Inclisiran for the Treatment of Heterozygous Familial Hypercholesterolemia

Working towards full eradication of lipid-driven cardiovascular risk?

Lipid-driven cardiovascular disease (CVD) risk is caused by atherogenic apolipoprotein B (apoB) particles containing low-density lipoprotein cholesterol (LDL-C), triglycerides and lipoprotein(a) [Lp(a)] and resembles a large and modifiable proportion of the total CVD risk. While a surplus of novel lipid-lowering therapies has been developed in recent years, management of lipid-driven CVD risk in the Netherlands remains suboptimal. To lower LDL‑C levels, statins, ezetimibe and proprotein convertase subtilisin/kexin type 9 inhibiting antibodies are the current standard of therapy. With the approval of bempedoic acid and the silencing RNA inclisiran, therapeutic options are expanding continuously. Although the use of triglyceride-lowering therapies remains a matter of debate, post hoc analyses consistently show a benefit in subsets of patients with high triglyceride or low high-density lipoprotein cholesterol levels. Pemafibrate and novel apoC-III could be efficacious options when approved for clinical use. Lp(a)-lowering therapies such as pelacarsen are under clinical investigation, offering a potent Lp(a)-lowering effect. If proven effective in reducing cardiovascular endpoints, Lp(a) lowering holds promise to be the third axis of effective lipid-lowering therapies. Using these three components of lipid-lowering treatment, the contribution of apoB-containing lipid particles to the CVD risk may be fully eradicated in the next decade.

Chirality matters: stereo-defined phosphorothioate linkages at the termini of small interfering RNAs improve pharmacology in vivo

A critical challenge for the successful development of RNA interference-based therapeutics therapeutics has been the enhancement of their in vivo metabolic stability. In therapeutically relevant, fully chemically modified small interfering RNAs (siRNAs), modification of the two terminal phosphodiester linkages in each strand of the siRNA duplex with phosphorothioate (PS) is generally sufficient to protect against exonuclease degradation in vivo. Since PS linkages are chiral, we systematically studied the properties of siRNAs containing single chiral PS linkages at each strand terminus. We report an efficient and simple method to introduce chiral PS linkages and demonstrate that Rp diastereomers at the 5′ end and Sp diastereomers at the 3′ end of the antisense siRNA strand improved pharmacokinetic and pharmacodynamic properties in a mouse model. In silico modeling studies provide mechanistic insights into how the Rp isomer at the 5′ end and Sp isomer at the 3′ end of the antisense siRNA enhance Argonaute 2 (Ago2) loading and metabolic stability of siRNAs in a concerted manner.

An oral antisense oligonucleotide for PCSK9 inhibition

Inhibitors of proprotein convertase subtilisin/kexin type 9 (PCSK9) reduce low-density lipoprotein (LDL) cholesterol and are used for treatment of dyslipidemia. Current PCSK9 inhibitors are administered via subcutaneous injection. We present a highly potent, chemically modified PCSK9 antisense oligonucleotide (ASO) with potential for oral delivery. Past attempts at oral delivery using earlier-generation ASO chemistries and transient permeation enhancers provided encouraging data, suggesting that improving potency of the ASO could make oral delivery a reality. The constrained ethyl chemistry and liver targeting enabled by N-acetylgalactosamine conjugation make this ASO highly potent. A single subcutaneous dose of 90 mg reduced PCSK9 by >90% in humans with elevated LDL cholesterol and a monthly subcutaneous dose of around 25 mg is predicted to reduce PCSK9 by 80% at steady state. To investigate the feasibility of oral administration, the ASO was coformulated in a tablet with sodium caprate as permeation enhancer. Repeated oral daily dosing in dogs resulted in a bioavailability of 7% in the liver (target organ), about fivefold greater than the plasma bioavailability. Target engagement after oral administration was confirmed by intrajejunal administration of a rat-specific surrogate ASO in solution with the enhancer to rats and by plasma PCSK9 and LDL cholesterol lowering in cynomolgus monkey after tablet administration. On the basis of an assumption of 5% liver bioavailability after oral administration in humans, a daily dose of 15 mg is predicted to reduce circulating PCSK9 by 80% at steady state, supporting the development of the compound for oral administration to treat dyslipidemia.

Application of a risk stratification tool for familial hypercholesterolaemia in primary care: an observational cross-sectional study in an unselected urban population

OBJECTIVE

The Familial Hypercholesterolaemia Case Ascertainment Tool (FAMCAT) has been proposed to enhance case finding in primary care. In this study, we test application of the FAMCAT algorithm to describe risks of familial hypercholesterolaemia (FH) in a large unselected and ethnically diverse primary care cohort.

METHOD

We studied patients aged 18-65 years from three contiguous areas in inner London. We retrospectively applied the FAMCAT algorithm to routine primary care data and estimated the numbers of possible cases of FH and the potential service implications of subsequent investigation and management.

RESULTS

Of the 777 128 patients studied, the FAMCAT score estimated between 11 736 and 23 798 (1.5%-3.1%) individuals were likely to have FH, depending on an assumed FH prevalence of 1 in 250 or 1 in 500, respectively. There was over-representation of individuals of South Asian ethnicity among those likely to have FH, with this cohort making up 41.9%-45.1% of the total estimated cases, a proportion which significantly exceeded their 26% representation in the study population.

CONCLUSIONS

We have demonstrated feasibility of application of the FAMCAT as an aid to case finding for FH using routinely recorded primary care data. Further research is needed on validity of the tool in different ethnic groups and more refined consideration of family history should be explored. While FAMCAT may aid case finding, implementation requires information on the cost-effectiveness of additional health services to investigate, diagnose and manage case ascertainment in those identified as likely to have FH.

The effectiveness and value of bempedoic acid and inclisiran for heterozygous familial hypercholesterolemia and secondary prevention of ASCVD

DISCLOSURES: Funding for this summary was contributed by Arnold Ventures, California Health Care Foundation, The Donaghue Foundation, Harvard Pilgrim Health Care, and Kaiser Foundation Health Plan to the Institute for Clinical and Economic Review (ICER), an independent organization that evaluates the evidence on the value of health care interventions. ICER's annual policy summit is supported by dues from AbbVie, Aetna, America's Health Insurance Plans, Anthem, Alnylam, AstraZeneca, Biogen, Blue Shield of CA, Boehringer-Ingelheim, Cambia Health Services, CVS, Editas, Evolve Pharmacy, Express Scripts, Genentech/Roche, GlaxoSmithKline, Harvard Pilgrim, Health Care Service Corporation, HealthFirst, Health Partners, Humana, Johnson & Johnson (Janssen), Kaiser Permanente, LEO Pharma, Mallinckrodt, Merck, Novartis, National Pharmaceutical Council, Pfizer, Premera, Prime Therapeutics, Regeneron, Sanofi, Spark Therapeutics, uniQure, and United Healthcare. Agboola, McKenna, and Pearson are employed by ICER. Lin and Kazi received funding from ICER for work on this report.

Liver-Targeted Delivery of Oligonucleotides with N-Acetylgalactosamine Conjugation

The potential therapeutic application of oligonucleotides (ONs) that selectively suppress target genes through antisense and RNA interference mechanisms has attracted great attention. The clinical applications of ONs have overcome multiple obstacles and become one of the most active areas for the development of novel therapeutics. To achieve efficient and specific cellular internalization, conjugation of a variety of functional groups to ONs has been the subject of intensive investigations over the past decade. Among them, a promising liver-targeted N-acetylgalactosamine (GalNAc) ligand has been evaluated in multiple preclinical and clinical trials for improving the cellular uptake and tissue specific delivery of ONs. GalNAc-based delivery relies on the fact that liver hepatocytes abundantly and specifically express the asialoglycoprotein receptor that binds and uptakes circulating glycoproteins via receptor-mediated endocytosis. In recent years, encouraging progress has been made in the field of GalNAc conjugates. This review aims to provide an overview of GalNAc-mediated liver-targeted delivery of small interfering RNA and antisense oligonucleotides, and the immense effort as well as recent advances in the development of GalNAc-conjugated agents are described.

