Evinacumab Improved the Homozygous Familial Hypercholesterolemia Lipid Metabolism: A Case Report

Homozygous familial hypercholesterolemia (HoFH) is a rare genetic disorder characterized by high levels of low-density lipoprotein cholesterol (LDL-C) and increased risk of early onset atherosclerosis. Evinacumab, an angiopoietin-like protein 3 (ANGPTL3)-inhibiting monoclonal antibody, lowers LDL-C independently of LDL receptor activity. However, its effects on other lipid-related markers remain poorly investigated in real-world clinical practice. We herein report a 54-year-old Japanese woman with genetically confirmed compound heterozygous familial hypercholesterolemia (FH) treated with evinacumab in combination with other lipid-lowering agents. Lipoprotein apheresis was continued every two weeks throughout the treatment. Serum sampling before and after evinacumab administration found that, following evinacumab initiation, LDL-C decreased from 324 to 205 mg/dL (reduction of 119 mg/dL, -36.7%) and triglycerides from 155 to 51 mg/dL (reduction of 103 mg/dL, -66.8%). Notably, atherosclerosis-related markers showed substantial reductions, with remnant-like particle cholesterol (RLP-C) decreasing from 10.5 to ＜2.0 mg/dL, small dense LDL-C (sdLDL-C) from 80.2 to 22.1 mg/dL, and malondialdehyde-modified LDL (MDA-LDL) from 105 to 87 mg/dL. Apolipoproteins (ApoB, ApoC2, ApoC3, ApoE, and ApoA5) decreased as well. No significant changes were observed in lipoprotein (a), free fatty acids, interleukin-6, or high-sensitivity C-reactive protein levels. This is the first clinical report to comprehensively evaluate the lipid-modifying effects of evinacumab in a Japanese HoFH patient. In this case, evinacumab was highly efficacious against atherosclerosis-related markers and apolipoproteins, beyond simple LDL-C reduction, suggesting additional cardiovascular benefits. These findings provide mechanistic insights that may inform therapeutic strategies for the management of HoFH.