Efficacy, Safety, and Tolerability of Inclisiran in Patients With Homozygous Familial Hypercholesterolemia: Results From the ORION-5 Randomized Clinical Trial

Early-onset familial hypercholesterolemia: A case of extensive xanthomas and premature coronary artery disease

Key Clinical Message

Early recognition and management of familial hypercholesterolemia (FH) are crucial, especially in patients with extensive xanthomas and premature coronary artery disease. Prompt diagnosis and aggressive lipid-lowering therapy can significantly reduce morbidity and mortality rates. Careful clinical assessment in resource-limited settings is essential for optimal outcomes.

Abstract

Familial hypercholesterolemia (FH) is an autosomal dominant inherited disorder that causes chronically elevated levels of low-density lipoprotein (LDL) cholesterol. Based on LDL levels, FH can be heterozygous or homozygous, further established through clinical features, laboratory findings, and genetic analysis. Elevated cholesterol levels cause atherosclerosis, coronary artery disease, myocardial infarction, and sudden death. Xanthomas are a clinical manifestation of FH that reveal the underlying systemic genetic disease. We present the case of a 47-year-old male with triple vessel coronary artery disease and widespread xanthomas, diagnosed with homozygous FH based on "The Dutch Lipid Clinic Network Diagnostic Criteria for Familial Hypercholesterolemia." Lifelong therapy with lipid-lowering medications and lifestyle changes is necessary in such cases.

From clinical development to real-world outcomes with inclisiran

PURPOSE OF REVIEW

Inclisiran is a small interfering RNA that blocks hepatocyte production of the PCSK9 (proprotein convertase subtilisin/kexin type 9) protein by specifically targeting PCKS9 mRNA in the cytoplasm. This results in reduced degradation of LDL receptors and thus lowers LDL cholesterol by around 50% in addition to other lipid-lowering therapies. beyond 6 years of therapy. This review covers the latest published data and outlines future studies currently in process.

RECENT FINDINGS

To date, half a million doses have been given worldwide with no untoward adverse events thus far. The twice-yearly injections make it potentially very user-friendly. The large phase 3a trials saw no diminution of effect with time up to nearly 7 years. Very large phase 3b randomized controlled trials are underway and may produce significant reductions in major adverse cardiovascular events.

SUMMARY

Inclisiran has been evaluated in numerous trials, primarily the ORION 926, ORION 1027 and ORION 1128 studies, which demonstrated that in patients already on maximally tolerated statin therapy, biannual inclisiran injections reduced LDL cholesterol by up to 52% compared to placebo with a good safety profile. The only observed side effects were mild and transient at the injection site. As mentioned in the accompanying video, this adds to our armamentarium of lipid treatments.

Gene therapy for polygenic or complex diseases

Gene therapy utilizes nucleic acid drugs to treat diseases, encompassing gene supplementation, gene replacement, gene silencing, and gene editing. It represents a distinct therapeutic approach from traditional medications and introduces novel strategies for genetic disorders. Over the past two decades, significant advancements have been made in the field of gene therapy, leading to the approval of various gene therapy drugs. Gene therapy was initially employed for treating genetic diseases and cancers, particularly monogenic conditions classified as orphan diseases due to their low prevalence rates; however, polygenic or complex diseases exhibit higher incidence rates within populations. Extensive research on the etiology of polygenic diseases has unveiled new therapeutic targets that offer fresh opportunities for their treatment. Building upon the progress achieved in gene therapy for monogenic diseases and cancers, extending its application to polygenic or complex diseases would enable targeting a broader range of patient populations. This review aims to discuss the strategies of gene therapy, methods of gene editing (mainly CRISPR-CAS9), and carriers utilized in gene therapy, and highlight the applications of gene therapy in polygenic or complex diseases focused on applications that have either entered clinical stages or are currently undergoing clinical trials.

