Advantages and Disadvantages of Inclisiran: A Small Interfering Ribonucleic Acid Molecule Targeting PCSK9—A Narrative Review

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.

Atherosclerotic cardiovascular disease landscape in Singapore

Cardiovascular disease (CVD) is the leading cause of death worldwide, accounting for over one-third of all deaths in Singapore. An analysis of age-standardized mortality rates (ASMR) for CVD in Singapore revealed a deceleration in the initial rapid decline in ASMR. A decrease in smoking prevalence may have contributed to the initial rapid decline in ASMR. Furthermore, other major risk factors, such as diabetes mellitus, hypertension, elevated low-density lipoprotein levels, and obesity, are steadily rising. Singapore's CVD economic burden is estimated to be 8.1 billion USD (11.5 billion SGD). The burden of CVD can only be reduced using individual and population-based approaches. Prevention programs must also be developed based on an understanding of risk trends. Therefore, this article attempts to capture the burden of CVD, trends in risk factor control, preventive care, disparities, and current unmet needs, particularly in atherosclerotic cardiovascular disease management in Singapore.

Atherosclerosis Residual Lipid Risk-Overview of Existing and Future Pharmacotherapies

Patients with atherosclerotic disease remain at increased risk of future events despite receiving optimal medical treatment. This residual risk is widely heterogeneous, but lipoprotein particles and their content play a major role in determining future cardiovascular events. Beyond low-density lipoprotein cholesterol (LDL-c), other lipoprotein particles have not demonstrated similar contribution to the progression of atherosclerosis. Statins, ezetimibe, and more recently, proprotein convertase subtilisin kexin 9 (PCSK9) inhibitors and bempedoic acid have confirmed the causal role of LDL-c in the development of atherosclerosis. Data on high-density lipoprotein cholesterol (HDL-c) suggested a possible causal role for atherosclerosis; nonetheless, HDL-c-raising treatments, including cholesteryl-ester transfer protein (CETP) inhibitors and niacin, failed to confirm this relationship. On the other hand, mendelian randomisation revealed that triglycerides are more implicated in the development of atherosclerosis. Although the use of highly purified eicosapentaenoic acid (EPA) was associated with a reduction in the risk of adverse cardiovascular events, this beneficial effect did not correlate with the reduction in triglycerides level and has not been consistent across large phase 3 trials. Moreover, other triglyceride-lowering treatments, such as fibrates, were not associated with a reduction in future cardiovascular risk. Studies assessing agents targeting angiopoietin-like 3 (lipoprotein lipase inhibitor) and apolipoprotein C3 antisense will add further insights into the role of triglycerides in atherosclerosis. Emerging lipid markers such as lipoprotein (a) and cholesterol efflux capacity may have a direct role in the progression of atherosclerosis. Targeting these biomarkers may provide incremental benefits in reducing cardiovascular risk when added to optimal medical treatment. This Review aims to assess available therapies for current lipid biomarkers and provide mechanistic insight into their potential role in reducing future cardiovascular risk.

Advancements in Omics and Breakthrough Gene Therapies: A Glimpse into the Future of Peripheral Artery Disease

Peripheral artery disease (PAD), a highly prevalent global disease, associates with significant morbidity and mortality in affected patients. Despite progress in endovascular and open revascularization techniques for advanced PAD, these interventions grapple with elevated rates of arterial restenosis and vein graft failure attributed to intimal hyperplasia (IH). Novel multiomics technologies, coupled with sophisticated analyses tools recently powered by advances in artificial intelligence, have enabled the study of atherosclerosis and IH with unprecedented single-cell and spatial precision. Numerous studies have pinpointed gene hubs regulating pivotal atherogenic and atheroprotective signaling pathways as potential therapeutic candidates. Leveraging advancements in viral and nonviral gene therapy (GT) platforms, gene editing technologies, and cutting-edge biomaterial reservoirs for delivery uniquely positions us to develop safe, efficient, and targeted GTs for PAD-related diseases. Gene therapies appear particularly fitting for ex vivo genetic engineering of IH-resistant vein grafts. This manuscript highlights currently available state-of-the-art multiomics approaches, explores promising GT-based candidates, and details GT delivery modalities employed by our laboratory and others to thwart mid-term vein graft failure caused by IH, as well as other PAD-related conditions. The potential clinical translation of these targeted GTs holds the promise to revolutionize PAD treatment, thereby enhancing patients' quality of life and life expectancy.

