Updates in Drug Treatment of Severe Hypertriglyceridemia

Novel Therapeutics for Familial Chylomicronemia Syndrome

PURPOSE OF REVIEW

This review discusses new treatment approaches for familial chylomicronemia syndrome (FCS), a rare disorder affecting triglyceride metabolism. The focus is on antisense oligonucleotides (ASO) and small-interfering RNA (siRNA) therapies targeting APOC3 and angiopoietin-like protein 3 (ANGPTL3).

RECENT FINDINGS

Volanesorsen, an ASO targeting APOC3, has shown effectiveness in managing FCS, multifactorial chylomicronemia, and familial partial lipodystrophy, but its use is limited by thrombocytopenia. Emerging therapies, Olezarsen (ASO anti-APOC3) and Plozasiran (siRNA anti-APOC3), both conjugated with GalNAc, show promise in reducing acute pancreatitis risk without platelet concerns. ANGPTL3 inhibition requires residual lipoprotein lipase (LPL) activity, with only siRNA-based therapies-zodasiran and solbinsiran-under investigation. Suppressing APOC3 expression and targeting ANGPTL3 via siRNA offer significant potential, but long-term studies are needed to confirm their efficacy and safety. Future research may explore gene-editing strategies using lipid nanoparticle-based CRISPR-Cas9 delivery for more durable treatment outcomes.

Proteomic Profiling of Age-Related Proteins Following Extracorporeal Apheresis

Lipoprotein apheresis (LA) is often the last option to adequately reduce lipoproteins in patients with familial hypercholesterolemia and lipoprotein (a) hyperlipidemia. Characterized by mild side effects, it is now the most effective method of preventing major cardiovascular events (CVEs). This benefit is due not only to the lowering of lipoprotein levels, but probably also to many other pleiotropic effects that have been extensively described in the literature. These include the reduction of inflammatory signaling substances, fibrinogen, plasminogen or components of the oxidative stress response. Here, we performed a proteomic analysis of 12 patients treated with therapeutic apheresis using two different pore size filters to quantify the effect on age-related plasma proteins. This study showed that important proteins such as α-2-macroglobulin, apolipoprotein C-III, complement C1s subcomponent, C4b-binding protein alpha chain, CD5 antigen-like and pregnancy zone protein, whose role in numerous aging processes has been well described, were significantly reduced by apheresis treatment. We conclude that therapeutic apheresis may be a promising approach to reduce these age-related proteins and that these treatments may become an essential part of managing cardiovascular risk in an aging population.

Modern therapy of patients with lupus erythematosus must include appropriate management of their heightened rates of atherosclerotic cardiovascular events: a literature update

Atherosclerotic cardiovascular disease (ASCVD) remains the biggest killer of patients with lupus erythematosus (LE) and the general non-autoimmune population. In this literature update on LE and ASCVD, we focused on published work since our earlier review article, meaning from 2021 to the present, with an emphasis on cutaneous LE. Several themes emerged. First, new work shows that patients with lupus still exhibit a high burden of conventional risk factors for ASCVD events. Second, recent studies continue to implicate possible effects of lupus disease activity to worsen rates of ASCVD events beyond predictions from conventional risk factors. Third, new work on estimating the risk of future ASCVD events in patients with lupus supports arterial-wall imaging, inclusion of lupus-specific factors, estimators of ASCVD event risk that take lupus status into account and considering lupus as a diabetes equivalent or even as a diabetes-plus-smoking equivalent in this context. Technologies for arterial-wall imaging continue to improve and will likely play an increasing role in ASCVD assessment and management. Fourth, purported cardiovascular benefits from certain disease-modifying antirheumatic drugs such as antimalarials have become less clear. Fifth, earlier treatment of atherosclerosis, which is a lifelong disease, can be accomplished with diet, exercise, smoking cessation and new classes of safe and effective medications for lipid-lowering and blood pressure control. Benefits on subclinical arterial disease by imaging and on ASCVD events have been reported, supporting the concept that ASCVD is eminently manageable in this autoimmune condition. Sixth, despite the heightened risk for ASCVD events in patients with lupus, available therapeutic approaches remain unused or underused and, accordingly, event rates remain high.Raising awareness among patients and healthcare providers about ASCVD assessment and management in patients with LE is essential. Greater vigilance is needed to prevent ASCVD events in patients with lupus by addressing dyslipidaemias, hypertension, smoking, obesity and physical inactivity.

Comparison of Patients With Familial Chylomicronemia Syndrome and Multifactorial Chylomicronemia Syndrome

CONTEXT

Patients with rare familial chylomicronemia syndrome (FCS) and relatively common multifactorial chylomicronemia syndrome (MCS) both express severe hypertriglyceridemia, defined as plasma triglyceride concentration ≥10 mmol/L (≥885 mg/dL). Clinically there can be confusion between the 2 conditions.