The emerging landscape of peptide-based inhibitors of PCSK9

Proprotein convertase subtilisin/kexin type 9 (PCSK9) is a clinically validated target for treating cardiovascular disease (CVD) due to its involvement in cholesterol metabolism. Although approved monoclonal antibodies (alirocumab and evolocumab) that inhibit PCSK9 function are very effective in lowering cholesterol, their limitations, including high treatment costs, have so far prohibited widespread use. Accordingly, there is great interest in alternative drug modalities to antibodies. Like antibodies, peptides are valuable therapeutics due to their high target potency and specificity. Furthermore, being smaller than antibodies means they have access to more drug administration options, are less likely to induce adverse immunogenic responses, and are better suited to affordable production. This review surveys the current peptide-based landscape aimed towards PCSK9 inhibition, covering pre-clinical to patented drug candidates and comparing them to current cholesterol lowering therapeutics. Classes of peptides reported to be inhibitors include nature-inspired disulfide-rich peptides, combinatorially derived cyclic peptides, and peptidomimetics. Their functional activities have been validated in biophysical and cellular assays, and in some cases pre-clinical mouse models. Recent efforts report peptides with potent sub-nanomolar binding affinities to PCSK9, which highlights their potential to achieve antibody-like potency. Studies are beginning to address pharmacokinetic properties of PCSK9-targeting peptides in more detail. We conclude by highlighting opportunities to investigate their biological effects in pre-clinical models of cardiovascular disease. The anticipation concerning the PCSK9-targeting peptide landscape is accelerating and it seems likely that a peptide-based therapeutic for treating PCSK9-mediated hypercholesterolemia may be clinically available in the near future.

Emerging Role of Long Non-Coding RNAs in Diabetic Vascular Complications

Chronic metabolic disorders such as obesity and diabetes are associated with accelerated rates of macrovascular and microvascular complications, which are leading causes of morbidity and mortality worldwide. Further understanding of the underlying molecular mechanisms can aid in the development of novel drug targets and therapies to manage these disorders more effectively. Long non-coding RNAs (lncRNAs) that do not have protein-coding potential are expressed in a tissue- and species-specific manner and regulate diverse biological processes. LncRNAs regulate gene expression in cis or in trans through various mechanisms, including interaction with chromatin-modifying proteins and other regulatory proteins and via posttranscriptional mechanisms, including acting as microRNA sponges or as host genes of microRNAs. Emerging evidence suggests that major pathological factors associated with diabetes such as high glucose, free fatty acids, proinflammatory cytokines, and growth factors can dysregulate lncRNAs in inflammatory, cardiac, vascular, and renal cells leading to altered expression of key inflammatory genes and fibrotic genes associated with diabetic vascular complications. Here we review recent reports on lncRNA characterization, functions, and mechanisms of action in diabetic vascular complications and translational approaches to target them. These advances can provide new insights into the lncRNA-dependent actions and mechanisms underlying diabetic vascular complications and uncover novel lncRNA-based biomarkers and therapies to reduce disease burden and mortality.

The Role of RNA-Targeted Therapeutics to Reduce ASCVD Risk: What Have We Learned Recently?

PURPOSE OF REVIEW

To discuss advances on the RNA-targeted therapies to treat dyslipidemia with the aim of reducing atherosclerotic cardiovascular disease (ASCVD).

RECENT FINDINGS

Genetic studies have paved the way for therapies that reduce translation of proteins that play causal roles in dyslipidemia and atherosclerosis like proprotein convertase subtilisin/kexin type 9 (PCSK9), apolipoprotein B-100 (apoB), apolipoprotein(a) [apo(a)], apolipoprotein C3 (apoC3), and angiopoietin-like 3 (ANGPTL3). Either antisense oligonucleotide (ASO) therapies and small interfering RNA (siRNA) molecules inhibit protein synthesis and consequently improve dyslipidemia. Most of these molecules contain N-acetylgalactosamine (GalNAc) moieties that have high specificity for hepatocytes and therefore reduce concentration in other tissues. Inclisiran, an siRNA for PCSK9, has shown robust LDL-C reductions, with good tolerability, in severe forms of hypercholesterolemia as well as in high cardiovascular disease patients with injections every 3 to 6 months. Pelacarsen is an ASO against apolipoprotein(a) that reduces Lp(a) up to 80% with good tolerability. Either inclisiran or pelacarsen is being tested to show it can prevent ASCVD. AMG 890, an siRNA compound aimed at reducing apo(a) synthesis, is also under investigation. Volanesorsen is an ASO against apoC3 that reduces triglyceride levels up to 70% and is being tested in severe hypertriglyceridemic patients. Vupanorsen is an ASO against ANGPTL3 that reduced triglyceride levels 36-53% among moderate hypertriglyceridemic individuals. Interestingly, it also reduces ApoC3 and non-HDL cholesterol and apoB; however, it lowers HDL cholesterol. RNA-targeted therapies are being extensively tested for dyslipidemia treatment with promising results.

Novel RNAi-Based Therapies for Atherosclerosis

PURPOSE OF REVIEW

Atherosclerosis, defined by inflammation and accumulation of cholesterol, extracellular matrix, and cell debris into the arteries is a common factor behind cardiovascular diseases (CVD), such as coronary artery disease, peripheral artery disease, and stroke. In this review, we discuss and describe novel RNA interference (RNAi)-based therapies in clinical trials and on the market.

RECENT FINDINGS

The first RNAi-based therapies have entered clinical use for the control of atherosclerosis risk factors, i.e., blood cholesterol levels. The most advanced treatment is silencing of proprotein convertase subtilisin/kexin type 9 (PCSK9) with a drug called inclisiran, which has been approved for the treatment of hypercholesterolemia in late 2020, and results in a robust decrease in plasma cholesterol levels. As the new RNAi therapies for atherosclerosis are now entering markets, the usefulness of these therapies will be further evaluated in larger patient cohorts. Thus, it remains to be seen how fast, effectively and eminently these new drugs consolidate their niche within the cardiovascular disease drug palette.

Targeting NF-κB with Nanotherapy in a Mouse Model of Adult T-Cell Leukemia/Lymphoma

Adult T-cell leukemia/lymphoma (ATLL) is an aggressive, clonal malignancy of mature T cells caused by human T-cell leukemia virus type 1. Although it is a rare tumor type, it serves as an excellent model of a virus driven process that transforms cells and engenders a highly malignant tumor that is extraordinarily difficult to treat. The viral transcriptional transactivator (Tax) in the HTLV-1 genome directly promotes tumorigenesis, and Tax-induced oncogenesis depends on its ability to constitutively activate NF-κB signaling. Accordingly, we developed and evaluated a nano-delivery system that simultaneously inhibits both canonical (p65) and noncanonical (p100) NF-κB signaling pathways locally in tumors after systemic administration. Our results demonstrate that siRNA is delivered rapidly to ATLL tumors after either i.p. or i.v. injection. The siRNA treatment significantly reduced both p65 and p100 mRNA and protein expression. Anti-NF-κB nanotherapy significantly inhibited tumor growth in two distinct tumor models in mice: a spontaneous Tax-driven tumor model, and a Tax tumor cell transplant model. Moreover, siRNA nanotherapy sensitized late-stage ATLL tumors to the conventional chemotherapeutic agent etoposide, indicating a pleiotropic benefit for localized siRNA nanotherapeutics.

Beyond Statins and PCSK9 Inhibitors: Updates in Management of Familial and Refractory Hypercholesterolemias

PURPOSE OF REVIEW

Elevation in apolipoprotein B-containing lipoproteins in the blood is a cause of atherosclerosis. Statins have changed the preventive cardiology scenario, and more recently monoclonal proprotein convertase subtilisin kexin type 9 (PCSK9) inhibitors were added as robust agents to further reduce pro-atherogenic lipoproteins and therefore prevent cardiovascular events. However, despite this many dyslipidemic individuals persist with inadequate LDL-C levels and still at risk. The purpose of this review was to discuss current status and describe advances in therapies beyond statins and monoclonal PCSK9 inhibitors.

