Inhibition Of Proprotein Convertase Research Articles

Abstract 4138035: Inclisiran in Routine Clinical Practice: Results from a Nationwide Study of >5,000 Patients

Introduction: Inclisiran is a small interfering RNA drug which inhibits proprotein convertase subtilisin/kexin type 9 (PCSK9). Inclisiran was recently approved for the treatment of hypercholesterolemia and durably lowers LDL levels by around 50% with injections once every six months based on the results of large, randomized controlled trials. However, no nationwide studies have evaluated the use or effectiveness of Inclisiran in routine clinical practice. Goals/Aims: To characterize the use and effectiveness of Inclisiran in routine clinical practice in a large nationwide cohort. Methods/Approach: We used the Truveta healthcare database, a large nationwide database of electronic health records, to study patients who were administered Inclisiran up to September 2023. Patient demographic characteristics and lipid levels before and after treatment were summarized. Means and 95% confidence intervals were estimated using t-tests. Results/Data: A total of 5,256 patients (median age 71, first quartile 65, third quartile 76) were prescribed Inclisiran, of whom 2,919 (55.5%) were Female. In terms of race, most of the patients identified as White (81.0%), and a smaller proportion as African American (7.3%), Asian (2.1%), or American Indian/Alaska Native (0.5%); 7.3% of patients identified as more than one race or did not provide race data. Mean LDL and HDL levels (mg/dL) before Inclisiran were 125 (95% CI 123-127) and 51 (95% CI 51-52) respectively and after Inclisiran were 88 (95% CI 85-90) and 50 (95% CI 49-51) respectively. The mean difference in LDL after treatment was -39 (95% CI -42 to -37) mg/Dl for a mean percent change of -22% (95% CI -25% to -19%). Effects of Inclisiran on LDL levels are shown in Figure 1. At the conference, we will compare effects of Inclisiran to those of Alirocumab and Evolocumab (two older monoclonal antibodies against PCSK9) using a propensity score overlap weighting design. Conclusions: In a large cohort of patients administered Inclisiran in routine clinical practice, Inclisiran use was associated with substantial decreases in LDL levels, but those decreases were nonetheless smaller than the effects seen in randomized controlled trials of the drug.

12369 Clinical Experience With Inclisiran At An Academic Center

Abstract Disclosure: L. Chavez Marin: None. M. Gonzalez: None. M.F. Linton: None. B.G. Carranza Leon: None. Background: Inclisiran, a small interfering RNA (siRNA) molecule designed to inhibit proprotein convertase subtilisin/kexin type 9 (PCSK9), is the only siRNA approved for management of elevated low-density lipoprotein cholesterol (LDL-C) in both primary (for patients with familial hypercholesterolemia) and secondary prevention of cardiovascular disease. In clinical trials, Inclisiran has been shown to reduce LDL-C by more than 50% in populations at high cardiovascular risk. However, real world data about its tolerability and efficacy is still limited. Methods: We conducted an electronic medical record search to identify subjects who were prescribed Inclisiran at a lipid clinic within Vanderbilt University Medical Center (Nashville, USA). Subjects were included if they received at least one dose of Inclisiran and had pre- and post- LDL-C levels. Subjects taking other LDL-C lowering medications like statins, ezetimibe, bempedoic acid, and PCSK-9 inhibitors were included. Pre- and post- LDL-C averages were calculated and analyzed with 95% confidence intervals. The reasons for medication discontinuation were also examined. Results: Out of 69 subjects identified, only 19 met criteria for inclusion, while 32 never received a dose due to cost burden and insurance denial. The other 18 subjects were not included due to inadequate lab results at the time of data collection. In subjects who received at least one dose of Inclisiran, average pre-LDL-C was 142 mg/dL [CI: 34.7] while post-LDL-C was 77 mg/dL [CI: 24.0], notable for a 46% decrease in LDL-C levels. These subjects were also receiving another lipid lowering agent, like a statin, or had previously used a monoclonal antibody-PCSK-9 inhibitor. Those without prior use of PCSK-9 inhibitors were also analyzed. Average pre-LDL-C was 109.5 mg/dL [CI: 15.8] while post-LDL-C was 39.8 mg/dL [CI: 17.2], which revealed a 64% decrease in LDL-C levels. The main reason for discontinuation of Inclisiran was insurance denial followed by individual preference. Only one subject discontinued Inclisiran due to experiencing a generalized rash. Conclusions: Inclisiran is an effective and overall well-tolerated medication indicated for the management of elevated LDL cholesterol. Our study revealed that for individuals with above goal LDL-C, despite maximum tolerated therapy with a statin, additional LDL-C lowering benefits can be seen with Inclisiran use. However, insurance approval and cost burden seem to be the main barriers for access. Presentation: 6/3/2024

Investigating Ethanolic Extract from Acehnese Lime (Citrus aurantifolia) Peel as Potential Anti-Hypercholesterolemia Agent

