Efficacy and Safety of Alirocumab in Adults With Homozygous Familial Hypercholesterolemia The ODYSSEY HoFH Trial

BACKGROUND Homozygous familial hypercholesterolemia (HoFH) is characterized by extremely elevated low-density lipoprotein-cholesterol (LDL-C) levels and early onset atherosclerotic cardiovascular disease despite treatment with conventional lipid-lowering treatment. OBJECTIVES This study was designed to assess LDL-C reduction with the proprotein convertase subtilisin/kexin type 9 inhibitor alirocumab in adult patients with HoFH. METHODS This randomized, double-blind, placebo-controlled, parallel-group, phase 3 study evaluated efficacy and safety of alirocumab 150 mg every 2 weeks. The primary endpoint was percent reduction from baseline in LDL-C versus placebo after 12 weeks of treatment. RESULTS Patients (N = 69) were randomized 2:1 to alirocumab or placebo. At baseline, background lipid-lowering treatment included 67 patients receiving statin (59 patients on high-intensity statin); 50 patients on ezetimibe; 10 patients on lomitapide; and 10 patients undergoing apheresis. Mean baseline LDL-C was 259.6 mg/dl in the placebo group and 295.0 mg/dl in the alirocumab group. At week 12, the least squares mean difference in LDL-C percent change from baseline was -35.6% (alirocumab [-26.9%] vs. placebo [8.6%]; p < 0.0001). Reductions (least squares mean difference) in other atherogenic lipids at week 12 were: apolipoprotein B, -29.8%; non-high-density lipoprotein cholesterol, -32.9%; total cholesterol, -26.5%; and lipoprotein(a), -28.4% (all p < 0.0001). No serious adverse events, permanent treatment discontinuations, or deaths due to treatment-emergent adverse events were reported during the double-blind treatment period. CONCLUSIONS In the largest randomized controlled interventional trial in HoFH patients to date, alirocumab resulted in significant and clinically meaningful reductions in LDL-C at week 12. Alirocumab was generally well tolerated, with a safety profile comparable to that of placebo. (c) 2020 The Authors. Published by Elsevier on behalf of the American College of Cardiology Foundation. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).