Real-World Outcomes with Lomitapide Use in Paediatric Patients with Homozygous Familial Hypercholesterolaemia

Modern approaches to the management of homozygous familial hypercholesterolemia in the Middle East and North Africa

Homozygous familial hypercholesterolaemia (HoFH) is a severe form of FH in which inheritance of two defective or null mutations in genes associated with metabolism of low-density lipoprotein cholesterol (LDL-C) results in extremely high LDL-C, premature atherosclerotic cardiovascular disease (ASCVD) and mortality. Treatment of HoFH comprises a multi-modal approach of statins, ezetimibe, lipoprotein apheresis; and inhibitors of proprotein convertase subtilisin/kexin type, angiopoietin-like protein 3 (ANGPTL3) and microsomal triglyceride transfer protein. These treatments are generally costly, and patients also often require treatment for ASCVD consequent to HoFH. Therefore, in the interests of both economics and preservation of life, disease prevention via genetic screening and counselling is rapidly becoming a key element in the overall management of HoFH. Guidelines are available to assist diagnosis and treatment of HoFH; however, while advancements have been made in the management of the disease, there has been little systematic attention paid to prevention. Additionally, the Middle East/North Africa (MENA) region has a higher prevalence of HoFH than most other regions - chiefly due to consanguinity. This has led to the establishment of regional lipid clinics and awareness programs that have thrown education and awareness of HoFH into sharp focus. Incorporation of principles of prevention, education, awareness, and data from real-world use of existing therapeutics will significantly enhance the effectiveness of future guidelines for the management of HoFH, particularly in the MENA region.

Real-world safety and efficacy of lomitapide in homozygous familial hypercholesterolemia: interim report of special-use survey in Japan

Aim: To evaluate the safety and efficacy of lomitapide in real-world clinical practice in Japan. Patients & methods: Interim analysis of 39 patients with homozygous familial hypercholesterolemia from an all-case surveillance study. Results: Median lomitapide dose (across 42 months) was 9.8 mg/day. 74 drug-related adverse events (AEs) were reported in 24 (61.5%) patients, including 14 (35.9%) with liver-related AEs, 19 (48.7%) with gastrointestinal disorders and 1 (2.6%) bleeding disorder. Lomitapide dose was reduced for 39.2% of drug-related AEs, withdrawn temporarily for 12.2%, and discontinued for 1 event (1.4%). Mean ± SD blood LDL-C level decreased from 225.9 ± 172.0 mg/dl (5.8 ± 4.5 mmol/l) predose to 159.4 ± 93.0 mg/dl (4.1 ± 2.4 mmol/l) at 12 months (p = 0.0245). Conclusion: This interim analysis suggests lomitapide is safe and effective in real-world clinical practice in Japan.

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.

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.

LIPID LOWERING COMBINATION THERAPY. From prevention to atherosclerosis plaque treatment

Statins have contributed to the prevention of numerous atherosclerotic cardiovascular (CV) events and cardiovascular deaths in the past three decades. The benefit of statins is mainly mediated by the lowering of LDLc. According to scientific evidence, the current international guidelines recommend very low LDLc goals in patients at high/very high cardiovascular risk because they are associated with fewer CV events and improvements in atherosclerotic plaques. However, these goals often cannot be obtained with statins alone. Recent RCTs have demonstrated that these CV benefits can also be obtained with nonstatin LDLc-lowering drugs such as PCSK9 inhibitors (alirocumab and evolocumab), ezetimibe and bempedoic acid, while evidence with inclisiran is upcoming. Icosapent ethyl, a lipid metabolism modifier, has also shown an effect on event reduction. Physicians should take advantage of the currently available lipid-lowering therapies, choosing the drug or combination of drugs that is most appropriate for each patient according to his or her CV risk and baseline LDLc concentration. Strategies implementing combination therapies from early stages or even from the outset may increase the number of patients attaining LDLc goals, thereby preventing new CV episodes and improving existing atherosclerotic lesions. DATA AVAILABILITY: No data was used for the research described in the article.