Advances in targeting LDL cholesterol: PCSK9 inhibitors and beyond

There is a direct relationship between the duration and level of exposure to low density lipoprotein cholesterol (LDL-C) levels over one's lifespan and cardiovascular events. Early treatment to lower elevated LDL-C is crucial for better outcomes with multiple therapies currently available to reduce atherogenic lipoproteins. Statins remain the foundation of LDL-C lowering therapy as one of the most cost-effective drugs to reduce atherosclerotic events (ASCVD) and mortality. Nonetheless, LDL-driven goal attainment remains suboptimal globally, highlighting a considerable need for non-statin therapies to address residual risk related to statin intolerance, non-adherence, and inherited lipoprotein disorders. LDL-C lowering interventions beyond statins include ezetimibe, PCSK9 monoclonal antibodies, inclisiran and bempedoic acid with specific guideline recommendations as to when to consider each. For patients with homozygous familial hypercholesterolemia requiring more advanced therapy, lomitapide and evinacumab are available, providing mechanisms that are not LDL receptor dependent. Lipoprotein apheresis remains an effective option for clinical familial hypercholesterolemia as well as elevated lipoprotein (a). There are investigational therapies being explored to add to our current armamentarium including CETP inhibitors, a third-generation PCSK9 inhibitor (small recombinant fusion protein oral PCSK9 inhibitor) and gene editing which aims to directly restore or disrupt genes of interest at the DNA level. This article is a brief review of the pharmacotherapy options beyond statins for lowering LDL-C and their impact on ASCVD risk reduction. Our primary aim is to guide physicians on the role these therapies play in achieving appropriate LDL-C goals, with an algorithm of when to consider each based on efficacy, safety and outcomes.

Inclisiran: A Systematic Review Exploring the Revolutionary Approach of Twice-Yearly Dosing Regimen in the Treatment of Hypercholesterolemia

The global burden of hyperlipidemia is on the rise, along with an increase in associated cardiovascular complications. Since most of the patients affected by hyperlipidemia are elderly individuals with multiple comorbidities, the introduction of even a single additional drug for asymptomatic conditions such as hyperlipidemia can drastically reduce treatment compliance due to their long medication history. Hence, researchers are trying to come up with a drug with a long duration of action requiring less frequent dosing without compromising compliance and improving the outcome. This led to the discovery of inclisiran, a "wonder drug" that utilizes small interference RNA and requires only twice-yearly administration to maintain patients' lipid levels at optimal levels. We conducted a systematic review by following standardized guidelines on the long-term efficacy and safety of the new drug, inclisiran, in the treatment of hypercholesterolemia. We conducted an advanced search on PubMed using the MeSH strategy and then employed appropriate keywords to search other major databases, such as PubMed Central and Medline, using various inclusion and exclusion criteria, which yielded 94 articles from various databases. We narrowed down the search to 10 randomized controlled trials (ORION trials) after removing duplicates and screening for irrelevant titles for inclusion in the study. The ORION trials on inclisiran evaluated the drug's impact on various parameters, such as low-density lipoprotein-cholesterol (LDL-C), proprotein convertase subtilisin/kexin type 9 (PCSK9), high-density lipoprotein (non-HDL), apolipoprotein B (apoB), and so on, while considering the safety aspects of the drug. All the trials indicate greater efficacy of inclisiran and long-term maintenance of the results achieved when compared to a placebo and showed a long dosing interval, thereby increasing treatment compliance. Additionally, as the drug's dose increased, we observed greater reductions in the mentioned parameters without a significant increase in the incidence of adverse events. According to the review's data analysis, inclisiran, with its greater efficacy, has the potential to replace conventional pharmacological therapy in the near future, with the best results achieved when combined with lifestyle modifications. However, a long-term assessment of the drug's efficacy and safety is required before implementing it in clinical practice to identify any potential safety concerns, particularly related to the administration of higher dosage over a longer period.

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.

Consensus document on diagnosis and management of familial hypercholesterolemia from the Italian Society for the Study of Atherosclerosis (SISA)

AIMS

Familial Hypercholesterolemia (FH) is a genetic disorder of lipoprotein metabolism that causes an increased risk of premature atherosclerotic cardiovascular disease (ASCVD). Although early diagnosis and treatment of FH can significantly improve the cardiovascular prognosis, this disorder is underdiagnosed and undertreated. For these reasons the Italian Society for the Study of Atherosclerosis (SISA) assembled a Consensus Panel with the task to provide guidelines for FH diagnosis and treatment.

DATA SYNTHESIS

Our guidelines include: i) an overview of the genetic complexity of FH and the role of candidate genes involved in LDL metabolism; ii) the prevalence of FH in the population; iii) the clinical criteria adopted for the diagnosis of FH; iv) the screening for ASCVD and the role of cardiovascular imaging techniques; v) the role of molecular diagnosis in establishing the genetic bases of the disorder; vi) the current therapeutic options in both heterozygous and homozygous FH. Treatment strategies and targets are currently based on low-density lipoprotein cholesterol (LDL-C) levels, as the prognosis of FH largely depends on the magnitude of LDL-C reduction achieved by lipid-lowering therapies. Statins with or without ezetimibe are the mainstay of treatment. Addition of novel medications like PCSK9 inhibitors, ANGPTL3 inhibitors or lomitapide in homozygous FH results in a further reduction of LDL-C levels. LDL apheresis is indicated in FH patients with inadequate response to cholesterol-lowering therapies.