Italian Association of Hospital Cardiologists Position Paper 'Gender discrepancy: time to implement gender-based clinical management'

It has been well assessed that women have been widely under-represented in cardiovascular clinical trials. Moreover, a significant discrepancy in pharmacological and interventional strategies has been reported. Therefore, poor outcomes and more significant mortality have been shown in many diseases. Pharmacokinetic and pharmacodynamic differences in drug metabolism have also been described so that effectiveness could be different according to sex. However, awareness about the gender gap remains too scarce. Consequently, gender-specific guidelines are lacking, and the need for a sex-specific approach has become more evident in the last few years. This paper aims to evaluate different therapeutic approaches to managing the most common women's diseases.

First Report of Inclisiran Utilization for Hypercholesterolemia Treatment in Real-world Clinical Settings in a Middle East Population

PURPOSE

Inclisiran is the first small interfering RNA-based treatment approved for reducing pro-atherogenic lipoproteins in patients with heterozygous familial hypercholesterolemia or clinical atherosclerotic cardiovascular disease, who require additional lowering of low-density lipoprotein cholesterol (LDL-C). We report the first evaluation of the effects of inclisiran in a Middle East population.

METHODS

We conducted a retrospective review of patients initiating inclisiran treatment at an outpatient diabetology, endocrinology, and cardiology center between May 2021 and December 2022. All patients followed up for 90 days or more, or with at least 1 lipid determination post initiation were included. Participants were categorized into primary prevention (n = 57) and secondary prevention (n = 89) groups according to previous atherosclerotic cardiovascular disease.

FINDINGS

Inclisiran was initiated in 146 patients; mean (SD) age was 54.8 (12.12) years, 82 patients (56.2%) were male, 28 patients (19.2%) had received a diagnosis of familial hypercholesterolemia, 89 patients (61%) had received a diagnosis of diabetes mellitus, and 35 patients (23.9%) had a statin intolerance. Median (interquartile range) follow-up was 137 (90 to 193) days. At 90 days, median (interquartile range) reductions in serum LDL-C and triglycerides were -37.9% (-9.5% to -51.2%) and -12.0% (-9.8% to -40.5%), respectively, in primary prevention and -54.1% (-17.1% to -71.4%) and -15.3% (-14% to -38.8%), respectively, in secondary prevention (all, P < 0.001). LDL-C goals were attained in 110 patients (75.3%). Nonattainment of LDL-C goal was attributed to system effect in 26 patients (72.2%), biological effect in 5 patients (13.9%), and discontinuation of treatment in 5 patients (13.9%). Therapy was well tolerated.

IMPLICATIONS

This study is the first from the Middle East and North Africa region that reported the real-world efficacy and safety profile of inclisiran in a mixed-risk population of patients with heterozygous familial hypercholesterolemia and other non-familial hypercholesterolemia indications. Clinically meaningful and sustained reductions in pro-atherogenic lipids with good tolerability were observed after inclisiran initiation. Fewer AEs were reported in this predominantly Arabic population, consistent with previous safety reports for inclisiran. It is important to note that no patient stopped inclisiran treatment due to AEs. Strengths of our study included an optimal cohort, patient heterogeneity, and high retention. In addition, we were able to report mean robust effects of inclisiran and good medication tolerability, quite like randomized studies and open-label extension periods. Despite this, our study had some limitations, including selection bias due to the retrospective design and the absence of a comparative group.

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.

Serious Adverse Events of Inclisiran in Patients With Hypercholesterolemia, a Meta-Analysis of ORION Trials

BACKGROUND

Several studies have been conducted over the years to find an effective and safe therapeutic agent to treat hypercholesterolemia. Inclisiran is a novel drug being studied for its efficacy and safety in reducing low-density lipoprotein cholesterol levels in patients to reduce the risk of cardiovascular diseases. No previous study was done to review the trials for the serious adverse events of this drug. The primary objective of this research is to investigate the incidence of serious adverse events of this drug.

DESIGN

A systematic review and meta-analysis of clinical trials is performed.

METHODS

A systematic search of PubMed, Embase, and ClinicalTrials.gov, from their inception till July 3, 2023, was performed for ORION trials, studying the efficacy and safety of inclisiran. The random-effects model was used in the meta-analysis to provide a pooled proportion of serious adverse events. The risk of bias in each study was assessed by the Cochrane Risk of Bias Tool.

RESULTS

From 319 studies searched from the databases, only 8 relevant articles remained after a detailed evaluation. These studies, having a total of 4981 patients, were involved in the analysis, with a pooled estimate showing a nonsignificant incidence of serious adverse events. Each adverse event was studied individually, and product issues and endocrine disorders had the highest odds ratio among them. All included studies were classified as moderate quality.

