Integrated guidance on the care of familial hypercholesterolemia from the International FH Foundation

MTP Gene Variants and Response to Lomitapide in Patients with Homozygous Familial Hypercholesterolemia

Homozygous familial hypercholesterolemia (HoFH) is a rare genetic disorder, which leads to premature cardiovascular diseases. Microsomal triglyceride transport protein (MTP) inhibitors, such as lomitapide, offer a new therapeutic approach for treating these patients. We evaluated the lipid lowering (LL) efficacy of lomitapide according to several gene variants in MTP. Four clinically and/or molecularly defined HoFH patients were treated with lomitapide in addition to conventional high intensity LL therapy and regular lipoprotein apheresis. Two patients responded to the therapy, with a significant reduction of LDL cholesterol (LDL-C＞50%, hyper-responders). Sequencing of all exonic and intronic flanking regions of the MTP gene in all patients revealed 36 different variants. The hyper-responders to lomitapide shared six common variants: rs17533489, rs79194015, rs745075, rs41275715, rs1491246, and rs17533517, which were not seen in hypo-responders (reduction in LDL-C＜50%). We suggest that in HoFH variants in the MTP gene may impact on the therapeutic response to lomitapide, but this requires further investigation.

Treatment Gaps in Adults With Heterozygous Familial Hypercholesterolemia in the United States: Data From the CASCADE-FH Registry

BACKGROUND

Cardiovascular disease burden and treatment patterns among patients with familial hypercholesterolemia (FH) in the United States remain poorly described. In 2013, the FH Foundation launched the Cascade Screening for Awareness and Detection (CASCADE) of FH Registry to address this knowledge gap.

METHODS AND RESULTS

We conducted a cross-sectional analysis of 1295 adults with heterozygous FH enrolled in the CASCADE-FH Registry from 11 US lipid clinics. Median age at initiation of lipid-lowering therapy was 39 years, and median age at FH diagnosis was 47 years. Prevalent coronary heart disease was reported in 36% of patients, and 61% exhibited 1 or more modifiable risk factors. Median untreated low-density lipoprotein cholesterol (LDL-C) was 239 mg/dL. At enrollment, median LDL-C was 141 mg/dL; 42% of patients were taking high-intensity statin therapy and 45% received >1 LDL-lowering medication. Among FH patients receiving LDL-lowering medication(s), 25% achieved an LDL-C <100 mg/dL and 41% achieved a ≥50% LDL-C reduction. Factors associated with prevalent coronary heart disease included diabetes mellitus (adjusted odds ratio 1.74; 95% confidence interval 1.08-2.82) and hypertension (2.48; 1.92-3.21). Factors associated with a ≥50% LDL-C reduction from untreated levels included high-intensity statin use (7.33; 1.86-28.86) and use of >1 LDL-lowering medication (1.80; 1.34-2.41).

CONCLUSIONS

FH patients in the CASCADE-FH Registry are diagnosed late in life and often do not achieve adequate LDL-C lowering, despite a high prevalence of coronary heart disease and risk factors. These findings highlight the need for earlier diagnosis of FH and initiation of lipid-lowering therapy, more consistent use of guideline-recommended LDL-lowering therapy, and comprehensive management of traditional coronary heart disease risk factors.

Familial Hypercholesterolemia

Familial hypercholesterolemia is a common, inherited disorder of cholesterol metabolism that leads to early cardiovascular morbidity and mortality. It is underdiagnosed and undertreated. Statins, ezetimibe, bile acid sequestrants, niacin, lomitapide, mipomersen, and low-density lipoprotein (LDL) apheresis are treatments that can lower LDL cholesterol levels. Early treatment can lead to substantial reduction of cardiovascular events and death in patients with familial hypercholesterolemia. It is important to increase awareness of this disorder in physicians and patients to reduce the burden of this disorder.