CONCLUSION

FH is a common, treatable genetic disorder and, although our understanding of this disease has improved, many challenges still remain with regard to its identification and management.

Proprotein convertase subtilisin/kexin type 9-inhibition across different patient populations

PURPOSE OF REVIEW

Monoclonal antibodies (mAb) targeting proprotein convertase subtilisin/kexin type 9 (PCSK9) have been established in cardiovascular risk prevention. The purpose of this review is to summarize the effects of PCSK9 inhibitors across different patient populations.

RECENT FINDINGS

Long-term data on the use of evolocumab and alirocumab shows persisting low- density lipoprotein cholesterol (LDL-C) lowering and good tolerability. PCSK9 inhibitors are effective and safe in both sexes, in pediatric patients as well as in the elderly. Initiation of PCSK9 mAb during acute myocardial infarction is safe and leads to beneficial morphological plaque changes. The PCSK9 inhibitors evolocumab, alirocumab and inclisiran lower LDL-C in patients with heterozygous familial hypercholesterolemia (FH), while the response of patients with homozygous FH is heterogeneous. New areas of application beyond lipid lowering are currently investigated.

SUMMARY

PCSK9 inhibitors are safe, well tolerated, and effective in primary and secondary prevention in a wide range of patient populations.

Inclisiran: the preclinical discovery and development of a novel therapy for the treatment of atherosclerosis

INTRODUCTION

Atherosclerotic cardiovascular disease (ASCVD) remains a leading cause of global morbidity and mortality. Lipid lowering therapy (LLT) constitutes the cornerstone of ASCVD prevention and treatment. However, several patients fail to achieve therapeutic goals due to low treatment adherence or limitations of standard-of-care (SoC) LLTs. Inclisiran represents a pivotal low-density lipoprotein cholesterol (LDL-C) lowering agent aiming to address current unmet needs in LLT. It is the first available small interfering RNA (siRNA) LLT, specifically targeting PCSK9 mRNA and leading to post-transcriptional gene silencing (PTGS) of the PCSK9 gene.

AREAS COVERED

Promising phase III trials revealed an ~ 50% reduction in LDL-C levels with subcutaneous inclisiran administration on days 1 and 90, followed by semiannual booster shots. Coupled with inclisiran's favorable safety profile, these findings led to its approval by both the EMA and FDA. Herein, the authors highlight the preclinical discovery and development of this agent and provide the reader with their expert perspectives.

EXPERT OPINION

The evolution of gene-silencing treatments offers new perspectives in therapeutics. Inclisiran appears to have the potential to revolutionize ASCVD prevention and treatment, benefiting millions of patients. Ensuring widespread availability of Inclisiran, as well as managing additional healthcare costs that may arise, should be of paramount importance.

Evolution of LDL-C lowering medications and their cardiovascular benefits: Past, present, and future

Cardiovascular disease (CVD) is the leading cause of morbidity and mortality worldwide. Hyperlipidemia, particularly elevated low-density lipoprotein cholesterol (LDL-C) is one of the major risk factors for CVD. Major landmark cardiovascular outcome clinical trials demonstrated that LDL-C lowering medications reduce cardiovascular events, and the lower the LDL-C the better the outcome. This article discusses the evolution of LDL-C lowering medications starting from bile acid sequestrants (BAS), statin therapy, bempedoic acid, the proprotein convertase subtilisin kexin 9 (PCSK9) synthesis inhibitor, novel small interfering RNA-based therapy (inclisiran) to the most recent oral PCSK9 inhibitors (MK-0616) which is currently under phase 3 clinical trial studies.

PCSK9-directed therapies: an update

PURPOSE OF REVIEW

Two large cardiovascular outcomes trials of monoclonal antibodies against proprotein convertase subtilisin/kexin type 9 (PCSK9) demonstrated that therapeutic inhibition of extracellular PCSK9 markedly reduces LDL cholesterol concentration and cardiovascular risk. Several novel strategies to inhibit PCSK9 function are in development. Different mechanisms of action may determine specific properties with potential relevance for patient care.

