclerosis Society/European Society of Cardiology LDL-C goals were achieved in 43.3% of patients with HeFH and 37.5% of patients with HoFH. Conclusions PCKS9i prescribed to patients with familial hypercholesterolemia in clinical practice showed LDL-C-lowering efficacy similar to that observed in controlled trials. However, 2 of 5 HeFH cases and 2 of 6 HoFH cases achieved the recommended LDL-C goals. The full achievement of European Atherosclerosis Society/European Society of Cardiology LDL-C goals should require a lower threshold for PCKS9i initiation and a combination of multiple therapies.