CONCLUSION

Following systematic review and meta-analysis, we found no significant differences in any serious adverse events following the administration of inclisiran. However, larger ongoing trials will provide additional data to evaluate the safety profile of this agent.

The combination use of inclisiran and statins versus statins alone in the treatment of dyslipidemia in mainland China: a cost-effectiveness analysis

Objective: Statin is well-established as a classical lipid-lowering drug, and its cost has reduced considerably in the past years. Inclisiran is a new and effective lipid-lowering drug given as a subcutaneous injection at 6-month intervals. This study aims to evaluate the cost-effectiveness of the combination use of inclisiran and statin versus statin alone for dyslipidemia in the mainland China population. Methods: The Markov decision-making model was used, and the clinical data and real-world data were collected at the University of Hong Kong-Shenzhen Hospital (HKU-SZH). Patients with cardiovascular disease (CVD) and blood lipid levels above the target on statin therapy were included as the target population and analyzed for cardiovascular events, future medical expenses, and the calculation made for the total life cost, quality-adjusted life years (QALYs), and incremental cost-effectiveness ratios (ICERs). Sensitivity analysis was conducted to evaluate the influence of parameter uncertainty on the base-case analysis results. Results: If inclisiran was priced at Chinese renminbi (RMB) 20,000.00 (USD 2,973.49) per injection, patients in the inclisiran and statin group would incur an incremental cost of RMB 449,233.56 (USD 66,789.60) compared with the statin group, and they would obtain 0.21 more QALYs in their life cycle. The subsequent ICER of RMB 2,127,756.78 (USD 316,343.32)/QALY was significantly higher than the willingness-to-pay (WTP) threshold of 3 times the per capita GDP of China, which was RMB 257,094.00 (USD 38,223.33)/QALY, suggesting that the combined use of inclisiran and statin was not cost-effective. If the price of inclisiran were reduced to RMB 2,500.00 (USD 371.69)/injection, the ICER of patients in the inclisiran and statin group would become RMB 257,790.63 (USD 38,326.91)/QALY, which is slightly lower than the WTP threshold of 3 times the per capita GDP of China, indicating that the combined use of inclisiran and statin would be cost-effective. Conclusion: If inclisiran is priced at RMB 20,000.00 (USD 2,973.49)/injection, then the combined use of inclisiran and statins is not cost-effective compared with statin alone. It will be economical only if the price of inclisiran is reduced by more than 88%.

A systematic review and meta-analysis of tolerability, cardiac safety and efficacy of inclisiran for the therapy of hyperlipidemic patients

BACKGROUND

Dyslipidaemia is a crucial risk factor for cardiovascular morbidity and mortality. A short interfering RNA called inclisiran diminishes circulating levels of PCSK9 and LDL-C by hindering PCSK9 translation in the liver.

METHODS

RCTs were electronically searched on PubMed, Cochrane Central, and Clinicaltrials.gov to assess the safety and efficacy of inclisiran. Cochrane Review Manager 5 was used to conduct the pooled analysis. Risk of bias was assessed and GRADE pro-GDT was utilized, respectively, to estimate the methodological quality and overall quality of evidence.

RESULTS

Of 218 records screened, four studies were included with 2203 participants in inclisiran and 1949 participants in the placebo group. Inclisiran was related to non-significant elevated risk of total adverse events[RR = 1.05(0.98,1.12), p = 0.16; I2 = 53%], non-serious adverse events[RR = 1.09(0.97,1.22),p = 0.15;I2 = 61%] and all-cause mortality[RR = 1.01(0.60,1.70),p = 0.97;I2 = 0%] whereas a lower risk of serious adverse events[RR = 0.94(0.70,1.25),p = 0.67;I2 = 73%], cardiac disorders [RR = 0.87(0.66,1.15),p = 0.33;I2 = 42%] and Major adverse cardiovascular events(MACE)[RR = 0.79(0.62,1.00),p = 0.05; I2 = 0%] as compared to placebo. Inclisiran was also linked to a substantial decline in the percentage of LDL-C, PCSK9, total cholesterol, and Apo B.

CONCLUSION

The pooled analysis of the existing evidence shows that inclisiran showed reduced risk of MACE along with excellent efficacy in managing dyslipidemia.

CLINICAL TRIAL REGISTRATION

www.clinicaltrials.gov identifiers are NCT03399370, NCT03397121, NCT03400800, and NCT02597127.