RECENT FINDINGS

Ezetimibe and lomitapide have been used for many years to further reduce LDL-C and longer term data reinforce their safety. Bempedoic acid, an inhibitor of adenosine triphosphate-citrate lyase, has been shown to add LDL-C reduction on top of statins and ezetimibe, furthermore it may be an alternative for statin intolerant patients. Inclisiran is a small interfering ribonucleic acid inhibitor that reduces the hepatic production of PCSK9 that induces robust LDL-C lowering, similar to monoclonal antibodies, with the advantage of 2 or 3 injections per year. So far, no safety signs were seen with its use. Evinacumab, a monoclonal antibody that binds angiopoietin-like protein 3 (ANGPTL3), induces robust LDL-C lowering in either homozygous familial hypercholesterolemia or severe hypercholesterolemia patients with good tolerability. Many high-risk individuals persist with elevated LDL-C, newer medications further lower LDL-C on top of standard lipid-lowering therapies and are well tolerated. Ongoing clinical trials may prove if these novel medications will reduce cardiovascular events with safety.

Inclisiran-Silencing the Cholesterol, Speaking up the Prognosis

The reduction of circulating low-density lipoprotein-cholesterol (LDL-C) is a primary target in cardiovascular risk reduction due to its well-established benefits in terms of decreased mortality. Despite the use of statin therapy, 10%-20% of high- and very-high-risk patients do not reach their LDL-C targets. There is an urgent need for improved strategies to manage dyslipidemia, especially among patients with homozygous familial hypercholesterolemia, but also in patients with established cardiovascular disease who fail to achieve LDL goals despite combined statin, ezetimibe, and PCSK9 inhibitor (PCSK9i) therapy. Inclisiran is a disruptive, first-in-class small interfering RNA (siRNA)-based therapeutic developed for the treatment of hypercholesterolemia that inhibits proprotein convertase subtilisin-kexin type 9 (PCSK9) synthesis, thereby upregulating the number of LDL receptors on the hepatocytes, thus lowering the plasma LDL-C concentration. Inclisiran decreases the LDL-C levels by over 50% with one dose every 6 months, making it a simple and well-tolerated treatment strategy. In this review, we summarize the general information regarding (i) the role of LDL-C in atherosclerotic cardiovascular disease, (ii) data regarding the role of PCSK9 in cholesterol metabolism, (iii) pleiotropic effects of PCSK9, and (iv) the effects of PCSK9 silencing. In addition, we focus on inclisiran, in terms of its (i) mechanism of action, (ii) biological efficacy and safety, (iii) results from the ORION trials, (iv) benefits of its combination with statins, and (v) its potential future role in atherosclerotic cardiovascular disease.

The Johns Hopkins Ciccarone Center's expanded 'ABC's approach to highlight 2020 updates in cardiovascular disease prevention

In recent years, improvement in outcomes related to cardiovascular disease is in part due to the prioritization and progress of primary and secondary prevention efforts. The Johns Hopkins Ciccarone Center for the Prevention of Cardiovascular Disease expanded 'ABC's approach is used to highlight key findings in Preventive Cardiology from 2020 and further emphasize the importance of cardiovascular prevention. This simplified approach helps clinicians focus on the most relevant and up to date recommendations for optimizing cardiovascular disease risk through accurate risk assessment and appropriate implementation of lifestyle, behavioral and pharmacologic interventions. While 2020 not only provided practice changing updates by way of clinical guidelines and randomized controlled trials on topics related to antithrombotic and lipid lowering therapy, diabetes management and risk assessment, it also provided promising data on how to improve dietary and exercise adherence and manage genetic risk. By providing clinicians with a systematic approach to cardiovascular prevention and key highlights from the prior year, the goal of significantly reducing the burden of cardiovascular disease worldwide can be achieved.

Lipid nanoparticle formulations for targeting leukocytes with therapeutic RNA in liver fibrosis

Obesity and low-grade inflammation are promoters of a multitude of diseases including liver fibrosis. Activation of the mobile leukocytes has a major impact on the outcome of inflammatory disease and can hence foster or mitigate liver fibrosis. This renders immunological targets valuable for directed interventions using nanomedicines. Particularly, RNA-based drugs formulated as lipid nanoparticles (LNP) can open new avenues for the personalized treatment of liver fibrosis both through specific interference and via the induction of the expression of functional and therapeutic proteins. Using microfluidics technology, all components, including lipid-anchored targeting ligands, are assembled in a single-step mixing process. A highlight is set to immunologically relevant liver cell types that are most vulnerable for being reached by LNP. A selection of LNP from other therapeutic fields applicable for reaching these cells in liver fbrosis is summarized. Furthermore, recent proceedings and major obstacles in the field of these targeted LNP are presented.

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.

Translating genetic association of lipid levels for biological and clinical application

PURPOSE OF REVIEW

This review focuses on the foundational evidence from the last two decades of lipid genetics research and describes the current status of data-driven approaches for transethnic GWAS, fine-mapping, transcriptome informed fine-mapping, and disease prediction.

RECENT FINDINGS

Current lipid genetics research aims to understand the association mechanisms and clinical relevance of lipid loci as well as to capture population specific associations found in global ancestries. Recent genome-wide trans-ethnic association meta-analyses have identified 118 novel lipid loci reaching genome-wide significance. Gene-based burden tests of whole exome sequencing data have identified three genes-PCSK9, LDLR, and APOB-with significant rare variant burden associated with familial dyslipidemia. Transcriptome-wide association studies discovered five previously unreported lipid-associated loci. Additionally, the predictive power of genome-wide genetic risk scores amalgamating the polygenic determinants of lipid levels can potentially be used to increase the accuracy of coronary artery disease prediction.

CONCLUSIONS

Lipids are one of the most successful group of traits in the era of genome-wide genetic discovery for identification of novel loci and plausible drug targets. However, a substantial fraction of lipid trait heritability remains unexplained. Further analysis of diverse ancestries and state of the art methods for association locus refinement could potentially reveal some of this missing heritability and increase the clinical application of the genomic association results.

PCSK9 Biology and Its Role in Atherothrombosis

It is now about 20 years since the first case of a gain-of-function mutation involving the as-yet-unknown actor in cholesterol homeostasis, proprotein convertase subtilisin/kexin type 9 (PCSK9), was described. It was soon clear that this protein would have been of huge scientific and clinical value as a therapeutic strategy for dyslipidemia and atherosclerosis-associated cardiovascular disease (CVD) management. Indeed, PCSK9 is a serine protease belonging to the proprotein convertase family, mainly produced by the liver, and essential for metabolism of LDL particles by inhibiting LDL receptor (LDLR) recirculation to the cell surface with the consequent upregulation of LDLR-dependent LDL-C levels. Beyond its effects on LDL metabolism, several studies revealed the existence of additional roles of PCSK9 in different stages of atherosclerosis, also for its ability to target other members of the LDLR family. PCSK9 from plasma and vascular cells can contribute to the development of atherosclerotic plaque and thrombosis by promoting platelet activation, leukocyte recruitment and clot formation, also through mechanisms not related to systemic lipid changes. These results further supported the value for the potential cardiovascular benefits of therapies based on PCSK9 inhibition. Actually, the passive immunization with anti-PCSK9 antibodies, evolocumab and alirocumab, is shown to be effective in dramatically reducing the LDL-C levels and attenuating CVD. While monoclonal antibodies sequester circulating PCSK9, inclisiran, a small interfering RNA, is a new drug that inhibits PCSK9 synthesis with the important advantage, compared with PCSK9 mAbs, to preserve its pharmacodynamic effects when administrated every 6 months. Here, we will focus on the major understandings related to PCSK9, from its discovery to its role in lipoprotein metabolism, involvement in atherothrombosis and a brief excursus on approved current therapies used to inhibit its action.