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.

Current Treatment Options in Homozygous Familial Hypercholesterolemia

Homozygous familial hypercholesterolemia (HoFH) is the rare form of familial hypercholesterolemia causing extremely high low-density lipoprotein cholesterol (LDL-C) levels, leading to atherosclerotic cardiovascular disease (ASCVD) in the first decades of life, if left untreated. Early diagnosis and effective lipid lowering therapy (LLT) are crucial for the prevention of early ASCVD in patients with HoFH. On-treatment LDL-C levels are the best predictor of survival. However, due to the absent or defective LDL-receptor activity, most individuals with HoFH are resistant to conventional LLT, that leads to LDL-C clearance by upregulating LDL-receptors. We are at the dawn of a new era of effective pharmacotherapies for HoFH patients, with new agents providing an LDL-receptor independent cholesterol reduction. In this context, the present review provides a summary of the currently available therapies and emerging therapeutic agents for the management of patients with HoFH, in light of recent evidence and guideline recommendations.

New algorithms for treating homozygous familial hypercholesterolemia

PURPOSE OF REVIEW

We reviewed current and future therapeutic options for patients with homozygous familial hypercholesterolemia (HoFH) and place this evidence in context of an adaptable treatment algorithm.

RECENT FINDINGS

Lowering LDL-C levels to normal in patients with HoFH is challenging, but a combination of multiple lipid-lowering therapies (LLT) is key. Patients with (near) absence of LDL receptor expression are most severely affected and frequently require regular lipoprotein apheresis on top of combined pharmacologic LLT. Therapies acting independently of the LDL receptor pathway, such as lomitapide and evinacumab, are considered game changers for many patients with HoFH, and may reduce the need for lipoprotein apheresis in future. Liver transplantation is to be considered a treatment option of last resort. Headway is being made in gene therapy strategies, either aiming to permanently replace or knock out key lipid-related genes, with first translational steps into humans being made. Cardiovascular disease risk management beyond LDL-C, such as residual Lp(a) or inflammatory risk, should be evaluated and addressed accordingly in HoFH.

SUMMARY

Hypercholesterolemia is notoriously difficult to control in most patients with HoFH, but multi-LLT, including newer drugs, allows reduction of LDL-C to levels unimaginable until a few years ago. Cost and availability of these new therapies are important future challenges to be addressed.

New Trends and Therapies for Familial Hypercholesterolemia

Familial hypercholesterolemia (FH) is associated with an elevated risk of atherosclerosis. The finding of monogenic defects indicates higher atherosclerotic risk in comparison with hypercholesterolemia of other etiologies. However, in heterozygous FH, cardiovascular risk is heterogeneous and depends not only on high cholesterol levels but also on the presence of other biomarkers and genes. The development of atherosclerosis risk scores specific for heterozygous FH and the use of subclinical coronary atherosclerosis imaging help with identifying higher-risk individuals who may benefit from further cholesterol lowering with PCSK9 inhibitors. There is no question about the extreme high risk in homozygous FH, and intensive LDL-cholesterol-lowering therapy must be started as soon as possible. These patients have gained life free of events in comparison with the past, but a high atherosclerosis residual risk persists. Furthermore, there is also the issue of aortic and supra-aortic valve disease development. Newer therapies such as inhibitors of microsomal transfer protein and angiopoietin-like protein 3 have opened the possibility of LDL-cholesterol normalization in homozygous FH and may provide an alternative to lipoprotein apheresis for these patients. Gene-based therapies may provide more definite solutions for lowering high LDL cholesterol and consequent atherosclerosis risk for people with FH.

