Efficacy and safety of ezetimibe monotherapy in children with heterozygous familial or nonfamilial hypercholesterolemia

Maternal Ezetimibe Concentrations Measured in Breast Milk and Its Use in Breastfeeding Infant Exposure Predictions

BACKGROUND

Lactating mothers taking ezetimibe, an antihyperlipidemic agent, may be hesitant to breastfeed despite the known benefit of breastfeeding to both mother and infant. Currently, no data exist on the presence or concentration of ezetimibe and its main active metabolite, ezetimibe-glucuronide (EZE-glucuronide), in human breast milk.

METHODS

Voluntary breast milk samples containing ezetimibe and EZE-glucuronide were attained from lactating mothers taking ezetimibe as part of their treatment. An assay was developed and validated to measure ezetimibe and EZE-glucuronide concentrations in breast milk. A workflow that utilized a developed and evaluated pediatric physiologically based pharmacokinetic (PBPK) model, the measured concentrations in milk, and weight-normalized breast milk intake volumes was applied to predict infant exposures and determine the upper area under the curve ratio (UAR).

RESULTS

Fifteen breast milk samples from two maternal-infant pairs were collected. The developed liquid chromatography-tandem mass spectrometry (LC-MS/MS) assay showed an analytical range of 0.039-5.0 ng/mL and 0.39-50.0 ng/mL for ezetimibe and EZE-glucuronide, respectively. The measured concentrations in the breast milk samples were 0.17-1.02 ng/mL and 0.42-2.65 ng/mL of ezetimibe and EZE-glucuronide, respectively. The evaluated pediatric PBPK model demonstrated minimal exposure overlap in adult therapeutic dose and breastfed infant simulated area under the concentration-time curve from time zero to 24 h (AUC24). Calculated UAR across infant age groups ranged from 0.0015 to 0.0026.

CONCLUSIONS

PBPK model-predicted ezetimibe and EZE-glucuronide exposures and UAR suggest that breastfeeding infants would receive non-therapeutic exposures. Future work should involve a 'mother-infant pair study' to ascertain breastfed infant plasma ezetimibe and EZE-glucuronide concentrations to confirm the findings of this work.

International Atherosclerosis Society guidance for implementing best practice in the care of familial hypercholesterolaemia

This contemporary, international, evidence-informed guidance aims to achieve the greatest good for the greatest number of people with familial hypercholesterolaemia (FH) across different countries. FH, a family of monogenic defects in the hepatic LDL clearance pathway, is a preventable cause of premature coronary artery disease and death. Worldwide, 35 million people have FH, but most remain undiagnosed or undertreated. Current FH care is guided by a useful and diverse group of evidence-based guidelines, with some primarily directed at cholesterol management and some that are country-specific. However, none of these guidelines provides a comprehensive overview of FH care that includes both the lifelong components of clinical practice and strategies for implementation. Therefore, a group of international experts systematically developed this guidance to compile clinical strategies from existing evidence-based guidelines for the detection (screening, diagnosis, genetic testing and counselling) and management (risk stratification, treatment of adults or children with heterozygous or homozygous FH, therapy during pregnancy and use of apheresis) of patients with FH, update evidence-informed clinical recommendations, and develop and integrate consensus-based implementation strategies at the patient, provider and health-care system levels, with the aim of maximizing the potential benefit for at-risk patients and their families worldwide.

Childhood Screening for Familial Hypercholesterolemia: JACC Review Topic of the Week

Screening for familial hypercholesterolemia (FH) in childhood remains controversial. Existing guidelines offer practitioners conflicting advice despite generally agreeing on the evidence and areas in which evidence is lacking, including a lack of long-term clinical trials demonstrating coronary event reduction as a result of screening and long-term data on statin side effects. A limitation of existing evidence-based frameworks is reliance on 1 evidence grading system to determine recommendations. However, rigorous evidence evaluation alternatives relevant to FH exist. FH is considered a tier 1 genetic condition, meaning that identification and treatment will improve health outcomes among those affected. Elevated low-density lipoprotein cholesterol, the primary consequence of FH, can be considered causal for atherosclerosis and coronary heart disease. Incorporating these concepts into existing evidence pathways allows the inclusion of surrogate clinical trial outcomes (low-density lipoprotein cholesterol reduction and atherosclerosis regression) and observational data on medication safety, strengthening the evidence for pediatric screening for FH.

Recent advances in the management and implementation of care for familial hypercholesterolaemia

Familial hypercholesterolaemia (FH) is a common autosomal semi-dominant and highly penetrant disorder of the low-density lipoprotein (LDL) receptor pathway, characterised by lifelong elevated levels of low-density lipoprotein cholesterol (LDL-C) and increased risk of atherosclerotic cardiovascular disease (ASCVD). However, many patients with FH are not diagnosed and do not attain recommended LDL-C goals despite maximally tolerated doses of potent statin and ezetimibe. Over the past decade, several cholesterol-lowering therapies such as those targeting proprotein convertase subtilisin/kexin type 9 (PCSK9) or angiopoietin-like 3 (ANGPTL3) with monoclonal antibody or ribonucleic acid (RNA) approaches have been developed that promise to close the treatment gap. The availability of new therapies with complementary modes of action of lipid metabolism has enabled many patients with FH to attain guideline-recommended LDL-C goals. Emerging therapies for FH include liver-directed gene transfer of the LDLR, vaccines targeting key proteins involved in cholesterol metabolism, and CRISPR-based gene editing of PCSK9 and ANGPTL3, but further clinical trials are required. In this review, current and emerging treatment strategies for lowering LDL-C, and ASCVD risk-stratification, as well as implementation strategies for the care of patients with FH are reviewed.