Adherence to pharmacotherapy: sine qua non for reducing cumulative risk of premature coronary disease in familial hypercholesterolemia

PURPOSE OF REVIEW

Familial hypercholesterolemia (FH) is a dominant and highly penetrant monogenic disorder present from birth that markedly elevates plasma low-density lipoprotein (LDL)-cholesterol concentration and, if untreated, leads to atherosclerotic cardiovascular disease (ASCVD). The risk of ASCVD can be substantially reduced with lipid-lowering treatment (LLT). However, adherence to LLT remains a major challenge in FH patients and an under-recognized issue. We review several barriers to treatment adherence and implementation strategies for improving adherence in patients with FH.

RECENT FINDINGS

Barriers that negatively affect patient adherence to treatment include the misunderstanding of perceived and actual risk of FH and the benefits of LLT, inadequate knowledge, lack of standardization of treatment, insufficient monitoring of LDL-cholesterol level, and inequalities in healthcare resources. Education of patients, carers and healthcare providers, guideline-directed treatment goals, regular monitoring, medication regimen simplification and greater access to established and new drugs are crucial enablers for improving adherence to treatment. However, given FH is present from birth, strategies for life-long adherence from childhood or young adulthood is critically important and requires further study. To be effective, strategies should be multifaceted, targeted and patient-centred involving a multidisciplinary-team with support from family, communities and peer groups.

SUMMARY

FH confers a significant risk for ASCVD from a young age. Achieving better medication adherence is foundational for improving clinical outcomes and reducing the burden of atherosclerosis over a lifetime. Identification of key barriers and enablers are critical for implementing better adherence to treatment across the life-course of patients with FH.

EZH2 as a potential therapeutic target for gastrointestinal cancers

Gastrointestinal (GI) cancers continue to be a major cause of mortality and morbidity globally. Understanding the molecular pathways associated with cancer progression and severity is essential for creating effective cancer treatments. In cancer research, there is a notable emphasis on Enhancer of zeste homolog 2 (EZH2), a key player in gene expression influenced by its irregular expression and capacity to attach to promoters and alter methylation status. This review explores the impact of EZH2 signaling on various GI cancers, such as colorectal, gastric, pancreatic, hepatocellular, esophageal, and cholangiocarcinoma. The primary function of EZH2 signaling is to facilitate the accelerated progression of cancer cells. Additionally, EZH2 has the capacity to modulate the reaction of GI cancers to chemotherapy and radiotherapy. Numerous pathways, including long non-coding RNAs and microRNAs, serve as upstream regulators of EZH2 in these types of cancer. EZH2's enzymatic activity enables it to attach to target gene promoters, resulting in methylation that modifies their expression. EZH2 could be considered as an independent prognostic factor, with increased expression correlating with a worse disease prognosis. Additionally, a range of gene therapies including small interfering RNA, and anti-tumor agents are being explored to target EZH2 for cancer treatment. This comprehensive review underscores the current insights into EZH2 signaling in gastrointestinal cancers and examines the prospect of therapies targeting EZH2 to enhance patient outcomes.

Tafolecimab in Chinese patients with non-familial hypercholesterolemia (CREDIT-1): a 48-week randomized, double-blind, placebo-controlled phase 3 trial

Background

Tafolecimab, a fully human proprotein convertase subtilisin/kexin type 9 (PCSK9) monoclonal antibody developed for the treatment of hypercholesterolemia, demonstrated robust lipid-lowering efficacy and favorable safety in previous short-term studies. We aimed to assess the long-term efficacy and safety of tafolecimab in Chinese non-familial hypercholesterolemia (non-FH) patients.

Methods

Non-FH patients at high or very-high cardiovascular risk with screening low-density lipoprotein cholesterol (LDL-C) level ≥1.8 mmol/L or non-FH patients with screening LDL-C level ≥3.4 mmol/L and on stable lipid-lowering therapy for at least 4 weeks, were randomized in a 2:2:1:1 ratio to receive subcutaneous tafolecimab 450 mg Q4W, tafolecimab 600 mg Q6W, placebo 450 mg Q4W, or placebo 600 mg Q6W, respectively, in the 48-week double-blind treatment period. The primary endpoint was the percent change from baseline to week 48 in LDL-C levels.

