Alirocumab: A Review in Hypercholesterolemia

Isolation of PCSK9-specific nanobodies from synthetic libraries using a combined protein selection strategy

Nanobodies (Nbs) hold great potential to replace conventional antibodies in various biomedical applications. However, conventional methods for their discovery can be time-consuming and expensive. We have developed a reliable protein selection strategy that combines magnetic activated cell sorting (MACS)-based screening of yeast surface display (YSD) libraries and functional ligand-binding identification by Tat-based recognition of associating proteins (FLI-TRAP) to isolate antigen-specific Nbs from synthetic libraries. This combined process enabled isolation of three unique Nb clones (NbT15, NbT21, and NbT22) that all bound specifically to a target antigen, namely proprotein convertase subtilisin/kexin type 9 (PCSK9) as well as a gain-of-function PCSK9 mutant (D374Y). All three clones bound to PCSK9 and blocked the interaction between the low-density lipoprotein receptor (LDLR) and either wild-type PCSK9 or the D374Y mutant. Overall, our combined protein selection method enables rapid and straightforward identification of potent antigen-specific Nbs in a manner that can be executed in a basic laboratory setting without the need for specialized equipment. We anticipate that our strategy will be a valuable addition to the protein engineering toolkit, allowing development of Nbs or virtually any other synthetic binding protein for a wide range of applications.

Expanding therapeutic options: overview of novel pharmacotherapies for dyslipidemia

INTRODUCTION

Dyslipidemia plays a crucial role in the development of atherosclerotic cardiovascular diseases.

AREAS COVERED

This article explores the emerging therapeutic targets for the treatment of dyslipidemia and provides novel insights into this field. Thus, it aims to contribute to the understanding and advancement of therapeutic options for managing dyslipidemia.

EXPERT OPINION

Optimizing the use of available first- and second-line lipid-lowering drugs allows us to adequately control low-density lipoprotein cholesterol (LDL-C) levels, even in statin-intolerant individuals and in patients at high and very high risk of developing cardiovascular diseases who must reach more aggressive LDL-C targets. The drugs under development will further improve our ability to manage the overall lipid-related cardiovascular disease risk and target other dyslipidemia biomarkers.

Advances in Treatment of Dyslipidemia

Dyslipidemias have emerged as prevalent disorders among patients, posing significant risks for the development and progression of cardiovascular diseases. These conditions are characterized by elevated levels of total cholesterol (TC), triglycerides (TGs), and low-density lipoprotein cholesterol (LDL-C). This review delves into the current treatment approach, focusing on equalizing these parameters while enhancing the overall quality of life for patients. Through an extensive analysis of clinical trials, we identify disorders that necessitate alternative treatment strategies, notably familial hypercholesterolemia. The primary objective of this review is to consolidate existing information concerning drugs with the potential to revolutionize dyslipidemia management significantly. Among these promising pharmaceuticals, we highlight alirocumab, bempedoic acid, antisense oligonucleotides, angiopoietin-like protein inhibitors, apolipoprotein C-III (APOC3) inhibitors, lomitapide, and cholesterol ester transfer protein (CETP) inhibitors. Our review demonstrates the pivotal roles played by each of these drugs in targeting specific parameters of lipid metabolism. We outline the future landscape of dyslipidemia treatment, envisaging a more tailored and effective therapeutic approach to address this widespread medical concern.

New Therapeutic Approaches in Treatment of Dyslipidaemia—A Narrative Review

Dyslipidaemia is a well-known risk factor for the development of cardiovascular disease, a leading cause of morbidity and mortality in developed countries. As a consequence, the medical community has been dealing with this problem for decades, and traditional statin therapy remains the cornerstone therapeutic approach. However, clinical trials have observed remarkable results for a few agents effective in the treatment of elevated serum lipid levels. Ezetimibe showed good but limited results when used in combination with statins. Bempedoic acid has been thoroughly studied in multiple clinical trials, with a reduction in LDL cholesterol by approximately 15%. The first approved monoclonal antibodies for the treatment of dyslipidaemia, PCSK9 inhibitors, are currently used as second-line treatment for patients with unregulated lipid levels on statin or statin combination therapy. A new siRNA molecule, inclisiran, demonstrates great potential, particularly concerning compliance, as it is administered twice yearly and pelacarsen, an antisense oligonucleotide that targets lipoprotein(a) and lowers its levels. Volanesorsen is the first drug that was designed to target chylomicrons and lower triglyceride levels, and olezarsen, the next in-line chylomicron lowering agent, is currently being researched. The newest possibilities for the treatment of dyslipidaemia are ANGPTL3 inhibitors with evinacumab, already approved by the FDA, and EMA for the treatment of familial hypercholesterolemia. This article provides a short summary of new agents currently used or being developed for lipid lowering treatment.