Efficacy and Safety of Lomitapide in Homozygous Familial Hypercholesterolaemia: A Systematic Review

Background

Homozygous familial hypercholesterolaemia (HoFH) patients have little or no low-density lipoprotein receptor (LDLR) function. HMG-CoA (3-hydroxy-3-methyl glutaryl coenzyme A) reductase inhibitors (statins) and proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors have limited lipid-lowering effects, therefore, there is an urgent need to develop new HoFH treatments. In 2012, the US Food and Drug Administration (FDA) approved the administration of lomitapide for lowering low-density lipoprotein cholesterol (LDL-C) levels. However, lomitapide is associated with various gastrointestinal disorders, elevated hepatic alanine aminotransferase (ALT) levels and other adverse reactions, thus, its long-term efficacy and safety in pediatrics and adults should be evaluated. A systematic review conducted in 2017 reported the efficacy and safety of lomitapide in Family hypercholesterolaemia (FH) patients. In this systematic review, we elucidate on the efficacy and safety of lomitapide in HoFH patients.

Methods

A search was conducted in PubMed, Embase, Web of Science and Cochrane library databases to identify valid studies involving lomitapide-treated HoFH patients published before 11th August 2021.

Results

A total of 18 clinical studies involving 120 lomitapide-treated HoFH patients were identified. Lomitapide significantly suppressed LDL-C levels in HoFH patients. Clinical manifestations for lomitapide in children were comparable to those in adults. The most common adverse events were gastrointestinal disturbances and elevated ALT levels. However, most patients tolerated the treatment-associated adverse reactions. Low-fat diets and drug dose adjustments were appropriate measures for controlling the treatment-associated adverse reactions.

Conclusions

In pediatric and adult HoFH patients, lomitapide significantly suppresses LDL-C levels, therefore, it is an important option for HoFH treatment. The most common adverse events of lomitapide treatment include gastrointestinal disorders and elevated hepatic ALT levels. Despite the limitations, lomitapide is feasible for long-term treatment of HoFH patients, with dietary and safety monitoring.

Registration Number in PROSPERO

CRD42021284425.

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.

Advancements in the Treatment of Homozygous Familial Hypercholesterolemia

Homozygous familial hypercholesterolemia (HoFH) is a rare genetic disorder with extreme elevations of low-density lipoprotein cholesterol (LDL-C) leading to premature atherosclerotic cardiovascular disease (ASCVD) as early as in childhood. Management of HoFH centers around aggressive and adequate reduction of LDL-C levels to slow the trajectory of ASCVD development. Historically, lowering LDL-C levels in HoFH has been challenging because of both the markedly elevated LDL-C levels (often ＞400 mg/dL) and reduced response to treatment options, such as statins, for which the mechanism of action requires a functional LDL receptor. However, the treatment landscape for HoFH has rapidly progressed over the last decade. While statins and ezetimibe remain first-line treatment, patients often require addition of multiple therapies to achieve goal LDL-C levels. The PCSK9 inhibitors are an important recent addition to the available treatment options, along with lomitapide, bile acid sequestrants, and, possibly, bempedoic acid. Additionally, ANGPTL3 has emerged as an important therapeutic target, with evinacumab being the first available ANGPTL3 inhibitor on the market for the treatment of patients with HoFH. For patients who cannot achieve adequate LDL-C reduction, lipoprotein apheresis may be necessary, with the added benefit of reducing lipoprotein(a) levels that carries an added risk if also elevated in patients with HoFH. Finally, gene therapy and genome editing using CRISPR/Cas-9 are moving through clinical development and may dramatically alter the future landscape of treatment for HoFH.

A Case Series Assessing the Effects of Lomitapide on Carotid Intima-Media Thickness in Adult Patients with Homozygous Familial Hypercholesterolaemia in a Real-World Setting

INTRODUCTION

Homozygous familial hypercholesterolaemia (HoFH) is characterised by extremely elevated levels of low-density lipoprotein cholesterol (LDL-C) and results from multiple mutations in genes affecting the LDL receptor pathway. Patients are at risk of premature atherosclerotic cardiovascular disease (ASCVD) and premature death. Lomitapide is a microsomal triglyceride transfer protein inhibitor developed to treat HoFH, but cardiovascular outcome data are lacking.

