Mipomersen, an apolipoprotein B synthesis inhibitor, reduces atherogenic lipoproteins in patients with severe hypercholesterolemia at high cardiovascular risk: a randomized, double-blind, placebo-controlled trial

The relationship between triglyceride/high-density lipoprotein cholesterol ratio and the severity of coronary artery disease in patients presenting with acute coronary syndrome

BACKGROUND

The SYNTAX score is a score that grades the severity and complexity of coronary lesions. In this study, we aimed to investigate the relationship between triglyceride/high-density lipoprotein cholesterol (triglyceride/HDL-C) ratio and SYNTAX scores in patients presenting with non-ST elevation myocardial infarction (NSTEMI).

METHODS

This prospective study included 258 patients who presented at our center with STEMI, and underwent coronary angiography (CAG). The triglyceride/HDL-C ratio was calculated, and the relationship of this ratio with the SYNTAX score was determined with univariate and multivariate linear regression analyses.

RESULTS

The patients were separated into two groups according to the triglyceride/HDL-C ratios as low (<3.88) and high (≥3.88). The SYNTAX scores of the group with a high triglyceride/HDL-C score were determined to be significantly high ( P  < 0.001). When the SYNTAX scores were separated into two groups as low (≤22) and high (>23), a statistically significant correlation was determined between a high SYNTAX score and a high triglyceride/HDL-C ratio ( P  < 0.001). Logistic regression analysis was performed for the SYNTAX score, and the BMI value [odds ratio (OR) = 0.91, 95% confidence interval (CI): 0.85-0.98] and the triglyceride/HDL-C ratio (OR = 6.86, 95% CI: 3.45-13.65) alone were determined to be independent determinants of the SYNTAX score.

CONCLUSION

The most important result obtained from this study was that the triglyceride/HDL-C ratio, which is an index that has recently started to be frequently used, was a marker of greater coronary anatomic complexity (SYNTAX score >22), independently of other parameters in patients who presented with NSTEMI and underwent CAG.

Residual Cardiovascular Risk: Role of Remnants Cholesterol, Monocyte/HDL Ratio and Lipoprotein Ratios on Personalized Cardiovascular Prevention

Cardiovascular diseases represent the leading cause of death in the world and are subject to limitations in prevention strategies despite the use of very effective drugs. The concept of residual risk (RR) is intrinsically related to that of global risk of which it represents a very significant percentage. In the cardiovascular field, the term RR refers to the probability of incurring a major cardiovascular event, despite adequate control of the risk factors present in the individual patient. A significant portion of the RR in the cardiovascular field results from the underestimation of additional risk factors not subjected to adequate intervention such as, for example, triglyceride levels in patients treated for the presence of hypertension and/or hypercholesterolemia. The control of the RR therefore appears as an essential condition for the effective reduction of the global risk profile and is based on an integrated intervention that combines all the different prevention strategies derived from the available evidence and capable of interacting on the basis of a strengthening reciprocal between lifestyle and pharmacological and nutraceutical intervention methods.

Updates on Non-Statin LDL-Lowering Therapy

PURPOSE OF REVIEW

There is ample evidence of the benefits and safety of low-density lipoprotein (LDL)-lowering therapies in the prevention of atherosclerotic cardiovascular disease. While statins remain the first-line agent for LDL reduction, several new therapies are now available. This narrative review provides an overview of currently available non-statin LDL-lowering agents, specifically mechanisms of action and data on efficacy and safety. It also discusses recommendations on their use in clinical practice.

RECENT FINDINGS

Ezetimibe, PCSK9 inhibitors, and bempedoic acid have proven safe and efficacious in reducing cardiovascular events in large randomized controlled trials. Inclisiran is a promising agent that suppresses PCSK9 mRNA translation and is currently under investigation in a large clinical outcomes randomized controlled trial assessing its effect on clinical outcomes. Expert consensus advocates for lower LDL targets in higher risk patients and escalation to or a combination of non-statin therapies as needed to achieve these goals.

Cholesterol-Lowering Strategies for Cardiovascular Disease Prevention: The Importance of Intensive Treatment and the Simplification of Medical Therapy

Cardiovascular diseases (CVDs) are a leading global cause of mortality and are primarily driven by atherosclerotic coronary artery disease. Their pathogenesis involves multi-factorial mechanisms, among which low-density lipoprotein (LDL) plays a causative role. Recent ESC/EAS guidelines advocate for a shift toward new risk estimation algorithms that better emphasize non-fatal cardiovascular events, lifetime risk prediction, and tailored pharmacological approaches, including statin + ezetimibe and triple therapy, in specific cases. Intensive lipid-lowering therapy has been shown to be pivotal, especially in post-acute coronary events. Intracoronary imaging has revealed insights into the composition of plaque and demonstrated the significant regression that can be achieved through the use of statins such as rosuvastatin and atorvastatin. The positive effects of Proprotein Convertase Subtilisin/Kexin type 9 (PCSK9) inhibitors, particularly alirocumab and evolocumab, on plaque regression, have been demonstrated. Inclisiran, which targets PCSK9 gene expression, significantly reduces LDL cholesterol. The associated challenges include hesitancy to prescribe intensive regimens and limited treatment adherence, highlighting the need for pharmacological combinations to improve therapeutic outcomes.

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.

Antihyperlipidemic Treatment Options in Statin Resistance and Intolerance

Cardiovascular disease is the global leading cause of death and hypercholesterolemia is implicated as one of its top contributors. Moreover, there is growing recognition that lower low-density lipoprotein cholesterol levels offer greater protection against cardiovascular disease. Statins are the first-line lipid-lowering agents for both primary and secondary prevention of cardiovascular disease in patients with hypercholesterolemia. However, statin resistance and intolerance lead to undertreatment in patients who would likely derive the most benefit from antihyperlipidemic drugs. Several non-statin therapies are increasingly prescribed to such patients, most commonly ezetimibe and the PCSK9 monoclonal antibodies, but numerous other options have been developed in recent years and investigations into new therapies are ongoing. The use of these non-statin therapies requires the clinician to take a highly personalized approach to cholesterol reduction in complex patients. In this review, we describe current non-statin options for statin-resistant and statin-intolerant patients in addition to areas of active research.

Targeting the Liver with Nucleic Acid Therapeutics for the Treatment of Systemic Diseases of Liver Origin

Systemic diseases of liver origin (SDLO) are complex diseases in multiple organ systems, such as cardiovascular, musculoskeletal, endocrine, renal, respiratory, and sensory organ systems, caused by irregular liver metabolism and production of functional factors. Examples of such diseases discussed in this article include primary hyperoxaluria, familial hypercholesterolemia, acute hepatic porphyria, hereditary transthyretin amyloidosis, hemophilia, atherosclerotic cardiovascular diseases, α-1 antitrypsin deficiency-associated liver disease, and complement-mediated diseases. Nucleic acid therapeutics use nucleic acids and related compounds as therapeutic agents to alter gene expression for therapeutic purposes. The two most promising, fastest-growing classes of nucleic acid therapeutics are antisense oligonucleotides (ASOs) and small interfering RNAs (siRNAs). For each listed SDLO disease, this article discusses epidemiology, symptoms, genetic causes, current treatment options, and advantages and disadvantages of nucleic acid therapeutics by either ASO or siRNA drugs approved or under development. Furthermore, challenges and future perspectives on adverse drug reactions and toxicity of ASO and siRNA drugs for the treatment of SDLO diseases are also discussed. In summary, this review article will highlight the clinical advantages of nucleic acid therapeutics in targeting the liver for the treatment of SDLO diseases. SIGNIFICANCE STATEMENT: Systemic diseases of liver origin (SDLO) contain rare and common complex diseases caused by irregular functions of the liver. Nucleic acid therapeutics have shown promising clinical advantages to treat SDLO. This article aims to provide the most updated information on targeting the liver with antisense oligonucleotides and small interfering RNA drugs. The generated knowledge may stimulate further investigations in this growing field of new therapeutic entities for the treatment of SDLO, which currently have no or limited options for treatment.