RECENT FINDINGS

For the monoclonal antibodies evolocumab und alirocumab as first-generation PCSK9 inhibitors, follow-up data of up to 8 years of exposure complement the information on efficacy and safety available from outcome trials. For the small-interfering RNA inclisiran as second-generation PCSK9 inhibitor, several phase III trials have been published and a cardiovascular outcome trial has completed recruitment and is ongoing. Third-generation PCSK9 inhibitors encompass, among others, orally available drugs such as MK-0616 and the fusion protein lerodalcibep. Additional strategies to inhibit PCSK9 include vaccination and gene editing.

SUMMARY

Long-term inhibition of PCSK9 with monoclonal antibodies is safe and conveys sustained cardiovascular benefit. Novel strategies to inhibit PCSK9 function such as orally available drugs, RNA targeting, and one-time treatment with gene editing may further enhance the therapeutic armamentarium and enable novel preventive strategies.

New Insights Into the Treatment of Hyperlipidemia: Pharmacological Updates and Emerging Treatments

Cardiovascular diseases are the leading causes of global mortality and morbidity. Hyperlipidemia is a significant risk factor for atherosclerosis and subsequent cardiovascular diseases. Hyperlipidemia is characterized by imbalances in blood cholesterol levels, particularly elevated low-density lipoprotein cholesterol and triglycerides, and is influenced by genetic and environmental factors. Current management consists of lifestyle modifications and pharmacological interventions most commonly consisting of statins. This review paper explores pathophysiology, management strategies, and pharmacotherapies including commonly used well-established medications including statins, fibrates, and ezetimibe, exciting novel therapies including proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors, and RNA interference therapies (inclisiran), lomitapide, and bempedoic acid, highlighting their mechanisms of action, clinical efficacy, and safety profiles. Additionally, emerging therapies under clinical trials including ApoC-III inhibitors, DGAT2 inhibitors, ACAT2 Inhibitors, and LPL gene therapies are examined for their potential to improve lipid homeostasis and cardiovascular outcomes. The evolving landscape of hyperlipidemia management underscores the importance of continued research into both established therapies and promising new candidates, offering hope for more effective treatment strategies in the future.

Surgical Treatment of Multiple Large Tuberous and Tendinous Xanthoma Secondary to Familial Hypercholesterolaemia: A Case Report

Xanthomas are well-circumscribed skin lesions that are commonly seen in patients with familial hypercholesterolemia (FH). The aim of this report is to present a rare case of multiple large tuberous and tendinous xanthomas. A 17-year-old female patient in this report presented with multiple asymptomatic and papulo-nodular masses in both sides of palms, elbows, buttocks, knees, and Achilles tendons. Surgical removal of the masses was carried out in combination with lipid-lowering therapy. A following up of 3 months showed all wounds were healing well, and no recurrence of masses was observed. Therefore, for patients with xanthomas related with familial hypercholesterolaemia, lipid-lowering therapy has reportedly reduced the size of masses, but surgical treatment may be essential for large xanthomas caused pain or limitation of daily activities.

Novel and Emerging LDL-C Lowering Strategies: A New Era of Dyslipidemia Management

Atherosclerotic cardiovascular disease (ASCVD) represents a major global health challenge, significantly contributing to mortality rates. This chronic inflammatory condition affecting blood vessels is intricately linked to hypercholesterolemia, with elevated levels of low-density lipoprotein cholesterol (LDL-C) recognized as a central and modifiable risk factor. The effectiveness of lipid-lowering therapy (LLT) in mitigating ASCVD risk is well established, with studies revealing a substantial reduction in major ischemic events correlating with LDL-C reduction. While statins, often combined with ezetimibe, remain fundamental in dyslipidemia management, a significant proportion of patients on statin therapy continue to experience cardiovascular events. Recent pharmacological advancements, driven by a deeper understanding of atherogenesis, have unveiled novel therapeutic targets and potent drugs. Notably, agents like bempedoic acid and proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors (evolocumab, alirocumab, inclisiran) have emerged as effective options to intensify LLT and achieve LDL-C goals, addressing limitations associated with statins, such as myopathy. Molecular insights into alternative pathways have spurred the investigation of emerging agents, offering promising perspectives for novel medications with efficacy comparable to established treatments, associated with advantages in cost and administration. This review provides a comprehensive overview of the evolving landscape of lipid-lowering strategies, highlighting the progress made in addressing ASCVD risk and the potential of upcoming therapies to further optimize cardiovascular prevention.