Lepodisiran, an Extended-Duration Short Interfering RNA Targeting Lipoprotein(a): A Randomized Dose-Ascending Clinical Trial

New insights into the therapeutic options to lower lipoprotein(a)

BACKGROUND

Elevated levels of lipoprotein(a) [Lp(a)] represent a risk factor for cardiovascular disease including aortic valve stenosis, myocardial infarction and stroke. While the patho-physiological mechanisms linking Lp(a) with atherosclerosis are not fully understood, from genetic studies that lower Lp(a) levels protect from CVD independently of other risk factors including lipids and lipoproteins. Hereby, Lp(a) has been considered an appealing pharmacological target.

RESULTS

However, approved lipid lowering therapies such as statins, ezetimibe or PCSK9 inhibitors have a neutral to modest effect on Lp(a) levels, thus prompting the development of new strategies selectively targeting Lp(a). These include antisense oligonucleotides and small interfering RNAs (siRNAs) directed towards apolipoprotein(a) [Apo(a)], which are in advanced phase of clinical development. More recently, additional approaches including inhibitors of Apo(a) and gene editing approaches via CRISPR-Cas9 technology entered early clinical development.

CONCLUSION

If the results from the cardiovascular outcome trials, designed to demonstrate whether the reduction of Lp(a) of more than 80% as observed with pelacarsen, olpasiran or lepodisiran translates into the decrease of cardiovascular mortality and major adverse cardiovascular events, will be positive, lowering Lp(a) will become a new additional target in the management of patients with elevated cardiovascular risk.

Management of dyslipidemia in coronary artery disease: the present and the future

Coronary artery disease (CAD) remains a leading cause of global morbidity and mortality, necessitating continuous refinement in the management of dyslipidemia, one of its major risk factors, to mitigate cardiovascular risks. Previous studies have proven the critical role of immediate and robust low-density lipoprotein cholesterol (LDL-C) reduction in the aftermath of acute coronary syndrome (ACS). Emphasizing the evidence supporting this approach, we delve into the impact of early intervention on cardiovascular outcomes and propose optimal strategies for achieving rapid LDL-C lowering, while also providing the rationale for early proprotein convertase subtilisin/kexin 9 inhibitor use after an ACS. Given the importance of the residual lipidemic risk, we present an overview of emerging therapeutic avenues poised to reshape dyslipidemia management, such as bempedoic acid, lipoprotein(a) inhibition, ApoC3 modulation, and angiopoietin-like protein 3 targeting. This comprehensive review amalgamates current evidence with future prospects, offering a holistic perspective on the management of dyslipidemia in CAD. By exploring both the urgency for immediate post-ACS LDL-C reduction and the exciting advancements on the horizon, this article provides a roadmap for clinicians navigating the intricate landscape of lipid-lowering therapies in CAD.

The Off-Treatment Effects of Olpasiran on Lipoprotein(a) Lowering: OCEAN(a)-DOSE Extension Period Results

BACKGROUND

Olpasiran, a small interfering RNA (siRNA), blocks lipoprotein(a) (Lp(a)) production by preventing translation of apolipoprotein(a) mRNA. In phase 2, higher doses of olpasiran every 12 weeks (Q12W) reduced circulating Lp(a) by >95%.

OBJECTIVES

This study sought to assess the timing of return of Lp(a) to baseline after discontinuation of olpasiran, as well as longer-term safety.

METHODS

OCEAN(a)-DOSE (Olpasiran Trials of Cardiovascular Events And LipoproteiN[a] Reduction-DOSE Finding Study) was a phase 2, dose-finding trial that enrolled 281 participants with atherosclerotic cardiovascular disease and Lp(a) >150 nmol/L to 1 of 4 active doses of olpasiran vs placebo (10 mg, 75 mg, 225 mg Q12W, or an exploratory dose of 225 mg Q24W given subcutaneously). The last dose of olpasiran was administered at week 36; after week 48, there was an extended off-treatment follow-up period for a minimum of 24 weeks.

RESULTS

A total of 276 (98.2%) participants entered the off-treatment follow-up period. The median study exposure (treatment combined with off-treatment phases) was 86 weeks (Q1-Q3: 79-99 weeks). For the 75 mg Q12W dose, the off-treatment placebo-adjusted mean percent change from baseline in Lp(a) was -76.2%, -53.0%, -44.0%, and -27.9% at 60, 72, 84, and 96 weeks, respectively (all P < 0.001). The respective off-treatment changes in Lp(a) for the 225 mg Q12W dose were -84.4%, -61.6%, -52.2%, and -36.4% (all P < 0.001). During the extension follow-up phase, no new safety concerns were identified.