OBJECTIVE

To compare clinical and biochemical phenotypes in patients with genotypically characterized FCS and MCS.

METHODS

We performed targeted sequencing of DNA from 193 patients with severe hypertriglyceridemia, classified them as having either FCS or MCS, and compared clinical and biochemical characteristics.

RESULTS

Patients with FCS were significantly younger than patients with MCS (31.4 ± 16.7 vs 51.0 ± 11.3 years; P = .003), with earlier age at symptom onset (15.0 ± 15.8 vs 37.8 ± 8.8 years; P = .00066), lower body mass index (23.3 ± 3.1 vs 30.7 ± 5.0 kg/m2; P = .000016), and higher prevalence of pancreatitis events (81.8% vs 35.2%; P = .003). Furthermore, patients with FCS had a higher ratio of triglyceride to total cholesterol (ie, 4.18 ± 0.92 vs 1.08 ± 0.51; P < .0001) and lower plasma apolipoprotein B (ie, 0.56 ± 0.15 vs 1.02 ± 0.43 g/L; P < .0001) than patients with MCS. Patients with MCS with heterozygous pathogenic variants had a relatively more severe clinical presentation than other MCS genetic subgroups.

CONCLUSION

Patients with FCS have notable phenotypic differences from patients with MCS, although there is overlap. While genetic analysis of patients with persistent severe hypertriglyceridemia can definitively diagnose FCS, 8.8% of patients with MCS with sustained refractory hypertriglyceridemia behave functionally as if they have FCS, which should influence their eligibility for novel therapies for severe hypertriglyceridemia.

Olezarsen in patients with hypertriglyceridemia at high cardiovascular risk: Rationale and design of the Essence-TIMI 73b trial

BACKGROUND

Elevated triglycerides are an important risk factor for atherosclerosis. However, the magnitude of triglyceride lowering with currently available therapies is modest and the impact of triglyceride-lowering on atherosclerosis remains undefined. Olezarsen is an antisense oligonucleotide (ASO) targeting mRNA for apolipoprotein C-III (apoC-III), an inhibitor of triglyceride clearance.

METHODS

The Essence-TIMI 73b trial (NCT05610280) is a randomized, double-blind, placebo-controlled phase 3 trial of olezarsen 50 mg or 80 mg every 4 weeks compared with placebo. The trial enrolled adults with either moderate hypertriglyceridemia (200-499 mg/dL) plus increased cardiovascular risk, or severe hypertriglyceridemia (≥500 mg/dL). The primary endpoint is the percent change in triglyceride levels from baseline to 6 months, reported as the difference between each olezarsen dose group and pooled placebo. A coronary computed tomography angiography (CTA) substudy will examine changes in noncalcified plaque volume from baseline to 12 months.

RESULTS

A total of 1,478 patients were randomized at 160 sites in North America and Europe. The median age is 63 (IQR 56-69) years, 39% are women, and 71% are non-Hispanic White. Overall, 60% of patients have diabetes, and 42% have atherosclerotic cardiovascular disease. At randomization, 97% were receiving lipid-lowering therapies, including 82% on a statin. The median baseline triglyceride level was 249 (195-339) mg/dL and 9% of patients had triglycerides ≥500 mg/dL at enrollment. Approximately 1000 patients completed a baseline CTA, of whom 555 (55%) had measurable noncalcified coronary plaque and continued in the substudy.

DISCUSSION

Targeting apoC-III to facilitate clearance of triglyceride-rich lipoproteins is a potential therapeutic strategy for lowering triglyceride levels, regressing atherosclerosis, and reducing cardiovascular risk. The phase 3 Essence-TIMI 73b trial, which has enrolled nearly 1,500 patients, including over 550 in a coronary CTA substudy, should provide key insights into the efficacy and safety of olezarsen in patients with largely moderate hypertriglyceridemia and elevated cardiovascular risk.

TRIAL REGISTRATION

Clinicaltrials.gov: NCT05610280.

Targeting apolipoprotein C-III: a game changer for pancreatitis prevention in severe hypertriglyceridemia

PURPOSE OF REVIEW

The aim of this review is to examine recent advancements in RNA-targeted therapies for the management of severe hypertriglyceridemia (sHTG) and prevention of sHTG-associated acute pancreatitis.

RECENT FINDINGS

Recent developments in RNA-targeted therapies, aimed at inhibiting apolipoprotein C-III (apoC-III), have demonstrated substantial and sustained reductions in triglyceride levels. Novel therapies, including antisense oligonucleotides (ASOs) and small interfering RNA (siRNA), such as volanesorsen, olezarsen, and plozasiran, have shown promising results in recent trials. These therapies not only effectively lower plasma triglyceride levels but also significantly reduce the incidence of acute pancreatitis.

