Real-World Effectiveness and Safety of Evinacumab in Children and Adults With Homozygous Familial Hypercholesterolemia: A Multisite US Perspective—Brief Report

BACKGROUND: Homozygous familial hypercholesterolemia (HoFH) is an autosomal semidominant disorder characterized by extreme elevations in LDL-C (low-density lipoprotein cholesterol) and early-onset atherosclerotic cardiovascular disease. Evinacumab is a monoclonal antibody administered by monthly intravenous infusion that binds ANGPTL3 (angiopoietin-like 3) and when added to standard lipid-lowering therapies lowers LDL-C by ≈50% in HoFH clinical trials. Studies examining the real-world effectiveness and safety of evinacumab are limited. METHODS: We performed a retrospective study to assess the effectiveness and safety of evinacumab in patients with HoFH in clinical practice at 6 US academic medical centers. The primary end point was the percent change in LDL-C from baseline to first follow-up and to the most recent follow-up after evinacumab initiation. Secondary end points were percent change in non–high-density lipoprotein cholesterol (non–HDL-C), triglycerides, total cholesterol, HDL-C, and achievement of an LDL-C <70 mg/dL. Adverse events were recorded. RESULTS: Twenty-four patients (mean age, 40 [range, 5–84] years) with HoFH were followed for a median of 48 weeks. Fifty percent were female, 66.7% had atherosclerotic cardiovascular disease, 87.5% were on a statin, 83.3% were on ezetimibe, 66.7% were on PCSK9i (proprotein convertase subtilisin/kexin type 9 inhibitors), 24% were on lomitapide, and 33.3% were undergoing lipoprotein apheresis. Significant reductions in LDL-C, non–HDL-C, total cholesterol, triglycerides, and HDL-C were observed both at the first follow-up (4 weeks) and the most recent follow-up (48 weeks); mean±SEM percent change from baseline to the most recent follow-up was as follows: LDL-C, −53.2% (±4.1); non–HDL-C, −52.7% (±3.9); triglycerides, −47.4% (±5.1); total cholesterol, −48.9% (±4.0); and HDL-C, −30.2% (±4.1); P <0.001 for all. Significantly more patients achieved LDL-C <70 mg/dL after evinacumab was added. Nine (37.5%) patients reported adverse events during or following evinacumab infusions. Treatment was discontinued by 1 patient because of back pain. CONCLUSIONS: Across 6 US academic medical centers, evinacumab was generally well tolerated by patients with HoFH and lowered LDL-C by ≈50%, consistent with results from clinical trials.