Antiplatelet Effects of PCSK9 Inhibitors in Primary Hypercholesterolemia

Proprotein convertase subtilisin-kexin type 9 (PCSK9) inhibitors are a novel group of hypolipidemic drugs that are recommended particularly for high-risk hypercholesterolemia patients, including those with primary hypercholesterolemia (PH), where lifelong exposure to high low-density lipoprotein (LDL) cholesterol levels results in an elevated risk of atherosclerosis at an early age. The onset and progression of atherosclerosis is significantly influenced by activated platelets. Oxidized LDL influences platelet activation by interacting with their surface receptors and remodeling the composition of their cell membrane. This results in platelet aggregation, endothelial cell activation, promotion of inflammation and oxidative stress, and acceleration of lipid accumulation in atherosclerotic plaques. PCSK9 inhibitors reduce platelet activation by both significantly lowering LDL levels and reducing the LDL receptor-mediated activation of platelets by PCSK9. They also work synergistically with other hypolipidemic and antithrombotic drugs, including statins, ezetimibe, acetylsalicylic acid, clopidogrel, and ticagrelor, which enhances their antiplatelet and LDL-lowering effects. In this review, we summarize the currently available evidence on platelet hyperreactivity in PH, the effects of PCSK9 inhibitors on platelets, and their synergism with other drugs used in PH therapy.

Triglyceride-Rich Lipoproteins and Their Remnants as Silent Promoters of Atherosclerotic Cardiovascular Disease and Other Metabolic Disorders: A Review

While targeting elevated serum levels of low-density lipoprotein cholesterol has been the mainstay of atherosclerosis prevention and treatment for decades, the evidence regarding the atherogenic role of hypertriglyceridemia is still controversial. Various epidemiological population-based studies on statin-treated subjects nominated triglycerides, triglyceride-rich lipoproteins (namely, chylomicrons and very-low-density lipoprotein particles), and their remnants as major determinants of the substantial residual cardiovascular risk. With the triglyceride-glucose index and triglyceride to high-density lipoprotein ratio emerging as surrogate indicators of peripheral artery disease and atherosclerotic cerebrovascular disease, one can conclude that further research addressing the intricate relationship between triglycerides and atherosclerosis is warranted. Therefore, this review aims to provide insight into the current clinical and epidemiological state of knowledge on the relationship between triglycerides and atherosclerotic cardiovascular disease. It also intends to highlight the connection between triglycerides and other metabolic disorders, including diabetes mellitus, and the potential benefits of triglyceride-lowering agents on cardiovascular outcomes and all-cause mortality.

From traditional pharmacological towards nucleic acid-based therapies for cardiovascular diseases

Nucleic acid-based therapeutics are currently developed at large scale for prevention and management of cardiovascular diseases (CVDs), since: (i) genetic studies have highlighted novel therapeutic targets suggested to be causal for CVD; (ii) there is a substantial recent progress in delivery, efficacy, and safety of nucleic acid-based therapies; (iii) they enable effective modulation of therapeutic targets that cannot be sufficiently or optimally addressed using traditional small molecule drugs or antibodies. Nucleic acid-based therapeutics include (i) RNA-targeted therapeutics for gene silencing; (ii) microRNA-modulating and epigenetic therapies; (iii) gene therapies; and (iv) genome-editing approaches (e.g. CRISPR-Cas-based): (i) RNA-targeted therapeutics: several large-scale clinical development programmes, using antisense oligonucleotides (ASO) or short interfering RNA (siRNA) therapeutics for prevention and management of CVD have been initiated. These include ASO and/or siRNA molecules to lower apolipoprotein (a) [apo(a)], proprotein convertase subtilisin/kexin type 9 (PCSK9), apoCIII, ANGPTL3, or transthyretin (TTR) for prevention and treatment of patients with atherosclerotic CVD or TTR amyloidosis. (ii) MicroRNA-modulating and epigenetic therapies: novel potential therapeutic targets are continually arising from human non-coding genome and epigenetic research. First microRNA-based therapeutics or therapies targeting epigenetic regulatory pathways are in clinical studies. (iii) Gene therapies: EMA/FDA have approved gene therapies for non-cardiac monogenic diseases and LDL receptor gene therapy is currently being examined in patients with homozygous hypercholesterolaemia. In experimental studies, gene therapy has significantly improved cardiac function in heart failure animal models. (iv) Genome editing approaches: these technologies, such as using CRISPR-Cas, have proven powerful in stem cells, however, important challenges are remaining, e.g. low rates of homology-directed repair in somatic cells such as cardiomyocytes. In summary, RNA-targeted therapies (e.g. apo(a)-ASO and PCSK9-siRNA) are now in large-scale clinical outcome trials and will most likely become a novel effective and safe therapeutic option for CVD in the near future. MicroRNA-modulating, epigenetic, and gene therapies are tested in early clinical studies for CVD. CRISPR-Cas-mediated genome editing is highly effective in stem cells, but major challenges are remaining in somatic cells, however, this field is rapidly advancing.

Inclisiran: A Novel Agent for Lowering Apolipoprotein B-Containing Lipoproteins

ABSTRACT

Hypercholesterolemia is a leading cause of cardiovascular morbidity and mortality. Accordingly, efforts to lower apolipoprotein B-containing lipoproteins in plasma are the centerpiece of strategies for cardiovascular prevention and treatment in primary and secondary management. Despite the importance of this endeavor, many patients do not achieve appropriate low density lipoprotein cholesterol (LDL-C) and non-high density lipoprotein cholesterol (non-HDL-C) goals, even among those who have experienced atherosclerotic cardiovascular disease (ASCVD). The development of new LDL-C-lowering medications with alternative mechanisms of action will facilitate improved goal achievement in high risk patients. Inclisiran is a novel small interfering ribonucleic acid (siRNA)-based drug that is experimental in the US and approved for clinical use in the EU. It lowers LDL-C and other apolipoprotein B-containing lipoproteins by reducing production of Proprotein Convertase Subtilisin/Kexin Type 9 (PCSK9), a protein that normally contributes to LDL-receptor (LDLR) degradation, thereby increasing LDLR density and recycling in hepatocytes. Although the lipid-lowering efficacy of inclisiran is comparable to results achieved with PCSK9-blocking monoclonal antibodies (PCSK9i) (alirocumab and evolocumab), there are several important differences between the two drug classes. First, inclisiran reduces levels of PCSK9 both intracellularly and extracellularly by blocking translation of and degrading PCSK9 messenger RNA. Second, the long biological half-life of inclisiran produces sustained LDL-C-lowering with twice yearly dosing. Third, although PCSK9i drugs are proven to reduce ASCVD events, clinical outcomes trials with inclisiran are still in progress. In this manuscript, we review the clinical development of inclisiran, its mechanism of action, lipid-lowering efficacy, safety and tolerability, and potential clinical role of this promising new agent.

Genetics in Drug Discovery

Drug discovery is a complex process with high attrition rate: only about half of the compounds in advanced preclinical stages actually enter human trials. Key to these failures is our lack of understanding of human biology and the difficulties in translating our preclinical knowledge into cures. Here, we examine how genetics can be leveraged in drug discovery to understand and alter human biology.

Distribution and biotransformation of therapeutic antisense oligonucleotides and conjugates

Drug properties of antisense oligonucleotides (ASOs) differ significantly from those of traditional small-molecule therapeutics. In this review, we focus on ASO disposition, mainly as characterized by distribution and biotransformation, of nonconjugated and conjugated ASOs. We introduce ASO chemistry to allow the following in-depth discussion on bioanalytical methods and determination of distribution and elimination kinetics at low concentrations over extended periods of time. The resulting quantitative data on the parent oligonucleotide, and the identification and quantification of formed metabolites define the disposition. Proper quantitative understanding of disposition is pivotal for nonclinical to clinical predictions, supports communication with health agencies, and increases the probability of delivering optimal ASO therapy to patients.