SUMMARY

SHTG is a high-burden metabolic disorder that is associated with a significantly increased incidence and severity of acute pancreatitis. Traditional lifestyle interventions and conventional therapies, including fibrates and n-3 fatty acids, often provide only modest reductions in triglycerides and fail to prevent sHTG-associated acute pancreatitis. The emergence of novel and targeted RNA-therapies represents a potential breakthrough in the management of sHTG and acute pancreatitis prevention.

Lipids dysregulation in diseases: core concepts, targets and treatment strategies

Lipid metabolism is a well-regulated process essential for maintaining cellular functions and energy homeostasis. Dysregulation of lipid metabolism is associated with various conditions, including cardiovascular diseases, neurodegenerative disorders, and metabolic syndromes. This review explores the mechanisms underlying lipid metabolism, emphasizing the roles of key lipid species such as triglycerides, phospholipids, sphingolipids, and sterols in cellular physiology and pathophysiology. It also examines the genetic and environmental factors contributing to lipid dysregulation and the challenges of diagnosing and managing lipid-related disorders. Recent advancements in lipid-lowering therapies, including PCSK9 inhibitors, ezetimibe, bempedoic acid, and olpasiran, provide promising treatment options. However, these advancements are accompanied by challenges related to cost, accessibility, and patient adherence. The review highlights the need for personalized medicine approaches to address the interplay between genetics and environmental factors in lipid metabolism. As lipidomics and advanced diagnostic tools continue to progress, a deeper understanding of lipid-related disorders could pave the way for more effective therapeutic strategies.

The association of lipids and novel non-statin lipid-lowering drug target with osteoporosis: evidence from genetic correlations and Mendelian randomization

BACKGROUND

It remains controversial whether lipids affect osteoporosis (OP) or bone mineral density (BMD), and causality has not been established. This study aimed to investigate the genetic associations between lipids, novel non-statin lipid-lowering drug target genes, and OP and BMD.

METHODS

Mendelian randomization (MR) method was used to explore the genetic associations between 179 lipid species and OP, BMD. Drug-target MR analysis was used to explore the causal associations between angiopoietin-like protein 3 (ANGPTL3) and apolipoprotein C3 (APOC3) inhibitors on BMD.

RESULTS

The IVW results with Bonferroni correction indicated that triglyceride (TG) (51:3) (OR = 1.0029; 95% CI: 1.0014-1.0045; P = 0.0002) and TG (56:6) (OR = 1.0021; 95% CI: 1.0008-1.0033; P = 0.0011) were associated with an increased risk of OP; TG (51:2) (OR = 0.9543; 95% CI: 0.9148-0.9954; P = 0.0298) was associated with decreased BMD; and ANGPTL3 inhibitor (OR = 1.1342; 95% CI: 1.0393-1.2290; P = 0.0093) and APOC3 inhibitor (OR = 1.0506; 95% CI: 1.0155-1.0857; P = 0.0058) was associated with increased BMD.

CONCLUSIONS

MR analysis indicated causal associations between genetically predicted TGs and OP and BMD. Drug-target MR analysis showed that ANGPTL3 and APOC3 have the potential to serve as novel non-statin lipid-lowering drug targets to treat or prevent OP.

Current and Emerging Treatment Options for Hypertriglyceridemia: State-of-the-Art Review

Hypertriglyceridemia (HTG) is associated with a residual risk of atherosclerotic cardiovascular disease. Extremely elevated triglyceride (TG) concentrations, particularly due to familial chylomicronemia syndrome (FCS), pose a risk for acute pancreatitis. Standard therapies with statins, fibrates, omega-3 fatty acids, and niacin may be insufficient to reduce elevated TG levels and improve clinical outcomes in patients with HTG. Novel antisense oligonucleotides and small interfering ribonucleic acids target the key modulators of TG-rich lipoprotein catabolism. Among apolipoprotein C-III (apoC-III) inhibitors, olezarsen and plozasiran appear to be safer alternatives for volanesorsen regarding the risk of drug-induced thrombocytopenia in patients with FCS or severe HTG. After the failure of vupanorsen, a new angiopoietin-like protein 3 (ANGPTL3) inhibitor, zodasiran, demonstrated the potential to decrease TG levels in patients with moderate HTG. Meanwhile, the fibroblast growth factor 21 (FGF21) analog, pegozafermin, became another candidate for the treatment of severe HTG. This comprehensive review outlines pharmacological targets in TG-rich lipoprotein metabolism, discusses international guidelines, and summarizes the latest evidence from clinical trials to provide insight into the current and emerging treatment options for primary HTG.