Non-coding RNA therapeutics in cardiovascular diseases and risk factors: Systematic review

At present, RNA-based therapy which includes therapies using non-coding RNAs (ncRNAs), antisense oligonucleotides (ASOs), and aptamers are gaining widespread attention as possible ways to target genes in various cardiovascular diseases (CVDs), thereby serving as a promising therapeutic approach for CVDs and risk factors management. However, data are primarily in an early stage. A systematic review was carried out using literature from several databases (Pubmed, Cochrane, Scopus, and DOAJR) following the PRISMA guidelines. Of the 64 articles reviewed, 39 papers were included in this review with three main types of RNAs: aptamers, antisense oligonucleotides (ASOs), and small-interfering RNA (siRNA). All studies were human clinical trials. RNA-based therapies were demonstrated to be efficacious in treating various CVDs and controlling cardiovascular risk factors. They are generally safe and well-tolerated. However, data are still in the early stage and warrant further investigation.

Antisense oligonucleotides: a novel Frontier in pharmacological strategy

Antisense oligonucleotides (ASOs) are short single stranded synthetic RNA or DNA molecules, whereas double-stranded RNA nucleotide sequences are called small interfering RNA (siRNA). ASOs bind to complementary nucleic acid sequences impacting the associated functions of the targeted nucleic acids. They represent an emerging class of drugs that, through a revolutionary mechanism of action, aim to directly regulate disease-causing genes and their variants, providing an alternative tool to traditional "protein-specific" therapies. The majority of the ASOs are designed to treat orphan genetic disorders that in most of the cases are seriously disabling and still lacking an adequate therapy. In order to translate ASOs into clinical success, constant technological advances have been instrumental in overcoming several pharmacological, toxicological and formulation limitations. Accordingly, chemical structures have been recently implemented and new bio-conjugation and nanocarriers formulation strategies explored. The aim of this work is to offer an overview of the antisense technology with a comparative analysis of the oligonucleotides approved by the Food and Drug Administration (FDA) and the European Medicines Agency (EMA).

Low-density lipoprotein subclasses over the menopausal transition and risk of coronary calcification and carotid atherosclerosis: the SWAN Heart and HDL ancillary studies

OBJECTIVE

Perimenopausal women experience a steep increase in low-density lipoprotein cholesterol (LDL-C) that is related to a higher risk of carotid plaque later in life. Low-density lipoprotein subclasses have been linked to cardiovascular diseases beyond LDL-C, promising a better risk stratification. We aim to characterize changes in LDL subclasses and assess their associations with presence of coronary artery calcium (CAC score ≥10) and carotid intima-media thickness (cIMT) over the menopausal transition (MT) and by menopause stage.

METHODS

Nuclear magnetic resonance spectroscopy LDL subclasses were measured for a maximum of five time points. Coronary artery calcification and cIMT were measured for a maximum of two time points. LOESS (locally weighted regression with scatter smoothing) plots, linear mixed-effects models, and generalized estimating equations were used for analyses.

RESULTS

The study included 471 women (baseline: age, 50.2 ± 2.7 years; 79.0% premenopausal/early perimenopausal), of whom 221 had data on CAC or cIMT. Low-density lipoprotein subclasses increased over the MT, whereas intermediate density-lipoprotein particles declined. In adjusted models, higher total LDL particles (LDL-P) and apolipoprotein B were associated with greater CAC prevalence and greater cIMT. Although none of the associations were modified by menopause stage, higher LDL-C, apolipoprotein B, and total LDL-P were associated with greater cIMT during the perimenopause or postmenopause stages, whereas higher LDL-C and small LDL-P were associated with greater CAC prevalence, mainly during perimenopause.

CONCLUSIONS

During the MT, women experience significant increases in LDL subclasses found to be related to greater cIMT levels and CAC prevalence. Whether these changes could better predict future risk of hard cardiovascular disease events beyond LDL-C remains a research question to address.

Lipoprotein(a): Just an Innocent Bystander in Arterial Hypertension?

Elevated plasma lipoprotein(a) [Lp(a)] is a relatively common and highly heritable trait conferring individuals time-dependent risk of developing atherosclerotic cardiovascular disease (CVD). Following its first description, Lp(a) triggered enormous scientific interest in the late 1980s, subsequently dampened in the mid-1990s by controversial findings of some prospective studies. It was only in the last decade that a large body of evidence has provided strong arguments for a causal and independent association between elevated Lp(a) levels and CVD, causing renewed interest in this lipoprotein as an emerging risk factor with a likely contribution to cardiovascular residual risk. Accordingly, the 2022 consensus statement of the European Atherosclerosis Society has suggested inclusion of Lp(a) measurement in global risk estimation. The development of highly effective Lp(a)-lowering drugs (e.g., antisense oligonucleotides and small interfering RNA, both blocking LPA gene expression) which are still under assessment in phase 3 trials, will provide a unique opportunity to reduce "residual cardiovascular risk" in high-risk populations, including patients with arterial hypertension. The current evidence in support of a specific role of Lp(a) in hypertension is somehow controversial and this narrative review aims to overview the general mechanisms relating Lp(a) to blood pressure regulation and hypertension-related cardiovascular and renal damage.

Long-term outcomes of moyamoya disease versus atherosclerosis-associated moyamoya vasculopathy using high-resolution MR vessel wall imaging

OBJECTIVES

We aimed to compare the long-term outcomes and surgical benefits between moyamoya disease (MMD) and atherosclerosis-associated moyamoya vasculopathy (AS-MMV) using high-resolution MRI (HRMRI).

METHODS

MMV patients were retrospectively included and divided into the MMD and AS-MMV groups according to vessel wall features on HRMRI. Kaplan-Meier survival and Cox regression were performed to compare the incidence of cerebrovascular events and prognosis of encephaloduroarteriosynangiosis (EDAS) treatment between MMD and AS-MMV.

RESULTS

Of the 1173 patients (mean age: 42.4±11.0 years; male: 51.0%) included in the study, 881 were classified into the MMD group and 292 into the AS-MMV group. During the average follow-up of 46.0±24.7 months, the incidence of cerebrovascular events in the MMD group was higher compared with that in the AS-MMV group before (13.7% vs 7.2%; HR 1.86; 95% CI 1.17 to 2.96; p=0.008) and after propensity score matching (6.1% vs 7.3%; HR 2.24; 95% CI 1.34 to 3.76; p=0.002). Additionally, patients treated with EDAS had a lower incidence of events than those not treated with EDAS, regardless of whether they were in the MMD (HR 0.65; 95% CI 0.42 to 0.97; p=0.043) or AS-MMV group (HR 0.49; 95% CI 0.51 to 0.98; p=0.048).

CONCLUSIONS

Patients with MMD had a higher risk of ischaemic stroke than those with AS-MMV, and patients with both MMD and AS-MMV could benefit from EDAS. Our findings suggest that HRMRI could be used to identify those who are at a higher risk of future cerebrovascular events.