Screening for Lipid Disorders in Children and Adolescents: Updated Evidence Report and Systematic Review for the US Preventive Services Task Force

Importance

Lipid screening in childhood and adolescence can lead to early dyslipidemia diagnosis. The long-term benefits of lipid screening and subsequent treatment in this population are uncertain.

Objective

To review benefits and harms of screening and treatment of pediatric dyslipidemia due to familial hypercholesterolemia (FH) and multifactorial dyslipidemia.

Data Sources

MEDLINE and the Cochrane Central Register of Controlled Trials through May 16, 2022; literature surveillance through March 24, 2023.

Study Selection

English-language randomized clinical trials (RCTs) of lipid screening; recent, large US cohort studies reporting diagnostic yield or screen positivity; and RCTs of lipid-lowering interventions.

Data Extraction and Synthesis

Single extraction, verified by a second reviewer. Quantitative synthesis using random-effects meta-analysis.

Main Outcomes and Measures

Health outcomes, diagnostic yield, intermediate outcomes, behavioral outcomes, and harms.

Results

Forty-three studies were included (n = 491 516). No RCTs directly addressed screening effectiveness and harms. Three US studies (n = 395 465) reported prevalence of phenotypically defined FH of 0.2% to 0.4% (1:250 to 1:500). Five studies (n = 142 257) reported multifactorial dyslipidemia prevalence; the prevalence of elevated total cholesterol level (≥200 mg/dL) was 7.1% to 9.4% and of any lipid abnormality was 19.2%. Ten RCTs in children and adolescents with FH (n = 1230) demonstrated that statins were associated with an 81- to 82-mg/dL greater mean reduction in levels of total cholesterol and LDL-C compared with placebo at up to 2 years. Nonstatin-drug trials showed statistically significant lowering of lipid levels in FH populations, but few studies were available for any single drug. Observational studies suggest that statin treatment for FH starting in childhood or adolescence reduces long-term cardiovascular disease risk. Two multifactorial dyslipidemia behavioral counseling trials (n = 934) demonstrated 3- to 6-mg/dL greater reductions in total cholesterol levels compared with the control group, but findings did not persist at longest follow-up. Harms reported in the short-term drug trials were similar in the intervention and control groups.

Conclusions and Relevance

No direct evidence on the benefits or harms of pediatric lipid screening was identified. While multifactorial dyslipidemia is common, no evidence was found that treatment is effective for this condition. In contrast, FH is relatively rare; evidence shows that statins reduce lipid levels in children with FH, and observational studies suggest that such treatment has long-term benefit for this condition.

Updates in the management of pediatric dyslipidemia

PURPOSE OF REVIEW

Pediatric dyslipidemias increase the risk of atherosclerosis and clinical cardiovascular disease and are the leading cause of morbidity and mortality. Lifestyle modifications and pharmacotherapies have measurably improved abnormal lipids and reduced cardiovascular events. The review will focus on current standards of care and investigative medications with the potential to improve cardiovascular health in children and adults.

RECENT FINDINGS

Lifestyle interventions and statins remain cornerstones in the treatment of pediatric hyperlipidemias. Bile acid sequestrants and ezetimibe continue to be used in the pediatric population as well. In recent years, successful clinical trials have approved use of proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors in children with familial hypercholesterolemia. Use of angiopoietin-like protein 3 (ANGPTL3) inhibitors is also promising as it causes marked improvement in low-density lipoprotein cholesterol with safe side effect profiles. Additional medications undergoing pediatric clinical trials include inclisiran, bempedoic acid, and lomitapide.

SUMMARY

Recent advances in pharmacotherapy, especially for treatment of familial hypercholesterolemia, greatly impact treatment of dyslipidemias in children. Despite the overall progress in the development of these medications, therapies targeted towards treating hypertriglyceridemia have lagged behind. Continuing research for the treatment of pediatric dyslipidemias remains an important endeavor to reduce the risk of atherosclerosis and future cardiovascular events in children.

How Genetic Variants in Children with Familial Hypercholesterolemia Not Only Guide Detection, but Also Treatment

Familial hypercholesterolemia (FH) is a hereditary disorder that causes severely elevated low-density lipoprotein (LDL-C) levels, which leads to an increased risk for premature cardiovascular disease. A variety of genetic variants can cause FH, namely variants in the genes for the LDL receptor (LDLR), apolipoprotein B (APOB), proprotein convertase subtilisin/kexin type 9 (PCSK9), and/or LDL-receptor adaptor protein 1 (LDLRAP1). Variants can exist in a heterozygous form (HeFH) or the more severe homozygous form (HoFH). If affected individuals are diagnosed early (through screening), they benefit tremendously from early initiation of lipid-lowering therapy, such as statins, and cardiovascular imaging to detect possible atherosclerosis. Over the last years, due to intensive research on the genetic basis of LDL-C metabolism, novel, promising therapies have been developed to reduce LDL-C levels and subsequently reduce cardiovascular risk. Results from studies on therapies focused on inhibiting PCSK9, a protein responsible for degradation of the LDLR, are impressive. As the effect of PCSK9 inhibitors (PCSK9-i) is dependent of residual LDLR activity, this medication is less potent in patients without functional LDLR (e.g., null/null variant). Novel therapies that are expected to become available in the near future focused on inhibition of another major regulatory protein in lipid metabolism (angiopoietin-like 3 (ANGPTL3)) might dramatically reduce the frequency of apheresis in children with HoFH, independently of their residual LDLR. At present, another independent risk factor for premature cardiovascular disease, elevated levels of lipoprotein(a) (Lp(a)), cannot be effectively treated with medication. Further understanding of the genetic basis of Lp(a) metabolism, however, offers a possibility for the development of novel therapies.