Targeting noncoding RNAs to treat atherosclerosis

Noncoding RNAs (ncRNAs) are pivotal for various pathological processes, impacting disease progression. The potential for leveraging ncRNAs to prevent or treat atherosclerosis and associated cardiovascular diseases is of great significance, especially given the increasing prevalence of atherosclerosis in an ageing and sedentary population. Together, these diseases impose a substantial socio-economic burden, demanding innovative therapeutic solutions. This review explores the potential of ncRNAs in atherosclerosis treatment. We commence by examining approaches for identifying and characterizing atherosclerosis-associated ncRNAs. We then delve into the functional aspects of ncRNAs in atherosclerosis development and progression. Additionally, we review current RNA and RNA-targeting molecules in development or under approval for clinical use, offering insights into their pharmacological potential. The importance of improved ncRNA delivery strategies is highlighted. Finally, we suggest avenues for advanced research to accelerate the use of ncRNAs in treating atherosclerosis and mitigating its societal impact. LINKED ARTICLES: This article is part of a themed issue Non-coding RNA Therapeutics. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v182.2/issuetoc.

An unusual case of type I hyperlipidemia - infant with acute encephalopathy, bulging fontanel, vomiting and pink blood: a case report

BACKGROUND

Familial chylomicronemia syndrome (FCS) is a rare genetic disorder with heterogeneous presentation, where acute encephalopathy is rarely described in literature. Therefore, initial neurologic symptoms could make the diagnosis and treatment challenging.

CASE PRESENTATION

A four-month-old male infant presented with acute encephalopathy, vomiting, bulging fontanel, decreased appetite and failure to thrive. He had extremely lipemic serum and anemia. Intracranial computed tomography (CT) revealed lipid collection which was suspected to be epidermoid cyst, and also lipid deposits with extra-axial and intravascular location. This was initially described as a ruptured intracranial epidermoid cyst with dissemination of lipid content, including intravascular dissemination. Together with clinical signs of raised intracranial pressure it was discussed whether the cyst should be surgically removed. Since the blood sample appearence was milky and the child was rather stable, surgery wasn't performed and the treatment with exchange transfusion (ET) was started immediately. Only after ET it was possible to obtain laboratory results including lipid status (triglycerides were 106.8 mmol/l). At that point we suspected that the underlining cause is a genetic disease. Three cycles of plasmapheresis followed ET, after which symptoms resolved almost completely, despite remaining lipid deposits on brain CT scan and brain ultrasound, with some signs of regression. After these repeated imaging studies, it was concluded that the 'cyst' was actually the largest brain lipid collection. The definitive genetic diagnosis confirmed FCS. A short course of insulin, antioxidants and fibrates was initially given, but discontinued after the diagnosis confirmation due to lack of supporting data in the literature. Effective and the only maintenance treatment was the diet consisting of formula low in fat and high in medium-chain triglycerides. On the discharge the infant's neurological status, except mild hypotonia, was normal, he was thriving well, had good appetite and no anemia.

CONCLUSIONS

This is a rare case of FCS presenting with neurological symptoms that mimicked the clinical picture of ruptured intracranial epidermoid cyst, which was initially the differential diagnosis of this case. Initial interpretation of imaging studies didn't delay treatment. With the right treatment, the symptoms of the disease could be reversible with satisfactory outcome.

Nucleic acid drugs: recent progress and future perspectives

High efficacy, selectivity and cellular targeting of therapeutic agents has been an active area of investigation for decades. Currently, most clinically approved therapeutics are small molecules or protein/antibody biologics. Targeted action of small molecule drugs remains a challenge in medicine. In addition, many diseases are considered 'undruggable' using standard biomacromolecules. Many of these challenges however, can be addressed using nucleic therapeutics. Nucleic acid drugs (NADs) are a new generation of gene-editing modalities characterized by their high efficiency and rapid development, which have become an active research topic in new drug development field. However, many factors, including their low stability, short half-life, high immunogenicity, tissue targeting, cellular uptake, and endosomal escape, hamper the delivery and clinical application of NADs. Scientists have used chemical modification techniques to improve the physicochemical properties of NADs. In contrast, modified NADs typically require carriers to enter target cells and reach specific intracellular locations. Multiple delivery approaches have been developed to effectively improve intracellular delivery and the in vivo bioavailability of NADs. Several NADs have entered the clinical trial recently, and some have been approved for therapeutic use in different fields. This review summarizes NADs development and evolution and introduces NADs classifications and general delivery strategies, highlighting their success in clinical applications. Additionally, this review discusses the limitations and potential future applications of NADs as gene therapy candidates.

Safety and Efficacy of the Novel RNA Interference Therapies for Hypertriglyceridemia and Mixed Hyperlipidemia Management: A Systematic Review and Meta-analysis

BACKGROUND

No meta-analysis has holistically analyzed and summarized the safety and therapeutic efficacy of the newer RNA interference (RNAi) therapies, olezarsen, plozasiran, and zodasiran, in managing conditions associated with hypertriglyceridemia (HTG).