METHODS

We evaluated detailed data from five HoFH patients and one patient with heterozygous FH (HeFH) and a very severe phenotype. We also analysed confirmatory data from a further 8 HoFH cases. In total, we analysed data from patients in seven global centres in six countries who were all treated with lomitapide with long-term follow-up. Carotid intima-media thickness (CIMT) imaging was recorded on an ad hoc basis to monitor ASCVD in HoFH.

RESULTS

Lomitapide resulted in marked decreases in LDL-C of 56.8-93.9% [77.7-93.9% in the 6 initial cases (mean nadir 64.8 ± 30.1 mg/dL); 56.8-86.0% in the 8 confirmatory cases (mean nadir 131.4 ± 38.2 mg/dL)]. CIMT regressed in 50% of cases (mean follow-up 5.0 ± 3.1 years in initial six cases, and 4.4 ± 1.4 years in confirmatory cases). In the remaining patients, CIMT showed little further change. In patients where assessments of plaque area were available, regression or stabilisation in CIMT was accompanied by clinically significant regression of plaque area.

CONCLUSIONS

Lomitapide reduces LDL-C levels in patients with HoFH and severe LDL-C phenotypes, and results in stabilisation and/or regression of CIMT, which is an established marker of ASCVD risk. Additional data are needed to determine if this confers a survival benefit in these very high-risk patients.

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.

Worldwide experience of homozygous familial hypercholesterolaemia: retrospective cohort study

BACKGROUND

Homozygous familial hypercholesterolaemia (HoFH) is a rare inherited disorder resulting in extremely elevated low-density lipoprotein cholesterol levels and premature atherosclerotic cardiovascular disease (ASCVD). Current guidance about its management and prognosis stems from small studies, mostly from high-income countries. The objective of this study was to assess the clinical and genetic characteristics, as well as the impact, of current practice on health outcomes of HoFH patients globally.

METHODS

The HoFH International Clinical Collaborators registry collected data on patients with a clinical, or genetic, or both, diagnosis of HoFH using a retrospective cohort study design. This trial is registered with ClinicalTrials.gov, NCT04815005.

FINDINGS

Overall, 751 patients from 38 countries were included, with 565 (75%) reporting biallelic pathogenic variants. The median age of diagnosis was 12·0 years (IQR 5·5-27·0) years. Of the 751 patients, 389 (52%) were female and 362 (48%) were male. Race was reported for 527 patients; 338 (64%) patients were White, 121 (23%) were Asian, and 68 (13%) were Black or mixed race. The major manifestations of ASCVD or aortic stenosis were already present in 65 (9%) of patients at diagnosis of HoFH. Globally, pretreatment LDL cholesterol levels were 14·7 mmol/L (IQR 11·6-18·4). Among patients with detailed therapeutic information, 491 (92%) of 534 received statins, 342 (64%) of 534 received ezetimibe, and 243 (39%) of 621 received lipoprotein apheresis. On-treatment LDL cholesterol levels were lower in high-income countries (3·93 mmol/L, IQR 2·6-5·8) versus non-high-income countries (9·3 mmol/L, 6·7-12·7), with greater use of three or more lipid-lowering therapies (LLT; high-income 66% vs non-high-income 24%) and consequently more patients attaining guideline-recommended LDL cholesterol goals (high-income 21% vs non-high-income 3%). A first major adverse cardiovascular event occurred a decade earlier in non-high-income countries, at a median age of 24·5 years (IQR 17·0-34·5) versus 37·0 years (29·0-49·0) in high-income countries (adjusted hazard ratio 1·64, 95% CI 1·13-2·38).

INTERPRETATION

Worldwide, patients with HoFH are diagnosed too late, undertreated, and at high premature ASCVD risk. Greater use of multi-LLT regimens is associated with lower LDL cholesterol levels and better outcomes. Significant global disparities exist in treatment regimens, control of LDL cholesterol levels, and cardiovascular event-free survival, which demands a critical re-evaluation of global health policy to reduce inequalities and improve outcomes for all patients with HoFH.