CONCLUSIONS

Olpasiran is a potent siRNA with prolonged effects on Lp(a) lowering. Participants receiving doses ≥75 mg Q12W sustained a ∼40% to 50% reduction in Lp(a) levels close to 1 year after the last dose. (Olpasiran Trials of Cardiovascular Events And LipoproteiN[a] Reduction-DOSE Finding Study [OCEAN(a)-DOSE]; NCT04270760).

RNA interference therapy in cardiology: will new targets improve therapeutic goals?

The discovery of RNA interference in 1998 opened avenues for the manipulation of gene expression, leading to the development of small interfering RNA (siRNA) drugs. Patisiran, the first FDA-approved siRNA medication, targets hereditary transthyretin amyloidosis with polyneuropathy. Givosiran, lumasiran and nedosiran further expand siRNA applications in treating rare genetic diseases, demonstrating positive outcomes. In cardiology, inclisiran, approved for hypercholesterolaemia, showcases sustained reductions in LDL cholesterol levels. However, ongoing research aims to establish its impact on cardiovascular outcomes. Lipoprotein(a), an independent risk factor for atherosclerotic cardiovascular disease, has become a focus of siRNA therapies, precipitating the development of specific siRNA drugs like olpasiran, zerlasiran and lepodisiran, with promising reductions in lipoprotein(a) levels. Research to assess the effectiveness of these medications in reducing events is currently under way. Zodasiran and plozasiran address potential risk factors for cardiovascular diseases, targeting triglyceride-rich lipoproteins. Zilebesiran, which targets hepatic angiotensinogen mRNA, has demonstrated a dose-related reduction in serum angiotensinogen levels, thereby lowering blood pressure in patients with systemic arterial hypertension. The evolving siRNA methodology presents a promising future in cardiology, with ongoing studies assessing its effectiveness in various conditions. In the future, larger studies will provide insights into improvements in cardiovascular outcomes, long-term safety and broader applications in the general population. This review highlights the historical timeline of the development of siRNA-based drugs, their clinical indications, potential side-effects and future perspectives.

Elevated lipoprotein(a) levels: A crucial determinant of cardiovascular disease risk and target for emerging therapies

Cardiovascular disease (CVD) remains a significant global health challenge despite advancements in prevention and treatment. Elevated Lipoprotein(a) [Lp(a)] levels have emerged as a crucial risk factor for CVD and aortic stenosis, affecting approximately 20 of the global population. Research over the last decade has established Lp(a) as an independent genetic contributor to CVD and aortic stenosis, beginning with Kare Berg's discovery in 1963. This has led to extensive exploration of its molecular structure and pathogenic roles. Despite the unknown physiological function of Lp(a), studies have shed light on its metabolism, genetics, and involvement in atherosclerosis, inflammation, and thrombosis. Epidemiological evidence highlights the link between high Lp(a) levels and increased cardiovascular morbidity and mortality. Newly emerging therapies, including pelacarsen, zerlasiran, olpasiran, muvalaplin, and lepodisiran, show promise in significantly lowering Lp(a) levels, potentially transforming the management of cardiovascular disease. However, further research is essential to assess these novel therapies' long-term efficacy and safety, heralding a new era in cardiovascular disease prevention and treatment and providing hope for at-risk patients.

Lipid nanoparticle (LNP) mediated mRNA delivery in cardiovascular diseases: Advances in genome editing and CAR T cell therapy

Cardiovascular diseases (CVDs) are the leading cause of global mortality among non-communicable diseases. Current cardiac regeneration treatments have limitations and may lead to adverse reactions. Hence, innovative technologies are needed to address these shortcomings. Messenger RNA (mRNA) emerges as a promising therapeutic agent due to its versatility in encoding therapeutic proteins and targeting "undruggable" conditions. It offers low toxicity, high transfection efficiency, and controlled protein production without genome insertion or mutagenesis risk. However, mRNA faces challenges such as immunogenicity, instability, and difficulty in cellular entry and endosomal escape, hindering its clinical application. To overcome these hurdles, lipid nanoparticles (LNPs), notably used in COVID-19 vaccines, have a great potential to deliver mRNA therapeutics for CVDs. This review highlights recent progress in mRNA-LNP therapies for CVDs, including Myocardial Infarction (MI), Heart Failure (HF), and hypercholesterolemia. In addition, LNP-mediated mRNA delivery for CAR T-cell therapy and CRISPR/Cas genome editing in CVDs and the related clinical trials are explored. To enhance the efficiency, safety, and clinical translation of mRNA-LNPs, advanced technologies like artificial intelligence (AGILE platform) in RNA structure design, and optimization of LNP formulation could be integrated. We conclude that the strategies to facilitate the extra-hepatic delivery and targeted organ tropism of mRNA-LNPs (SORT, ASSET, SMRT, and barcoded LNPs) hold great prospects to accelerate the development and translation of mRNA-LNPs in CVD treatment.