METHODS

Randomized controlled trials (RCTs) involving patients with HTG or mixed hyperlipidemia (MHL) receiving either olezarsen, plozasiran, or zodasiran in the intervention arm and a placebo in the control arm were searched through electronic databases. The primary outcome was the safety profile of the drugs studied; secondary outcomes included the percent change from baseline (CFB) in the lipid levels, including triglyceride (TG).

RESULTS

Six RCTs with 334 participants were evaluated. Olezarsen, plozasiran, and zodasiran were well-tolerated with no higher risk of serious adverse events or injection-site reactions. After 24 weeks, plozasiran increased alanine aminotransferase and HbA1c more than placebo, although the difference was insignificant at 48 weeks. Plozasiran and zodasiran had little effect on hyperglycemia worsening. Olezarsen increased the likelihood of mild platelet count decreases without clinical harm. At their longest clinical trial follow-up, the highest doses of olezarsen, plozasiran, and zodasiran lowered TG by 55.2%, 50.57%, and 51.2% of baseline levels. All three drugs decreased non-HDL-C and remnant cholesterol. Olezarsen and plozasiran lowered ApoC-III and increased HDL-C, whereas zodasiran reduced HDL-C. Zodasiran decreased LDL-C, whereas olezarsen and plozasiran had no effects on LDL-C. Plozasiran and zodasiran lowered apolipoprotein B, but not olezarsen.

CONCLUSION

The newer RNA interference (RNAi) therapies appear safe and have excellent TG-lowering efficacy in patients with HTG and MHL.

A novel lncRNA GM47544 modulates triglyceride metabolism by inducing ubiquitination-dependent protein degradation of APOC3

OBJECTIVE

Emerging evidence highlights the pivotal roles of long non-coding RNAs (lncRNAs) in lipid metabolism. Apoprotein C3 (ApoC3) is a well-established therapeutic target for hypertriglyceridemia and exhibits a strong association with cardiovascular disease. However, the exact mechanisms via which the lncRNAs control ApoC3 expression remain unclear.

METHODS

We identified a novel long noncoding RNA (lncRNA), GM47544, within the ApoA1/C3/A4/A5 gene cluster. Subsequently, the effect of GM47544 on intracellular triglyceride metabolism was analyzed. The diet-induced mouse models of hyperlipidemia and atherosclerosis were established to explore the effect of GM47544 on dyslipidemia and plaque formation in vivo. The molecular mechanism was explored through RNA sequencing, immunoprecipitation, RNA pull-down assay, and RNA immunoprecipitation.

RESULTS

GM47544 was overexpressed under high-fat stimulation. GM47544 effectively improved hepatic steatosis, reduced blood lipid levels, and alleviated atherosclerosis in vitro and in vivo. Mechanistically, GM47544 directly bound to ApoC3 and facilitated the ubiquitination at lysine 79 in ApoC3, thereby facilitating ApoC3 degradation via the ubiquitin-proteasome pathway. Moreover, we identified AP006216.5 as the human GM47544 transcript, which fulfills a comparable function in human hepatocytes.

CONCLUSIONS

The identification of GM47544 as a lncRNA modulator of ApoC3 reveals a novel mechanism of post-translational modification, with significant clinical implications for the treatment of hypertriglyceridemia and atherosclerosis.

Inhibitors of apolipoprotein C3, triglyceride levels, and risk of pancreatitis: a systematic review and meta-analysis

In recent years, novel apoC3 inhibitor therapies for the treatment of hypertriglyceridemia have been developed and assessed through phase II and III clinical trials. The objective of this study was to perform an updated meta-analysis on the impact of new apoC3 inhibitor drugs on triglyceride and apoC3 levels, as well as on the incidence of pancreatitis. We conducted a meta-analysis of randomized, placebo-controlled studies assessing the effects of apoC3 inhibitors therapy (antisense oligonucleotides and small interfering RNA) on triglyceride levels, apoC3 levels, and the occurrence of acute pancreatitis. This meta-analysis was performed according to PRISMA guidelines. The random-effects model was performed. Nine randomized clinical trials (n = 717 patients) were considered eligible for this systematic review. ApoC3 inhibitor drugs were consistently associated with decreased triglyceride levels (MD -57.0%; 95% CI -61.9 to -52.1, I2 82%) and lowered apoC3 values (MD -76; 95% CI -80.1 to -71.8, I2 77%) when compared to placebo. Furthermore, the use of apoC3 inhibitor drugs demonstrated a reduction in the risk of acute pancreatitis (OR 0.11; 95% CI 0.04 to 0.27, I2 0%). The present updated meta-analysis of randomized clinical trials demonstrated that the utilization of apoC3 inhibitors in patients with hypertriglyceridemia correlated with reduced apoC3 and triglyceride levels, along with a decreased risk of acute pancreatitis compared to the placebo.