Biochemical risk factors of atherosclerotic cardiovascular disease: from a narrow and controversial approach to an integral approach and precision medicine

INTRODUCTION

Guidelines of management of dyslipidemias and prevention of cardiovascular disease (CVD) are based on firm scientific evidence obtained by randomized controlled trials (RCTs). However, the role of elevated low-density lipoprotein-cholesterol (LDL-C)as a risk factor of CVD and therapies to lower LDL-C are frequently disputed by colleagues who disagree with the conclusions of the RCTs published. This review focuses on this dispute, and evaluates the current approach of management of dyslipidemias and CVD prevention to find modern alternatives for more precise diagnosis and therapy of dyslipidemic patients.

AREAS COVERED

Recent interest in lipoprotein(a) (Lp(a)) and remnants lipoproteins and in therapies that do not influence LDL-C levels primarily, such as anti-inflammatory drugs and icosapent ethyl, has revitalized our concern to optimize the care for patients with increased CVD risk without focusing simply on reduction of LDL-C by therapy with statins, ezitemibe, and proprotein convertase subtilisin-kexin type 9 (PCSK9) inhibitors.

EXPERT OPINION

The limited characterization of study populations by measurement of total cholesterol (TC), high-density lipoprotein-cholesterol (HDL-C) and triglycerides (TG) followed by measurement or calculation of LDL-C should be extended by a more integral approach in order to realize precision diagnostics and precision medicine, for the sake of personalized patient care.

Emerging Non-statin Treatment Options for Lowering Low-Density Lipoprotein Cholesterol

Low-density lipoprotein cholesterol (LDL-C) is a modifiable risk factor for the development of atherosclerotic cardiovascular disease. Statins have been the gold standard for managing cholesterol levels and reducing the risks associated with atherosclerotic cardiovascular disease; however, many patients do not achieve their cholesterol goals or are unable to tolerate this drug class due to adverse drug events. Recent studies of non-statin cholesterol lowering drugs (i.e., ezetimibe, PCSK9 inhibitors) have demonstrated cardiovascular benefits; and new drugs [i.e., bempedoic acid (BDA), inclisiran] have produced promising results in pre-clinical and clinical outcome trials. This narrative review aims to discuss the place in therapy of ezetimibe, PCSK9 inhibitors, BDA, and inclisiran and describe their relative pharmacokinetic (PK) profiles, efficacy and safety as monotherapy and combination therapy, and cardiovascular benefit(s) when used for hypercholesterolemia.

The Interdependency and Co-Regulation of the Vitamin D and Cholesterol Metabolism

Vitamin D and cholesterol metabolism overlap significantly in the pathways that contribute to their biosynthesis. However, our understanding of their independent and co-regulation is limited. Cardiovascular disease is the leading cause of death globally and atherosclerosis, the pathology associated with elevated cholesterol, is the leading cause of cardiovascular disease. It is therefore important to understand vitamin D metabolism as a contributory factor. From the literature, we compile evidence of how these systems interact, relating the understanding of the molecular mechanisms involved to the results from observational studies. We also present the first systems biology pathway map of the joint cholesterol and vitamin D metabolisms made available using the Systems Biology Graphical Notation (SBGN) Markup Language (SBGNML). It is shown that the relationship between vitamin D supplementation, total cholesterol, and LDL-C status, and between latitude, vitamin D, and cholesterol status are consistent with our knowledge of molecular mechanisms. We also highlight the results that cannot be explained with our current knowledge of molecular mechanisms: (i) vitamin D supplementation mitigates the side-effects of statin therapy; (ii) statin therapy does not impact upon vitamin D status; and critically (iii) vitamin D supplementation does not improve cardiovascular outcomes, despite improving cardiovascular risk factors. For (iii), we present a hypothesis, based on observations in the literature, that describes how vitamin D regulates the balance between cellular and plasma cholesterol. Answering these questions will create significant opportunities for advancement in our understanding of cardiovascular health.