Findings

A total of 618 patients were randomized and 614 patients received at least one dose of tafolecimab (n = 411) or placebo (n = 203). At week 48, tafolecimab induced significant reductions in LDL-C levels (treatment differences versus placebo [on-treatment estimand]: -65.0% [97.5% CI: -70.2%, -59.9%] for 450 mg Q4W; -57.3% [97.5% CI: -64.0%, -50.7%] for 600 mg Q6W; both P < 0.0001). Significantly more patients treated with tafolecimab achieved ≥50% LDL-C reductions, LDL-C < 1.8 mmol/L, and LDL-C < 1.4 mmol/L than placebo group at both dose regimens (all P < 0.0001). Furthermore, tafolecimab significantly reduced non-HDL-C, apolipoprotein B, and lipoprotein(a) levels. The most commonly-reported treatment emergent adverse events in the tafolecimab groups included upper respiratory infection, urinary tract infection and hyperuricemia.

Interpretation

Tafolecimab dosed at 450 mg Q4W and 600 mg Q6W was safe and showed superior lipid-lowering efficacy versus placebo, providing a novel treatment option for Chinese hypercholesterolemia patients.

Funding

This study was sponsored by Innovent Biologics, Inc.

The Promise of PCSK9 and Lipoprotein(a) as Targets for Gene Silencing Therapies

PURPOSE

High plasma concentrations of LDL and lipoprotein(a) (Lp[a]) are independent and causal risk factors for atherosclerotic cardiovascular disease (ASCVD). There is an unmet therapeutic need for high-risk patients with elevated levels of LDL-C and/or Lp(a). Recent advances in the development of nucleic acids for gene silencing (ie, triantennary N-acetylgalactosamine conjugated antisense-oligonucleotides [ASOs] and small interfering RNA [siRNA]) targeting proprotein convertase subtilisin/kexin type 9 (PCSK9) and Lp(a) offer effective and sustainable therapies.

METHODS

Related articles in the English language were identified through a search for original and review articles in the PubMed database using the following key terms: cardiovascular disease, dyslipidemia, PCSK9 inhibitors, Lp(a), LDL-cholesterol, familial hypercholesterolemia, siRNA, and antisense oligonucleotide and clinical trials (either alone or in combination).

FINDINGS

Inclisiran, the most advanced siRNA-treatment targeting hepatic PCSK9, is well tolerated, producing a >30% reduction on LDL-C levels in randomized controlled trials. Pelacarsen is the most clinical advanced ASO, whereas olpasiran and SLN360 are the 2 siRNAs directed against the mRNA of the LPA gene. Evidence suggests that all Lp(a)-targeting agents are safe and well tolerated, with robust and sustained reduction in plasma Lp(a) concentration up to 70% to 90% in individuals with elevated Lp(a) levels.

IMPLICATIONS

Cumulative evidence from clinical trials supports the value of ASO and siRNA therapies targeting the synthesis of PCSK9 and Lp(a) for lowering LDL-C and Lp(a) in patients with established ASCVD or high risk of ASCVD. Further research is needed to examine whether gene silencing therapy could improve clinical outcomes in patients with elevated LDL and/or Lp(a) levels. Confirmation of the tolerability and cost-effectiveness of long-term inhibition of PCSK9 and Lp(a) with this approach is essential.

Inclisiran: a new generation of lipid-lowering siRNA therapeutic

Atherosclerotic heart disease (AHD) is a major cause of morbidity and mortality worldwide. Lowering low-density lipoprotein cholesterol (LDL-C) levels is a key strategy to prevent and treat AHD. Inclisiran is a novel siRNA drug that targets proprotein convertase subtilisin/kexin type 9 (PCSK9) gene expression and reduces LDL-C levels with only two or three injections per year. This review summarizes the mechanism, efficacy, safety, and applications of Inclisiran in various populations and settings, based on recent literature. It also compares Inclisiran with other lipid-lowering drugs, especially other PCSK9 inhibitors. We conclude that Inclisiran is a promising lipid-lowering agent that can provide convenience and effectiveness for patients with high cardiovascular risk. However, some challenges and limitations remain for Inclisiran, such as its long-term safety and efficacy, its cost-effectiveness and accessibility, and its interactions and synergies with other drugs. These issues need further investigation and evaluation in future studies.