FUNDING

Amsterdam University Medical Centers, Location Academic Medical Center; Perelman School of Medicine at the University of Pennsylvania; and European Atherosclerosis Society.

Childhood Hypertriglyceridemia: Is It Time for a New Approach?

PURPOSE OF REVIEW

Hypertriglyceridemia (HTG) is widely prevalent in youth. There is an unmet need for effective medications in the management of HTG in youth. The purpose of this review is to summarize the approach to HTG in acute and chronic settings, and highlight emerging therapies targeted at specific genes, proteins, and enzymes to selectively alter triglyceride (TG) metabolism.

RECENT FINDINGS

Genetic and lifestyle factors play a significant role in the pathophysiology of HTG. Severe elevation of TG poses a risk of acute pancreatitis, while mild-to-moderate HTG increases the risk for premature atherosclerotic cardiovascular disease (ASCVD) and, increasingly, has been linked with non-alcoholic fatty liver disease. Although a variety of therapeutic agents are in development, strict adherence to a heart healthy lifestyle, including dietary changes, remain the cornerstone of management for youth with HTG. In addition to lifestyle changes, pharmacological interventions, including fibrates, omega 3 fatty acids, and statins may be considered for management of moderate-to-severe HTG. In view of its association with premature cardiovascular disease (CVD), non-high-density-lipoprotein-C (non-HDL-C) is an important target for therapy in children with moderate HTG. Management of HTG is dependent on its etiology, concomitant symptoms, and degree of TG elevation. The last two decades have seen remarkable changes in drug development, specifically those that act through the lipoprotein lipase complex, including new targeted treatments such as inhibitors of apolipoprotein C3 and angiopoietin-like protein 3.

Familial hypercholesterolemia - treatment update in children, systematic review

Familial hypercholesterolaemia is one of the most common genetic diseases, and its first symptoms occur in childhood. Proper diagnosis and treatment prevent young patients from severe consequences in their future. The treatment of this dyslipidaemia is still evolving, and new promising agents are being discovered. In this review we summarize the old and new treatment methods of familial hypercholesterolaemia, giving an update estimated on the latest publications.

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.

Dyslipidemia in childhood and adolescence: from screening to management

PURPOSE OF REVIEW

To summarize types of dyslipidemia frequently encountered during childhood and adolescence, with a focus on screening, diagnosis, and management.

RECENT FINDINGS

It is important that screening for atherosclerotic cardiovascular disease (ASCVD) begin in childhood. Genetic testing allows for increased awareness of dyslipidemia and more targeted intervention. Pharmacologic treatment of pediatric dyslipidemias has a good safety profile and can reduce adult ASCVD risk.

SUMMARY

Much of what is known about pediatric dyslipidemia has been extrapolated from adult data, but recently, there have been increasing investigations within the pediatric population to better guide diagnosis and management of these disorders.

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.

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.

Lomitapide-a Microsomal Triglyceride Transfer Protein Inhibitor for Homozygous Familial Hypercholesterolemia

PURPOSE OF REVIEW

Homozygous familial hypercholesterolemia (HoFH) is a rare, genetic condition characterized by high levels of Low density lipoprotein cholesterol (LDL-C); overt, early-onset atherosclerotic cardiovascular disease (ASCVD); and premature cardiovascular events and mortality. Lomitapide is a first-in-class microsomal triglyceride transfer protein inhibitor for the treatment of HoFH. This review provides an update on data emerging from real-world studies of lomitapide following on from its pivotal phase 3 clinical trial in HoFH.