Evolocumab: A Review in Hyperlipidemia

Evolocumab (Repatha(®)) is a monoclonal antibody targeting proprotein convertase subtilisin/kexin type 9 (PCSK9) that is administered subcutaneously at a dosage of 140 mg every 2 weeks or 420 mg once monthly. Across 12-week phase III trials in patients with primary hypercholesterolemia or mixed dyslipidemia, evolocumab was more effective than placebo (treatment difference -54.8 to -76.3%) and/or ezetimibe (treatment difference -36.9 to -47.2%) at reducing low-density lipoprotein cholesterol (LDL-C) levels, including when added to statin therapy, when administered to statin-intolerant patients, when administered as monotherapy, and in patients with heterozygous familial hypercholesterolemia who were receiving statins with or without other lipid-lowering drugs. Evolocumab also significantly lowered LDL-C levels (treatment difference of ≈30% vs. placebo) in patients with homozygous familial hypercholesterolemia when added to statins with or without ezetimibe in a 12-week phase III trial. The efficacy of evolocumab was maintained in the longer term, and it was well tolerated. In conclusion, subcutaneous evolocumab is a valuable new treatment for use in primary hypercholesterolemia or mixed dyslipidemia and homozygous familial hypercholesterolemia, particularly in patients unable to reach LDL-C goals despite treatment with statins with or without other lipid-lowering therapies and in patients who do not tolerate or are not able to receive statins.

Familial hypercholesterolemia

Familial hypercholesterolemia is a common, inherited disorder of cholesterol metabolism that leads to early cardiovascular morbidity and mortality. It is underdiagnosed and undertreated. Statins, ezetimibe, bile acid sequestrants, niacin, lomitapide, mipomersen, and low-density lipoprotein (LDL) apheresis are treatments that can lower LDL cholesterol levels. Early treatment can lead to substantial reduction of cardiovascular events and death in patients with familial hypercholesterolemia. It is important to increase awareness of this disorder in physicians and patients to reduce the burden of this disorder.

Counterpoint: The evidence does not support universal screening and treatment in children

Few pediatric guidelines have generated the amount or intensity of controversy that the pediatric lipid guidelines have. In the following article, I will synthesize the arguments against universal lipid screening and treatment in childhood. Direct evidence that relates the presence of cardiovascular risk factors in childhood to cardiovascular disease outcomes in adulthood is unavailable, and as a consequence, the guidelines were formulated based on a chain of indirect evidence. The debate centers on the strength of the indirect evidence that links risk factors present in childhood to adult disease outcomes. The arguments against universal lipid screening and treatment of children include (1) a history of unanticipated harms caused by screening tests or treatments that were enacted based on indirect evidence, (2) the poor test performance characteristics of lipid profiles in childhood when used as a screening test, (3) problems with the effectiveness of lipid testing done in the office setting, and (4) concerns regarding the safety of statins when used in children.

A comparison of European and US guidelines for familial hypercholesterolaemia

PURPOSE OF REVIEW

To compare the European and US guidelines for familial hypercholesterolaemia, but also all the European and US position/consensus papers on heterozygous and homozygous familial hypercholesterolaemia published recently.

RECENT FINDINGS

It has been established that the prevalence of familial hypercholesterolaemia was previously markedly underestimated. The disease is characterized by a lifelong significant increase in LDL cholesterol (LDL-C) levels and therefore premature atherosclerotic cardiovascular disease. Recommendations on familial hypercholesterolaemia have been included as a special chapter in the recent European (European Society of Cardiology/European Atherosclerosis Society) guidelines on dyslipidaemia, whereas in the new US (American College of Cardiology/American Heart Association) lipid guidelines they have been included only generally and these guidelines avoid mentioning familial hypercholesterolaemia explicitly. Both of these guidelines recommend statins in high doses as the treatment option. However, in the American College of Cardiology/American Heart Association guidelines, there is no requirement to attain a specific LDL-C target which is different from the European Society of Cardiology/European Atherosclerosis Society guidelines. Although these two guidelines differ markedly in a number of aspects, they both stress the need to diagnose familial hypercholesterolaemia patients as early as possible and to treat them with intensive LDL-C-lowering therapy.

SUMMARY

All the guidelines and consensus papers stress that earlier diagnosis and effective treatment can markedly improve life expectancy among familial hypercholesterolaemia patients.

Homozygous autosomal dominant hypercholesterolaemia: prevalence, diagnosis, and current and future treatment perspectives

PURPOSE OF REVIEW

Homozygous autosomal dominant hypercholesterolemia (hoADH) is a rare genetic disorder caused by mutations in LDL receptor, apolipoprotein B, and/or proprotein convertase subtilisin-kexin type 9. Both the genetic mutations and the clinical phenotype vary largely among individual patients, but patients with hoADH are typically characterized by extremely elevated LDL-cholesterol (LDL-C) levels, and a very high-risk for premature cardiovascular disease. Current lipid-lowering therapies include bile acid sequestrants, statins, and ezetimibe. To further decrease LDL-C levels in hoADH, lipoprotein apheresis is recommended, but this therapy is not available in all countries.