Considerations in the Preclinical Assessment of the Safety of Antisense Oligonucleotides

The nucleic acid therapeutics field has made tremendous progress in the past decades. Continuous advances in chemistry and design have led to many successful clinical applications, eliciting even more interest from researchers including both academic groups and drug development companies. Many preclinical studies in the field focus on improving the delivery of antisense oligonucleotide drugs (ONDs) and/or assessing their efficacy in target tissues, often neglecting the evaluation of toxicity, at least in early phases of development. A series of consensus recommendations regarding regulatory considerations and expectations have been generated by the Oligonucleotide Safety Working Group and the Japanese Research Working Group for the International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use S6 and Related Issues (WGS6) in several white papers. However, safety aspects should also be kept in sight in earlier phases while screening and designing OND to avoid subsequent failure in the development phase. Experts and members of the network "DARTER," a COST Action funded by the Cooperation in Science and Technology of the EU, have utilized their collective experience working with OND, as well as their insights into OND-mediated toxicities, to generate a series of consensus recommendations to assess OND toxicity in early stages of preclinical research. In the past few years, several publications have described predictive assays, which can be used to assess OND-mediated toxicity in vitro or ex vivo to filter out potential toxic candidates before moving to in vivo phases of preclinical development, that is, animal toxicity studies. These assays also have the potential to provide translational insight since they allow a safety evaluation in human in vitro systems. Yet, small preliminary in vivo studies should also be considered to complement this early assessment. In this study, we summarize the state of the art and provide guidelines and recommendations on the different tests available for these early stage preclinical assessments.

Monoclonal Antibodies, Gene Silencing and Gene Editing (CRISPR) Therapies for the Treatment of Hyperlipidemia-The Future Is Here

Hyperlipidemia is a significant risk factor for atherosclerotic cardiovascular disease. Undertreatment of elevated lipids persists despite existing therapies. Here, we provide an update on monoclonal antibodies, gene silencing therapies, and gene editing techniques for the management of hyperlipidemia. The current era of cutting-edge pharmaceuticals targeting low density lipoprotein cholesterol, PCSK9, lipoprotein (a), angiopoietin-like 3, and apolipoprotein C3 are reviewed. We outline what is known, studies in progress, and futuristic goals. This review of available and upcoming biotechnological lipid therapies is presented for clinicians managing patients with familial hyperlipidemia, statin intolerance, hypertriglyceridemia, or elevated lipoprotein (a) levels.

Lipid Biomarkers and Atherosclerosis-Old and New in Cardiovascular Risk in Childhood

Lipids are a complex group of molecules in the body, essential as structural, functional and metabolic components. When disbalanced, they are regarded as a cardiovascular risk factor, traditionally in cholesterol level evaluation. However, due to their complex nature, much research is still needed for a comprehensive understanding of their role in atherosclerosis, especially in the young. Several new lipid biomarkers are emerging, some already researched to a point, such as lipoproteins and apolipoproteins. Other lipid molecules are also being increasingly researched, including oxidized forms due to oxidative inflammation in atherosclerosis, and sphingolipids. For many, even those less new, the atherogenic potential is not clear and no clinical recommendations are in place to aid the clinician in using them in everyday clinical practice. Moreover, lipids' involvement in atherogenesis in children has yet to be elucidated. This review summarizes the current knowledge on lipids as biomarkers of cardiovascular risk in the paediatric population.

What Can RNA-Based Therapy Do for Monogenic Diseases?

The use of RNA-based approaches to treat monogenic diseases (i.e., hereditary disorders caused by mutations in single genes) has been developed on different fronts. One approach uses small antisense oligonucleotides (ASOs) to modulate RNA processing at various stages; namely, to enhance correct splicing, to stimulate exon skipping (to exclude premature termination codon variants), to avoid undesired messenger RNA (mRNA) transcript degradation via the nonsense-mediated decay (NMD) pathway, or to induce mRNA degradation where they encode toxic proteins (e.g., in dominant diseases). Another approach consists in administering mRNA, which, like gene therapy, is a mutation-agnostic approach with potential application to any recessive monogenic disease. This is simpler than gene therapy because instead of requiring targeting of the nucleus, the mRNA only needs to be delivered to the cytoplasm. Although very promising (as demonstrated by COVID-19 vaccines), these approaches still have potential for optimisation, namely regarding delivery efficiency, adverse drug reactions and toxicity.

Mechanisms of unusual response to lipid-lowering therapy: PCSK9 inhibition

The efficacy of proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibition has broadened lipid-lowering therapy thus providing decreased risk in atherosclerotic cardiovascular disease. Unfortunately, the widespread use of PCSK9 inhibitors (PCSK9i), ie, monoclonal antibodies, has led to the findings of unusual responsiveness, ie, a phenomenon defined as an LDL-C reduction of <30% vs the average LDL-C reduction efficacy of 50-60%. This unusual responsiveness to PCSK9i is attributable to several factors, ie, lack of adherence, impaired absorption, poor distribution or early elimination as well as abnormal effects of PCSK9i in the presence of anti-antibodies or mutations in PCSK9 and LDLR. Unexpectedly increased lipoprotein (Lp)(a) also appear to contribute to the unusual responsiveness scenario. Identification of these responses and mechanisms underlying them are essential for effective management of LDL-C and cardiovascular risk. In this review, we describe plausible reasons underlying this phenomenon supported by findings of clinical trials. We also elaborate on the need for education and regular follow-up to improve adherence. Collectively, the review provides a summary of the past, present, and future of mechanisms and countermeasures revolving around unusual responses to PCSK9i therapy.

Lipoprotein(a): Cardiovascular Disease, Aortic Stenosis and New Therapeutic Option

Atherosclerosis is a chronic and progressive inflammatory process beginning early in life with late clinical manifestation. This slow pathological trend underlines the importance to early identify high-risk patients and to treat intensively risk factors to prevent the onset and/or the progression of atherosclerotic lesions. In addition to the common Cardiovascular (CV) risk factors, new markers able to increase the risk of CV disease have been identified. Among them, high levels of Lipoprotein(a)-Lp(a)-lead to very high risk of future CV diseases; this relationship has been well demonstrated in epidemiological, mendelian randomization and genome-wide association studies as well as in meta-analyses. Recently, new aspects have been identified, such as its association with aortic stenosis. Although till recent years it has been considered an unmodifiable risk factor, specific drugs have been developed with a strong efficacy in reducing the circulating levels of Lp(a) and their capacity to reduce subsequent CV events is under testing in ongoing trials. In this paper we will review all these aspects: from the synthesis, clearance and measurement of Lp(a), through the findings that examine its association with CV diseases and aortic stenosis to the new therapeutic options that will be available in the next years.

Recent lipoprotein(a) trials

PURPOSE OF REVIEW

Lipoprotein(a) (Lp(a)) is a genetically determined independent risk factor for cardiovascular disease and calcific aortic stenosis; thus, serum levels are minimally affected by conventional treatments for hypercholesterolemia and hypertriglyceridemia. New RNA therapies directly targeting Lp(a) have demonstrated efficacy in decreasing serum levels. Several recent trials have demonstrated efficacy and safety of these RNA therapeutics.

RECENT FINDINGS

Single-stranded antisense oligonucleotides (ASOs) and small interfering RNA (siRNA) are two classes of RNA-targeted therapeutics that specifically target the LPA gene, which encodes for apolipoprotein(a), a dominant and rate-limiting component in the hepatic synthesis of Lp(a) particle. Pelacarsen (ASO), olpasiran (siRNA) and SLN360 (siRNA) are novel drugs that have demonstrated efficacy in lowering Lp(a) levels and excellent safety profiles.