Recent updates on therapeutic targeting of lipoprotein(a) with RNA interference

PURPOSE OF REVIEW

RNA interference (RNAi)-based therapies that target specific gene products have impacted clinical medicine with 16 FDA approved drugs. RNAi therapy focused on reducing plasma lipoprotein(a) [Lp(a)] levels are under evaluation.

RECENT FINDINGS

RNAi-based therapies have made significant progress over the past 2 decades and currently consist of antisense oligonucleotides (ASO) and small interfering RNA (siRNA). Chemical modification of the RNA backbone and conjugation of siRNA enables efficient gene silencing in hepatocytes allowing development of effective cholesterol lowering therapies. Multiple lines of evidence suggest a causative role for Lp(a) in atherosclerotic cardiovascular disease, and recent analyses indicate that Lp(a) is more atherogenic than low density lipoprotein- cholesterol (LDL-C). These findings have led to the 'Lp(a) hypothesis' that lowering Lp(a) may significantly improve cardiovascular outcomes. Four RNAi-based drugs have completed early phase clinical trials demonstrating >80% reduction in plasma Lp(a) levels. Phase 3 clinical trials examining clinical outcomes with these agents are currently underway.

SUMMARY

Currently, four RNAi-based drugs have been shown to be effective in significantly lowering plasma Lp(a) levels. Clinical outcome data from phase 3 trials will evaluate the Lp(a) hypothesis.

Lipoprotein(a) in the Year 2024: A Look Back and a Look Ahead

In fitting with the American Heart Association’s 100th anniversary of its founding and Arteriosclerosis, Thrombosis and Vascular Biology organizing a Centennial Collection to celebrate this event, lipoprotein(a) [Lp(a)] celebrates its 61st birthday in November 2024. There has been substantial progress in understanding the biology and pathophysiology of Lp(a) in the last 6 decades, including its discovery as a unique β-lipoprotein containing the pathognomonic apolipoprotein(a) moiety covalently bound to apolipoprotein B-100, its independent monogenetic association with cardiovascular disease and calcific aortic valve disease, its increased content of pro-atherogenic and pro-inflammatory of oxidized phospholipids relative to other lipoproteins and the development of RNA therapeutics to lower plasma Lp(a) levels. The validation or refutation of the “Lp(a) hypothesis”, namely that lowering plasma Lp(a) will lead to clinical benefit, is ongoing in 3 clinical outcomes trials. This essay reviews the discovery of Lp(a), summarizes the seminal pathophysiological findings since its discovery, discusses ongoing clinical trials with novel drugs and approaches, and provides a look ahead to unanswered questions.

Advances in Clinical Cardiology 2023: A Summary of Key Clinical Trials

INTRODUCTION

Over the course of 2023, numerous key clinical trials with valuable contributions to clinical cardiology were published or presented at major international conferences. This review seeks to summarise these trials and reflect on their clinical context.

METHODS

The authors collated and reviewed clinical trials presented at major cardiology conferences during 2023 including the American College of Cardiology (ACC), European Association for Percutaneous Cardiovascular Interventions (EuroPCR), European Society of Cardiology (ESC), Transcatheter Cardiovascular Therapeutics (TCT), American Heart Association (AHA), European Heart Rhythm Association (EHRA), Society for Cardiovascular Angiography and Interventions (SCAI), TVT-The Heart Summit (TVT) and Cardiovascular Research Technologies (CRT). Trials with a broad relevance to the cardiology community and those with potential to change current practice were included.

RESULTS

A total of 80 key cardiology clinical trials were identified for inclusion. Key trials in acute coronary syndrome (ACS) and antiplatelet management such as HOST-IDEA, T-PASS and STOP-DAPT3 were included in addition to several pivotal interventional trials such as ORBITA 2, MULTISTARS-AMI, ILUMIEN-IV, OCTIVUS and OCTOBER. Additionally, several trials evaluated new stent design and technology such as BIOSTEMI, PARTHENOPE and TRANSFORM. Structural intervention trials included long-term data from PARTNER 3, new data on the durability of transcatheter aortic valve intervention (TAVI), in addition to major new trials regarding transcatheter tricuspid valve intervention from TRISCEND II. Heart failure (HF) and prevention covered several key studies including DAPA-MI, STEP-HF, ADVOR, DICTATE HF and CAMEO-DAPA. In cardiac devices and electrophysiology, several trial exploring novel ablation strategies in atrial fibrillation (AF) such as PULSED AF and ADVENT were presented with further data evaluating the efficacy of anticoagulation in subclinical AF in NOAH-AFNET 6, FRAIL AF and AZALEA-TIMI 71.