Hyperlipidemia and Cardiovascular Risk in Children and Adolescents

Atherosclerotic cardiovascular disease (ASCVD) represents the major cause of morbidity and mortality worldwide. The onset of the atherosclerosis process occurs during childhood and adolescence, subsequently leading to the onset of cardiovascular disease as young adults. Several cardiovascular risk factors can be identified in children and adolescents; however, hyperlipidemia, in conjunction with the global obesity epidemic, has emerged as the most prevalent, playing a key role in the development of ASCVD. Therefore, screening for hyperlipidemia is strongly recommended to detect high-risk children presenting with these disorders, as these patients deserve more intensive investigation and intervention. Treatment should be initiated as early as possible in order to reduce the risk of future ASCVD. In this review, we will discuss lipid metabolism and hyperlipidemia, focusing on correlations with cardiovascular risk and screening and therapeutic management to reduce or almost completely avoid the development of ASCVD.

Update on management of paediatric dyslipidaemia

PURPOSE OF REVIEW

Atherosclerosis and associated cardiovascular risk factors originate in childhood; hence, early management of dyslipidaemia is vital. However, hypercholesterolemia remains untreated or undertreated in many youths. We review current therapies, drugs under investigation and consider potential future directions for the management of paediatric dyslipidaemia to highlight the recent evidence and new therapeutic options for future use.

RECENT FINDINGS

Cardiovascular disease (CVD) risk factors in childhood, including dyslipidaemia, are associated with CVD risk and clinical CVD events in adulthood. Recent data show that initiation of statin therapy in childhood in children with familial hypercholesterolemia reduces the risk of CVD in adulthood. Several well tolerated and efficacious treatment options have become available in recent times for the management of dyslipidaemia in youth. Many new lipid-lowering drugs are under investigation to widen the available choices. Some of these drugs are now available for use in paediatrics, while some remain targets for future use.

SUMMARY

We review available treatment options for paediatric dyslipidaemia management, discuss potential limitations and propose future directions. We also acknowledge the need for continued research in paediatrics for optimal paediatric dyslipidaemia management.

Atherosclerotic Cardiovascular Risk as an Emerging Priority in Pediatrics

Over the last decades, childhood and adolescence have emerged as an important window of opportunity to prevent atherosclerotic cardiovascular disease (ASCVD) later in life. Here, we discuss the underlying advances in the field. First, atherosclerosis development starts as early as childhood. Atherogenesis initiates in the iliac arteries and abdominal aorta and subsequently develops in higher regions of the arterial tree, as has been demonstrated in nonhuman primate studies and human autopsy studies. Obesity, hypertension, hyperlipidemia, and hyperglycemia at a young age can accelerate atherogenesis. Children and adolescents with obesity have a relative risk of ∼ 2.5 for ASCVD mortality later in life, compared to peers with a normal weight. Conversely, early prevention improves long-term cardiovascular outcomes. Second, we review disease-associated factors that add to the traditional risk factors. Various pediatric disorders carry similar or even higher risks of ASCVD than obesity, including chronic inflammatory disorders, organ transplant recipients, familial hypercholesterolemia, endocrine disorders, childhood cancer survivors, chronic kidney diseases, congenital heart diseases, and premature birth, especially after fetal growth restriction. The involved disease-associated factors that fuel atherogenesis are diverse and include inflammation, vascular, and endothelial factors. The diverse and growing list of pediatric groups at risk underscores that cardiovascular risk management has solidly entered the realm of general pediatrics. In a second review in this series, we will, therefore, focus on recent advances in cardiovascular risk assessment and management and their implications for pediatric practice.

Integrated guidance to enhance the care of children and adolescents with familial hypercholesterolaemia: Practical advice for the community clinician

Familial hypercholesterolaemia (FH) is a highly penetrant monogenic disorder present from birth that markedly elevates plasma low-density lipoprotein (LDL)-cholesterol (LDL-C) concentration and, if untreated, leads to premature atherosclerosis and coronary artery disease (CAD). At a prevalence of 1:250 individuals, with over 90% undiagnosed, recent estimates suggest that there are approximately 22 000 children and adolescents with FH in Australia and New Zealand. However, the overwhelming majority remain undetected and inadequately treated until adulthood or after their first cardiac event. The guidance in this paper aims to increase awareness about paediatric FH and provide practical advice for the diagnosis and management of FH in children and adolescents. Recommendations are given on the detection, diagnosis, assessment and management of FH in children and adolescents. Recommendations are also made on genetic testing, including counselling and the potential for universal screening programmes. Practical guidance on management includes treatment of non-cholesterol risk factors, and safe and appropriate use of LDL-C lowering therapies, including statins, ezetimibe, PCSK9 inhibitors and lipoprotein apheresis. Models of care for FH need to be adapted to local and regional health care needs and available resources. Targeting the detection of FH as a priority in children and young adults has the potential to alter the natural history of atherosclerotic cardiovascular disease and recognise the promise of early detection for improving long-term health outcomes. A comprehensive implementation strategy, informed by further research, including assessments of cost-benefit, will be required to ensure that this new guidance benefits all families with or at risk of FH.

Recent Advances on Familial Hypercholesterolemia in Children and Adolescents

Familial hypercholesterolemia is a common autosomal hereditary disorder characterized by elevated concentrations of low-density lipoprotein cholesterol and the development of premature atherosclerosis and cardiovascular disease. Early diagnosis, as well as prompt and aggressive treatment, are fundamental steps to prevent cardiovascular complications and a high rate of premature mortality in children and adolescents. Clinics and genetics are the two main aspects on which diagnosis is based. Widespread screening programs are a respectable option for the early detection of familial hypercholesterolemia. Different types of screening have been proposed so far; however, the optimal screening program has not yet been found. The treatment approach for both heterozygous and homozygous familial hypercholesterolemia in the pediatric population is multidisciplinary, including lifestyle modifications, standard lipid-lowering medications, and novel pharmacological agents. The latter show promising results, especially for patients who experience intolerance to other treatment or present with more severe conditions. Our purpose is to focus on the importance of the early detection of familial hypercholesterolemia, and to highlight the best therapeutic strategies, including the recent approaches based on current clinical evidence, that need to be adopted from the earliest stages of life.

