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

Use of Evolocumab in Familial Hyperlipidemia With Isolated Heart Transplant

We describe a novel use of evolocumab for successful postoperative lipid control in a patient with familial hyperlipidemia who underwent isolated heart transplantation. We believe that this case carries valuable lessons regarding post-transplant proprotein convertase subtilisin kexin 9 inhibitor use with implications for the future of combined organ allocation and transplantation waitlist times.

Mechanisms of Action of the US Food and Drug Administration-Approved Antisense Oligonucleotide Drugs

Antisense oligonucleotides (ASOs) are single stranded nucleic acids that target RNA. The US Food and Drug Administration has approved ASOs for several diseases. ASOs utilize three principal modes of action (MOA). The first MOA is initiated by base-pairing between the ASO and its target mRNA, followed by RNase H-dependent mRNA degradation. The second MOA is triggered by ASOs that occlude splice acceptor sites in pre-mRNAs leading to skipping of a mutation-bearing exon. The third MOA involves ASOs that sterically hinder mRNA function, often inhibiting translation. ASOs contain a variety of modifications to the sugar-phosphate backbone and bases that stabilize the ASO or render them resistant to RNase activity. RNase H-dependent ASOs include inotersen and eplontersen (for hereditary transthyretin amyloidosis), fomiversen (for opportunistic cytomegalovirus infection), mipomersen (for familial hypercholesterolemia), and tofersen [for amyotrophic lateral sclerosis (ALS)]. Splice modulating ASOs include nursinersen (for spinal muscular atrophy) and eteplirsen, golodirsen, viltolarsen, and casimersen (all for the treatment of Duchenne muscular dystrophy). In addition, a designer ASO, milasen, was used to treat a single individual afflicted with Batten disease. Since ASO design relies principally upon knowledge of mRNA sequence, the bench to bedside pipeline for ASOs is expedient compared with protein-directed drugs. [Graphical abstract available.].

Advances in Pharmacological Approaches for Managing Hypercholesterolemia: A Comprehensive Overview of Novel Treatments

Hypercholesterolemia plays a crucial role in the formation of lipid plaques, particularly with elevated low-density lipoprotein (LDL-C) levels, which are linked to increased risks of cardiovascular disease, cerebrovascular disease, and peripheral arterial disease. Controlling blood cholesterol values, specifically reducing LDL-C, is widely recognized as a key modifiable risk factor for decreasing the morbidity and mortality associated with cardiovascular diseases. Historically, statins, by inhibiting the enzyme β-hydroxy β-methylglutaryl-coenzyme A (HMG)-CoA reductase, have been among the most effective drugs. However, newer non-statin agents have since been introduced into hypercholesterolemia therapy, providing a viable alternative with a favorable cost-benefit ratio. This paper aims to delve into the latest therapies, shedding light on their mechanisms of action and therapeutic benefits.

Familial Hypercholesterolemia: Pitfalls and Challenges in Diagnosis and Treatment

Familial hypercholesterolemia (FH), a condition, which is characterized by a life-long exposure to markedly elevated low-density lipoprotein (LDL) concentrations from birth, and it still remains underdiagnosed and undertreated, despite the fact that its heterogeneous form represents one of the commonest genetic disorders to date. Indeed, only 10% of all estimated affected individuals have been diagnosed worldwide and for the most of them diagnosis comes too late, when atherosclerotic cardiovascular disease (ASCVD) has already been developed. Undiagnosed and undertreated FH leads to accelerated ASCVD with a high rate of premature deaths. Recently, several novel treatment modalities have been introduced, especially for the management of severe hypercholesterolemia. Nonetheless, a substantial number of FH patients still do not achieve guideline-recommended LDL cholesterol target values. In the present review we will summarize and critically discuss pitfalls and challenges in successful diagnosis and treatment of FH.

Genetics, Safety, Cost-Effectiveness, and Accessibility of Injectable Lipid-Lowering Agents: A Narrative Review

Cardiovascular disease causes significant personal, financial, and societal burden and is a major cause of mortality and morbidity globally. Dyslipidemia has proven to be a major factor that contributes to its increased incidence; thus, since a long time, low-density lipoprotein cholesterol-lowering therapies have been employed to reduce coronary artery disease-associated mortality. The first-line therapy for hyperlipidemia and dyslipidemia is statins. Evidence showed that statins decrease the level of LDL-C resulting in a lower risk of CVD (20-25% for every decrease of 1 mmol/L). However, due to statin intolerance in some patients and despite using maximal doses, they have not been successful in lowering cardiovascular-associated mortality. Moreover, bococizumab was recently suspended due to its higher immunogenicity with time, resulting in less efficacy with long-term use. Alternatives to statins are PCSK9 inhibitors which are administered subcutaneously every two or four weeks. They are injectables with considerable lipid-lowering properties. This narrative review discusses their genetics, safety, tolerability, and cost-effectiveness. It also quantifies their benefit in certain subgroups by analyzing the findings from recent randomized clinical trials. Current data from phase 2 and 3 trials (ORION, ODYSSEY, and FOURIER) suggest a favorable profile for evolocumab, alirocumab, and inclisiran with minimal tolerable side effects and superior efficacy in statin-intolerant patients. Their cost-effectiveness has not yet been established clearly, but future outcomes seem promising.