CONCLUSION

This article presents a summary of key clinical cardiology trials published and presented during the past year and should be of interest to both practising clinicians and researchers.

Perspective and Therapeutic Potential of the Noncoding RNA-Connexin Axis

Noncoding RNAs (ncRNAs) are a class of nucleotide sequences that cannot be translated into peptides. ncRNAs can function post-transcriptionally by splicing complementary sequences of mRNAs or other ncRNAs or by directly engaging in protein interactions. Over the past few decades, the pervasiveness of ncRNAs in cell physiology and their pivotal roles in various diseases have been identified. One target regulated by ncRNAs is connexin (Cx), a protein that forms gap junctions and hemichannels and facilitates intercellular molecule exchange. The aberrant expression and misdistribution of connexins have been implicated in central nervous system diseases, cardiovascular diseases, bone diseases, and cancer. Current databases and technologies have enabled researchers to identify the direct or indirect relationships between ncRNAs and connexins, thereby elucidating their correlation with diseases. In this review, we selected the literature published in the past five years concerning disorders regulated by ncRNAs via corresponding connexins. Among it, microRNAs that regulate the expression of Cx43 play a crucial role in disease development and are predominantly reviewed. The distinctive perspective of the ncRNA-Cx axis interprets pathology in an epigenetic manner and is expected to motivate research for the development of biomarkers and therapeutics.

Therapeutic Potential of Lipoprotein(a) Inhibitors

Increasing evidence has implicated lipoprotein(a) [Lp(a)] in the causality of atherosclerosis and calcific aortic stenosis. This has stimulated immense interest in developing novel approaches to integrating Lp(a) into the setting of cardiovascular prevention. Current guidelines advocate universal measurement of Lp(a) levels, with the potential to influence cardiovascular risk assessment and triage of higher-risk patients to use of more intensive preventive therapies. In parallel, considerable activity has been undertaken to develop novel therapeutics with the potential to achieve selective and substantial reductions in Lp(a) levels. Early studies of antisense oligonucleotides (e.g., mipomersen, pelacarsen), RNA interference (e.g., olpasiran, zerlasiran, lepodisiran) and small molecule inhibitors (e.g., muvalaplin) have demonstrated effective Lp(a) lowering and good tolerability. These agents are moving forward in clinical development, in order to determine whether Lp(a) lowering reduces cardiovascular risk. The results of these studies have the potential to transform our approach to the prevention of cardiovascular disease.

The importance of LDL-C lowering in atherosclerotic cardiovascular disease prevention: Lower for longer is better

Cumulative exposure to low-density lipoprotein cholesterol (LDL-C) is a key driver of atherosclerotic cardiovascular disease (ASCVD) risk. An armamentarium of therapies to achieve robust and sustained reduction in LDL-C can reduce ASCVD risk. The gold standard for LDL-C assessment is ultracentrifugation but in routine clinical practice LDL-C is usually calculated and the most accurate calculation is the Martin/Hopkins equation. For primary prevention, consideration of estimated ASCVD risk frames decision making regarding use of statins and other therapies, and tools such as risk enhancing factors and coronary artery calcium enable tailoring of risk assessment and decision making. In patients with diabetes, lipid lowering therapy is recommended in most patients to reduce ASCVD risk with an opportunity to tailor therapy based on other risk factors. Patients with primary hypercholesterolemia and familial hypercholesterolemia (FH) with baseline LDL-C greater than or equal to 190 mg/dL are at elevated risk, and LDL-C lowering with high-intensity statin therapy is often combined with non-statin therapies to prevent ASCVD. Secondary prevention of ASCVD, including in patients with prior myocardial infarction or stroke, requires intensive lipid lowering therapy and lifestyle modification approaches. There is no established LDL-C level below which benefit ceases or safety concerns arise. When further LDL-C lowering is required beyond lifestyle modifications and statin therapy, additional medications include oral ezetimibe and bempedoic acid, or injectables such as PCSK9 monoclonal antibodies or siRNA therapy. A novel agent that acts independently of hepatic LDL receptors is evinacumab, which is approved for patients with homozygous FH. Other emerging agents are targeted at Lp(a) and CETP. In light of the expanding lipid treatment landscape, this manuscript reviews the importance of early, intensive, and sustained LDL-C-lowering for primary and secondary prevention of ASCVD.