Hypertriglyceridemia Therapy: Past, Present and Future Perspectives

Hypertriglyceridemia therapy is essential for preventing cardiovascular diseases. Fibrates belong to an important class of lipid-lowering drugs useful for the management of dyslipidaemia. By acting on the peroxisome proliferator-activated receptor (PPAR)-α, these drugs lower serum triglyceride levels and raise high-density lipoprotein cholesterol. Fibrate monotherapy is associated with a risk of myopathy and this risk is enhanced when these agents are administered together with statins. However, whereas gemfibrozil can increase plasma concentrations of statins, fenofibrate has less influence on the pharmacokinetics of statins. Pemafibrate is a new PPAR-α-selective drug considered for therapy, and clinical trials are ongoing. Apart from this class of drugs, new therapies have emerged with different mechanisms of action to reduce triglycerides and the risk of cardiovascular diseases.

Efficacy and safety of omega-3-acid ethyl acetate 90 capsules in severe hypertriglyceridemia: A randomized, controlled, multicenter study

Omega-3-acid ethyl acetate 90 capsules (containing 465 mg of eicosapentaenoic acid and 375 mg docosahexaenoic acid) is composed of highly purified omega-3 polyunsaturated fatty acid (PUFA) ethyl esters, whose lipid-lowering effect for severe hypertriglyceridemia (HTG) treatment is unclear. This study aimed to evaluate the efficacy and safety of omega-3-acid ethyl acetate 90 capsules in patients with severe HTG. In this randomized, double-blind, placebo-controlled, multicenter study, 239 patients with severe HTG were enrolled and randomized (1:1) into omega-3 group (N = 122) and placebo group (N = 117) to receive 12-week corresponding treatments. Lipid-related indexes were obtained at treatment initiation (W0), 4 weeks (W4), W8, and W12 after treatment. Adverse events and adverse drug reactions were recorded. Triacylglycerols (TAG), total cholesterol (TC), non-high-density lipoprotein cholesterol (non-HDL-C), very-low-density lipoprotein cholesterol (VLDL-C), and apolipoprotein C-III (Apo C-III) at W4, W8, and W12 were decreased in the omega-3 group versus the placebo group (all p < 0.05). Moreover, the percentage changes of TAG, TC, non-HDL-C, and VLDL-C from W0 to W4, W8, and W12, and the percentage change of Apo C-III from W0 to W4 and W8, were more obvious in the omega-3 group compared with the placebo group (all p < 0.05). However, no difference was observed in the percentage changes of HDL-C, low-density lipoprotein cholesterol (LDL-C), and LDL-C/HDL-C ratio during follow-up between groups (all p > 0.05). Additionally, there was no discrepancy in adverse events and adverse drug reactions between groups (all p > 0.05). Omega-3-acid ethyl acetate 90 capsules exhibit satisfied lipid-lowering effect with tolerable safety profile in patients with severe HTG.

Pancreatic and cardiometabolic complications of severe hypertriglyceridaemia

PURPOSE OF REVIEW

This review endeavours to explore the aetiopathogenesis and impact of severe hypertriglyceridemia (SHTG) and chylomicronaemia on cardiovascular, and pancreatic complications and summarizes the novel pharmacological options for management.

RECENT FINDINGS

SHTG, although rare, presents significant diagnostic and therapeutic challenges. Familial chylomicronaemia syndrome (FCS), is the rare monogenic form of SHTG, associated with increased acute pancreatitis (AP) risk, whereas relatively common multifactorial chylomicronaemia syndrome (MCS) leans more towards cardiovascular complications. Despite the introduction and validation of the FCS Score, FCS continues to be underdiagnosed and diagnosis is often delayed. Longitudinal data on disease progression remains scant. SHTG-induced AP remains a life-threatening concern, with conservative treatment as the cornerstone while blood purification techniques offer limited additional benefit. Conventional lipid-lowering medications exhibit minimal efficacy, underscoring the growing interest in novel therapeutic avenues, that is, antisense oligonucleotides (ASO) and short interfering RNA (siRNA) targeting apolipoprotein C3 (ApoC3) and angiopoietin-like protein 3 and/or 8 (ANGPTL3/8).

SUMMARY

Despite advancements in understanding the genetic basis and pathogenesis of SHTG, diagnostic and therapeutic challenges persist. The rarity of FCS and the heterogenous phenotype of MCS underscore the need for the development of predictive models for complications and tailored personalized treatment strategies. The establishment of national and international registries is advocated to augment disease comprehension and identify high-risk individuals.

Etiology and emerging treatments for familial chylomicronemia syndrome

INTRODUCTION

Familial chylomicronemia syndrome (FCS) is a rare autosomal recessive condition. Effective treatment is important as patients are at risk for severe and potentially fatal acute pancreatitis. We review recent developments in pharmacologic treatment for FCS, namely biological inhibitors of apolipoprotein (apo) C-III and angiopoietin-like protein 3 (ANGPTL3).