SUMMARY

Lp(a) is an independent risk factor for cardiovascular disease. RNA-directed therapies, pelacarsen, olpasiran and SLN360, have shown efficacy in dramatically lowering serum Lp(a) levels. Outcomes data will be the next frontier of Lp(a) trials.

mRNA therapy for myocardial infarction: A review of targets and delivery vehicles

Cardiovascular diseases are the leading cause of death in the world. This is partly due to the low regenerative capacity of adult hearts. mRNA therapy is a promising approach under development for cardiac diseases. In mRNA therapy, expression of the target protein is modulated by delivering synthetic mRNA. mRNA therapy benefits cardiac regeneration by increasing cardiomyocyte proliferation, reducing fibrosis, and promoting angiogenesis. Because mRNA is translated in the cytoplasm, the delivery efficiency of mRNA into the cytoplasm and nucleus significantly affects its therapeutic efficacy. To improve delivery efficiency, non-viral vehicles such as lipid nanoparticles have been developed. Non-viral vehicles can protect mRNA from enzymatic degradation and facilitate the cellular internalization of mRNA. In addition to non-viral vehicles, viral vectors have been designed to deliver mRNA templates into cardiac cells. This article reviews lipid nanoparticles, polymer nanoparticles, and viral vectors that have been utilized to deliver mRNA into the heart. Because of the growing interest in lipid nanoparticles, recent advances in lipid nanoparticles designed for cardiac mRNA delivery are discussed. Besides, potential targets of mRNA therapy for myocardial infarction are discussed. Gene therapies that have been investigated in patients with cardiac diseases are analyzed. Reviewing mRNA therapy from a clinically relevant perspective can reveal needs for future investigations.

Antisense Oligonucleotide Therapy for the Nervous System: From Bench to Bedside with Emphasis on Pediatric Neurology

Antisense oligonucleotides (ASOs) are disease-modifying agents affecting protein-coding and noncoding ribonucleic acids. Depending on the chemical modification and the location of hybridization, ASOs are able to reduce the level of toxic proteins, increase the level of functional protein, or modify the structure of impaired protein to improve function. There are multiple challenges in delivering ASOs to their site of action. Chemical modifications in the phosphodiester bond, nucleotide sugar, and nucleobase can increase structural thermodynamic stability and prevent ASO degradation. Furthermore, different particles, including viral vectors, conjugated peptides, conjugated antibodies, and nanocarriers, may improve ASO delivery. To date, six ASOs have been approved by the US Food and Drug Administration (FDA) in three neurological disorders: spinal muscular atrophy, Duchenne muscular dystrophy, and polyneuropathy caused by hereditary transthyretin amyloidosis. Ongoing preclinical and clinical studies are assessing the safety and efficacy of ASOs in multiple genetic and acquired neurological conditions. The current review provides an update on underlying mechanisms, design, chemical modifications, and delivery of ASOs. The administration of FDA-approved ASOs in neurological disorders is described, and current evidence on the safety and efficacy of ASOs in other neurological conditions, including pediatric neurological disorders, is reviewed.

Current Options and Future Perspectives in the Treatment of Dyslipidemia

Low-density lipoprotein cholesterol (LDL-C) plays a crucial role in the development of atherosclerosis. Statin therapy is the standard treatment for lowering LDL-C in primary and secondary prevention. However, some patients do not reach optimal LDL-C target levels or do not tolerate statins, especially when taking high doses long-term. Combining statins with different therapeutic approaches and testing other new drugs is the future key to reducing the burden of cardiovascular disease (CVD). Recently, several new cholesterol-lowering drugs have been developed and approved; others are promising results, enriching the pharmacological armamentarium beyond statins. Triglycerides also play an important role in the development of CVD; new therapeutic approaches are also very promising for their treatment. Familial hypercholesterolemia (FH) can lead to CVD early in life. These patients respond poorly to conventional therapies. Recently, however, new and promising pharmacological strategies have become available. This narrative review provides an overview of the new drugs for the treatment of dyslipidemia, their current status, ongoing clinical or preclinical trials, and their prospects. We also discuss the new alternative therapies for the treatment of dyslipidemia and their relevance to practice.

Circulating growth differentiation factor 15 levels and apolipoprotein B to apolipoprotein A1 ratio in coronary artery disease patients with type 2 diabetes mellitus

BACKGROUND

Clinical investigations have found that there was a close association between T2DM and adverse cardiovascular events, with possible mechanisms included inflammation, apoptosis, and lipid metabolism disorders. High serum GDF-15 concentration and the apolipoprotein B/apolipoprotein A1 ratio (ApoB/ApoA1) are involved in the above-mentioned mechanisms and are thought to be related to the occurrence of adverse cardiovascular events. However, it remains unclear whether circulating GDF-15 levels and the ApoB/ApoA1 ratio are related to T2DM patients with CAD.

METHODS

T2DM patients with or without CAD were eligible for this study. According to the inclusion and exclusion criteria, 502 T2DM patients were enrolled between January 2021 and December 2021 and were then divided into T2DM group (n = 249) and CAD group (n = 253). The ApoB, ApoA1 and GDF-15 concentrations were measured at hospital admission and the ApoB/ApoA1 ratio was then calculated.

RESULTS

Compared with T2DM group, serum GDF-15 levels and ApoB/ApoA1 ratio increased in CAD group. Furthermore, a positive relationship between the occurrence of CAD in diabetic population and circulating GDF-15 concentrations and ApoB/ApoA1 ratio was observed in logistic regression analysis (p < 0.01). Restrictive cubic spline analysis after adjusted for multiple risky variables showed that serum GDF-15 or ApoB/ApoA1 ratio correlated positively with CAD.

CONCLUSIONS

Circulating GDF-15 levels and serum ApoB/ApoA1 ratio vary in CAD group and T2DM group. ApoB/ApoA1 and GDF-15 may be helpful for predicting the occurrence of CAD in patients with T2DM.

The mechanistic pathways of oxidative stress in aortic stenosis and clinical implications

Despite the elucidation of the pathways behind the development of aortic stenosis (AS), there remains no effective medical treatment to slow or reverse its progress. Instead, the gold standard of care in severe or symptomatic AS is replacement of the aortic valve. Oxidative stress is implicated, both directly as well as indirectly, in lipid infiltration, inflammation and fibro-calcification, all of which are key processes underlying the pathophysiology of degenerative AS. This culminates in the breakdown of the extracellular matrix, differentiation of the valvular interstitial cells into an osteogenic phenotype, and finally, calcium deposition as well as thickening of the aortic valve. Oxidative stress is thus a promising and potential therapeutic target for the treatment of AS. Several studies focusing on the mitigation of oxidative stress in the context of AS have shown some success in animal and in vitro models, however similar benefits have yet to be seen in clinical trials. Statin therapy, once thought to be the key to the treatment of AS, has yielded disappointing results, however newer lipid lowering therapies may hold some promise. Other potential therapies, such as manipulation of microRNAs, blockade of the renin-angiotensin-aldosterone system and the use of dipeptidylpeptidase-4 inhibitors will also be reviewed.