The Role of Lipoprotein(a) in Peripheral Artery Disease

Lipoprotein(a) is a low-density-lipoprotein-like particle that consists of apolipoprotein(a) bound to apolipoprotein(b). It has emerged as an established causal risk factor for atherosclerotic cardiovascular disease, stroke, and aortic valve stenosis through multifactorial pathogenic mechanisms that include inflammation, atherogenesis, and thrombosis. Despite an estimated 20% of the global population having elevated lipoprotein(a) levels, testing remains underutilized due to poor awareness and a historical lack of effective and safe therapies. Although lipoprotein(a) has a strong association with coronary artery disease and cerebrovascular disease, its relationship with peripheral artery disease is less well established. In this article, we review the epidemiology, biology, and pathogenesis of lipoprotein(a) as it relates to peripheral artery disease. We also discuss emerging treatment options to help mitigate major adverse cardiac and limb events in this population.

High lipoprotein(a): Actionable strategies for risk assessment and mitigation

High levels of lipoprotein(a) [Lp(a)] are causal for atherosclerotic cardiovascular disease (ASCVD). Lp(a) is the most prevalent inherited dyslipidemia and strongest genetic ASCVD risk factor. This risk persists in the presence of at target, guideline-recommended, LDL-C levels and adherence to lifestyle modifications. Epidemiological and genetic evidence supporting its causal role in ASCVD and calcific aortic stenosis continues to accumulate, although various facets regarding Lp(a) biology (genetics, pathophysiology, and expression across race/ethnic groups) are not yet fully understood. The evolving nature of clinical guidelines and consensus statements recommending universal measurements of Lp(a) and the scientific data supporting its role in multiple disease states reinforce the clinical merit to start population screening for Lp(a) now. There is a current gap in the implementation of recommendations for primary and secondary cardiovascular disease (CVD) prevention in those with high Lp(a), in part due to a lack of protocols for management strategies. Importantly, targeted apolipoprotein(a) [apo(a)]-lowering therapies that reduce Lp(a) levels in patients with high Lp(a) are in phase 3 clinical development. This review focuses on the identification and clinical management of patients with high Lp(a). Specifically, we highlight the clinical value of measuring Lp(a) and its use in determining Lp(a)-associated CVD risk by providing actionable guidance, based on scientific knowledge, that can be utilized now to mitigate risk caused by high Lp(a).

Single Ascending and Multiple-Dose Trial of Zerlasiran, a Short Interfering RNA Targeting Lipoprotein(a): A Randomized Clinical Trial

Importance

Lipoprotein(a) is a causal risk factor for atherosclerotic cardiovascular disease (ASCVD) and calcific aortic stenosis, with no pharmacological treatments approved by regulatory authorities.

Objectives

To assess the safety and tolerability of zerlasiran, a short interfering RNA targeting hepatic synthesis of apolipoprotein(a), and effects on serum concentrations of lipoprotein(a).

Design, Setting, and Participants

Single- and multiple-dose study in healthy participants and patients with stable ASCVD, respectively, with lipoprotein(a) serum concentrations greater than 150 nmol/L, conducted at 7 research sites in the US, the Netherlands, UK, and Australia between November 18, 2020, and February 8, 2023, with last follow-up on August 23, 2023.

Interventions

Participants were randomized to receive (1) a single subcutaneous dose of placebo (n = 8), zerlasiran 300 mg (n = 6) or 600 mg (n = 6); or (2) 2 doses of placebo (n = 9), zerlasiran 200 mg (n = 9) at a 4-week interval or 300 mg (n = 9) or 450 mg (n = 9) at an 8-week interval.

Main Outcomes Measures

The primary outcome was safety and tolerability. Secondary outcomes included serum levels of zerlasiran and effects on lipoprotein(a) serum concentrations.

Results

Among 37 patients in the multiple-dose group (mean age, 56 [SD, 10.4] years; 15 [42%] women), 36 completed the trial. Among 14 participants with extended follow-up after single doses, 13 completed the trial. There were no serious adverse events. Median baseline lipoprotein(a) concentrations in the multiple-dose group were 288 (IQR, 199-352) nmol/L. Median changes in lipoprotein(a) concentration at 365 days after single doses were 14% (IQR, 13% to 15%) for the placebo group, -30% (IQR, -51% to -18%) for the 300 mg of zerlasiran group, and -29% (IQR, -39% to -7%) for the 600-mg dose group. After 2 doses, maximal median changes in lipoprotein(a) concentration were 19 (IQR, -17 to 28) nmol/L for the placebo group, -258 (IQR, -289 to -188) nmol/L for the 200 mg of zerlasiran group, -310 (IQR, -368 to -274) nmol/L for the 300-mg dose group, and -242 (IQR, -343 to -182) nmol/L for the 450-mg dose group, with maximal median percent change of 7% (IQR, -4% to 21%), -97% (IQR, -98% to -95%), -98% (IQR, -99% to -97%), and -99% (IQR, -99% to -98%), respectively, attenuating to 0.3% (IQR, -2% to 21%), -60% (IQR, -71% to -40%), -90% (IQR, -91% to -74%), and -89% (IQR, -91% to -76%) 201 days after administration.