RECENT FINDINGS

Recent registry data have confirmed that HoFH is characterized by delayed diagnosis, with many patients not receiving effective therapy until they are approaching the age when major adverse cardiovascular events may occur. Data from case series of varying sizes, and from a 163-patient registry of HoFH patients receiving lomitapide, have demonstrated that lomitapide doses are lower and adverse events less severe than in the phase 3 study. Lomitapide enables many patients to reach European Atherosclerosis Society LDL-C targets. Some patients are able to reduce frequency of lipoprotein apheresis or, in some cases, stop the procedure altogether-unless there is significant elevation of lipoprotein (a). Modelling analyses based on historical and clinical trial data indicate that lomitapide has the potential to improve cardiovascular outcomes and survival in HoFH. Real-world clinical experience with lomitapide has shown the drug to be effective with manageable, less marked adverse events than in formal clinical studies. Event modelling data suggest a survival benefit with lomitapide in HoFH.

Homozygous familial hypercholesterolemia: what treatments are on the horizon?

PURPOSE OF REVIEW

Homozygous familial hypercholesterolemia (HoFH) is a rare disorder associated with early atherosclerotic disease due to impairment of the LDL receptor (LDLR) pathway. Because of their molecular defect, current treatment options have limited success in bringing HoFH patient to LDL-C target and morbidity and mortality remain high. We review current and upcoming therapies directed at HoFH, including gene therapy.

RECENT FINDINGS

Recent real-world studies have confirmed the strength in lomitapide as a treatment adjunct to statins and other lipid-lowering therapies in HoFH patients. The approval of proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitor monoclonal antibodies has also been a welcome addition to the treatment armamentarium offering an additional average reduction in LDL-C levels of 24% when added to background lipid-lowering therapies in this population. Although achieving adequate LDL-C levels in this population is difficult, there are several therapies on the horizon that may help more patients reach goal. Evinacumab, a monoclonal antibody against ANGPTL3, has been shown to substantially reduce LDL-C of an average of 49%, independently of residual LDLR activity. RNA interference targeting PCSK9 and ANGPTL3 shows promise in clinical trials. Adeno-associated virus-mediated gene transfer and gene editing techniques are in early clinical and preclinical development.

SUMMARY

LDL-C lowering in HoFH patients remains very challenging. However, novel treatment options are emerging. Upcoming therapies directed at PCSK9 and ANPTL3 may offer additional LDL-C reduction, to help patients achieve adequate LDL-C levels. Gene therapy and gene editing techniques, if proven effective, may offer a unique opportunity to treat patients with a one-time treatment.

A Real-World Experience of Clinical, Biochemical and Genetic Assessment of Patients with Homozygous Familial Hypercholesterolemia

Homozygous familial hypercholesterolemia (HoFH), the severest form of familial hypercholesterolemia (FH), is characterized by very high LDL-cholesterol levels and a high frequency of coronary heart disease. The disease is caused by the presence of either a pathogenic variant at homozygous status or of two pathogenic variants at compound heterozygous status in the LDLR, APOB, PCSK9 genes. We retrospectively analyzed data of 23 HoFH patients (four children and 19 adults) identified during the genetic screening of 724 FH patients. Genetic screening was performed by sequencing FH causative genes and identifying large rearrangements of LDLR. Among the HoFH patients, four out of 23 (17.4%) were true homozygotes, whereas 19 out of 23 (82.6%) were compound heterozygotes for variants in the LDLR gene. Basal LDL-cholesterol was 12.9 ± 2.9 mmol/L. LDL-cholesterol levels decreased to 7.2 ± 1.8 mmol/L when treated with statin/ezetimibe and to 5.1 ± 3.1 mmol/L with anti-PCSK9 antibodies. Homozygous patients showed higher basal LDL-cholesterol and a poorer response to therapy compared with compound heterozygotes. Since 19 unrelated patients were identified in the Campania region (6,000,000 inhabitants) in southern Italy, the regional prevalence of HoFH was estimated to be at least 1:320,000. In conclusion, our results revealed a worse phenotype for homozygotes compared with compound heterozygotes, thereby highlighting the role of genetic screening in differentiating one genetic status from the other.