RECENT FINDINGS

Recently, the microsomal triglyceride transfer protein inhibitor lomitapide and the RNA antisense inhibitor of apolipoprotein B mipomersen were approved by the Food and Drug Administration/European Medicine Agency and the Food and Drug Administration, respectively. Several other LDL-C-lowering strategies and therapeutics targeting the HDL-C pathway are currently in the clinical stage of development.

SUMMARY

Novel therapies have been introduced for LDL-C-lowering and innovative drug candidates for HDL-C modulation for the treatment of hoADH. Here, we review the current available literature on the prevalence, diagnosis, and therapeutic strategies for hoADH.

The genetics of familial hypercholesterolemia and emerging therapies

Familial hypercholesterolemia (FH) results in very high levels of atherogenic low-density lipoprotein (LDL) cholesterol from the time of birth. Mutations of the genes encoding for the LDL receptor, apolipoprotein B and proprotein convertase subtilisin/kexin type 9, are causes for this autosomal dominant inherited condition. Heterozygous FH is very common, while homozygous FH is rare. Affected individuals can experience premature cardiovascular disease; most homozygous patients experience this before the age of 20 years. Since effective LDL cholesterol lowering therapies are available, morbidity and mortality are decreased. The use of statins is the first choice in therapy; combining other lipid-lowering medications is recommended to lower LDL cholesterol sufficiently. In some cases, lipoprotein apheresis is necessary. In heterozygous FH, these measures are effective to lower LDL cholesterol, but in severe cases and in homozygous FH there remains an unmet need. Emerging therapies, such as the recently approved microsomal triglyceride transfer protein inhibitor and the apolipoprotein B antisense oligonucleotide, might offer further options for these patients with very high cardiovascular risk. Early diagnosis and early treatment are important to reduce cardiovascular events and premature death.

Familial hypercholesterolemia: developments in diagnosis and treatment

BACKGROUND

Familial hypercholesterolemia (FH) is a congenital disorder of lipid metabolism characterized by a marked elevation of the plasma concentration of LDL (low-density lipoprotein) cholesterol beginning in childhood and by the early onset of coronary heart disease. It is among the commonest genetic disorders, with an estimated prevalence in Germany of at least 1 per 500 persons.

METHOD

Review of pertinent literature retrieved by a selective search.

RESULTS

FH is underdiagnosed and undertreated in Germany. It is clinically diagnosed on the basis of an elevated LDL cholesterol concentration (>190 mg/dL [4.9 mmol/L]), a family history of hypercholesterolemia, and early coronary heart disease, or the demonstration of xanthomas. The gold standard of diagnosis is the identification of the underlying genetic defect, which is possible in 80% of cases and enables the identification of affected relatives of the index patient. The recommended goals of treatment, based on the results of observational studies, are to lower the LDL cholesterol concentration by at least 50% or to less than 100 mg/dL (2.6 mmol/L) (for children: <135 mg/dL [3.5 mmol/L]). The target value is lower for patients with clinically overt atherosclerosis (<70 mg/dL [1.8 mmol/L]). Statins, combined with a health-promoting lifestyle, are the treatment of choice. Lipoprotein apheresis is used in very severe cases; its therapeutic effects on clinical endpoints and its side effect profile have not yet been documented in randomized controlled trials.

CONCLUSION

Familial hypercholesterolemia is a common disease that can be diagnosed simply and reliably on clinical grounds and by molecular genetic testing. Timely diagnosis and appropriate treatment can lower the risk of atherosclerosis in heterozygous patients to that of the general population.

Current Treatment of Familial Hypercholesterolaemia

Familial hypercholesterolaemia is an autosomal-dominant disorder associated with mutations in the LDL receptor gene resulting in markedly elevated plasma low-density lipoprotein cholesterol levels. FH is significantly underrecognised with as many as 1 in 300 having the heterozygous form and 1 in 1 million having the homozygous form of the disease. Early diagnosis and treatment of FH is paramount to reduce the risk of premature atherosclerotic cardiovascular disease and death. The goal of treatment is to reduce LDL-C by 50 % from baseline levels with lifestyle modification, pharmacologic lipid-lowering therapy, LDL apheresis and in rare cases, liver transplantation. Pharmacologic treatment ranges from statin medications to newer agents such as lomitapide, mipomersin and PCSK9 inhibitors. Combination therapy is frequently required to achieve goal lipoprotein level reductions and prevent complications.