Conclusions

Zerlasiran was well tolerated and reduced lipoprotein(a) concentrations with infrequent administration.

Trial Registration

ClinicalTrials.gov Identifier: NCT04606602.

Independent Relationship of Lipoprotein(a) and Carotid Atherosclerosis With Long-Term Risk of Cardiovascular Disease

BACKGROUND

Lipoprotein(a) (Lp(a)) is considered to be a causal risk factor of atherosclerotic cardiovascular disease (ASCVD), but whether there is an independent or joint association of Lp(a) and atherosclerotic plaque with ASCVD risk remains uncertain. This study aims to assess ASCVD risk independently or jointly conferred by Lp(a) and carotid atherosclerotic plaque.

METHODS AND RESULTS

A total of 5471 participants with no history of cardiovascular disease at baseline were recruited and followed up for ASCVD events (all fatal and nonfatal acute coronary and ischemic stroke events) over a median of 11.5 years. Independent association of Lp(a), or the joint association of Lp(a) and carotid plaque with ASCVD risk, was explored using Cox proportional hazards models. Overall, 7.6% of the participants (60.0±7.9 years of age; 2649 [48.4%] men) had Lp(a) ≥50 mg/dL, and 539 (8.4/1000 person-years) incident ASCVD events occurred. Lp(a) concentrations were independently associated with long-term risk of total ASCVD events, as well as coronary events and ischemic stroke events. Participants with Lp(a) ≥50 mg/dL had a 62% higher risk of ASCVD incidence (95% CI, 1.19-2.21) than those with Lp(a) <10 mg/dL, and they exhibited a 10-year ASCVD incidence of 11.7%. This association exists even after adjusting for prevalent plaque. Moreover, participants with Lp(a) ≥30 mg/dL and prevalent plaque had a significant 4.18 times higher ASCVD risk than those with Lp(a) <30 mg/dL and no plaque.

CONCLUSIONS

Higher Lp(a) concentrations are independently associated with long-term ASCVD risk and may exaggerate cardiovascular risk when concomitant with atherosclerotic plaque.

Recent Progress of Small Interfering RNA Delivery on the Market and Clinical Stage

Small interfering RNAs (siRNAs) are promising therapeutic strategies, and five siRNA drugs have been approved by the Food and Drug Administration (FDA) and the European Commission (EC). This marks a significant milestone in the development of siRNA for clinical applications. The approved siRNA agents can effectively deliver siRNAs to the liver and treat liver-related diseases. Currently, researchers have developed diverse delivery platforms for transporting siRNAs to different tissues such as the brain, lung, muscle, and others, and a large number of siRNA drugs are undergoing clinical trials. Here, these delivery technologies and the latest advancements in clinical applications are summarized, and this Review provides a concise overview of the strategies employed for siRNA delivery to both hepatic and extrahepatic tissues.

A focused update to the 2019 NLA scientific statement on use of lipoprotein(a) in clinical practice

Since the 2019 National Lipid Association (NLA) Scientific Statement on Use of Lipoprotein(a) in Clinical Practice was issued, accumulating epidemiological data have clarified the relationship between lipoprotein(a) [Lp(a)] level and cardiovascular disease risk and risk reduction. Therefore, the NLA developed this focused update to guide clinicians in applying this emerging evidence in clinical practice. We now have sufficient evidence to support the recommendation to measure Lp(a) levels at least once in every adult for risk stratification. Individuals with Lp(a) levels <75 nmol/L (30 mg/dL) are considered low risk, individuals with Lp(a) levels ≥125 nmol/L (50 mg/dL) are considered high risk, and individuals with Lp(a) levels between 75 and 125 nmol/L (30-50 mg/dL) are at intermediate risk. Cascade screening of first-degree relatives of patients with elevated Lp(a) can identify additional individuals at risk who require intervention. Patients with elevated Lp(a) should receive early, more-intensive risk factor management, including lifestyle modification and lipid-lowering drug therapy in high-risk individuals, primarily to reduce low-density lipoprotein cholesterol (LDL-C) levels. The U.S. Food and Drug Administration approved an indication for lipoprotein apheresis (which reduces both Lp(a) and LDL-C) in high-risk patients with familial hypercholesterolemia and documented coronary or peripheral artery disease whose Lp(a) level remains ≥60 mg/dL [∼150 nmol/L)] and LDL-C ≥ 100 mg/dL on maximally tolerated lipid-lowering therapy. Although Lp(a) is an established independent causal risk factor for cardiovascular disease, and despite the high prevalence of Lp(a) elevation (∼1 of 5 individuals), measurement rates are low, warranting improved screening strategies for cardiovascular disease prevention.