Adverse Drug Reactions and Toxicity of the Food and Drug Administration-Approved Antisense Oligonucleotide Drugs

The market for large molecule biologic drugs has grown rapidly, including antisense oligonucleotide (ASO) drugs. ASO drugs work as single-stranded synthetic oligonucleotides that reduce production or alter functions of disease-causing proteins through various mechanisms, such as mRNA degradation, exon skipping, and ASO-protein interactions. Since the first ASO drug, fomivirsen, was approved in 1998, the U.S. Food and Drug Administration (FDA) has approved 10 ASO drugs to date. Although ASO drugs are efficacious in treating some diseases that are untargetable by small-molecule chemical drugs, concerns on adverse drug reactions (ADRs) and toxicity cannot be ignored. Illustrative of this, mipomersen was recently taken off the market due to its hepatotoxicity risk. This paper reviews ADRs and toxicity from FDA drug labeling, preclinical studies, clinical trials, and postmarketing real-world studies on the 10 FDA-approved ASO drugs, including fomivirsen and pegaptanib, mipomersen, nusinersen, inotersen, defibrotide, eteplirsen, golodirsen, viltolarsen, and casimersen. Unique and common ADRs and toxicity for each ASO drug are summarized here. The risk of developing hepatotoxicity, kidney toxicity, and hypersensitivity reactions co-exists for multiple ASO drugs. Special precautions need to be in place when certain ASO drugs are administrated. Further discussion is extended on studying the mechanisms of ADRs and toxicity of these drugs, evaluating the existing physiologic and pathologic states of patients, optimizing the dose and route of administration, and formulating personalized treatment plans to improve the clinical utility of FDA-approved ASO drugs and discovery and development of new ASO drugs with reduced ADRs. SIGNIFICANCE STATEMENT: The current review provides a comprehensive analysis of unique and common ADRs and the toxicity of FDA-approved ASO drugs. The information can help better manage the risk of severe hepatotoxicity, kidney toxicity, and hypersensitivity reactions in the usage of currently approved ASO drugs and the discovery and development of new and safer ASO drugs.

Pathogenic role of microRNAs in atherosclerotic ischemic stroke: Implications for diagnosis and therapy

Ischemic stroke resulting from atherosclerosis (particularly in the carotid artery) is one of the major subtypes of stroke and has a high incidence of death. Disordered lipid homeostasis, lipid deposition, local macrophage infiltration, smooth muscle cell proliferation, and plaque rupture are the main pathological processes of atherosclerotic ischemic stroke. Hepatocytes, macrophages, endothelial cells and vascular smooth muscle cells are the main cell types participating in these processes. By inhibiting the expression of the target genes in these cells, microRNAs play a key role in regulating lipid disorders and atherosclerotic ischemic stroke. In this article, we listed the microRNAs implicated in the pathology of atherosclerotic ischemic stroke and aimed to explain their pro- or antiatherosclerotic roles. Our article provides an update on the potential diagnostic use of miRNAs for detecting growing plaques and impending clinical events. Finally, we provide a perspective on the therapeutic use of local microRNA delivery and discuss the challenges for this potential therapy.

RNA Therapeutics: the Next Generation of Drugs for Cardiovascular Diseases

Purpose of Review

RNA therapeutics are a new and rapidly expanding class of drugs to prevent or treat a wide spectrum of diseases. We discuss the defining characteristics of the diverse family of molecules under the RNA therapeutics umbrella.

Recent Findings

RNA therapeutics are designed to regulate gene expression in a transient manner. For example, depending upon the strategy employed, RNA therapies offer the versatility to replace, supplement, correct, suppress, or eliminate the expression of a targeted gene. RNA therapies include antisense nucleotides, microRNAs and small interfering RNAs, RNA aptamers, and messenger RNAs. Further, we discuss the mechanism(s) by which different RNA therapies either reduce or increase the expression of their targets.

Summary

We review the RNA therapeutics approved (and those in trials) to treat cardiovascular indications. RNA-based therapeutics are a new, rapidly growing class of drugs that will offer new alternatives for an increasing array of cardiovascular conditions.

Apolipoproteins in vascular biology and atherosclerotic disease

Apolipoproteins are important structural components of plasma lipoproteins that influence vascular biology and atherosclerotic disease pathophysiology by regulating lipoprotein metabolism. Clinically important apolipoproteins related to lipid metabolism and atherogenesis include apolipoprotein B-100, apolipoprotein B-48, apolipoprotein A-I, apolipoprotein C-II, apolipoprotein C-III, apolipoprotein E and apolipoprotein(a). Apolipoprotein B-100 is the major structural component of VLDL, IDL, LDL and lipoprotein(a). Apolipoprotein B-48 is a truncated isoform of apolipoprotein B-100 that forms the backbone of chylomicrons. Apolipoprotein A-I provides the scaffolding for lipidation of HDL and has an important role in reverse cholesterol transport. Apolipoproteins C-II, apolipoprotein C-III and apolipoprotein E are involved in triglyceride-rich lipoprotein metabolism. Apolipoprotein(a) covalently binds to apolipoprotein B-100 to form lipoprotein(a). In this Review, we discuss the mechanisms by which these apolipoproteins regulate lipoprotein metabolism and thereby influence vascular biology and atherosclerotic disease. Advances in the understanding of apolipoprotein biology and their translation into therapeutic agents to reduce the risk of cardiovascular disease are also highlighted.

A Bibliometric Analysis of Familial Hypercholesterolemia From 2011 to 2021

Familial Hypercholesterolemia (FH), an autosomal dominant genetic disease, is increasingly emerging as a global threat. To learn more about the development of FH, 1 617 papers about FH and related research were retrieved in the Web of Science Core Collection from 2011 to 2021. Then, these publications were scientometrically analyzed based on CiteSpace and VOSviewer in terms of spatiotemporal distribution, author distribution, subject categories, topic distribution, and references. The results showed that research on FH is at a stable stage. More FH research has been conducted in developed countries, implying the necessity for strengthening international cooperation and exchanges. We have obtained scholars, institutions, relevant journals, and representative literatures that play an important role in FH. The research direction of FH is on the mechanisms of FH and its complications, diagnosis, statin therapy, and new lipid-lowering drug therapy. Care is the research frontier in FH, and it is in an explosive period.

Lipoprotein(a), a Lethal Player in Calcific Aortic Valve Disease

Calcified aortic valve disease (CAVD) is the most common valvular cardiovascular disease with increasing incidence and mortality. The primary treatment for CAVD is surgical or transcatheter aortic valve replacement and there remains a lack of effective drug treatment. Recently, lipoprotein (a) (Lp(a)) has been considered to play a crucial role in CAVD pathophysiology. Multiple studies have shown that Lp(a) represents an independent risk factor for CAVD. Moreover, Lp(a) mediates the occurrence and development of CAVD by affecting aortic valve endothelial dysfunction, indirectly promoting foam cell formation through oxidized phospholipids (OxPL), inflammation, oxidative stress, and directly promotes valve calcification. However, there is a lack of clinical trials with Lp(a) reduction as a primary endpoint. This review aims to explore the relationship and mechanism between Lp(a) and CAVD, and focuses on the current drugs that can be used as potential therapeutic targets for CAVD.

Reduction of Off-Target Effects of Gapmer Antisense Oligonucleotides by Oligonucleotide Extension

Aim

Antisense oligonucleotide (ASO) has the potential to induce off-target effects by inadvertent binding of ASOs to unintended RNAs that have a sequence similar to the target RNA. In the present study, we focused on the association between oligonucleotide length and off-target effects. Oligonucleotide extension is assumed to have bilateral effects on hybridization-dependent changes in gene expression, i.e., one is the decrease of off-target effects based on the reduced number of off-target candidate genes with perfect matches, and the other is the increase of off-target effects based on the increased binding affinity between the ASO and the complementary RNAs that leads to better tolerability for mismatches.