How Genetic Variants in Children with Familial Hypercholesterolemia Not Only Guide Detection, but Also Treatment

Familial hypercholesterolemia (FH) is a hereditary disorder that causes severely elevated low-density lipoprotein (LDL-C) levels, which leads to an increased risk for premature cardiovascular disease. A variety of genetic variants can cause FH, namely variants in the genes for the LDL receptor (LDLR), apolipoprotein B (APOB), proprotein convertase subtilisin/kexin type 9 (PCSK9), and/or LDL-receptor adaptor protein 1 (LDLRAP1). Variants can exist in a heterozygous form (HeFH) or the more severe homozygous form (HoFH). If affected individuals are diagnosed early (through screening), they benefit tremendously from early initiation of lipid-lowering therapy, such as statins, and cardiovascular imaging to detect possible atherosclerosis. Over the last years, due to intensive research on the genetic basis of LDL-C metabolism, novel, promising therapies have been developed to reduce LDL-C levels and subsequently reduce cardiovascular risk. Results from studies on therapies focused on inhibiting PCSK9, a protein responsible for degradation of the LDLR, are impressive. As the effect of PCSK9 inhibitors (PCSK9-i) is dependent of residual LDLR activity, this medication is less potent in patients without functional LDLR (e.g., null/null variant). Novel therapies that are expected to become available in the near future focused on inhibition of another major regulatory protein in lipid metabolism (angiopoietin-like 3 (ANGPTL3)) might dramatically reduce the frequency of apheresis in children with HoFH, independently of their residual LDLR. At present, another independent risk factor for premature cardiovascular disease, elevated levels of lipoprotein(a) (Lp(a)), cannot be effectively treated with medication. Further understanding of the genetic basis of Lp(a) metabolism, however, offers a possibility for the development of novel therapies.

Associations of Lipids and Lipid-Lowering Drugs with Risk of Vascular Dementia: A Mendelian Randomization Study

Accumulating observational studies suggested that hypercholesterolemia is associated with vascular dementia (VaD); however, the causality between them remains unclear. Hence, the aim of this study is to infer causal associations of circulating lipid-related traits [including high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), triglyceride (TG), apolipoprotein A-I (apoA-I), and apolipoprotein B (apoB)] with VaD jointly using univariable MR (uvMR), multivariable MR (mvMR) and bidirectional two-sample MR methods. Then, the summary-data-based MR (SMR) and two-sample MR analysis were conducted to investigate the association of lipid-lowering drugs target genes expression (including HMGCR, PCSK9, NPC1L1, and APOB) and LDL-C level mediated by these target genes with VaD. The results of forward MR analyses found that genetically predicted HDL-C, LDL-C, TG, apoA-I, and apoB concentrations were not significantly associated with the risk of VaD (all p > 0.05). Notably, there was suggestive evidence for a causal effect of genetically predicted VaD on HDL-C via reverse MR analysis [odds ratio (OR), 0.997; 95% confidence interval (CI), 0.994−0.999; p = 0.022]. On the contrary, the MR results showed no significant relationship between VaD with LDL-C, TG, apoA-I, and apoB. The results for the SMR method found that there was no evidence of association for expression of HMGCR, PCSK9, NPC1L1, and APOB gene with risk of VaD. Furthermore, the result of MR analysis provided evidence for the decreased LDL-C level mediated by gene HMGCR reduced the risk of VaD (OR, 18.381; 95% CI, 2.092−161.474; p = 0.009). Oppositely, none of the IVW methods indicated any causal effects for the other three genes. Using genetic data, this study provides evidence that the VaD risk may cause a reduction of HDL-C level. Additionally, the finding supports the hypothesis that lowering LDL-C levels using statins may be an effective prevention strategy for VaD risk, which requires clinical trials to confirm this result in the future.

HCDT: an integrated highly confident drug-target resource

Drug-target association plays an important role in drug discovery, drug repositioning, drug synergy prediction, etc. Currently, a lot of drug-related databases, such as DrugBank and BindingDB, have emerged. However, these databases are separate, incomplete and non-uniform with different criteria. Here, we integrated eight drug-related databases; collected, filtered and supplemented drugs, target genes and experimentally validated (highly confident) associations and built a highly confident drug-target (HCDT: http://hainmu-biobigdata.com/hcdt) database. HCDT database includes 500 681 HCDT associations between 299 458 drugs and 5618 target genes. Compared to individual databases, HCDT database contains 1.1 to 254.2 times drugs, 1.8-5.5 times target genes and 1.4-27.7 times drug-target associations. It is normative, publicly available and easy for searching, browsing and downloading. Together with multi-omics data, it will be a good resource in analyzing the drug functional mechanism, mining drug-related biological pathways, predicting drug synergy, etc. Database URL: http://hainmu-biobigdata.com/hcdt.