A meta-analysis of medications directed against PCSK9 in familial hypercholesterolemia

BACKGROUND AND AIMS

Several medications targeting PCSK9 reduce LDL-cholesterol (LDL-C) in heterozygous familial hypercholesterolemia (HeFH). We aimed to assess in patients diagnosed clinically as HeFH, whether LDL-C reduction varied by different therapeutic approaches to PCSK9-targeting or by the underlying genetic variant.

METHODS

We conducted a random-effects meta-analysis of randomised clinical trials assessing PCSK9-targeting therapies, namely alirocumab, evolocumab and inclisiran, in patients with clinically diagnosed HeFH and restricted analyses to those patients in whom genotypic data were available. A search of MEDLINE and Embase identified eligible trials published between inception and June 29, 2020. We included trials of sufficient duration to allow for a stable treatment effect: ~12 weeks for monoclonal antibodies (mAbs) (alirocumab, evolocumab) and ~1 year for small interfering RNA (siRNA) (inclisiran). Single-moderator meta-regression comparing mean percentage LDL-C reduction between mAbs and siRNA as well as PCSK9-targeting therapies between different genotypes was used to assess heterogeneity.

RESULTS

Eight trials of HeFH met our inclusion criteria, including 1887 genotyped patients. Among monogenic HeFH cases (N = 1347) the LDL-C reduction from baseline was 46.12% (95%CI 48.4-43.9) for siRNA and 50.4% (59.3-41.4) for mAbs compared to control, without evidence of significant heterogeneity between treatment (Q_M = 0.32, df = 1, p = 0.57). Irrespective of therapeutic approach to PCSK9-targeting, reductions in LDL-C were generally consistent across genetic variants (LDL-Receptor variants, LDL-Receptor variants of unknown significance, Apolipoprotein B variants, two variants and no variant) (Q_M = 8.3, df = 4, p = 0.08).

CONCLUSIONS

Among patients with HeFH, the LDL-C-lowering effect of PCSK9-targeting medications did not show statistical heterogeneity across different drug-classes and across genetic variants.

Homozygous Familial Hypercholesterolemia

Familial hypercholesterolemia (FH) is an inherited disorder with retarded clearance of plasma LDL caused by mutations of the genes involved in the LDL receptor-mediated pathway and most of them exhibit autosomal dominant inheritance. Homozygotes of FH (HoFH) may have plasma LDL-C levels, which are at least twice as high as those of heterozygous FH (HeFH) and therefore four times higher than normal levels. Prevalence of HoFH had been estimated as 1 in 1,000,000 before but more recent genetic analysis surveys predict 1 in 170,000 to 300,000. Since LDL receptor activity is severely impaired, HoFH patients do not or very poorly respond to medications to enhance activity, such as statins, and have a poorer prognosis compared to HeFH. HoFH should therefore be clinically distinguished from HeFH. Thorough family studies and genetic analysis are recommended for their accurate diagnosis.

Fatal cardiovascular complications could develop even in the first decade of life for HoFH, so aggressive lipid-lowering therapy should be initiated as early as possible. Direct removal of plasma LDL by lipoprotein apheresis has been the principal measure for these patients. However, this treatment alone may not achieve stable LDL-C target levels and combination with drugs should be considered. The lipid-lowering effects of statins and PCSK9 inhibitors substantially vary depending on the remaining LDL receptor activity of individual patients. On the other hand, the action an MTP inhibitor is independent of LDL receptor activity, and it is effective in most HoFH cases.

This review summarizes the key clinical issues of HoFH as well as insurance coverage available under the Japanese public healthcare system.

Targeted Therapy in Cardiovascular Disease: A Precision Therapy Era

Targeted therapy refers to exploiting the specific therapeutic drugs against the pathogenic molecules (a protein or a gene) or cells. The drug specifically binds to disease-causing molecules or cells without affecting normal tissue, thus enabling personalized and precision treatment. Initially, therapeutic drugs included antibodies and small molecules, (e.g. nucleic acid drugs). With the advancement of the biology technology and immunotherapy, the gene editing and cell editing techniques are utilized for the disease treatment. Currently, targeted therapies applied to treat cardiovascular diseases (CVDs) mainly include protein drugs, gene editing technologies, nucleic acid drugs and cell therapy. Although targeted therapy has demonstrated excellent efficacy in pre-clinical and clinical trials, several limitations need to be recognized and overcome in clinical application, (e.g. off-target events, gene mutations, etc.). This review introduces the mechanisms of different targeted therapies, and mainly describes the targeted therapy applied in the CVDs. Furthermore, we made comparative analysis to clarify the advantages and disadvantages of different targeted therapies. This overview is expected to provide a new concept to the treatment of the CVDs.

Practical guidance for combination lipid-modifying therapy in high- and very-high-risk patients: A statement from a European Atherosclerosis Society Task Force

BACKGROUND AND AIMS

This European Atherosclerosis Society (EAS) Task Force provides practical guidance for combination therapy for elevated low-density lipoprotein cholesterol (LDL-C) and/or triglycerides (TG) in high-risk and very-high-risk patients.

METHODS

Evidence-based review.

RESULTS

Statin-ezetimibe combination treatment is the first choice for managing elevated LDL-C and should be given upfront in very-high-risk patients with high LDL-C unlikely to reach goal with a statin, and in primary prevention familial hypercholesterolaemia patients. A proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitor may be added if LDL-C levels remain high. In high and very-high-risk patients with mild to moderately elevated TG levels (>2.3 and < 5.6 mmol/L [>200 and < 500 mg/dL) on a statin, treatment with either a fibrate or high-dose omega-3 fatty acids (icosapent ethyl) may be considered, weighing the benefit versus risks. Combination with fenofibrate may be considered for both macro- and microvascular benefits in patients with type 2 diabetes mellitus.

CONCLUSIONS

This guidance aims to improve real-world use of guideline-recommended combination lipid modifying treatment.

Docosanoic acid conjugation to siRNA enables functional and safe delivery to skeletal and cardiac muscles

Oligonucleotide therapeutics hold promise for the treatment of muscle- and heart-related diseases. However, oligonucleotide delivery across the continuous endothelium of muscle tissue is challenging. Here, we demonstrate that docosanoic acid (DCA) conjugation of small interfering RNAs (siRNAs) enables efficient (~5% of injected dose), sustainable (>1 month), and non-toxic (no cytokine induction at 100 mg/kg) gene silencing in both skeletal and cardiac muscles after systemic injection. When designed to target myostatin (muscle growth regulation gene), siRNAs induced ~55% silencing in various muscle tissues and 80% silencing in heart, translating into a ~50% increase in muscle volume within 1 week. Our study identifies compounds for RNAi-based modulation of gene expression in skeletal and cardiac muscles, paving the way for both functional genomics studies and therapeutic gene modulation in muscle and heart.

Novel therapies for familial hypercholesterolemia

PURPOSE OF REVIEW

Familial hypercholesterolemia is a genetic disorder of defective clearance and subsequent increase in serum LDL cholesterol (LDL-C) with a resultant increased risk of premature atherosclerotic cardiovascular disease. Despite treatment with traditional lipid-lowering therapies (LLT), most patients with familial hypercholesterolemia are unable to achieve target LDL-C. We review current and future novel therapeutic options available for familial hypercholesterolemia.

RECENT FINDINGS

The use of proprotein convertase subtilisin kexin type 9 (PCSK9) inhibitors are effective in lowering LDL-C in patients with familial hypercholesterolemia, with a reduction in LDL-C of 60% in heterozygous familial hypercholesterolemia (HeFH) and up to 35% in homozygous familial hypercholesterolemia (HoFH). Inclisiran, another novel agent, is a small-interfering ribonucleic acid that reduces hepatic production of PCSK9 to provide a prolonged and sustained reduction in LDL-C of nearly 50% in HeFH. However, both agents require LDL receptor (LDLR) activity. Evinacumab, a novel monoclonal antibody against angiopoetin-like 3 (ANGPTL3), reduces LDL-C by 50% independent of LDLR activity.