Potential Role of Thyroid Receptor β Agonists in the Treatment of Hyperlipidemia

Thyroid hormones have important effects on cellular development, growth, and metabolism and are necessary for the healthy function of almost all tissues. Hyperthyroid patients with excess thyroid hormone levels experience tachycardia, fatigue, muscle wasting, and osteoporosis. However, although high thyroid hormone levels have adverse effects, efforts have been made to harness the beneficial effects, such as reduced serum low-density lipoprotein (LDL) cholesterol levels, elevated basal metabolic rate, and weight loss. Thyroid hormones interact with nuclear thyroid hormone receptors (TRs), and cholesterol levels are reduced through TRβ, whereas extrahepatic adverse actions are primarily connected to TRα. Thus, to develop a useful compound for clinical use, efforts have been focusing on developing compounds with isomer-specific functions based on the structure of thyroid hormones, i.e., thyromimetics that are liver and/or TRβ specific. In this short review, we discuss the development of the early thyromimetics that enabled, through modern molecular techniques, the progress towards improved design of TRβ-selective thyromimetics. We also address the early promise shown in human clinical trials and the current status of these drugs and other emerging compounds.

Familial Hypercholesterolemia: New Horizons for Diagnosis and Effective Management

Familial hypercholesterolemia (FH) is a common genetic cause of premature cardiovascular disease (CVD). The reported prevalence rates for both heterozygous FH (HeFH) and homozygous FH (HoFH) vary significantly, and this can be attributed, at least in part, to the variable diagnostic criteria used across different populations. Due to lack of consistent data, new global registries and unified guidelines are being formed, which are expected to advance current knowledge and improve the care of FH patients. This review presents a comprehensive overview of the pathophysiology, epidemiology, manifestations, and pharmacological treatment of FH, whilst summarizing the up-to-date relevant recommendations and guidelines. Ongoing research in FH seems promising and novel therapies are expected to be introduced in clinical practice in order to compliment or even substitute current treatment options, aiming for better lipid-lowering effects, fewer side effects, and improved clinical outcomes.

Pharmabiotics as an Emerging Medication for Metabolic Syndrome and Its Related Diseases

Metabolic syndrome (MetS) is a cluster of metabolic risk factors associated with central obesity, hyperglycemia, insulin resistance, dyslipidemia and high blood pressure. In recent decades, because of the remarkable increase in both prevalence and severity, MetS and its related diseases such as cardiovascular diseases (CVDs), obesity, hypertension and diabetes have become the main global burden and challenge in strategic management involving prevention and treatment. However, currently, the preventions and treatments based on pharmaceutical interventions do not provide a solution for MetS and its related diseases. Recently, gut microbiota showed clear evidence of preventing and/or treating MetS, shedding light on treating MetS and its related diseases through a completely different approach. In this review, we will interpret the effects of current pharmaceutical drugs used in preventing and treating MetS and its related diseases to understand remaining issues of those interventions. We will explore the possibility of developing gut microbiota as pharmabiotics in a completely new medication option for treating MetS and its related diseases.

Cell-based, bioluminescent assay for monitoring the interaction between PCSK9 and the LDL receptor

Monitoring the expression of cell-surface receptors, their interaction with extracellular ligands, and their fate upon ligand binding is important for understanding receptor function and developing new therapies. We describe a cell-based method that utilizes bioluminescent protein complementation technology to interrogate binding of a cellular receptor with its extracellular protein ligand, specifically LDL receptor (LDLR) and proprotein convertase subtilisin/kexin type 9 (PCSK9). Purified, full-length tagged PCSK9 is added to assay wells containing cells that stably express LDLR with an extracellular complementary tag. When the tagged PCSK9 binds the receptor, a bright luminescence signal is generated. The interaction is detected at the cell membrane with add-and-read simplicity, no wash steps, and flexibility, allowing data to be collected in endpoint format, kinetically, or with bioluminescent imaging. The assay is flexible, is rapid, and reports accurate biology. It is amenable to 96-well and 384-well formats, and the robustness allows for screening of new drug candidates (Z′ = 0.83). The assay reports correct potencies for antibody titrations across a 50%–150% potency range and detects potency changes due to heat stress, suggesting that it may be useful during drug development. This assay technology can be broadly applied when studying other receptors with their extracellular ligands, whether protein or small-molecule binding partners.