Evinacumab: a new option in the treatment of homozygous familial hypercholesterolemia

INTRODUCTION

Familial hypercholesterolemia is a genetic disorder characterized by elevated levels of low-density lipoprotein cholesterol (LDL-C) since birth and an exceedingly high risk of premature cardiovascular disease, especially in the homozygous form (HoFH). Despite the availability of effective cholesterol-lowering drugs, substantial LDL-C and cardiovascular risk reductions in these patients are still problematic, especially in those carrying mutations in the low-density lipoprotein receptor (LDLR) gene.

AREAS COVERED

Loss-of-function mutations in angiopoietin-like 3 (ANGPTL3) encoding gene are associated with lower levels of LDL-C and reduced cardiovascular risk; the pharmacological inhibition of ANGPTL3 reduces LDL-C levels independently of LDLR. This approach can thus improve the treatment of HoFH using a monoclonal antibody targeting ANGPTL3 (evinacumab).

EXPERT OPINION

Most lipid-lowering agents available so far are insufficient to achieve an appropriate response in HoFH patients. The inhibition of ANGPTL3 with evinacumab halves LDL-C levels in HoFH patients by an LDLR-independent mechanism. The results obtained so far have clearly indicated a promising improvement in the management of these patients. As the reduction of CV risk is proportional to the absolute reduction in LDL-C levels, we can expect that treatment with evinacumab, added to the maximally tolerated lipid-lowering therapy, will turn into a significant clinical benefit.

Inflammation and atherosclerosis: signaling pathways and therapeutic intervention

Atherosclerosis is a chronic inflammatory vascular disease driven by traditional and nontraditional risk factors. Genome-wide association combined with clonal lineage tracing and clinical trials have demonstrated that innate and adaptive immune responses can promote or quell atherosclerosis. Several signaling pathways, that are associated with the inflammatory response, have been implicated within atherosclerosis such as NLRP3 inflammasome, toll-like receptors, proprotein convertase subtilisin/kexin type 9, Notch and Wnt signaling pathways, which are of importance for atherosclerosis development and regression. Targeting inflammatory pathways, especially the NLRP3 inflammasome pathway and its regulated inflammatory cytokine interleukin-1β, could represent an attractive new route for the treatment of atherosclerotic diseases. Herein, we summarize the knowledge on cellular participants and key inflammatory signaling pathways in atherosclerosis, and discuss the preclinical studies targeting these key pathways for atherosclerosis, the clinical trials that are going to target some of these processes, and the effects of quelling inflammation and atherosclerosis in the clinic.

New Therapies for Primary Hyperlipidemia

Primary hyperlipidemias include a heterogeneous set of monogenic and polygenic conditions characterized by a strong family aggregation, severe forms of hypercholesterolemia and/or hypertriglyceridemia, appearance early on life, and a high risk of cardiovascular events and/or recurrent pancreatitis. In real life, a small proportion of the primary hyperlipidemia cases is recognized and treated properly. Our goal is to present an update of current and upcoming therapies for patients with primary hyperlipidemia. Recently, new lipid-lowering medications have obtained authorization from the U.S. Food and Drug Administration and the European Medicines Agency. These drugs target metabolic pathways, including (adenosine 5'-triphosphates)-citrate lyase (bempedoic acid), proprotein convertase subtilisin/kexin 9 (inclisiran), apolipoprotein CIII (volanesorsen), and angiopoietin-like 3 (volanesorsen), that have additive effects with the actions of the currently available therapies (i.e., statins, ezetimibe or fibrates). We discuss the potential clinical indications for the novel medications. To conclude, the addition of these new medications to the therapeutic options for primary hyperlipidemia patients may increase the likelihood of achieving the treatment targets. Also, it could be a safer alternative for patients with side effects for the currently available drugs.

Hsp40s play distinct roles during the initial stages of apolipoprotein B biogenesis

Apolipoprotein B (ApoB) is the primary component of atherogenic lipoproteins, which transport serum fats and cholesterol. Therefore, elevated levels of circulating ApoB are a primary risk factor for cardiovascular disease. During ApoB biosynthesis in the liver and small intestine under nutrient-rich conditions, ApoB cotranslationally translocates into the endoplasmic reticulum (ER) and is lipidated and ultimately secreted. Under lipid-poor conditions, ApoB is targeted for ER Associated Degradation (ERAD). Although prior work identified select chaperones that regulate ApoB biogenesis, the contributions of cytoplasmic Hsp40s are undefined. To this end, we screened ApoB-expressing yeast and determined that a class A ER-associated Hsp40, Ydj1, associates with and facilitates the ERAD of ApoB. Consistent with these results, a homologous Hsp40, DNAJA1, functioned similarly in rat hepatoma cells. DNAJA1 deficient cells also secreted hyperlipidated lipoproteins, in accordance with attenuated ERAD. In contrast to the role of DNAJA1 during ERAD, DNAJB1-a class B Hsp40-helped stabilize ApoB. Depletion of DNAJA1 and DNAJB1 also led to opposing effects on ApoB ubiquitination. These data represent the first example in which different Hsp40s exhibit disparate effects during regulated protein biogenesis in the ER, and highlight distinct roles that chaperones can play on a single ERAD substrate.