Hipercolesterolemia familiar homocigota. Primer caso en España tratado con lomitapide, un inhibidor de la síntesis de lipoproteínas con apolipoproteína B

Lomitapide: a review of its clinical use, efficacy, and tolerability

Lomitapide is an inhibitor of MTP, an enzyme located in the endoplasmic reticulum of hepatocytes and enterocytes. This enzyme is responsible for the synthesis of very low-density lipoproteins in the liver and chylomicrons in the intestine. Lomitapide has been approved by the US Food and Drug Administration, European Medicines Agency, and other regulatory agencies for the treatment of hypercholesterolemia in adult patients with homozygous familial hypercholesterolemia. Clinical trials have shown that lomitapide reduces low-density-lipoprotein cholesterol levels by around 40% in homozygous familial hypercholesterolemia patients on treatment with statins with or without low-density-lipoprotein apheresis, with an acceptable safety and tolerance profile. The most common adverse events are gastrointestinal symptoms that decrease in frequency with long-term treatment, and the increase in liver fat remains stable. This review analyzes the clinical use, efficacy, and tolerability of lomitapide.

Efficacy and Safety of Lomitapide in Hypercholesterolemia

BACKGROUND

Despite extensive use of statins, patients with hypercholesterolemia, especially homozygous familial hypercholesterolemia (HoFH), do not achieve recommended targets of low-density lipoprotein cholesterol (LDL-C). There is an urgent need for novel options that could reduce proatherogenic lipoprotein cholesterol levels. Lomitapide, a microsomal triglyceride transport protein (MTP) inhibitor, was approved three years ago as an orphan drug for the treatment of patients with HoFH.

OBJECTIVE

Our aim was to systematically evaluate the efficacy and safety of lomitapide and to provide guidance for clinicians.

METHODS

We searched the PubMed, Embase, and Cochrane library databases and ClinicalTrials.gov to identify valid studies published before 31 October 2016 that included lomitapide-treated patients who did or did not undergo lipid-lowering therapy. We assessed the quality of different studies. Data were extracted and evaluated for quality by two reviewers.

RESULTS

Studies reporting lomitapide therapy included one randomized controlled trial, three single-arm studies, and five case reports. In patients with HoFH, lomitapide reduced levels of LDL-C, total cholesterol, apolipoprotein B, and triglycerides with or without other lipid-lowering therapy, including apheresis. In non-HoFH patients with moderate hypercholesterolemia and hypertriglyceridemia, lomitapide also showed favorable effects on changes in LDL-C and triglycerides. However, both HoFH and non-HoFH patients experienced a reduction in high-density lipoprotein cholesterol (HDL-C) and apolipoprotein A-1 (ApoA-1). The most common adverse event was gastrointestinal disorder, and others included liver transaminase elevation and hepatic fat accumulation. Long-term use of lomitapide was associated with an increased risk of progressing to steatohepatitis and fibrosis.

CONCLUSIONS

Lomitapide improved most lipid parameters but not HDL-C or ApoA-1 in patients with HoFH and in non-HoFH patients, and gastrointestinal disorders were the most common adverse event. The possible benefits of lomitapide should be further evaluated and viewed against its possible long-term side effects.

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.

Homozygous Familial Hypercholesterolemia in Spain

Background—

Homozygous familial hypercholesterolemia (HoFH) is a rare disease characterized by elevated plasma levels of low-density lipoprotein cholesterol (LDL-C) and extremely high risk of premature atherosclerotic cardiovascular disease. HoFH is caused by mutations in several genes, including LDL receptor ( LDLR ), apolipoprotein B ( APOB ), proprotein convertase subtilisin/kexin type 9 ( PCSK9 ), and LDL protein receptor adaptor 1 ( LDLRAP1 ). No epidemiological studies have assessed HoFH prevalence or the clinical and molecular characteristics of this condition. Here, we aimed to characterize HoFH in Spain.

Methods and Results—

Data were collected from the Spanish Dyslipidemia Registry of the Spanish Atherosclerosis Society and from all molecular diagnoses performed for familial hypercholesterolemia in Spain between 1996 and 2015 (n=16 751). Clinical data included baseline lipid levels and atherosclerotic cardiovascular disease events. A total of 97 subjects were identified as having HoFH—of whom, 47 were true homozygous (1 for APOB , 5 for LDLRAP1 , and 41 for LDLR ), 45 compound heterozygous for LDLR , 3 double heterozygous for LDLR and PSCK9 , and 2 double heterozygous for LDLR and APOB . No PSCK9 homozygous cases were identified. Two variants in LDLR were identified in 4.8% of the molecular studies. Over 50% of patients did not meet the classical HoFH diagnosis criteria. The estimated HoFH prevalence was 1:450 000. Compared with compound heterozygous cases, true homozygous cases showed more aggressive phenotypes with higher LDL-C and more atherosclerotic cardiovascular disease events.

Conclusions—

HoFH frequency in Spain was higher than expected. Clinical criteria would underestimate the actual prevalence of individuals with genetic HoFH, highlighting the importance of genetic analysis to improve familial hypercholesterolemia diagnosis accuracy.