PCSK9 inhibitor, ezetimibe, and bempedoic acid: Evidence-based therapies for statin-intolerant patients

Statins are first-line therapy for treating dyslipidemia because of their low-density lipoprotein cholesterol (LDL-C) lowering efficacy, superior event-reduction data and unrivaled cost-effectiveness. Yet, many people are intolerant of statins, whether due to true adverse events or the nocebo effect, so within one year about two-thirds of primary prevention patients and one-third of secondary prevention patients are no longer taking their prescription. Statins still dominate this landscape, but other agents, often used in combination, potently reduce LDL-C levels, regress atherosclerosis and lower risk of major adverse cardiovascular events (MACE). Ezetimibe lowers LDL-C by reducing intestinal absorption of cholesterol. Proprotein convertase subtilisin/kexin type 9 inhibitors (PCSK9i) lower LDL-C by increasing the number and durability of hepatic LDL receptors. Bempedoic acid reduces hepatic cholesterol synthesis. Ezetimibe, PCSK9i and bempedoic are evidence-based, non-statin therapies that synergistically lower LDL-C and reduce risk of MACE; they also have benign side-effect profiles and are generally well tolerated.

A Systematic Review of the Randomized Controlled Trials of Gemcabene and Its Therapeutic Uses

Statins are the most widely used drugs for reducing lipid and cholesterol levels in the blood. However, statins have shown some adverse effects and less acceptance among patients; hence, new drugs have been promoted in the market. Furthermore, gemcabenes were discovered in 1995 and are now in phase II and III clinical trials. Gemcabene acts by inhibiting incorporation of 14C-acetate into hepatocytes and stops the mechanism of fatty acids and cholesterol synthesis. In this review the six randomized controlled trials (RCTs) were scrutinized from the two databases by using keywords "Gemcabene" AND "Randomized Controlled Trial." The trials were mainly on animal models, and two studies were found to be associated with human subjects. The study concluded that gemcabene was effective as an anti-inflammatory agent and reduced lipid levels and the progression of fibrosis. Hence, further controlled trials are needed to determine its efficacy and safety in human subjects, along with the identification of adverse effects.

Inclisiran: A Review in Hypercholesterolemia

Inclisiran (Leqvio^®) is a first-in-class, subcutaneously administered, small interfering RNA (siRNA) that prevents hepatic synthesis of proprotein convertase subtilisin/kexin type 9 (PCSK9), thereby decreasing circulating low-density lipoprotein cholesterol (LDL-C). In the EU, inclisiran is indicated in adults with primary hypercholesterolemia or mixed dyslipidemia, as an adjunct to diet. It is intended for use in patients unable to reach LDL-C goals on maximally tolerated statin therapy, with or without other lipid-lowering therapies (LLTs). In patients who are statin intolerant or for whom a statin is contraindicated, it can be used with or without other LLTs. In clinical trials, twice-yearly injections of inclisiran (after initial doses at days 1 and 90) approximately halved LDL-C levels in patients with, or at high risk of developing, atherosclerotic cardiovascular disease (ASCVD) who had hypercholesterolemia, irrespective of whether or not their existing treatment included a statin. The safety and tolerability profile of the drug was similar to placebo, although mild to moderate, transient injection-site adverse reactions were more frequent with inclisiran. Pending confirmation of the expected reduction in cardiovascular (CV) events with inclisiran, it is a valuable additional/alternative antihyperlipidemic agent to a statin, as its infrequent maintenance dosing regimen confers a convenience advantage over other non-statin LLTs.

Effectiveness and safety of Inclisiran in hyperlipidemia treatment: An overview of systematic reviews

BACKGROUND

This paper aimed to comprehensively evaluate the effectiveness and safety of Inclisiran in treating hyperlipidemia through an overview of systematic reviews (SRs).

METHODS

The Cochrane Library, EMBASE, PubMed, CNKI, WANGFANG database, VIP database, ClinicalTrials.gov, and ICRT were searched electronically to collect SRs and meta-analysis of Inclisiran in hyperlipidemia treatment from the establishment of the database till May 2022. Two researchers independently screened the relevant literature, then the assessment of multiple systematic reviews tool was made into assess the methodological quality of the included studies. Data extracted were used to perform the study through RevMan5.3 software. The grading of recommendations assessment, development, and evaluation tool was used to grade the quality of the evidence of the outcomes included in the SRs. Prospero ID: CRD 42022326845.

RESULTS

A total of 10 relevant SRs were included, involving 7 randomized controlled trials. The assessment results of the assessment of multiple systematic reviews tool suggested that the quality of the SRs included needed to be improved. The reduced level of low-density lipoprotein cholesterol of the experimental group was lower than the control group, and the difference in the amount of effectiveness was statistically significant (MD = -50.13, 95%CI: -56.2 to -44.06, P < .00001). The grading of recommendations assessment, development, and evaluation results showed that out of 27 outcomes, 8 were high-quality, 3 were of medium quality, 6 were of low quality, and 10 were of the most inferior quality.