Methods

To determine the effects of oligonucleotide extension of gapmer ASOs on off-target effects, an extensive microarray analysis was performed using human cells treated with a 14-mer gapmer ASO and the extended 18-mer derivatives with the same core 14-mer region.

Results and Discussion

Our data indicated that change in gene expression in the cells treated with 18-mer ASOs was significantly smaller than those with a 14-mer ASO, showing the decrease of off-target effects by oligonucleotide extension.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40291-021-00573-z.

Deliver the promise: RNAs as a new class of molecular entities for therapy and vaccination

The concepts of developing RNAs as new molecular entities for therapies have arisen again and again since the discoveries of antisense RNAs, direct RNA-protein interactions, functional noncoding RNAs, and RNA-directed gene editing. The feasibility was demonstrated with the development and utilization of synthetic RNA agents to selectively control target gene expression, modulate protein functions or alter the genome to manage diseases. Rather, RNAs are labile to degradation and cannot cross cell membrane barriers, making it hard to develop RNA medications. With the development of viable RNA technologies, such as chemistry and pharmaceutics, eight antisense oligonucleotides (ASOs) (fomivirsen, mipomersen, eteplirsen, nusinersen, inotersen, golodirsen, viltolarsen and casimersen), one aptamer (pegaptanib), and three small interfering RNAs (siRNAs) (patisiran, givosiran and lumasiran) have been approved by the United States Food and Drug Administration (FDA) for therapies, and two mRNA vaccines (BNT162b2 and mRNA-1273) under Emergency Use Authorization for the prevention of COVID-19. Therefore, RNAs have become a great addition to small molecules, proteins/antibodies, and cell-based modalities to improve the public health. In this article, we first summarize the general characteristics of therapeutic RNA agents, including chemistry, common delivery strategies, mechanisms of actions, and safety. By overviewing individual RNA medications and vaccines approved by the FDA and some agents under development, we illustrate the unique compositions and pharmacological actions of RNA products. A new era of RNA research and development will likely lead to commercialization of more RNA agents for medical use, expanding the range of therapeutic targets and increasing the diversity of molecular modalities.

Harnessing the Potential of CRISPR/Cas in Atherosclerosis: Disease Modeling and Therapeutic Applications

Atherosclerosis represents one of the major causes of death globally. The high mortality rates and limitations of current therapeutic modalities have urged researchers to explore potential alternative therapies. The clustered regularly interspaced short palindromic repeats-associated protein 9 (CRISPR/Cas9) system is commonly deployed for investigating the genetic aspects of Atherosclerosis. Besides, advances in CRISPR/Cas system has led to extensive options for researchers to study the pathogenesis of this disease. The recent discovery of Cas9 variants, such as dCas9, Cas9n, and xCas9 have been established for various applications, including single base editing, regulation of gene expression, live-cell imaging, epigenetic modification, and genome landscaping. Meanwhile, other Cas proteins, such as Cas12 and Cas13, are gaining popularity for their applications in nucleic acid detection and single-base DNA/RNA modifications. To date, many studies have utilized the CRISPR/Cas9 system to generate disease models of atherosclerosis and identify potential molecular targets that are associated with atherosclerosis. These studies provided proof-of-concept evidence which have established the feasibility of implementing the CRISPR/Cas system in correcting disease-causing alleles. The CRISPR/Cas system holds great potential to be developed as a targeted treatment for patients who are suffering from atherosclerosis. This review highlights the advances in CRISPR/Cas systems and their applications in establishing pathogenetic and therapeutic role of specific genes in atherosclerosis.

The Effect of Mipomersen in the Management of Patients with Familial Hypercholesterolemia: A Systematic Review and Meta-Analysis of Clinical Trials

Background: Familial hypercholesterolemia (FH) lead to significant adverse effects in coronary arteries. Mipomersen is a second-generation antisense oligonucleotide that inhibits the synthesis of apolipoprotein B-100, an essential component of low density lipoprotein (LDL), and thus decreases the production of LDL. We aimed to determine the effect of mipomersen in patients with FH. Methods: We searched Ovid Medline, Ovid EMBASE, WHO ICTRP search portal, ISI database, the reference lists of relevant articles, and also Google Scholar to retrieve articles. All randomized controlled trials (RCTs) comparing patients with FH receiving mipomersen as an add-on and a parallel group receiving a placebo or no intervention were selected. Results: Five studies with more than 500 patients were included. All had low risk of bias. Pooling data showed that mipomersen probably reduces LDL compared with placebo [mean difference: −24.79, 95% CI (−30.15, −19.43)] but with a moderate level of certainty. There was a high level of evidence for injection site reactions [RR = 2.56, CI (1.47–4.44)] and a low level for increased serum alanine transaminase (ALT) > 3 times upper limit of normal (ULN) [RR = 5.19, CI (1.01–26.69)]. Conclusion: A moderate level of evidence in decreasing serum LDL indicates that we are uncertain if this drug provides benefit in any outcome important to patients. Although a low level of evidence for an increase in serum ALT leaves uncertainty about this adverse effect, injection site reactions in 10% or more of patients can be an important concern.

The Role of Antisense Therapies Targeting Lipoprotein(a)

ABSTRACT

Atherosclerotic cardiovascular disease (ASCVD) continues to be the leading cause of preventable death in the United States. Elevated low-density lipoprotein cholesterol (LDL-C) is well known to result in cardiovascular disease. Mainstay therapy for reducing LDL-C and ASCVD risk is statin therapy. Despite achieving desired LDL-C levels with lipid-lowering therapy, cardiovascular residual risk often persists. Elevated lipoprotein(a) [Lp(a)] levels have been highlighted as an inherent independent predictor of ASCVD, and decreasing Lp(a) levels may result in a significant reduction in the residual risk in high-risk patients. To date, there are no approved medications to lower Lp(a) levels. Nicotinic acid, proprotein convertase subtilisin/kexin 9 inhibitors, and antisense oligonucleotide have demonstrated modest to potent Lp(a) reduction. Spotlight has been placed on antisense oligonucleotides and their role in Lp(a) lowering. APO(a)LRx is in the frontline for selectively decreasing Lp(a) concentrations and ongoing research may prove that this medication may lower Lp(a)-mediated residual risk, translating into cardiovascular benefit.

Lipoprotein(a) as a unique primary risk factor for early atherosclerotic peripheral arterial disease

Elevated plasma lipoprotein(a) is a relatively common condition that contributes to many cardiovascular diseases. However, the awareness and testing for this condition remain low. Herein, we present a case of an otherwise healthy and active man who developed symptoms of peripheral arterial disease starting at age 49, and was found to have hyper-lipoprotein(a) as his only notable risk factor. Diagnosis was not made until years later, after an extensive workup. Upon further screening, he was also found to have subclinical coronary and carotid artery atherosclerotic disease. The patient was treated with aspirin, statin, niacin and angioplasty to bilateral superficial femoral arteries with good symptom resolution. Early screening of his son also revealed a similarly elevated lipoprotein(a) level. It is important to raise awareness of this condition and its relationship to early-onset peripheral arterial disease so patients and their families can be appropriately identified, counselled and treated.

Umbrella Review on Non-Statin Lipid-Lowering Therapy

OBJECTIVES

The main aim of this review was to summarize current evidence on approved and emerging non-statin lipid-lowering therapies.

