Role of PCSK9 Inhibitors in High Risk Patients with Dyslipidemia: Focus on Familial Hypercholesterolemia

Background: Familial hypercholesterolemia (FH) is an inherited autosomal dominant disorder that is characterized by substantially increased Low-Density Lipoprotein Cholesterol (LDL-C) levels. Patients with FH have a significantly higher risk for Cardiovascular (CV) events, and the timely reduction of LDL-C is of paramount importance to ameliorate the risk for CV disease. Among the available lipid-lowering therapies, the novel Proprotein Convertase Subtilisin/Kexin type 9 (PCSK9) inhibitors have emerged as a very promising class of drugs for the management of such patients.

Objective: The purpose of this review is to present available data on the efficacy and safety of the two available PCSK9 inhibitors in patients with FH, and importantly to discuss potential differences between the two drugs.

Methods: A comprehensive literature search was performed to identify available data from clinical studies evaluating the impact of evolocumab or alirocumab on lipid and CV parameters in patients with FH.

Results: Several studies have assessed the lipid-lowering profile of PCSK9 inhibitors in patients with FH. Both evolocumab and alirocumab were found to significantly reduce LDL-C by more than 50-60% in FH patients. Furthermore, data also support a lower rate of lipid apheresis in FH patients receiving a PCSK9 inhibitor. In terms of CV outcomes, both drugs were found to possess CV-ameliorating effects of the same extent in patients with CV disease. However, alirocumab reduced all-cause mortality, as well, a finding not observed with evolocumab. Several differences in the study population characteristics might explain this and other mild differences observed in the CV trials of these drugs.

Conclusion: Available evidence suggests similar potency of alirocumab and evolocumab in reducing lipids and CV events.