SUMMARY

Achieving a target LDL-C in familial hypercholesterolemia can be challenging with standard LLT; however, novel therapeutic modalities show remarkable reductions in LDL-C allowing nearly all patients with HeFH and a significant proportion of patients with HoFH to achieve acceptable LDL-C levels.

Role of PCSK9 Inhibitors in Patients with Familial Hypercholesterolemia

Patients with familial hypercholesterolemia (FH) are at high or very high risk for cardiovascular disease. Those with heterozygous FH (HeFH) often do not reach low-density lipoprotein cholesterol (LDL-C) targets with statin and ezetimibe therapy, and those with homozygous FH (HoFH) usually require additional lipid-modifying therapies. Drugs that inhibit proprotein convertase subtilisin/kexin type 9 (PCSK9) offer a novel approach to reduce LDL-C. The monoclonal antibodies, alirocumab and evolocumab, given by subcutaneous injection every 2 or 4 weeks produce reductions in LDL-C of 50% to 60% in patients with HeFH, allowing many of them to achieve their LDL-C goals. Patients with HoFH show a reduced and more variable LDL-C response, which appears to depend on residual LDL receptor activity, and those with receptor-negative mutations may show no response. Inclisiran is a long-acting small interfering RNA therapeutic agent that inhibits the synthesis of PCSK9. Subcutaneous doses of 300 mg can reduce LDL-C by more than 50% for at least 6 months and the responses in HeFH and HoFH patients are similar to those achieved with monoclonal antibodies. These PCSK9 inhibitors are generally well tolerated and they provide a new opportunity for effective treatment for the majority of patients with FH.

Atherosclerosis: Conventional intake of cardiovascular drugs versus delivery using nanotechnology - A new chance for causative therapy?

Atherosclerosis is the leading cause of death in developed countries. The pathogenetic mechanism relies on a macrophage-based immune reaction to low density lipoprotein (LDL) deposition in blood vessels with dysfunctional endothelia. Thus, atherosclerosis is defined as a chronic inflammatory disease. A plethora of cardiovascular drugs have been developed and are on the market, but the major shortcoming of standard medications is that they do not address the root cause of the disease. Statins and thiazolidinediones that have recently been recognized to exert specific anti-atherosclerotic effects represent a potential breakthrough on the horizon. But their whole potential cannot be realized due to insufficient availability at the pathological site and severe off-target effects. The focus of this review will be to elaborate how both groups of drugs could immensely profit from nanoparticulate carriers. This delivery principle would allow for their accumulation in target macrophages and endothelial cells of the atherosclerotic plaque, increasing bioavailability where it is needed most. Based on the analyzed literature we conclude design criteria for the delivery of statins and thiazolidinediones with nanoparticles for anti-atherosclerotic therapy. Nanoparticles need to be below a diameter of 100 nm to accumulate in the atherosclerotic plaque and should be fabricated using biodegradable materials. Further, the thiazolidinediones or statins must be encapsulated into the particle core, because especially for thiazolidindiones the uptake into cells is prerequisite for their mechanism of action. For optimal uptake into targeted macrophages and endothelial cells, the ideal particle should present ligands on its surface which bind specifically to scavenger receptors. The impact of statins on the lectin-type oxidized LDL receptor 1 (LOX1) seems particularly promising because of its outstanding role in the inflammatory process. Using this pioneering concept, it will be possible to promote the impact of statins and thiazolidinediones on macrophages and endothelial cells and significantly enhance their anti-atherosclerotic therapeutic potential.

2021 Canadian Cardiovascular Society Guidelines for the Management of Dyslipidemia for the Prevention of Cardiovascular Disease in Adults

The 2021 guidelines primary panel selected clinically relevant questions and produced updated recommendations, on the basis of important new findings that have emerged since the 2016 guidelines. In patients with clinical atherosclerosis, abdominal aortic aneurysm, most patients with diabetes or chronic kidney disease, and those with low-density lipoprotein cholesterol ≥ 5 mmol/L, statin therapy continues to be recommended. We have introduced the concept of lipid/lipoprotein treatment thresholds for intensifying lipid-lowering therapy with nonstatin agents, and have identified the secondary prevention patients who have been shown to derive the largest benefit from intensification of therapy with these agents. For all other patients, we emphasize risk assessment linked to lipid/lipoprotein evaluation to optimize clinical decision-making. Lipoprotein(a) measurement is now recommended once in a patient's lifetime, as part of initial lipid screening to assess cardiovascular risk. For any patient with triglycerides ˃ 1.5 mmol/L, either non-high-density lipoprotein cholesterol or apolipoprotein B are the preferred lipid parameter for screening, rather than low-density lipoprotein cholesterol. We provide updated recommendations regarding the role of coronary artery calcium scoring as a clinical decision tool to aid the decision to initiate statin therapy. There are new recommendations on the preventative care of women with hypertensive disorders of pregnancy. Health behaviour modification, including regular exercise and a heart-healthy diet, remain the cornerstone of cardiovascular disease prevention. These guidelines are intended to provide a platform for meaningful conversation and shared-decision making between patient and care provider, so that individual decisions can be made for risk screening, assessment, and treatment.

Treatment and prevention of lipoprotein(a)-mediated cardiovascular disease: the emerging potential of RNA interference therapeutics

Lipid- and lipoprotein-modifying therapies have expanded substantially in the last 25 years, resulting in reduction in the incidence of major adverse cardiovascular events. However, no specific lipoprotein(a) [Lp(a)]-targeting therapy has yet been shown to reduce cardiovascular disease risk. Many epidemiological and genetic studies have demonstrated that Lp(a) is an important genetically determined causal risk factor for coronary heart disease, aortic valve disease, stroke, heart failure, and peripheral vascular disease. Accordingly, the need for specific Lp(a)-lowering therapy has become a major public health priority. Approximately 20% of the global population (1.4 billion people) have elevated levels of Lp(a) associated with higher cardiovascular risk, though the threshold for determining ‘high risk’ is debated. Traditional lifestyle approaches to cardiovascular risk reduction are ineffective at lowering Lp(a). To address a lifelong risk factor unmodifiable by non-pharmacological means, Lp(a)-lowering therapy needs to be safe, highly effective, and tolerable for a patient population who will likely require several decades of treatment. N-acetylgalactosamine-conjugated gene silencing therapeutics, such as small interfering RNA (siRNA) and antisense oligonucleotide targeting LPA, are ideally suited for this application, offering a highly tissue- and target transcript-specific approach with the potential for safe and durable Lp(a) lowering with as few as three or four doses per year. In this review, we evaluate the causal role of Lp(a) across the cardiovascular disease spectrum, examine the role of established lipid-modifying therapies in lowering Lp(a), and focus on the anticipated role for siRNA therapeutics in treating and preventing Lp(a)-related disease.