Lomitapide and Mipomersen-Inhibiting Microsomal Triglyceride Transfer Protein (MTP) and apoB100 Synthesis

PURPOSE OF REVIEW

The goal of this review is to evaluate the role of inhibiting the synthesis of lipoproteins when there is no or little residual LDL-receptor function as in patients with homozygous familial hypercholesterolaemia. Lomitapide is administered orally once a day while mipomersen is given by subcutaneous injection once a week. Lomitapide inhibits microsomal triglyceride transfer protein while mipomersen is an antisense oligonucleotide directed against apoB100.

RECENT FINDINGS

The pivotal registration trials for lomitapide and mipomersen were published in 2013 and 2010, respectively. More recently published data from extension trials and cohort studies provides additional information on long-term safety and efficacy. The mean LDL cholesterol reduction was 50% with lomitapide in its single-arm open-label registration trial. Mipomersen reduced LDL cholesterol by approximately 25% in its double-blind, placebo-controlled registration study. Both lomitapide and mipomersen therapy are associated with variable increases in hepatic fat content. The long-term safety of increased hepatic fat content in patients receiving these therapies is uncertain and requires further study. Both drugs may cause elevated transaminase in some patients, but no cases of severe liver injury have been reported. Lomitapide may also cause gastrointestinal discomfort and diarrhoea, especially if patients consume high-fat meals and patients are advised to follow a low-fat diet supplemented with essential fatty acids and fat-soluble vitamins. Mipomersen may cause injection-site and influenza-like reactions. The effect of lomitapide and mipomersen on cardiovascular outcomes has not been studied, but circumstantial evidence suggests that the LDL cholesterol lowering achieved with these two agents may reduce cardiovascular event rates.

Xanthomas Regression in an 8-Year-Old Boy Treated With Lomitapide

This case reports on an 8-year-old boy with homozygous familial hypercholesterolemia with large tuberous xanthomas over his hands, elbows, buttocks, knees, and feet. Lomitapide 40 mg daily (steadily increased) was added to his classical lipid-lowering therapy. A 50% reduction in the thickness, hardness, size, and color intensity of xanthomas was reported after 2 years of treatment. (Level of Difficulty: Intermediate.)

Microsomal triglyceride transfer protein inhibitor (lomitapide) efficacy in the treatment of patients with homozygous familial hypercholesterolaemia

Aims

The aim of this study was to evaluate the effect of microsomal triglyceride transfer protein inhibitor (lomitapide) in patients with homozygous familial hypercholesterolaemia.

Methods and results

In 12 homozygous familial hypercholesterolaemia patients treated with lipid-lowering drugs ± biweekly lipoprotein apheresis sessions (nine patients), daily lomitapide was added. The lipid profile (total cholesterol, low-density lipoprotein cholesterol, triglycerides, high-density lipoprotein cholesterol) before and after lomitapide treatment was evaluated. The follow-up period with lomitapide treatment was 3–24 months (13.8 ± 7.9). The median baseline low-density lipoprotein cholesterol level was 900 mg/dl (348–1070), after lipid-lowering drugs therapy was 383.5 mg/dl (214–866) and after lipid-lowering drugs + time-averaged level was 288 mg/dl (183.7–716.6). The addition of lomitapide lowered low-density lipoprotein cholesterol levels further by 56.8% compared to lipid-lowering drugs alone (mean reduction 262, 95% confidence interval (105.5–418.7), p = 0.005) and by 54% (mean reduction 182.9, 95% confidence interval (−342 – −23), p = 0.031) comparing to lipid-lowering drugs + lipoprotein apheresis (time-averaged level). The time-averaged level of low-density lipoprotein cholesterol in lipid-lowering drugs + lipoprotein apheresis patients compared with lipid-lowering drugs + lomitapide was 54% in favour of lomitapide ( p = 0.031).

Conclusions

Treatment with lomitapide in homozygous familial hypercholesterolaemia patients has a beneficial effect with a constant decrease of low-density lipoprotein cholesterol by 57% compared with classical lipid-lowering therapy and by 54% compared with classical lipid-lowering therapy and time-averaged level of low-density lipoprotein cholesterol.