METHODS AND MATERIALS

Recent literature on U.S. FDA approved non-statin lipid-lowering therapies and evolving lipid-lowering drugs currently under development was reviewed.

RESULTS AND DISCUSSION

In the past 20 years, the emergence of non-statin cholesterol-lowering drugs has changed the landscape of dyslipidemia management. Food and Drug Administration approval of non-statin lipid-lowering therapies such as ezetimibe, proprotein convertase subtilisin/Kexin type 9 (PCSK9) inhibitors (evolocumab, alirocumab), bempedoic acid and combination of bempedoic acid and ezetimibe, evinacumab and other triglyceride-lowering agents (eg, icosapent ethyl) has emerged. The European Commission has also recently approved inclisiran for treatment of hypercholesterolemia and mixed hypercholesterolemia even though FDA has put the approval of this drug on hold. Recent guidelines have incorporated PCSK9 inhibitors to treat patients with primary hyperlipidemia and patients with very high-risk ASCVD, who could not achieve adequate lipid-lowering with combination therapy of maximally tolerated statin and ezetimibe. Icosapent ethyl use as an adjunct therapy to statins is also recommended to reduce the risk of ASCVD in patients with hypertriglyceridemia.

CONCLUSION

Despite cost limitations, the uptake of PCSK9 inhibitors is increasing. Approval of bempedoic acid alone or in combination with ezetimibe has provided additional oral lipid-lowering drug alternatives to ezetimibe. Various lipid-lowering drug targets are under investigation.

Delivery of oligonucleotide-based therapeutics: challenges and opportunities

Nucleic acid-based therapeutics that regulate gene expression have been developed towards clinical use at a steady pace for several decades, but in recent years the field has been accelerating. To date, there are 11 marketed products based on antisense oligonucleotides, aptamers and small interfering RNAs, and many others are in the pipeline for both academia and industry. A major technology trigger for this development has been progress in oligonucleotide chemistry to improve the drug properties and reduce cost of goods, but the main hurdle for the application to a wider range of disorders is delivery to target tissues. The adoption of delivery technologies, such as conjugates or nanoparticles, has been a game changer for many therapeutic indications, but many others are still awaiting their eureka moment. Here, we cover the variety of methods developed to deliver nucleic acid-based therapeutics across biological barriers and the model systems used to test them. We discuss important safety considerations and regulatory requirements for synthetic oligonucleotide chemistries and the hurdles for translating laboratory breakthroughs to the clinic. Recent advances in the delivery of nucleic acid-based therapeutics and in the development of model systems, as well as safety considerations and regulatory requirements for synthetic oligonucleotide chemistries are discussed in this review on oligonucleotide-based therapeutics.

Genetics of Triglyceride-Rich Lipoproteins Guide Identification of Pharmacotherapy for Cardiovascular Risk Reduction

OBJECTIVE

Despite aggressive reduction of low-density lipoprotein cholesterol (LDL-C), there is a residual risk of cardiovascular disease (CVD). Hypertriglyceridemia is known to be associated with increased CVD risk, independently of LDL-C. Triglycerides are one component of the heterogenous class of triglyceride-rich lipoproteins (TGRLs).

METHODS/RESULTS

Growing evidence from biology, epidemiology, and genetics supports the contribution of TGRLs to the development of CVD via a number of mechanisms, including through proinflammatory, proapoptotic, and procoagulant pathways.

CONCLUSION

New genetics-guided pharmacotherapies to reduce levels of triglycerides and TGRLs and thus reduce risk of CVD have been developed and will be discussed here.

Advances in biological therapies for dyslipidemias and atherosclerosis

Atherosclerosis is a multifactorial disease influenced by genetics, lifestyle and environmental factors. Despite therapeutic advances that reduce the risk of cardiovascular events, atherosclerosis-related diseases remain the leading cause of mortality worldwide. Precise targeting of genes involved in lipoprotein metabolism is an emerging approach for atherosclerosis prevention and treatment. This article focuses on the latest developments, clinical potential and current challenges of monoclonal antibodies, vaccines and genome/transcriptome modification strategies, including antisense oligonucleotides, genome/base editing and gene therapy. Multiple lipid lowering biological therapies have already been approved by the FDA with impressive results to date, while many more promising targets are being pursued in clinical trials or pre-clinical animal models.

Recent Updates of Lipoprotein(a) and Cardiovascular Disease

In recent years, epidemiological studies, genome-wide association studies, and Mendelian randomization studies have shown a strong association between increased levels of lipoproteins and increased risks of coronary heart disease and cardiovascular disease (CVD). Although lipoprotein(a) [Lp(a)] was an independent risk factor for ASCVD, the latest international clinical guidelines do not recommend direct reduction of plasma Lp(a) concentrations. The main reason was that there is no effective clinical medicine that directly lowers plasma Lp(a) concentrations. However, recent clinical trials have shown that proprotein convertase subtilisin/kexin-type 9 inhibitors (PCSK9) and second-generation antisense oligonucleotides can effectively reduce plasma Lp(a) levels. This review will present the structure, pathogenicity, prognostic evidences, and recent advances in therapeutic drugs for Lp(a).

Interrogation of selected genes influencing serum LDL-Cholesterol levels in patients with well characterized NAFLD

BACKGROUND

The clinical significance of rare mutations in LDL metabolism genes on nonalcoholic fatty liver disease (NAFLD) severity is not well understood.

OBJECTIVE

To examine the significance of mutations in LDL metabolism genes including apolipoprotein B (APOB), proprotein convertase subtilisin kexin 9 (PCSK9) and LDL receptor (LDLR) in patients with NAFLD.

METHODS

Patients with biopsy-confirmed NAFLD from the NASH Clinical Research Network studies were stratified into 3 groups of LDL-C (≤50 mg/dL, 130-150 mg/dL, ≥ 190 mg/dL) and then 120 (40 per group) were randomly selected from the strata. We examined the presence of mutations on LDL genes and analyzed its association with selected NAFLD-related features. Multivariable analyses were adjusted for age, race, gender and use of statins.

RESULTS

Among 40 patients with LDL-C ≤ 50 mg/dL, 7 (18%) patients had heterozygous variants in APOB and 2 had heterozygous variants in PCSK9 (5%). We also found heterozygous mutations in 3 (8%) patients with LDL-C ≥ 190 mg/dL; 2 and 1 located in LDLR and APOE genes, respectively. Compared to wild-type controls with LDL-C ≤ 50, APOB carriers displayed higher levels of alanine aminotransferase (85.86 ± 35.14 U/L vs 45.61 ± 20.84 U/L, Adj. P = 0.002) and steatosis >66% (57% vs 24%, Adj. P = 0.050). These associations remained statistically significant after excluding statin users. Other histological features of NAFLD severity were not different between wild-type controls and APOB mutation carriers.

CONCLUSION

Mutations in the APOB gene are common among NAFLD patients with very low LDL-C and may be associated with increased aminotransferase levels and steatosis severity.