AREAS COVERED

FCS follows a biallelic inheritance pattern in which an individual inherits two pathogenic loss-of-function alleles of one of the five causal genes - LPL (in 60-80% of patients), GPIHBP1, APOA5, APOC2, and LMF1 - leading to the absence of lipolytic activity. Patients present from childhood with severely elevated triglyceride (TG) levels >10 mmol/L. Most patients with severe hypertriglyceridemia do not have FCS. A strict low-fat diet is the current first-line treatment, and existing lipid-lowering therapies are minimally effective in FCS. Apo C-III inhibitors are emerging TG-lowering therapies shown to be efficacious and safe in clinical trials. ANGPTL3 inhibitors, another class of emerging TG-lowering therapies, have been found to require at least partial lipoprotein lipase activity to lower plasma TG in clinical trials. ANGPTL3 inhibitors reduce plasma TG in patients with multifactorial chylomicronemia but not in patients with FCS who completely lack lipoprotein lipase activity.

EXPERT OPINION

Apo C-III inhibitors currently in development are promising treatments for FCS.

Triglyceride-rich lipoproteins and cardiovascular diseases

The global prevalence of cardiovascular diseases (CVD) continues to rise steadily, making it a leading cause of mortality worldwide. Atherosclerosis (AS) serves as a primary driver of these conditions, commencing silently at an early age and culminating in adverse cardiovascular events that severely impact patients' quality of life or lead to fatality. Dyslipidemia, particularly elevated levels of low-density lipoprotein cholesterol (LDL-C), plays a pivotal role in AS pathogenesis as an independent risk factor. Research indicates that abnormal LDL-C accumulation within arterial walls acts as a crucial trigger for atherosclerotic plaque formation. As the disease progresses, plaque accumulation may rupture or dislodge, resulting in thrombus formation and complete blood supply obstruction, ultimately causing myocardial infarction, cerebral infarction, and other common adverse cardiovascular events. Despite adequate pharmacologic therapy targeting LDL-C reduction, patients with cardiometabolic abnormalities remain at high risk for disease recurrence, highlighting the importance of addressing lipid risk factors beyond LDL-C. Recent attention has focused on the causal relationship between triglycerides, triglyceride-rich lipoproteins (TRLs), and their remnants in AS risk. Genetic, epidemiologic, and clinical studies suggest a causal relationship between TRLs and their remnants and the increased risk of AS, and this dyslipidemia may be an independent risk factor for adverse cardiovascular events. Particularly in patients with obesity, metabolic syndrome, diabetes, and chronic kidney disease, disordered TRLs and its remnants levels significantly increase the risk of atherosclerosis and cardiovascular disease development. Accumulation of over-synthesized TRLs in plasma, impaired function of enzymes involved in TRLs lipolysis, and impaired hepatic clearance of cholesterol-rich TRLs remnants can lead to arterial deposition of TRLs and its remnants, promoting foam cell formation and arterial wall inflammation. Therefore, understanding the pathogenesis of TRLs-induced AS and targeting it therapeutically could slow or impede AS progression, thereby reducing cardiovascular disease morbidity and mortality, particularly coronary atherosclerotic heart disease.

Targeting Lipoprotein(a): Can RNA Therapeutics Provide the Next Step in the Prevention of Cardiovascular Disease?

Numerous genetic and epidemiologic studies have demonstrated an association between elevated levels of lipoprotein(a) (Lp[a]) and cardiovascular disease. As a result, lowering Lp(a) levels is widely recognized as a promising strategy for reducing the risk of new-onset coronary heart disease, stroke, and heart failure. Lp(a) consists of a low-density lipoprotein-like particle with covalently linked apolipoprotein A (apo[a]) and apolipoprotein B-100, which explains its pro-thrombotic, pro-inflammatory, and pro-atherogenic properties. Lp(a) serum concentrations are genetically determined by the apo(a) isoform, with shorter isoforms having a higher rate of particle synthesis. To date, there are no approved pharmacological therapies that effectively reduce Lp(a) levels. Promising treatment approaches targeting apo(a) expression include RNA-based drugs such as pelacarsen, olpasiran, SLN360, and lepodisiran, which are currently in clinical trials. In this comprehensive review, we provide a detailed overview of RNA-based therapeutic approaches and discuss the recent advances and challenges of RNA therapeutics specifically designed to reduce Lp(a) levels and thus the risk of cardiovascular disease.