The Role of Non-statin Lipid-Lowering Medications in Youth with Hypercholesterolemia

PURPOSE OF REVIEW

Lifestyle modification is additive to lipid-lowering medications in the treatment of heterozygous familial hypercholesterolemia (HeFH), which does not respond sufficiently to statin therapy. While both are also important in homozygous familial hypercholesterolemia (HoFH), additional measures such as apheresis may be needed. The purpose of this review is to identify non-statin medications to lower cholesterol that are available for children and adolescents as adjunctive therapy.

RECENT FINDINGS

Ezetimibe is commonly used as second-line pharmacotherapy for treatment of HeFH and HoFH. Colesevelam, a bile acid sequestrant, may be considered for adjunct therapy. Since 2015, the PCSK9 inhibitor evolocumab has been available for adolescents, and its FDA approval has now expanded to age 10 years. The ANGPTL3 inhibitor evinacumab has been approved for children age 12 years and older. A clinical trial for lomitapide is in progress. Approvals for PCSK9 and ANGPTL3 inhibitors have expanded opportunities for children and adolescents with HeFH and HoFH to achieve lower LDL-C levels.

Case Studies in Pediatric Lipid Disorders and Their Management

CONTEXT

Identification of modifiable risk factors, including genetic and acquired disorders of lipid and lipoprotein metabolism, is increasingly recognized as an opportunity to prevent premature cardiovascular disease (CVD) in at-risk youth. Pediatric endocrinologists are at the forefront of this emerging public health concern and can be instrumental in beginning early interventions to prevent premature CVD-related events during adulthood.

AIM

In this article, we use informative case presentations to provide practical approaches to the management of pediatric dyslipidemia.

CASES

We present 3 scenarios that are commonly encountered in clinical practice: isolated elevation of low-density lipoprotein cholesterol (LDL-C), combined dyslipidemia, and severe hypertriglyceridemia. Treatment with statin is indicated when the LDL-C is ≥190 mg/dL (4.9 mmol/L) in children ≥10 years of age. For LDL-C levels between 130 and 189 mg/dL (3.4-4.89 mmol/L) despite dietary and lifestyle changes, the presence of additional risk factors and comorbid conditions would favor statin therapy. In the case of combined dyslipidemia, the primary treatment target is LDL-C ≤130 mg/dL (3.4 mmol/L) and the secondary target non-high-density lipoprotein cholesterol <145 mg/dL (3.7 mmol/L). If the triglyceride is ≥400 mg/dL (4.5 mmol/L), prescription omega-3 fatty acids and fibrates are considered. In the case of triglyceride >1000 mg/dL (11.3 mmol/L), dietary fat restriction remains the cornerstone of therapy, even though the landscape of medications is changing.

CONCLUSION

Gene variants, acquired conditions, or both are responsible for dyslipidemia during childhood. Extreme elevations of triglycerides can lead to pancreatitis. Early identification and management of dyslipidemia and cardiovascular risk factors is extremely important.

Advances in familial hypercholesterolaemia in children

Familial hypercholesterolaemia is a common, dominantly inherited disease that results in high concentrations of low-density lipoprotein cholesterol and in premature cardiovascular disease. To prevent cardiovascular disease and premature mortality, patients with the condition need to be identified and to start treatment early in life. In this Review, we discuss the treatment of heterozygous and homozygous familial hypercholesterolaemia in children, including lifestyle modifications, current pharmacological treatment options, and promising novel lipid-lowering treatments. In particular, these new therapies are expected to improve outcomes for patients with severe heterozygous familial hypercholesterolaemia or statin intolerance. For patients with homozygous familial hypercholesterolaemia, lipoprotein apheresis is currently the most valuable therapy available, but new approaches might reduce the need for this effective yet invasive, time-consuming, and expensive treatment.

Treatment of Dyslipidaemia in Children

Childhood dyslipidaemia is one of the main traditional cardiovascular risk factors that initiate and exacerbate the atherosclerotic process. Healthcare providers may play a key role in the management of children with lipid abnormalities; however, they have to properly evaluate the normal lipid values and know the available treatment options in children and adolescents. Current guidelines recommend healthy behaviours as the first-line treatment for childhood dyslipidaemia. The therapeutic lifestyle changes should focus on dietary modifications, daily physical activity, reduction in body weight and tobacco smoking cessation. Parents play a key role in promoting their children's healthy habits. In children with more severe forms of lipid abnormalities and in those who do not benefit from healthy behaviours, pharmacological therapy should be considered. Safe and effective medications are already available for children and adolescents. Statins represent the first-line pharmacological option, while ezetimibe and bile acid sequestrants are usually used as second-line drugs. Despite their limited use in children, other lipid-lowering agents (already approved for adults) are currently available or under study for certain categories of paediatric patients (e.g., familial hypercholesterolemia). Further studies are needed to evaluate the long-term efficacy, safety and tolerability of novel lipid-lowering drugs, especially in children.

Current Approach to the Diagnosis and Treatment of Heterozygote and Homozygous FH Children and Adolescents

Purpose of Review

To elucidate the current approach of care in pediatric patients with familial hypercholesterolemia (FH). We sought an answer to the question whether the advances and major changes in lipid management are relevant and apply to children and adolescents.

Recent Findings

Latest research findings clearly demonstrate that lowering cholesterol levels at a young age prevents vascular atherosclerotic changes and decreases cardiovascular events in adulthood and emphasizes the importance of early detection and intervention in the pediatric FH patients group.

