Abstract 14270: The Effect of Evinacumab on Apheresis Eligibility in Patients With Homozygous Familial Hypercholesterolemia

Abstract

Background: Homozygous familial hypercholesterolemia (HoFH) is a rare genetic lipid disorder characterized by elevated low-density lipoprotein cholesterol (LDL-C) levels and premature atherosclerotic cardiovascular disease. Evinacumab, a fully human monoclonal antibody against angiopoietin-like protein 3, has demonstrated approximately 50% reductions in LDL-C in HoFH patients when added to maximally tolerated lipid-lowering therapies. Objective: In this post-hoc analysis, we assessed the effect of evinacumab on the eligibility for apheresis using predefined US and EU apheresis criteria. Methods: This was a double-blind, placebo-controlled, 24-week phase 3 trial (NCT03399786) that randomized patients 2:1 to evinacumab 15 mg/kg intravenously every 4 weeks (Q4W; n=43) or placebo (n=22). We assessed the proportion of patients who met per protocol US apheresis criteria (LDL-C ≥300 mg/dL), newer US criteria for FH (LDL-C ≥300 mg/dL or LDL-C ≥160 mg/dL with coronary heart disease or peripheral artery disease) and per protocol EU apheresis criteria (LDL-C >160 mg/dL [primary prevention] or >120 mg/dL [secondary prevention]) at baseline and week 24. Results: Under the newer US criteria (2018), 62.8% (n=27) of evinacumab-treated patients and 54.5% (n=12) placebo-treated patients qualified for apheresis at baseline (Table). Following 24 weeks of treatment, 48.8% of all evinacumab versus 9.1% of all placebo patients no longer qualified for apheresis. Similar results were observed using EU apheresis criteria, where 46.5% of evinacumab-treated patients shifted from qualifying for apheresis at baseline to not qualifying at week 24, compared with 4.5% of placebo-treated patients. The majority of evinacumab (65.1%) and placebo (68.2%) patients did not qualify for per protocol US apheresis at baseline, however a shift of 27.9% and 9.1% was observed, respectively. Conclusions: Evinacumab has the potential to reduce the need for apheresis in patients with HoFH.