Executive summary of the Hellenic Atherosclerosis Society guidelines for the diagnosis and treatment of dyslipidemias - 2023

Atherosclerotic cardiovascular disease (ASCVD) remains the main cause of death worldwide, and thus its prevention, early diagnosis and treatment is of paramount importance. Dyslipidemia represents a major ASCVD risk factor that should be adequately managed at different clinical settings. 2023 guidelines of the Hellenic Atherosclerosis Society focus on the assessment of ASCVD risk, laboratory evaluation of dyslipidemias, new and emerging lipid-lowering drugs, as well as diagnosis and treatment of lipid disorders in women, the elderly and in patients with familial hypercholesterolemia, acute coronary syndromes, heart failure, stroke, chronic kidney disease, diabetes, autoimmune diseases, and non-alcoholic fatty liver disease. Statin intolerance is also discussed.

Understanding Hypertriglyceridemia: Integrating Genetic Insights

Hypertriglyceridemia is an exceptionally complex metabolic disorder characterized by elevated plasma triglycerides associated with an increased risk of acute pancreatitis and cardiovascular diseases such as coronary artery disease. Its phenotype expression is widely heterogeneous and heavily influenced by conditions as obesity, alcohol consumption, or metabolic syndromes. Looking into the genetic underpinnings of hypertriglyceridemia, this review focuses on the genetic variants in LPL, APOA5, APOC2, GPIHBP1 and LMF1 triglyceride-regulating genes reportedly associated with abnormal genetic transcription and the translation of proteins participating in triglyceride-rich lipoprotein metabolism. Hypertriglyceridemia resulting from such genetic abnormalities can be categorized as monogenic or polygenic. Monogenic hypertriglyceridemia, also known as familial chylomicronemia syndrome, is caused by homozygous or compound heterozygous pathogenic variants in the five canonical genes. Polygenic hypertriglyceridemia, also known as multifactorial chylomicronemia syndrome in extreme cases of hypertriglyceridemia, is caused by heterozygous pathogenic genetic variants with variable penetrance affecting the canonical genes, and a set of common non-pathogenic genetic variants (polymorphisms, using the former nomenclature) with well-established association with elevated triglyceride levels. We further address recent progress in triglyceride-lowering treatments. Understanding the genetic basis of hypertriglyceridemia opens new translational opportunities in the scope of genetic screening and the development of novel therapies.

VLDL Biogenesis and Secretion: It Takes a Village

The production and secretion of VLDLs (very-low-density lipoproteins) by hepatocytes has a direct impact on liver fat content, as well as the concentrations of cholesterol and triglycerides in the circulation and thus affects both liver and cardiovascular health, respectively. Importantly, insulin resistance, excess caloric intake, and lack of physical activity are associated with overproduction of VLDL, hepatic steatosis, and increased plasma levels of atherogenic lipoproteins. Cholesterol and triglycerides in remnant particles generated by VLDL lipolysis are risk factors for atherosclerotic cardiovascular disease and have garnered increasing attention over the last few decades. Presently, however, increased risk of atherosclerosis is not the only concern when considering today's cardiometabolic patients, as they often also experience hepatic steatosis, a prevalent disorder that can progress to steatohepatitis and cirrhosis. This duality of metabolic risk highlights the importance of understanding the molecular regulation of the biogenesis of VLDL, the lipoprotein that transports triglycerides and cholesterol out of the liver. Fortunately, there has been a resurgence of interest in the intracellular assembly, trafficking, degradation, and secretion of VLDL by hepatocytes, which has led to many exciting new molecular insights that are the topic of this review. Increasing our understanding of the biology of this pathway will aid to the identification of novel therapeutic targets to improve both the cardiovascular and the hepatic health of cardiometabolic patients. This review focuses, for the first time, on this duality.

The chylomicron saga: time to focus on postprandial metabolism

Since statins have had such tremendous therapeutic success over the last three decades, the field of atherosclerosis has become somewhat LDL-centric, dismissing the relevance of triglycerides (TG), particularly chylomicrons, in atherogenesis. Nonetheless, 50% of patients who take statins are at risk of developing atherosclerotic cardiovascular disease (ASCVD) and are unable to achieve their goal LDL-C levels. This residual risk is mediated, in part by triglyceride rich lipoproteins (TRL) and their remnants. Following his seminal investigation on the subject, Zilversmit proposed that atherosclerosis is a postprandial event in 1979 (1-4). In essence, the concept suggests that remnant cholesterol-rich chylomicron (CM) and very-low density lipoprotein (VLDL) particles play a role in atherogenesis. Given the foregoing, this narrative review addresses the most recent improvements in our understanding of postprandial dyslipidemia. The primary metabolic pathways of chylomicrons are discussed, emphasizing the critical physiological role of lipoprotein lipase and apoCIII, the importance of these particles' fluxes in the postprandial period, their catabolic rate, the complexities of testing postprandial metabolism, and the role of angiopoietin-like proteins in the partition of CM during the fed cycle. The narrative is rounded out by the dysregulation of postprandial lipid metabolism in insulin resistance states and consequent CVD risk, the clinical evaluation of postprandial dyslipidemia, current research limits, and potential future study directions.