PCSK9 inhibitors are a new cholesterol-reducing class of medications. In this study, PCSK9 inhibition by alirocumab reduced LDL nicely by about 50% even in individuals with heterozygous familial hypercholesterolemia. Adverse event profile was overall similar between the alirocumab and placebo arm. A group of 1300 patients were followed for about 2 years.
Journal of Clinical Lipidology
Patients with heterozygous familial hypercholesterolemia (HeFH) are characterized by elevated LDL-C levels. Long-term effects of proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibition have not been thoroughly investigated in these patients.
Objective: We evaluated efficacy and safety of alirocumab, a PCSK9 inhibitor, vs placebo in patients with HeFH.
In total, 1257 patients with HeFH on maximally tolerated statin ± other lipid-lowering therapies from four 78-week ODYSSEY trials were analyzed. In FH I and II, patients with baseline LDL-C levels ≥70/100 mg/dL (n = 735), depending on documented cardiovascular disease history, received placebo or alirocumab 75 mg every 2 weeks (Q2W; with dose increase to 150 mg Q2W at week 12 if week 8 LDL-C was ≥70 mg/dL). Separately, data were pooled from HIGH FH (baseline LDL-C ≥160 mg/dL) and patients with HeFH from LONG TERM (baseline LDL-C ≥70 mg/dL), where patients received placebo or alirocumab 150 mg Q2W (n = 522).
At week 24, alirocumab reduced LDL-C levels by −48.8% (75/150 mg Q2W; placebo: +7.1%) and −55.0% (alirocumab 150 mg Q2W; placebo: +1.3%) (both P < .0001 vs placebo; intention-to-treat analysis). Least-squares mean LDL-C levels of 69.1 to 75.6 mg/dL (alirocumab 75/150 mg/dL Q2W; baseline: 141.3 mg/dL) and 72.2 to 82.3 mg/dL (alirocumab 150 mg Q2W; baseline: 168.4 mg/dL) were achieved at weeks 24 to 78 (on-treatment analysis). Additional beneficial effects were observed in other lipids. Treatment-emergent adverse event rates were similar in the alirocumab (80.5%) and placebo groups (83.0%).
In this large cohort of patients with HeFH, alirocumab significantly reduced LDL-C levels. Alirocumab was generally well tolerated.