PCSK9 Functions in Atherosclerosis Are Not Limited to Plasmatic LDL-Cholesterol Regulation

The relevance of PCSK9 in atherosclerosis progression is demonstrated by the benefits observed in patients that have followed PCSK9-targeted therapies. The impact of these therapies is attributed to the plasma lipid-lowering effect induced when LDLR hepatic expression levels are recovered after the suppression of soluble PCSK9. Different studies show that PCSK9 is involved in other mechanisms that take place at different stages during atherosclerosis development. Indeed, PCSK9 regulates the expression of key receptors expressed in macrophages that contribute to lipid-loading, foam cell formation and atherosclerotic plaque formation. PCSK9 is also a regulator of vascular inflammation and its expression correlates with pro-inflammatory cytokines release, inflammatory cell recruitment and plaque destabilization. Furthermore, anti-PCSK9 approaches have demonstrated that by inhibiting PCSK9 activity, the progression of atherosclerotic disease is diminished. PCSK9 also modulates thrombosis by modifying platelets steady-state, leukocyte recruitment and clot formation. In this review we evaluate recent findings on PCSK9 functions in cardiovascular diseases beyond LDL-cholesterol plasma levels regulation.

siRNAs containing 2'-fluorinated Northern-methanocarbacyclic (2'-F-NMC) nucleotides: in vitro and in vivo RNAi activity and inability of mitochondrial polymerases to incorporate 2'-F-NMC NTPs

We recently reported the synthesis of 2'-fluorinated Northern-methanocarbacyclic (2'-F-NMC) nucleotides, which are based on a bicyclo[3.1.0]hexane scaffold. Here, we analyzed RNAi-mediated gene silencing activity in cell culture and demonstrated that a single incorporation of 2'-F-NMC within the guide or passenger strand of the tri-N-acetylgalactosamine-conjugated siRNA targeting mouse Ttr was generally well tolerated. Exceptions were incorporation of 2'-F-NMC into the guide strand at positions 1 and 2, which resulted in a loss of the in vitro activity. Activity at position 1 was recovered when the guide strand was modified with a 5' phosphate, suggesting that the 2'-F-NMC is a poor substrate for 5' kinases. In mice, the 2'-F-NMC-modified siRNAs had comparable RNAi potencies to the parent siRNA. 2'-F-NMC residues in the guide seed region position 7 and at positions 10, 11 and 12 were well tolerated. Surprisingly, when the 5'-phosphate mimic 5'-(E)-vinylphosphonate was attached to the 2'-F-NMC at the position 1 of the guide strand, activity was considerably reduced. The steric constraints of the bicyclic 2'-F-NMC may impair formation of hydrogen-bonding interactions between the vinylphosphonate and the MID domain of Ago2. Molecular modeling studies explain the position- and conformation-dependent RNAi-mediated gene silencing activity of 2'-F-NMC. Finally, the 5'-triphosphate of 2'-F-NMC is not a substrate for mitochondrial RNA and DNA polymerases, indicating that metabolites should not be toxic.

Existing and emerging therapies for the treatment of familial hypercholesterolemia

Familial hypercholesterolemia (FH), an autosomal dominant disorder of LDL metabolism that is characterized by elevated LDL-cholesterol, is commonly encountered in patients with atherosclerotic coronary heart disease. Combinations of cholesterol-lowering therapies are often used to lower LDL-cholesterol in patients with FH; however, current treatment goals for LDL-cholesterol are rarely achieved in patients with homozygous FH (HoFH) and are difficult to achieve in patients with heterozygous FH (HeFH). Therapies that lower LDL-cholesterol through LDL receptor-mediated mechanisms have thus far been largely ineffective in patients with HoFH, particularly in those with negligible (<2%) LDL receptor activity. Among patients with HeFH who were at very high risk for atherosclerotic cardiovascular disease events, combined therapy consisting of a high dose of high-intensity statin, ezetimibe, and proprotein convertase subtilisin Kexin type 9 inhibitor failed to lower LDL-cholesterol to minimal acceptable goals in more than 50%. This article provides a framework for the use of available and emerging treatments that lower LDL-cholesterol in adult patients with HoFH and HeFH. A framework is provided for the use of angiopoietin-like protein 3 inhibitors in the treatment of HoFH and HeFH.

Lipid Lowering Drugs: Present Status and Future Developments

Purpose of review

Based on the recent data of the DA VINCI study, it is clear that, besides utilization of statins, there is a need to increase non-statin lipid lowering approaches to reduce the cardiovascular burden in patients at highest risk.

Recent findings

For hypercholesterolemia, the small synthetic molecule bempedoic acid has the added benefit of selective liver activation, whereas inclisiran, a hepatic inhibitor of the PCSK9 synthesis, has comparable effects with PCSK9 monoclonal antibodies. For hypertriglyceridemia, cardiovascular benefit has been achieved by the use of icosapent ethyl, whereas results with pemafibrate, a selective agonist of PPAR-α, are eagerly awaited. In the era of RNA-based therapies, new options are offered to dramatically reduce levels of lipoprotein(a) (APO(a)L_RX) and of triglycerides (ANGPTL3L_RX and APOCIII-L_Rx).

Summary

Despite the demonstrated benefits of statins, a large number of patients still remain at significant risk because of inadequate LDL-C reduction or elevated blood triglyceride-rich lipoproteins or lipoprotein(a). The area of lipid modulating agents is still ripe with ideas and major novelties are to be awaited in the next few years.

Lipid nanoparticle-mediated codelivery of Cas9 mRNA and single-guide RNA achieves liver-specific in vivo genome editing of Angptl3

Loss-of-function mutations in Angiopoietin-like 3 (Angptl3) are associated with lowered blood lipid levels, making Angptl3 an attractive therapeutic target for the treatment of human lipoprotein metabolism disorders. In this study, we developed a lipid nanoparticle delivery platform carrying Cas9 messenger RNA (mRNA) and guide RNA for CRISPR-Cas9-based genome editing of Angptl3 in vivo. This system mediated specific and efficient Angptl3 gene knockdown in the liver of wild-type C57BL/6 mice, resulting in profound reductions in serum ANGPTL3 protein, low density lipoprotein cholesterol, and triglyceride levels. Our delivery platform is significantly more efficient than the FDA-approved MC-3 LNP, the current gold standard. No evidence of off-target mutagenesis was detected at any of the nine top-predicted sites, and no evidence of toxicity was detected in the liver. Importantly, the therapeutic effect of genome editing was stable for at least 100 d after a single dose administration. This study highlights the potential of LNP-mediated delivery as a specific, effective, and safe platform for Cas9-based therapeutics.

Lipoprotein metabolism in familial hypercholesterolemia

Familial hypercholesterolemia (FH) is one of the most common genetic disorders in humans. It is an extremely atherogenic metabolic disorder characterized by lifelong elevations of circulating LDL-C levels often leading to premature cardiovascular events. In this review, we discuss the clinical phenotypes of heterozygous and homozygous FH, the genetic variants in four genes (LDLR/APOB/PCSK9/LDLRAP1) underpinning the FH phenotype as well as the most recent in vitro experimental approaches used to investigate molecular defects affecting the LDL receptor pathway. In addition, we review perturbations in the metabolism of lipoproteins other than LDL in FH, with a major focus on lipoprotein (a). Finally, we discuss the mode of action and efficacy of many of the currently approved hypocholesterolemic agents used to treat patients with FH, with a special emphasis on the treatment of phenotypically more severe forms of FH.

Risk of Recurrent Coronary Events in Patients With Familial Hypercholesterolemia; A 10-Years Prospective Study

Background and Aim: Real world evidence on long term treatment of patients with familial hypercholesterolemia (FH) is important. We studied the effects of intensive lipid lowering medication (LLM) and optimized lifestyle in the study TTTFH–Treat To Target FH.

Materials and Methods: Adults with a first known total cholesterol of mean (95% CI) 9.8 mmol/L (9.5, 10.1) were included consecutively in their routine consultation during 2006. Of the patients 86.4% had a pathogenic FH-mutation and the remaining were clinically diagnosed. We included 357 patients and 279 met for follow-up after median 10.0 (min 8.1, max 12.8) years.

Results: Mean (95% CI) low density lipoprotein (LDL-C) was reduced from 3.9 (3.8, 4.1) to 3.0 (2.9, 3.2). More men than women used high intensity statin treatment, 85.2 and 60.8%, respectively. Women (n = 129) had higher LDL-C; 3.3 mmol/L (3.0, 3.5), than men; (n = 144) 2.8 mmol/L (2.6, 3.0), p = 0.004. Add-on PCSK9 inhibitors (n = 25) reduced mean LDL-C to 2.0 (1.4, 2.6) mmol/L. At enrollment 57 patients (20.4%) had established atherosclerotic cardiovascular disease (ASCVD), and 46 (80.4%) of them experienced a new event during the study period. Similarly, 222 (79.6%) patients had no detectable ASCVD at enrollment, and 29 of them (13.1%) experienced a first-time event during the study period.