All we need to know about lipoprotein(a)

Lipoprotein(a) [Lp(a)], a genetically determined macromolecular complex, is independently and causally associated with atherosclerotic cardiovascular disease (ASCVD) and calcific aortic stenosis via proposed proinflammatory, prothrombotic, and proatherogenic mechanisms. While Lp(a) measurement standardization issues are being resolved, several guidelines now support testing Lp(a) at least once in each adult's lifetime for ASCVD risk prediction which can foster implementation of more aggressive primary or secondary prevention therapies. Currently, there are several emerging targeted Lp(a) lowering therapies in active clinical investigation for safety and cardiovascular benefit among both primary and secondary prevention populations. First degree relatives of patients with high Lp(a) should be encouraged to undergo cascade screening. Primary prevention patients with high Lp(a) should consider obtaining a coronary calcium score for further risk estimation and to guide further ASCVD risk factor management including consideration of low dose aspirin therapy. Secondary prevention patients with high Lp(a) levels should consider adding PCSK9 inhibition to statin therapy.

The Role of Genetics in Advancing Cardiometabolic Drug Development

PURPOSE OF REVIEW

The objective of this review is to explore the role of genetics in cardiometabolic drug development. The declining costs of sequencing and the availability of large-scale genomic data have deepened our understanding of cardiometabolic diseases, revolutionizing drug discovery and development methodologies. We highlight four key areas in which genetics is empowering drug development for cardiometabolic disease: (1) identifying drug candidates, (2) anticipating drug target failures, (3) silencing and editing genes, and (4) enriching clinical trials.

RECENT FINDINGS

Identifying novel drug targets through genetic discovery studies and the use of genetic variants as indicators of potential drug efficacy and safety have become critical components of cardiometabolic drug discovery. We highlight the successes of genetically-informed therapeutic strategies, such as PCSK9 and ANGPTL3 inhibitors in lipid lowering and the emerging role of polygenic risk scores in improving the efficiency of clinical trials. Additionally, we explore the potential of gene silencing and editing technologies, such as antisense oligonucleotides and small interfering RNA, showcasing their promise in addressing diseases refractory to conventional treatments. In this review, we highlight four use cases that demonstrate the vital role of genetics in cardiometabolic drug development: (1) identifying drug candidates, (2) anticipating drug target failures, (3) silencing and editing genes, and (4) enriching clinical trials. Through these advances, genetics has paved the way to increased efficiency of drug development as well as the discovery of more personalized and effective treatments for cardiometabolic disease.

Highlights of Cardiovascular Disease Prevention Studies Presented at the 2023 American Heart Association Scientific Sessions

PURPOSE OF REVIEW

Focused review highlighting ten select studies presented at the 2023 American Heart Association (AHA) Scientific Sessions.

RECENT FINDINGS

Included studies assessed semaglutide and cardiovascular outcomes in overweight or obese patients without diabetes (SELECT); dapagliflozin in patients with acute myocardial infarction without diabetes (DAPA-MI); effects of dietary sodium on systolic blood pressure in middle-aged individuals (CARDIA-SSBP); long-term blood pressure control after hypertensive pregnancy with physician guided self-management (POP-HT); effect and safety of zilebesiran, an RNA interference therapy, for sustained blood pressure reduction (KARDIA-1); recaticimab add-on therapy in patients with non-familial hypercholesterolemia and mixed hyperlipidemia (REMAIN-2); efficacy and safety of lepodisiran an extended duration short-interfering RNA targeting lipoprotein(a); safety and pharmacodynamic effects of an investigational DNA base editing medicine that inactivates the PCSK9 gene and lowers LDL cholesterol (VERVE-101); automated referral to centralized pharmacy services for evidence-based statin initiation in high-risk patients; and effects of intensive blood pressure lowering in reducing risk of cardiovascular events (ESPRIT). Research presented at the 2023 AHA Scientific Sessions emphasized innovative strategies in cardiovascular disease prevention and management.

Lipoprotein(a): from Causality to Treatment

PURPOSE OF REVIEW

This paper reviews the evidence why lipoprotein(a) (Lp(a)) is a causal risk factor for cardiovascular disease and how high Lp(a) concentrations should be managed now and with an outlook to the future.