Lime peels are rich in flavonoids, alkaloids, phenols, saponins, and tannins, exhibiting antibacterial, antioxidant, anti-inflammatory, anti-hypertensive, and anti-hypercholesterolemia properties. However, the specific active constituents of Acehnese lime peels and their impact on anti-hypercholesterolemia effects remain undisclosed. This present investigation aims to identify the active compounds in the ethanolic extract of locally obtained Acehnese lime (Citrus aurantifolia (Christm.) Swingle) peels and assess their potential as inhibitors of Proprotein Convertase Subtilisin/Kexin Type 9 (PCSK9) and 3-hydroxy-3-methylglutaryl-coenzyme-A (HMG Co-A) reductase using in-silico approach. The composition of the ethanolic extract Acehnese lime peel was determined through phytochemical analysis, 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay, gas chromatography-mass spectrometry (GC-MS) analysis, and predictions of biological activity, while the biological activities of their compounds were evaluated through molecular docking. Phytochemicals revealed the presence of phenolics, flavonoids, tannins, saponins, and terpenoids in the ethanolic extract of local Aceh lime peel. The total phenolic and flavonoid contents were 29.992 ± 0.274 mg gallic acid equivalents (GAE)/g extract and 5.983 ± 0.017 mg quercetin equivalents (QE)/g extract, respectively. The anti-oxidant activity was notably strong with an IC50 value of 49.51 ppm. GC-MS analysis identified 6-methoxychroman-2-one (27.64%) as the primary component in ethanolic extract Acehnese lime peel, along with neric acid (C13H22O2) known as a regulator of lipid metabolism (Pa: 0.941). In-silicoinvestigations indicated that pterin-6-carboxylic acid (-7.8 kcal/mol) exhibited a higher binding free energy for the PCSK9 receptor compared to simvastatin (-7.6 kcal/mol), whereas the active compound (R)-9-(2,3-dihydroxy-3-methylbutoxy)-4- exhibited the highest binding capacity for HMG Co-A reductase (-6.9 kcal/mol) compared to other compounds. These findings suggest that the ethanolic extract of Acehnese lime peels could serve as an effective inhibitor of PCSK9 and HMG Co-A reductase, highlighting its potential as a novel anti-hypercholesterolemia agent. Doi: 10.28991/HEF-2024-05-03-04 Full Text: PDF

Design of the “EAST” strategy in patients with asymptomatic intracranial atherosclerotic stenosis

IntroductionIntracranial atherosclerotic stenosis (ICAS) is one of the most common causes of stroke worldwide and confers a high risk of stroke recurrence, despite aggressive medical therapy. Asymptomatic ICAS (aICAS) is a frequent finding on neuroimaging, and it’s an independent risk factor for future stroke. Alirocumab is a monoclonal antibody that inhibits proprotein convertase subtilisin-kexin type 9 (PCSK9) and effectively lower low-density lipoprotein cholesterol levels. We hypothesize that extra alirocumab in addition to statin therapy (EAST) could stabilize intracranial plaques in patients with aICAS. Methods and analysisIn this prospective, randomized, open-label, blinded end-point study, we will use high-resolution vessel-wall magnetic resonance imaging (HR-vwMRI) to evaluate the efficacy and safety of alirocumab in patients with asymptomatic ICAS. Eighty patients with aICAS (50 %-99 %) caused by unstable plaques will be assigned to the arm of alirocumab plus statin therapy, or the arm of statin therapy in a 1:1 ratio. Patients will undergo HR-vwMRI at recruitment and after 6 months. The primary outcome is changes in plaque features evaluated by HR-vwMRI after 6 months’ treatment. This trial is being conducted at the first affiliated hospital of Nanjing medical university, China. Ethics and disseminationThe study has been approved by the Ethics Committee of the First Affiliated Hospital of Nanjing Medical University. Written informed consents will be obtained from all participants. Study results will be published as peer-reviewed articles. Trial registration numberClinicalTrials.gov, Identifier: NCT06080256.

Diagnostic utility of sortilin & other biomarkers in the diagnosis of carotid & coronary atherosclerosis in individuals with arterial hypertension.