Summary

FH is a common genetic disease caused by mutations in genes associated with the metabolism of low-density lipoproteins (LDL). The hallmark of FH is elevated LDL cholesterol (LDL-C) levels from birth and premature atherosclerotic cardiovascular disease (ASCVD). Often FH is either undiagnosed or diagnosed with a considerable delay, leading to vascular atherosclerotic changes and cardiovascular disease. Prompt identification of FH subjects is essential, to initiate early preventive measures. Safe and efficient pharmacological agents are approved for use in children and adolescents. Statins are the first line of therapy, in combination of ezetimibe. Unfortunately, these drugs do not warrant the achievement of therapeutic target, especially in HoFH patient. In the latter, lipoprotein apheresis (LA), which has been shown to be safe and effective, is strongly recommended. Finally, the new drugs still under study will allow a multimodal customized treatment. Lowering cholesterol levels at a young age hinders vascular atherosclerotic changes decreasing cardiovascular events in adulthood. Therefore, early detection, diagnosis, and intervention in FH patients are priority objectives.

Management of dyslipidemia in pediatric renal transplant recipients

Dyslipidemia after kidney transplantation is a common complication that has historically been underappreciated, especially in pediatric recipients. It is also a major modifiable risk factor for cardiovascular disease, a top cause of morbidity and mortality of transplant patients. While most knowledge about post-transplant dyslipidemia has been generated in adults, recommendations and treatment strategies also exist for children and are presented in this review. Awareness of these applicable guidelines and approaches is required, but not sufficient, for the reliable management of dyslipidemia in our patients, and additional needs and opportunities for comprehensive care in this area (e.g., quality improvement) are outlined.

Novel therapeutic targets and agents for pediatric dyslipidemia

Landmark studies have convincingly demonstrated that atherosclerosis begins in youth. While generally asymptomatic, an increasing number of youth with disorders of lipid and lipoprotein metabolism, such as familial hypercholesterolemia, are being identified through selective and universal screening. While a heart healthy lifestyle is the foundation of treatment for all youth with dyslipidemia, lipid-lowering therapy may be required by some to prevent morbidity and premature mortality, especially when initiated at a young age. When appropriate, use of statins has become standard of care for reducing low-density lipoprotein cholesterol, while fibrates may be beneficial in helping to lower triglycerides. Many therapeutic options commonly used in adults are not yet approved for use in youth less than 18 years of age. Although currently available lipid-lowering therapy is well tolerated and safe when administered to youth, response to treatment may vary and some conditions lack an efficient therapeutic option. Thus, newer agents are needed to aid in management. Many are in development and clinical trials in youth are currently in progress but will require FDA approval before becoming commercially available. Many utilize novel approaches to favorably alter lipid and lipoprotein metabolism. In the absence of long-term outcome data of youth who were treated beginning at an early age, clinical registries may prove to be useful in monitoring safety and efficacy and help to inform clinical decision-making. In this manuscript, we review currently available and novel therapeutic agents in development for the treatment of elevated cholesterol and triglycerides.

Genetics of Hypercholesterolemia: Comparison Between Familial Hypercholesterolemia and Hypercholesterolemia Nonrelated to LDL Receptor

Severe hypercholesterolemia (HC) is defined as an elevation of total cholesterol (TC) due to the increase in LDL cholesterol (LDL-C) >95th percentile or 190 mg/dl. The high values of LDL-C, especially when it is maintained over time, is considered a risk factor for the development of atherosclerotic cardiovascular disease (ASCVD), mostly expressed as ischemic heart disease (IHD). One of the best characterized forms of severe HC, familial hypercholesterolemia (FH), is caused by the presence of a major variant in one gene (LDLR, APOB, PCSK9, or ApoE), with an autosomal codominant pattern of inheritance, causing an extreme elevation of LDL-C and early IHD. Nevertheless, an important proportion of serious HC cases, denominated polygenic hypercholesterolemia (PH), may be attributed to the small additive effect of a number of single nucleotide variants (SNVs), located along the whole genome. The diagnosis, prevalence, and cardiovascular risk associated with PH has not been fully established at the moment. Cascade screening to detect a specific genetic defect is advised in all first- and second-degree relatives of subjects with FH. Conversely, in the rest of cases of HC, it is only advised to screen high values of LDL-C in first-degree relatives since there is not a consensus for the genetic diagnosis of PH. FH is associated with the highest cardiovascular risk, followed by PH and other forms of HC. Early detection and initiation of high-intensity lipid-lowering treatment is proposed in all subjects with severe HC for the primary prevention of ASCVD, with an objective of LDL-C <100 mg/dl or a decrease of at least 50%. A more aggressive reduction in LDL-C is necessary in HC subjects who associate personal history of ASCVD or other cardiovascular risk factors.

Advances with lipid-lowering drugs for pediatric patients with familial hypercholesterolemia

INTRODUCTION

Familial hypercholesterolemia (FH) is a frequent genetic disorder characterized by elevated LDL-cholesterol (LDL-C) and early onset of atherosclerosis.

AREAS COVERED

The authors provide an overview of the pediatric FH scenario, with emphasis on the role of statins as the preferred pharmacological therapy, discussing their potential benefits, as well as adverse effects, and the remaining uncertainties about their use in this population. They also comment on other lipid-lowering therapies.

EXPERT OPINION

Statin therapy is recommended after the ages of 8-10 years old for heterozygous FH patients and can reduce LDL-C by 24-50% depending on drug type and dosage. For more severe cases, higher doses and adjuvant therapies like ezetimibe may be necessary and treatment should be started at diagnosis, as is the case of homozygous FH. Statins reduce progression of subclinical vascular disease and may reduce early cardiovascular events. The available evidence indicates safety of statins in children with no apparent harms related to growth, sexual maturation, steroid hormones, glucose levels, cognitive function, or muscle and liver problems, in comparison with placebo. Newer treatments like lomitapide, PCSK9 inhibitors, bempedoic acid and evinacumab need to be adequately evaluated in pediatric FH patients with more severe dyslipidemia.