Conclusion: A mean LDL-C of 3.0 mmol/L was achievable in FH, treated intensively at a specialized clinic with few users of PCSK9 inhibitors. LDL-C was higher (0.5 mmol/L) in women than in men. In patients with ASCVD at enrollment, most (80.7%) experienced a new ASCVD event in the study period. The FH patients in primary prevention had more moderate CV risk, 13% in ten years.

Personalized medicine in lipid-modifying therapy

The choice of lipid-modifying treatment is largely based on the absolute level of cardiovascular risk and baseline lipid profile. Statins are the first-line treatment for most patients requiring reduction of low-density-lipoprotein cholesterol (LDL-C) and ezetimibe and proprotein convertase subtilisin/kexin type 9 inhibitors can be added to reach LDL-C targets. Statins have some adverse effects that are somewhat predictable based on phenotypic and genetic factors. Fibrates or omega-3 fatty acids can be added if triglyceride levels remain elevated. The RNA-targeted therapeutics in development offer the possibility of selective liver targeting for specific lipoproteins such as lipoprotein(a) and long-term reduction of LDL-C with infrequent administration of a small-interfering RNA may help to overcome the problem of adherence to therapy.

New and Emerging Therapies for Reduction of LDL-Cholesterol and Apolipoprotein B: JACC Focus Seminar 1/4

Adding to the foundation of statins, ezetimibe and proprotein convertase subtilisin-kexin type 9 inhibitors (PCSK9i), novel, emerging low-density lipoprotein cholesterol (LDL-C)-lowering therapies are under development for the prevention of cardiovascular disease. Inclisiran, a small interfering RNA molecule that inhibits PCSK9, only needs to be dosed twice a year and has the potential to help overcome current barriers to persistence and adherence to lipid-lowering therapies. Bempedoic acid, which lowers LDL-C upstream from statins, provides a novel alternative for patients with statin intolerance. Angiopoetin-like 3 protein (ANGPTL3) inhibitors have been shown to provide potent LDL-C lowering in patients with homozygous familial hypercholesterolemia without major adverse effects as seen with lomitapide and mipomersen, and may reduce the need for apheresis. Finally, CETP inhibitors may yet be effective with the development of obicetrapib. These novel agents provide the clinician the tools to effectively lower LDL-C across the entire range of LDL-C-induced elevation of cardiovascular risk, from primary prevention and secondary prevention to null-null homozygous familial hypercholesterolemia patients.

Pooled Patient-Level Analysis of Inclisiran Trials in Patients With Familial Hypercholesterolemia or Atherosclerosis

BACKGROUND

Inclisiran is a double-stranded small interfering RNA that suppresses proprotein convertase subtilisin-kexin type 9 (PCSK9) translation in the liver, leading to sustained reductions in low-density lipoprotein cholesterol (LDL-C) and other atherogenic lipoproteins with twice-yearly dosing.

OBJECTIVES

The purpose of this study was to conduct a patient-level pooled analysis from 3 phase 3 studies of inclisiran.

METHODS

Participants with heterozygous familial hypercholesterolemia (ORION-9 [Trial to Evaluate the Effect of Inclisiran Treatment on Low Density Lipoprotein Cholesterol (LDL-C) in Subjects With Heterozygous Familial Hypercholesterolemia (HeFH)]), atherosclerotic cardiovascular disease (ASCVD) (ORION-10 [Inclisiran for Participants With Atherosclerotic Cardiovascular Disease and Elevated Low-density Lipoprotein Cholesterol]), or ASCVD and ASCVD risk equivalents (ORION-11 [Inclisiran for Subjects With ASCVD or ASCVD-Risk Equivalents and Elevated Low-density Lipoprotein Cholesterol]) taking maximally tolerated statin therapy, with or without other LDL-C-lowering agents, were randomly assigned in a 1:1 ratio to receive either inclisiran or placebo, administered by subcutaneous injection on day 1, day 90, and every 6 months thereafter for 540 days. The coprimary endpoints were the placebo-corrected percentage change in LDL-C level from baseline to day 510 and the time-adjusted percentage change in LDL-C level from baseline after day 90 to day 540. Levels of other atherogenic lipoproteins and treatment-emergent adverse events were also assessed.

RESULTS

A total of 3,660 participants (n = 482, n = 1,561, and n = 1,617 from ORION-9, -10, and -11, respectively) underwent randomization. The placebo-corrected change in LDL-C with inclisiran at day 510 was -50.7% (95% confidence interval: -52.9% to -48.4%; p < 0.0001). The corresponding time-adjusted change in LDL-C was -50.5% (95% confidence interval: -52.1% to -48.9%; p < 0.0001). Safety was similar in both groups. Treatment-emergent adverse events at the injection site were more frequent with inclisiran than placebo (5.0% vs. 0.7%), but were predominantly mild, and none were severe or persistent. Liver and kidney function tests, creatine kinase values, and platelet counts did not differ between groups.

CONCLUSIONS

These pooled safety and efficacy data show that inclisiran, given twice yearly in addition to maximally tolerated statin therapy with or without other LDL-C lowering agents, is an effective, safe, and well-tolerated treatment to lower LDL-C in adults with heterozygous familial hypercholesterolemia, ASCVD, or ASCVD risk equivalents.

Lipoprotein(a): a genetic marker for cardiovascular disease and target for emerging therapies

Lipoprotein(a) [Lp(a)] is an established cardiovascular risk factor, and growing evidence indicates its causal association with atherosclerotic disease because of the proatherogenic low-density lipoprotein (LDL)-like properties and the prothrombotic plasminogen-like activity of apolipoprotein(a) [apo(a)]. As genetics significantly influences its plasma concentration, Lp(a) is considered an inherited risk factor of atherosclerotic cardiovascular disease (ASCVD), especially in young individuals. Moreover, it has been suggested that elevated Lp(a) may significantly contribute to residual cardiovascular risk in patients with coronary artery disease and optimal LDL-C levels. Nonetheless, the fascinating hypothesis that lowering Lp(a) could reduce the risk of cardiovascular events - in primary or secondary prevention - still needs to be demonstrated by randomized clinical trials. To date, no specific Lp(a)-lowering agent has been approved for reducing the lipoprotein levels, and current lipid-lowering drugs have limited effects. In the future, emerging therapies targeting Lp(a) may offer the possibility to further investigate the relation between Lp(a) levels and cardiovascular outcomes in randomized controlled trials, ultimately leading to a new era in cardiovascular prevention. In this review, we aim to provide an updated overview of current evidence on Lp(a) as well as currently investigated therapeutic strategies that specifically address the reduction of the lipoprotein.

Recent insights into low-density lipoprotein metabolism and therapy

PURPOSE OF REVIEW

Elevated levels of low-density lipoprotein cholesterol (LDL-C) are causal to atherosclerosis and, thus, the reduction of LDL-C represents a major objective for the prevention of cardiovascular disease. Aim of this review is to provide an overview on novel strategies to lower LDL-C.

RECENT FINDINGS

Although inhibiting liver cholesterol biosynthesis by statins is used as the main therapeutic approach to increase hepatic LDL-receptor expression and lower plasma cholesterol levels, novel insights into lipid and lipoprotein biology have led to the development of additional lipid-lowering therapies that can be used in combination with or as an alternative to statins in patients with statin-intolerance. New approaches include bempedoic acid, proprotein convertase subtilisin/kexin type 9 inhibitors, and angiopoietin-like protein 3 inhibitors.

SUMMARY

In the last decade, several novel therapeutic approaches have been tested and some of them have been approved as lipid-lowering agents. Some drugs are already available in clinical practice, whereas others are at late stages of development.