Phenotypic Differences Between Polygenic and Monogenic Hypobetalipoproteinemia

OBJECTIVE

Primary hypobetalipoproteinemia is characterized by LDL-C (low-density lipoprotein cholesterol) concentrations below the fifth percentile. Primary hypobetalipoproteinemia mostly results from heterozygous mutations in the APOB (apolipoprotein B) and PCSK9 genes, and a polygenic origin is hypothesized in the remaining cases. Hypobetalipoproteinemia patients present an increased risk of nonalcoholic fatty liver disease and steatohepatitis. Here, we compared hepatic alterations between monogenic, polygenic, and primary hypobetalipoproteinemia of unknown cause. Approach and Results: Targeted next-generation sequencing was performed in a cohort of 111 patients with hypobetalipoproteinemia to assess monogenic and polygenic origins using an LDL-C-dedicated polygenic risk score. Forty patients (36%) had monogenic hypobetalipoproteinemia, 38 (34%) had polygenic hypobetalipoproteinemia, and 33 subjects (30%) had hypobetalipoproteinemia from an unknown cause. Patients with monogenic hypobetalipoproteinemia had lower LDL-C and apolipoprotein B plasma levels compared with those with polygenic hypobetalipoproteinemia. Liver function was assessed by hepatic ultrasonography and liver enzymes levels. Fifty-nine percent of patients with primary hypobetalipoproteinemia presented with liver steatosis, whereas 21% had increased alanine aminotransferase suggestive of liver injury. Monogenic hypobetalipoproteinemia was also associated with an increased prevalence of liver steatosis (81% versus 29%, P<0.001) and liver injury (47% versus 0%) compared with polygenic hypobetalipoproteinemia.

CONCLUSIONS

This study highlights the importance of genetic diagnosis in the clinical care of primary hypobetalipoproteinemia patients. It shows for the first time that a polygenic origin of hypobetalipoproteinemia is associated with a lower risk of liver steatosis and liver injury versus monogenic hypobetalipoproteinemia. Thus, polygenic risk score is a useful tool to establish a more personalized follow-up of primary hypobetalipoproteinemia patients.

An evidence map of randomised controlled trials evaluating genetic therapies

OBJECTIVES

Genetic therapies replace or inactivate disease-causing genes or introduce new or modified genes. These therapies have the potential to cure in a single application rather than treating symptoms through repeated administrations. This evidence map provides a broad overview of the genetic therapies that have been evaluated in randomised controlled trials (RCTs) for efficacy and safety.

ELIGIBILITY CRITERIA

Two independent reviewers screened publications using predetermined eligibility criteria. Study details and data on safety and efficacy were abstracted from included trials. Results were visualised in an evidence map.

INFORMATION SOURCES

We searched PubMed, EMBASE, Web of Science, ClinicalTrials.gov and grey literature to November 2018.

RISK OF BIAS

Only RCTs were included in this review to reduce the risk of selection bias in the evaluation of genetic therapy safety and efficacy.

INCLUDED STUDIES

We identified 119 RCTs evaluating genetic therapies for a variety of clinical conditions.

SYNTHESIS OF RESULTS

On average, samples included 107 participants (range: 1-1022), and were followed for 15 months (range: 0-124). Interventions using adenoviruses (40%) to treat cardiovascular diseases (29%) were the most common.

DESCRIPTION OF THE EFFECT

In RCTs reporting safety and efficacy outcomes, in the majority (60%) genetic therapies were associated with improved symptoms but in nearly half (45%) serious adverse event (SAEs) were also reported. Improvement was reported in trials treating cancer, cardiovascular, ocular and muscular diseases. However, only 19 trials reported symptom improvement for at least 1 year.

STRENGTHS AND LIMITATIONS OF EVIDENCE

This is the first comprehensive evidence map of RCTs evaluating the safety and efficacy of genetic therapies. Evidence for long-term effectiveness and safety is still sparse. This lack of evidence has implications for the use, ethics, pricing and logistics of genetic therapies.

INTERPRETATION

This evidence map provides a broad overview of research studies that allow strong evidence statements regarding the safety and efficacy of genetic therapies. Most interventions improve symptoms, but SAE are also common. More research is needed to evaluate genetic therapies with regard to the potential to cure diseases.

RNA Drugs and RNA Targets for Small Molecules: Principles, Progress, and Challenges

RNA-based therapies, including RNA molecules as drugs and RNA-targeted small molecules, offer unique opportunities to expand the range of therapeutic targets. Various forms of RNAs may be used to selectively act on proteins, transcripts, and genes that cannot be targeted by conventional small molecules or proteins. Although development of RNA drugs faces unparalleled challenges, many strategies have been developed to improve RNA metabolic stability and intracellular delivery. A number of RNA drugs have been approved for medical use, including aptamers (e.g., pegaptanib) that mechanistically act on protein target and small interfering RNAs (e.g., patisiran and givosiran) and antisense oligonucleotides (e.g., inotersen and golodirsen) that directly interfere with RNA targets. Furthermore, guide RNAs are essential components of novel gene editing modalities, and mRNA therapeutics are under development for protein replacement therapy or vaccination, including those against unprecedented severe acute respiratory syndrome coronavirus pandemic. Moreover, functional RNAs or RNA motifs are highly structured to form binding pockets or clefts that are accessible by small molecules. Many natural, semisynthetic, or synthetic antibiotics (e.g., aminoglycosides, tetracyclines, macrolides, oxazolidinones, and phenicols) can directly bind to ribosomal RNAs to achieve the inhibition of bacterial infections. Therefore, there is growing interest in developing RNA-targeted small-molecule drugs amenable to oral administration, and some (e.g., risdiplam and branaplam) have entered clinical trials. Here, we review the pharmacology of novel RNA drugs and RNA-targeted small-molecule medications, with a focus on recent progresses and strategies. Challenges in the development of novel druggable RNA entities and identification of viable RNA targets and selective small-molecule binders are discussed. SIGNIFICANCE STATEMENT: With the understanding of RNA functions and critical roles in diseases, as well as the development of RNA-related technologies, there is growing interest in developing novel RNA-based therapeutics. This comprehensive review presents pharmacology of both RNA drugs and RNA-targeted small-molecule medications, focusing on novel mechanisms of action, the most recent progress, and existing challenges.

Lomitapide for treatment of homozygous familial hypercholesterolemia: The Québec experience

BACKGROUND AND AIMS

Homozygous familial hypercholesterolemia (HoFH) is an orphan disease, most often caused by bi-allelic mutations of the LDLR gene. Patients with HoFH have elevated LDL-C levels >13 mmol/L, tendinous xanthomata and severe, premature atherosclerotic cardiovascular disease (ASCVD). Untreated, most HoFH patients die of ASCVD in youth. New therapeutic modalities include lomitapide, an inhibitor of microsomal triglyceride transfer protein that lowers hepatic LDL-C production. We have recently identified 79 Canadian patients with HoFH. Here, we describe our experience with lomitapide in the province of Quebec, a geographic area known to have a high prevalence of HoFH.

METHODS

This is a retrospective case series of 12 HoFH patients followed at three lipidology centers in the province of Quebec.

RESULTS

Mean age of the patients was 44 ± 18 years; age at time of HoFH diagnosis ranged from 2 to 59 years. All patients were on a statin and ezetimibe 10 mg/day and five patients were treated with LDL apheresis. Treatment with lomitapide reduced LDL-C levels by 38% (intention-to-treat). Intolerable gastrointestinal side effects were observed in 3/12 patients and were the main reason for treatment discontinuation. Three patients tolerated lomitapide at doses ranging between 5 and 30 mg/day without major side effects. Downwards drug titration was necessary in the 6 remaining patients because of gastrointestinal side effects (n = 5) and elevated liver enzymes (n = 1), and 2 of them finally discontinued treatment.

CONCLUSIONS

Lomitapide may be used to further decrease LDL-C in HoFH patients; gastrointestinal side effects and hepatic toxicity may limit adherence.