Delineation of metabolic responses of Npc1-/-nih mice lacking the cholesterol-esterifying enzyme SOAT2 to acute treatment with 2-hydroxypropyl-β-cyclodextrin

Lipids present in lipoproteins cleared from the circulation are processed sequentially by three major proteins within the late endosomal/lysosomal (E/L) compartment of all cells: lysosomal acid lipase (LAL), Niemann-Pick (NPC) C2 and NPC1. When all three of these proteins are functioning normally, unesterified cholesterol (UC) exits the E/L compartment and is used in plasma membrane maintenance and various pathways in the endoplasmic reticulum including esterification by sterol O-acyltransferase 2 (SOAT2) or SOAT1 depending partly on cell type. Mutations in either NPC2 or NPC1 result in continual entrapment of UC and glycosphingolipids leading to neurodegeneration, pulmonary dysfunction, splenomegaly and liver damage. To date, the most effective agent for promoting release of entrapped UC in nearly all organs of NPC1-deficient mice and cats is 2-hydroxypropyl-β-cyclodextrin (2HPβCD). The cytotoxic nature of the liberated UC triggers various defenses including suppression of sterol synthesis and increased esterification. The present studies, using the Npc1-/-nih mouse model, measured the comparative quantitative importance of these two responses in the liver versus the spleen of Npc1-/-: Soat2+/+ and Npc1-/-: Soat2-/- mice in the 24 h following a single acute treatment with 2HPβCD. In the liver but not the spleen of both types of mice suppression of synthesis alone or in combination with increased esterification provided the major defense against the rise in unsequestered cellular UC content. These findings have implications for systemic 2HPβCD treatment in NPC1 patients in view of the purportedly low levels of SOAT2 activity in human liver.

Successful pharmacological management of a child with compound heterozygous familial hypercholesterolemia and review of the recent literature

Severe familial hypercholesterolemia (SFH) is characterized by markedly elevated low-density lipoprotein cholesterol (LDL-C) and severe early-onset cardiovascular disease if left untreated. We report on the decade-long therapeutic journey of a 15-year-old boy with SFH due to a severe compound heterozygous genotype. He presented at the age of 5 years with widespread xanthomas and LDL-C of 17.4 mmol/L. He was diagnosed with SFH, initially treated with colestyramine that was subsequently combined with simvastatin. At the age of 12 years, he was diagnosed to have supravalvular aortic stenosis and ezetimibe/atorvastatin was introduced in place of colestyramine/simvastatin. At the age of 14 years, he received triple therapy with evolocumab, initially at the recommended dose of 420 mg monthly and then reduced to 140 mg biweekly. Currently at the age of 15 years, he is on atorvastatin 40 mg ON, ezetimibe 10 mg OM, and evolocumab 140 mg biweekly, achieving LDL-C levels of 2.4 mmol/L. Genetic testing identified compound heterozygous mutations in the LDL receptor genes [c.(940 + 1_941-1) (1845 + 1_1846-1)dup] and exon 12, nucleotide c.1747 C > T, amino acid p.(His583Tyr). Medical management without lipoprotein apheresis can achieve target LDL-C in children with SFH. Our patient, who developed supravalvular aortic stenosis at the age of 12 years, needed early aggressive treatment when SFH guidelines and newer drugs for young children were unavailable. Our patient demonstrated that 140 mg biweekly of evolocumab has the same cholesterol-lowering effect as the recommended 420 mg monthly dose.

Nine-year overview of dyslipidemia management in children with heterozygous familial hypercholesterolemia: a university hospital outpatient lipid clinic project in Northwestern Greece

Background To assess the efficacy and safety of lipid-lowering treatment in children with heterozygous familial hypercholesterolemia (HeFH) aged ≤12 years attending a tertiary hospital-based outpatient lipid clinic. Methods Data in 318 children from the University Hospital of Ioannina (Northwestern Greece) Outpatient Lipid Clinic Project for Children and Adolescents with Dyslipidemia from March 2009 to December 2018 were analyzed. We assessed the efficacy and safety treatment alongside any possible predictors of the achievement of the treatment target. Results Of 318 children with hyperlipidemia, 72 were diagnosed having HeFH based on clinical criteria and genetic confirmation. Compared with non-familial hypercholesterolemia (non-FH) children, those with FH had a higher occurrence of positive family history of premature cardiovascular disease, and higher levels of total, low-density lipoprotein-cholesterol (LDL-C), apolipoprotein B (apoB) and lipoprotein (a) (Lp(a)). Treatment regimens included either atorvastatin 10-20 mg/day, rosuvastatin 5-10 mg/day, pitavastatin 2-4 mg/day monotherapy or in combination with ezetimibe. The treatment goal of LDL-C (<135 mg/dL, 3.5 mmol/L) was achieved in 69% of children treated. The achievement of the treatment targets correlated positively with male sex and inversely with the Dutch Lipid Clinic Network Score, baseline total, LDL-C and apoB levels. No clinically significant changes in liver or muscle-related laboratory tests were reported; no effect on growth or sexual maturation was noted. Conclusions This study confirms that lipid-lowering treatment in HeFH children initiated in the setting of a specialized tertiary hospital-based outpatient lipid clinic is efficacious and safe. Children of male sex and low baseline lipid values had a better achievement of treatment target.

Persistent Safety and Efficacy of Evolocumab in Patients with Statin Intolerance: a Subset Analysis of the OSLER Open-Label Extension Studies

PURPOSE

Evolocumab reduced low-density lipoprotein cholesterol (LDL-C) in 12-week trials in statin-intolerant patients (GAUSS-1 and GAUSS-2); however, the persistence of efficacy during longer-term treatment is unknown. This subset analysis of the open-label extension studies (OSLER-1 and OSLER-2) aimed to evaluate the safety and efficacy of evolocumab up to 2 years in statin-intolerant patients.

