Homozygous familial hypercholesterolemia is characterized by premature cardiovascular disease caused by markedly elevated levels of low-density lipoprotein (LDL) cholesterol. This disorder is associated with genetic variants that result in virtually absent (null–null) or impaired (non-null) LDL-receptor activity. Loss-of-function variants in the gene encoding angiopoietin-like 3 (ANGPTL3) are associated with hypolipidemia and protection against atherosclerotic cardiovascular disease. Evinacumab, a monoclonal antibody against ANGPTL3, has shown potential benefit in patients with homozygous familial hypercholesterolemia.

Combination lipid-lowering therapy as first line strategy in very high-risk patients.

Objective: The mechanism by which evinacumab, a fully human monoclonal antibody directed against ANGPTL3 (angiopoietin-like 3 protein) lowers plasma LDL (low-density lipoprotein) cholesterol levels in patients with homozygous familial hypercholesterolemia is unknown. We investigated apoB (apolipoprotein B) containing lipoprotein kinetic parameters in patients with homozygous familial hypercholesterolemia, before and after treatment with evinacumab. Approach and Results: Four patients with homozygous familial hypercholesterolemia underwent apoB kinetic analyses in 2 centers as part of a substudy of a trial evaluating the efficacy and safety of evinacumab in patients with homozygous familial hypercholesterolemia. The enrichment of apoB with the stable isotope (5,5,5- ² H ₃ )-Leucine was measured in VLDL (very LDL), IDL (intermediate-density lipoprotein), and LDL at different time points before and after intravenous administration of 15 mg/kg evinacumab. Evinacumab lowered LDL-cholesterol by 59±2% and increased IDL apoB and LDL apoB fractional catabolic rate in all 4 homozygous familial hypercholesterolemia subjects, by 616±504% and 113±14%, respectively. VLDL-apoB production rate decreased in 2 of the 4 subjects. Conclusions: In this small study, ANGPTL3 inhibition with evinacumab is associated with an increase in the fractional catabolic rate of IDL apoB and LDL apoB, suggesting that evinacumab lowers LDL-cholesterol predominantly by increasing apoB-containing lipoprotein clearance from the circulation. Additional studies are needed to unravel which factors are determinants in this biological pathway. Registration: URL: https://www.clinicaltrials.gov ; Unique identifier: NCT04722068.

Background and Aims: Recent data from a large American cohort of women strongly support universal one-time screening for LDL cholesterol, high-sensitivity C-reactive protein (hsCRP), and lipoprotein(a) [Lp(a)] in primary prevention. This study addresses the validity and generalizability of this novel primary prevention strategy in a large prospective European cohort of initially healthy men and women. Methods: Plasma levels of LDL cholesterol, hsCRP, and Lp(a) were measured at study entry in 17 087 participants from the EPIC-Norfolk study who were subsequently followed over a period of 20 years for major adverse cardiovascular events (MACEs). Competing risk- and multivariable-adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) for incident MACE across quintiles of each biomarker and sought evidence of independent as well as additive effects over time were calculated. Results: During the 20-year follow-up, a total of 3249 MACEs occurred. Increasing quintiles of baseline LDL cholesterol, hsCRP, and Lp(a) all predicted 20-year risks; the multivariable-adjusted HRs in a comparison of the top to bottom quintile were 1.78 (95% CI: 1.57–2.00) for LDL cholesterol, 1.55 (95% CI: 1.37–1.74) for hsCRP, and 1.19 (95% CI: 1.07–1.33) for Lp(a). Compared with individuals with no biomarker elevations, the multivariable-adjusted HRs for incident MACE were 1.33, 1.68, and 2.41 for those with one, two, or three biomarkers in the top quintile, respectively (all P < .001). Each biomarker demonstrated independent contributions to overall risk and findings were consistent in analyses stratified by sex. Conclusions: A single combined measure of LDL cholesterol, hsCRP, and Lp(a) among initially healthy European men and women was predictive of incident MACE during a 20-year period. These data replicate findings from a recent American cohort and strongly support universal screening for all three biomarkers in primary prevention.

Both plasma low-density lipoprotein (LDL) cholesterol levels and risk for premature cardiovascular disease are extremely elevated in patients with homozygous familial hypercholesterolemia (HoFH), despite the use of multiple cholesterol lowering treatments. Given its inborn nature, atherosclerotic plaques are commonly observed in young HoFH patients. Whether intensive lipid lowering strategies result in plaque regression in adolescent patients is unknown. Two HoFH patients with null/null LDLR variants, who participated in the R1500-CL-1629 randomized clinical trial (NCT03399786) evaluating the LDL cholesterol lowering effect of evinacumab (a human antibody directed against ANGPTL3; 15 mg/kg intravenously once monthly), were included in this study. Patients underwent coronary computed tomography angiography (CCTA) before randomization and after 6 months of treatment. Both patient A (aged 12) and B (aged 16) were treated with a statin, ezetimibe and weekly apheresis. Evinacumab decreased mean pre-apheresis LDL cholesterol levels from 5.51 ± 0.75 and 5.07 ± 1.45 mmol/l to 2.48 ± 0.31 and 2.20 ± 0.13 mmol/l and post-apheresis LDL levels from 1.45 ± 0.26 and 1.37 ± 39 mmol/l to 0.80 ± 0.16 and 0.78 ± 0.13 mmol/l in patient A and B, respectively. Total plaque volumes were reduced by 76% and 85% after 6 months of evinacumab treatment in patient A and B, respectively. We describe two severely affected young HoFH patients in whom profound plaque reduction was observed with CCTA after intensive lipid lowering therapy with statins, ezetimibe, LDL apheresis, and evinacumab. This shows that atherosclerotic plaques possess the ability to regress at young age, even in HoFH patients.