CONCLUSION

300mg Inclisiran with 2 injections a year has the best therapeutic effect, which can significantly reduce low-density lipoprotein cholesterol and total cholesterol, and increase high-density lipoprotein cholesterol levels in patients with hyperlipidemia. Inclisiran has a favorable safety profile, with no significant difference in the incidence of adverse reactions compared to a placebo. Most of the adverse effects were associated with the reaction on the injection site.

Current Understanding on the Role of Lipids in Macrophages and Associated Diseases

Lipid metabolism is the major intracellular mechanism driving a variety of cellular functions such as energy storage, hormone regulation and cell division. Lipids, being a primary component of the cell membrane, play a pivotal role in the survival of macrophages. Lipids are crucial for a variety of macrophage functions including phagocytosis, energy balance and ageing. However, functions of lipids in macrophages vary based on the site the macrophages are residing at. Lipid-loaded macrophages have recently been emerging as a hallmark for several diseases. This review discusses the significance of lipids in adipose tissue macrophages, tumor-associated macrophages, microglia and peritoneal macrophages. Accumulation of macrophages with impaired lipid metabolism is often characteristically observed in several metabolic disorders. Stress signals differentially regulate lipid metabolism. While conditions such as hypoxia result in accumulation of lipids in macrophages, stress signals such as nutrient deprivation initiate lipolysis and clearance of lipids. Understanding the biology of lipid accumulation in macrophages requires the development of potentially active modulators of lipid metabolism.

Familial Hypercholesterolaemia as a Predisposing Factor for Atherosclerosis

Lipid metabolism alterations are an important component of the pathogenesis of atherosclerosis. However, it is now clear that the atherogenesis process involves more than one mechanism, and more than one condition can predispose this condition. Multiple risk factors contribute to the atherosclerosis initiation and define its course. Familial hypercholesterolaemia is a disorder of lipid metabolism that often leads to atherosclerosis development. As is clear from the disease name, the hallmark is the increased levels of low-density lipoprotein cholesterol (LDL-C) in blood. This creates favourable conditions for atherogenesis. In this review, we briefly described the familial hypercholesterolaemia and summarized data on the relationship between familial hypercholesterolaemia and atherosclerosis.

Low-density lipoprotein particles in atherosclerosis

Among the diseases causing human death, cardiovascular disease (CVD) remains number one according to the World Health Organization report in 2021. It is known that atherosclerosis is the pathological basis of CVD. Low-density lipoprotein (LDL) plays a pivotal role in the initiation and progression of atherosclerotic CVD (ASCVD). LDL cholesterol (LDL-C) is the traditional biological marker of LDL. However, large numbers of patients who have achieved the recommended LDL-C goals still have ASCVD risk. In multiple prospective studies, LDL particle (LDL-P) is reported to be more accurate in predicting CVD risk than LDL-C. LDL-Ps differ in size, density and chemical composition. Numerous clinical studies have proved that the atherogenic mechanisms of LDL-Ps are determined not only by LDL number and size but also by LDL modifications. Of note, small dense LDL (sdLDL) particles possess stronger atherogenic ability compared with large and intermediate LDL subfractions. Besides, oxidized LDL (ox-LDL) is another risk factor in atherosclerosis. Among the traditional lipid-lowering drugs, statins induce dramatic reductions in LDL-C and LDL-P to a lesser extend. Recently, proprotein convertase subtilsin/kexin type 9 inhibitors (PCSK9i) have been demonstrated to be effective in lowering the levels of LDL-C, LDL-P, as well as CVD events. In this article, we will make a short review of LDL metabolism, discuss the discordance between LDL-C and LDL-P, outline the atherogenic mechanisms of action of LDL by focusing on sdLDL and ox-LDL, summarize the methods used for measurement of LDL subclasses, and conclude the advances in LDL-lowering therapies using statins and PCSK9i.

Berberine: Ins and outs of a nature-made PCSK9 inhibitor

Proprotein convertase subtilisin/kexin type 9 (PCSK9) is a secreted protein and a critical regulator of low-density lipoprotein-cholesterol (LDL-C) through inducing degradation of the LDL receptor (LDLR) within the hepatocyte lysosome. PCSK9 deficiency significantly improves the survival rate of cardiovascular disease (CVDs) patients. Up to now, various PCSK9 inhibition approaches have been tested. However, the currently available PCSK9 inhibitors' widespread use is limited due to their inconvenient method of administration and high cost. On the other hand, inhibiting PCSK9 with nutraceuticals is safe and affordable. The plant-derived compound berberine has shown anti-PCSK9 activity in several studies. Berberine is an isoquinoline quaternary alkaloid of phyto origin. Berberine treatment boosts the hepatic expression of LDLRs, while decreasing the expression and secretion of the LDLR modulator PCSK9. The current review presents a collection of in vitro and in vivo studies investigating berberine's effects on PCSK9 mRNA expression, protein level, and function.