METHODS

Patients who completed GAUSS-1 and GAUSS-2 were enrolled in the OSLER studies and rerandomized 2:1 to evolocumab (140 mg biweekly or 420 mg monthly) plus standard of care (SOC) or SOC during year 1, and thereafter, evolocumab plus SOC.

RESULTS

A total of 382 statin-intolerant patients who completed the GAUSS-1 and GAUSS-2 parent studies were enrolled and rerandomized into the OSLER studies. After year 1, 246 (98%) patients randomized to evolocumab plus SOC and 124 (95%) on SOC during year 1 remained in the OSLER studies; after year 2, 364 (95%) remained on study. Mean parent study baseline LDL-C concentration was 4.97-5.02 mmol/L (192-194 mg/dL). The median percentage reduction from baseline in LDL-C was 13% for SOC and 57% for evolocumab plus SOC at year 1, and 59% for evolocumab plus SOC at year 2. The patient incidence of muscle-related adverse events during year 1 in the SOC and evolocumab plus SOC groups was 16% and 14%, respectively, and 11% for evolocumab plus SOC at year 2. No patient discontinued the study due to adverse events.

CONCLUSION

Evolocumab plus SOC was persistently safe, tolerable, and efficacious for up to 2 years in statin-intolerant patients.

Knowns and unknowns in the care of pediatric familial hypercholesterolemia

Familial hypercholesterolemia (FH) is a common genetic disorder that causes elevated LDL cholesterol levels from birth. Untreated FH accelerates atherosclerosis and predisposes individuals to premature coronary artery disease (CAD) in adulthood. Mendelian randomization studies have demonstrated that LDL cholesterol has both a causal and cumulative effect on the risk of CAD. This supports clinical recommendations that children with FH commence pharmacological treatment from the age of 8 to 10 years, to reduce the burden of hypercholesterolemia. Worldwide, the majority of children with FH remain undiagnosed. Recent evidence suggests that the frequency of FH is at least 1 in 250 and this constitutes a public health issue. We review and identify the knowns and unknowns concerning the detection and management of pediatric FH that impact on the developing model of care for this condition.

Quantitation of the rates of hepatic and intestinal cholesterol synthesis in lysosomal acid lipase-deficient mice before and during treatment with ezetimibe

Esterified cholesterol (EC) and triglycerides, contained within lipoproteins taken up by cells, are hydrolysed by lysosomal acid lipase (LAL) in the late endosomal/lysosomal (E/L) compartment. The resulting unesterified cholesterol (UC) is transported via Niemann-Pick type C2 and C1 into the cytosolic compartment where it enters a putative pool of metabolically active cholesterol that is utilized in accordance with cellular needs. Loss-of-function mutations in LIPA, the gene encoding LAL, result in dramatic increases in tissue concentrations of EC, a hallmark feature of Wolman disease and cholesteryl ester storage disease (CESD). The lysosomal sequestration of EC causes cells to respond to a perceived deficit of sterol by increasing their rate of cholesterol synthesis, particularly in the liver. A similar compensatory response occurs with treatments that disrupt the enterohepatic movement of cholesterol or bile acids. Here we measured rates of cholesterol synthesis in vivo in the liver and small intestine of a mouse model for CESD given the cholesterol absorption inhibitor ezetimibe from weaning until early adulthood. Consistent with previous findings, this treatment significantly reduced the amount of EC sequestered in the liver (from 132.43±7.35 to 70.07±6.04mg/organ) and small intestine (from 2.78±0.21 to 1.34±0.09mg/organ) in the LAL-deficient mice even though their rates of hepatic and intestinal cholesterol synthesis were either comparable to, or exceeded those in matching untreated Lal-/- mice. These data reveal the role of intestinal cholesterol absorption in driving the expansion of tissue EC content and disease progression in LAL deficiency.

Familial hypercholesterolemia in childhood and adolescents: A hidden reality

Familial hypercholesterolemia (FH) is the most common genetic disorder in childhood, but in most cases is not detected. High levels of low-density lipoprotein cholesterol are present since the child's birth and this fact will suppose silent development of early atherosclerosis. In cases of homozygous FH, the coronary disease will appear before 20s and in cases of heterozygous FH will occur in middle age. Despite published data, there is not agreement about how and when perform the screening. Familial history of early cardiovascular disease plus presence of hypercholesterolemia in parents is crucial for detection and diagnosis. Actually, it is topic of discussion that it is necessary to achieve therapeutic goals from an early age to improve prognosis. Lifestyle changes are the first line therapy. Statins are the lipid-lowering drugs of choice but the optimal age to start therapy it is still controversial. In this article, current recommendations of expert consensus guidelines about the management and new line therapies of child and adolescents are reviewed.

An update on the assessment and management of metabolic syndrome, a growing medical emergency in paediatric populations

In the last decades the increasing rate of obesity in children and adolescents worldwide has led to the onset in paediatric age of metabolic syndrome, a disease commonly associated to adulthood. Central obesity, dyslipidaemia, hyperglycaemia, and hypertension are typical features of metabolic syndrome that seem to hesitate often in type 2 diabetes, cardiovascular disease, non-alcoholic fatty liver disease, and many other clinical conditions. Thus preventing and curing metabolic syndrome in paediatric patients is becoming an urgent need for public health. While diagnostic criteria and therapy of metabolic syndrome in adults are very well defined, there is no consensus on the definition of metabolic syndrome in children and adolescents as well as on healing approaches. The aim of this review is to describe the recent advances on the pathogenesis and clinical outcomes of paediatric metabolic syndrome. We then detail the therapeutic strategies (i.e. dietary regimens, physical exercise, nutraceuticals, and medications) employed to manage the disease. Finally, we analyse the safety profile of the drugs used in children and adolescents by performing a retrospective review of paediatric adverse reactions reported in the FDA's Adverse Event Reporting System database.