REVIEW FINDINGS

No optimal and widely available animal models exist to study the causality of the association between Lp(a) and cardiovascular disease. This has been a major handicap for the entire field. However, genetic studies turned the page. Already in the early 1990s, the principle of Mendelian randomization studies was applied for the first time ever (even if they were not named so at that time). Genetic variants of the LPA gene such as the apolipoprotein(a) isoform size, the number and sum of kringle IV repeats and later single nucleotide polymorphisms are strongly associated with life-long exposure to high Lp(a) concentrations as well as cardiovascular outcomes. This evidence provided a basis for the development of specific Lp(a)-lowering drugs that are currently in clinical testing phase. Lp(a) is one of the most important genetically determined risk factors for cardiovascular disease. With the specific Lp(a)-lowering therapies, we might get tools to fight this common risk factor in case the outcome trials will be positive.

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

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

Lipoprotein(a): A Review of Risk Factors, Measurements, and Novel Treatment Modalities

The study of lipoprotein(a) [Lp(a)] has long been a source of interest as a possible independent risk factor for atherosclerotic cardiovascular disease (ASCVD). The results of large sample observational studies, genome-wide association studies, and Mendelian randomization studies have been strong indicators supporting the link between ASCVD and Lp(a) despite early studies, with less sensitive assays, failing to show a connection. The recommendations for the indications and frequency of testing Lp(a) levels vary between US, Canadian, and European organizations due to the uncertain role of Lp(a) in ASCVD. The innovation of recent therapies, such as antisense oligonucleotides and small interfering RNA, designed to specifically target and reduce Lp(a) levels by targeting mRNA translation have once more thrust LP(a) into the spotlight of inquiry. These emerging modalities serve the dual purpose of definitively elucidating the connection between elevated Lp(a) levels and atherosclerotic cardiovascular risk, as well as the possibility of providing clinicians with the tools necessary to manage elevated Lp(a) levels in vulnerable populations. This review seeks to examine the mechanisms of atherogenicity of Lp(a) and explore the most current pharmacologic therapies currently in development.

Recommendations of the Experts of the Polish Cardiac Society (PCS) and the Polish Lipid Association (PoLA) on the diagnosis and management of elevated lipoprotein(a) levels

Lipoprotein(a) [Lp(a)] is made up of a low-density lipoprotein (LDL) particle and a specific apolipoprotein(a). The blood concentration of Lp(a) is approximately 90% genetically determined, and the main genetic factor determining Lp(a) levels is the size of the apo(a) isoform, which is determined by the number of KIV2 domain repeats. The size of the apo(a) isoform is inversely proportional to the blood concentration of Lp(a). Lp(a) is a strong and independent cardiovascular risk factor. Elevated Lp(a) levels ≥ 50 mg/dl (≥ 125 nmol/l) are estimated to occur in more than 1.5 billion people worldwide. However, determination of Lp(a) levels is performed far too rarely, including Poland, where, in fact, it is only since the 2021 guidelines of the Polish Lipid Association (PoLA) and five other scientific societies that Lp(a) measurements have begun to be performed. Determination of Lp(a) concentrations is not easy due to, among other things, the different sizes of the apo(a) isoforms; however, the currently available certified tests make it possible to distinguish between people with low and high cardiovascular risk with a high degree of precision. In 2022, the first guidelines for the management of patients with elevated lipoprotein(a) levels were published by the European Atherosclerosis Society (EAS) and the American Heart Association (AHA). The first Polish guidelines are the result of the work of experts from the two scientific societies and their aim is to provide clear, practical recommendations for the determination and management of elevated Lp(a) levels.

Molecular Therapies in Cardiovascular Diseases: Small Interfering RNA in Atherosclerosis, Heart Failure, and Hypertension

Small interfering RNA (siRNA) represents a novel, fascinating therapeutic strategy that allows for selective reduction in the production of a specific protein through RNA interference. In the cardiovascular (CV) field, several siRNAs have been developed in the last decade. Inclisiran has been shown to significantly reduce low-density lipoprotein cholesterol (LDL-C) circulating levels with a reassuring safety profile, also in older patients, by hampering proprotein convertase subtilisin/kexin type 9 (PCSK9) production. Olpasiran, directed against apolipoprotein(a) mRNA, prevents the assembly of lipoprotein(a) [Lp(a)] particles, a lipoprotein linked to an increased risk of ischemic CV disease and heart valve damage. Patisiran, binding transthyretin (TTR) mRNA, has demonstrated an ability to improve heart failure and polyneuropathy in patients with TTR amyloidosis, even in older patients with wild-type form. Zilebesiran, designed to reduce angiotensinogen secretion, significantly decreases systolic and diastolic blood pressure (BP). Thanks to their effectiveness, safety, and tolerability profile, and with a very low number of administrations in a year, thus overcoming adherence issues, these novel drugs are the leaders of a new era in molecular therapies for CV diseases.