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.

Antisense Oligonucleotides and Small Interfering RNA for the Treatment of Dyslipidemias

The burden of atherosclerotic disease worldwide necessitates implementing the treatment of its risk factors. Among them, hypercholesterolemia has a central role. In addition to conventional small organic compounds and the recently introduced monoclonal antibodies, new technologies are arising such as the antisense oligonucleotides and small interfering RNAs (siRNAs) that operate upstream, blocking the mRNA translation of the proteins specifically involved in lipid metabolism. In this review, we briefly explain the mechanisms of action of these molecules and discuss the difficulties related to their in vivo use as therapeutical agents. We go over the oligonucleotides tested in clinical trials that could potentially revolutionize the care of patients by acting on proteins involved in the lipoprotein metabolism and regulation, namely: angiopoietin-like protein 3 (ANGPTL3); lipoprotein a (Lp(a)); apolipoprotein B (Apo B); apolipoprotein C III (Apo C-III); and proprotein convertase subtilisin–kexin type 9 (PCSK9). Finally, the differences between ASOs and siRNAs, their future possible clinical applications, and the role of Inclisiran, a siRNA direct against PCSK9 to reduce LDL-C, were reviewed in detail.

Targeted Strategy in Lipid-Lowering Therapy

Dyslipidemia is characterized by a diminished lipid profile, including increased level of total cholesterol and low-density lipoprotein cholesterol (LDL-c) and reduced level of high-density lipoprotein cholesterol (HDL-c). Lipid-lowering agents represent an efficient tool for the prevention or reduction of progression of atherosclerosis, coronary heart diseases and metabolic syndrome. Statins, ezetimibe, and recently proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors are the most effective and used drugs in clinical lipid-lowering therapy. These drugs are mainly aimed to lower cholesterol levels by different mechanisms of actions. Statins, the agents of the first-line therapy—known as 3-hydroxy-3-methylglutaryl-CoA (HMG-CoA) reductase inhibitors—suppress the liver cholesterol synthesis. Ezetimibe as the second-line therapy can decrease cholesterol by inhibiting cholesterol absorption. Finally, the PCSK9 inhibitors act as an inducer of LDL excretion. In spite of their beneficial lipid-lowering properties, many patients suffer from their serious side effects, route of administration, or unsatisfactory physicochemical characteristics. Clinical demand for dose reduction and the improvement of bioavailability as well as pharmacodynamic and pharmacokinetic profile has resulted in the development of a new targeted therapy that includes nanoparticle carriers, emulsions or vaccination often associated with another more subtle form of administration. Targeted therapy aims to exert a more potent drug profile with lipid-lowering properties either alone or in mutual combination to potentiate their beneficial effects. This review describes the most effective lipid-lowering drugs, their favorable and adverse effects, as well as targeted therapy and alternative treatments to help reduce or prevent atherosclerotic processes and cardiovascular events.

A Comprehensive Review of PCSK9 Inhibitors

Cardiovascular disease (CVD) is the leading cause of death in the United States and worldwide. A major risk factor for this condition is increased serum low-density lipoprotein cholesterol (LDL-C) levels for which statins have been successful in reducing serum LDL-C to healthy concentrations. However, patients who are statin intolerant or those who do not achieve their treatment goals while on high-intensity statin therapy, such as those with familial hypercholesterolemia, remain at risk. With the discovery of PCSK9 inhibitors, the ability to provide more aggressive treatment for patients with homozygous and heterozygous familial hypercholesterolemia has increased. Ezetimibe reduces LDL-C by 15%-20% when combined with statin.^2,3 Protein convertase subtilisin/kexin type 9 (PCSK9) inhibitors have been found to achieve profound reductions in LDL-C (54%-74%) when added to statins. They have shown dramatic effects at lowering major adverse cardiovascular events (MACE) in high-risk patients⁴ with LDL-C levels ≥70 mg/dL and can be used in populations that are statin intolerant or not at goal levels with maximally tolerated statin therapy. PCSK9 inhibitors also produce minimal side effects. Myopathy, a common side effect for patients on statins, has been rare in patients on PCSK9 inhibitors. Randomized trials have shown that reduction in LDL-C has translated to clinical benefits even in patients who have not achieved their LDL-C target.