A 10-year experience using combined lipid-lowering pharmacotherapy in children and adolescents

BACKGROUND

Current pediatric guidelines for heterozygous familial hypercholesterolemia (HeFH) propose pharmacotherapy (PT) with statins from age 8 to 10 years; however, schemes with absorption inhibitors combined with statins, could be started earlier. The aim of the study was to show the 10-year results of a combined treatment protocol.

METHODS

Prospective, descriptive and analytical study. Pediatric patients (n=70; mean age at PT initiation 9.3 years [range, 2-17.5]) with HeFH who required PT between 2005 and 2015 were included. All patients ≥10 years, with LDL >190 mg/dL or >160 mg/dL with one cardiovascular risk factor (CVRF) or >130 mg/dL with two or more CVRF; and those patients 5-10 years and with LDL-C >240 mg/dL or a family history of a cardiovascular event before 40 years, were medicated. After a period on a lipid-lowering diet (LLD), all patients were started on ezetimibe. Patients who did not achieve the treatment goal were given statins. The variables were: age, age at PT initiation, duration of PT, initial LDL-C, mean LDL-C during ezetimibe monodrug therapy, mean LDL-C during combined PT, and percentage of LDL decrease.

RESULTS

LDL-C levels were: Baseline: 235 mg/dL±55; after 3 months on ezetimibe: 167 mg/dL±47 (decrease: -27.62%). In 18 patients who did not reach the treatment goal atorvastatin was added and their LDL-C decreased -41.5% (p: 0.02). Overall, mean final LDL-C was 155 mg/dL±30.4 (range, 98-257) and treatment goals were reached in 74% of the patients. No severe side effects were reported.

CONCLUSIONS

Combined and sequential treatment starting at early ages was shown to be safe and effective over this follow-up period.

My Approach to the Patient With Familial Hypercholesterolemia

Familial hypercholesterolemia (FH), a relatively common Mendelian genetic disorder, is associated with a dramatically increased lifetime risk of premature atherosclerotic cardiovascular disease due to elevated plasma low-density lipoprotein cholesterol (LDL-C) levels. The diagnosis of FH is based on clinical presentation or genetic testing. Early identification of patients with FH is of great public health importance because preventive strategies can lower the absolute lifetime cardiovascular risk and screening can detect affected relatives. However, low awareness, detection, and control of FH pose hurdles in the prevention of FH-related cardiovascular events. Of the estimated 0.65 million to 1 million patients with FH in the United States, less than 10% carry a diagnosis of FH. Based on registry data, a substantial proportion of patients with FH are receiving no or inadequate lipid-lowering therapy. Statins remain the mainstay of treatment for patients with FH. Lipoprotein apheresis and newly approved lipid-lowering drugs are valuable adjuncts to statin therapy, particularly when the LDL-C-lowering response is suboptimal. Monoclonal antibodies targeting proprotein convertase subtilisin/kexin type 9 provide an additional approximately 60% lowering of LDL-C levels and are approved for use in patients with FH. For homozygous FH, 2 new drugs that work independent of the LDL receptor pathway are available: an apolipoprotein B antisense oligonucleotide (mipomersen) and a microsomal triglyceride transfer protein inhibitor (lomitapide). This review attempts to critically examine the available data to provide a summary of the current evidence for managing patients with FH, including screening, diagnosis, treatment, and surveillance.

Nonstatin Low-Density Lipoprotein-Lowering Therapy and Cardiovascular Risk Reduction-Statement From ATVB Council

Pharmacological reduction of low-density lipoprotein (LDL) cholesterol using statin drugs is foundational therapy to reduce cardiovascular disease (CVD) risk. Here, we consider the place of nonstatin therapies that also reduce LDL cholesterol in prevention of CVD. Among conventional nonstatins, placebo-controlled randomized clinical trials showed that bile acid sequestrants, niacin, and fibrates given as monotherapy each reduce CVD end points. From trials in which patients' LDL cholesterol was already well controlled on a statin, adding ezetimibe incrementally reduced CVD end points, whereas adding a fibrate or niacin showed no incremental benefit. Among emerging nonstatins, monoclonal antibodies against proprotein convertase subtilisin kexin type 9 added to a statin and given for ≤78 weeks showed preliminary evidence of reductions in CVD outcomes. Although these promising early findings contributed to the recent approval of these agents in Europe and in North America, much larger and longer duration outcomes studies are ongoing for definitive proof of CVD benefits. Other nonstatin agents recently approved in the United States include lomitapide and mipomersen, which both act via distinctive LDL receptor independent mechanisms to substantially reduce LDL cholesterol in homozygous familial hypercholesterolemia. We also address some unanswered questions, including measuring alternative biochemical variables to LDL cholesterol, evidence for treating children with monitoring of subclinical atherosclerosis, and potential risks of extremely low LDL cholesterol. As evidence for benefit in CVD prevention accumulates, we anticipate that clinical practice will shift toward more assertive LDL-lowering treatment, using both statins and nonstatins initiated earlier in appropriately selected patients.

Optimizing Treatment of Familial Hypercholesterolemia in Children and Adolescents

Cardiovascular disease (CVD) is still the most prominent cause of death and morbidity in the world, and one of the major risk factors for developing CVD is hypercholesterolemia. Familial hypercholesterolemia (FH) is a dominantly inherited disorder characterized by markedly elevated plasma low-density lipoprotein cholesterol and premature coronary heart disease. Currently, several treatment options are available for children with FH. Lifestyle adjustments are the first step in treatment. If this is not sufficient, statins are the preferred initial pharmacological therapy and they have been proven effective and safe. However, treatment goals are often not achieved and, hence, there is a need for novel treatment options. Currently, several options are being studied in adults and first results are promising. However, studies in children are still to be awaited.