Background & objectives Cardiovascular diseases (CVDs) are a leading cause of mortality worldwide. The aim of this investigation was to study the role of biological markers in predicting the risk of carotid and coronary artery atherosclerosis. Methods A total of 161 males in the age group of 30-65 yr were included in this study. All participants underwent biochemical analyses [cholesterol, low density lipoprotein cholesterol (LDL-C), triglycerides, glucose, (interleukin) IL-8, IL-10, (proprotein convertase inhibitors subtilisin/kexin type 9) PCSK9, sortilin, creatinine]; ECG; echocardiography; coronary angiography; ultrasound doppler of brachiocephalic arteries. Based on PCSK9 levels, participants were divided into four groups: group 1, n=41 individuals with PCSK9 level of 100-250 ng/ml; group 2, n=37 individuals with PCSK9 level of 251-400 ng/ml; group 3, n=51 individuals with PCSK9 level of 401-600 ng/ml and group 4, n=32 individuals with PCSK9 level of 601-900 ng/ml. Results Sortilin level was the highest in group 2. Group 3 individuals had the highest level of IL-8. Correlation analysis of the entire data set revealed the relationship of relative left ventricular thickness index with age, cardiovascular risk, body mass index, intima-media thickness and left ventricular mass index; sortilin had a negative relationship of weak strength with age and smoking, a direct relationship between the risk of cardiovascular complications and with IL-10. Interpretation & conclusions Sortilin is the innovative marker of CVDs. In the present investigation, we demonstrated the clear increase in the inflammatory markers (IL-8) in individuals with subclinical atherosclerosis. This fact can be explained by the oxygen stress activation. In individuals with coronary artery stenosis (50% and more), the increase in IL-10 levels demonstrates, to our opinion, the activation of antioxidant protection activation.

Proprotein convertase subtilisin/kexin type 9 as a drug target for abdominal aortic aneurysm.

There are no current drug therapies to limit abdominal aortic aneurysm (AAA) growth. This review summarizes evidence suggesting that inhibiting proprotein convertase subtilisin/kexin type 9 (PCSK9) may be a drug target to limit AAA growth. Mendelian randomization studies suggest that raised LDL and non-HDL-cholesterol are causal in AAA formation. PCSK9 was reported to be upregulated in human AAA samples compared to aortic samples from organ donors. PCSK9 gain of function viral vectors promoted aortic expansion in C57BL/6 mice infused with angiotensin II. The effect of altering PCSK9 expression in the aortic perfusion elastase model was reported to be inconsistent. Mutations in the gene encoding PCSK9, which increase serum cholesterol, were associated with increased risk of human AAA. Patients with AAA also have a high risk of cardiovascular death, myocardial infarction and stroke. Recent research suggests that PCSK9 inhibition would substantially reduce the risk of these events. Past research suggests that drugs that inhibit PCSK9 have potential as a novel therapy for AAA to both limit aneurysm growth and reduce risk of cardiovascular events. A large multinational randomized controlled trial is needed to test if PCSK9 inhibition limits AAA growth and cardiovascular events.

Efficacy and Safety of Ongericimab in Chinese Patients With Primary Hypercholesterolemia and Mixed Dyslipidemia.

A phase 3 trial was conducted to evaluate the efficacy and safety of ongericimab, a monoclonal antibody that inhibits proprotein convertase subtilisin/kexin type 9, as an add-on treatment to optimized lipid-lowering therapy in Chinese patients with primary hypercholesterolemia and mixed dyslipidemia. A total of 806 patients who were receiving stable and optimized lipid-lowering therapy but did not achieve their low-density lipoprotein cholesterol (LDL-C) targets were enrolled and randomly assigned in a 2:1:2:1 ratio to receive either ongericimab 150 mg or matching placebo every 2 weeks, or ongericimab 300 mg or matching placebo every 4 weeks for 52 weeks. Efficacy and safety were evaluated in 802 patients who received at least 1 dose of ongericimab or placebo. The primary end point was the percentage change in LDL-C from baseline to week 24. Our findings demonstrated that the least-squares mean difference of percentage change in LDL-C from baseline to week 24 was -67.7% (95% CI, -72.5% to -63.0%; P<0.0001) in the ongericimab 150 mg every 2 weeks group compared with the placebo every 2 weeks group, and -61.2% (95% CI, -67.1% to -55.2%; P<0.0001) in the ongericimab 300 mg every 4 weeks group compared with the placebo every 4 weeks group. These reductions were sustained up to week 52. Furthermore, treatment with ongericimab favorably altered other lipid parameters. A similar incidence of adverse events was observed in the ongericimab and placebo groups. Ongericimab, as an add-on treatment to optimized lipid-lowering therapy, significantly reduced LDL-C and was well-tolerated in Chinese patients with primary hyperlipidemia and mixed dyslipidemia who did not achieve their LDL-C targets. URL: https://www.clinicaltrials.gov; Unique identifier: NCT04781114.

PCSK9 inhibition attenuates alcohol-associated neuronal oxidative stress and cellular injury

Alcohol Use Disorder (AUD) is a persistent condition linked to neuroinflammation, neuronal oxidative stress, and neurodegenerative processes. While the inhibition of proprotein convertase subtilisin/kexin type 9 (PCSK9) has demonstrated effectiveness in reducing liver inflammation associated with alcohol, its impact on the brain remains largely unexplored. This study aimed to assess the effects of alirocumab, a monoclonal antibody targeting PCSK9 to lower systemic low-density lipoprotein cholesterol (LDL-C), on central nervous system (CNS) pathology in a rat model of chronic alcohol exposure. Alirocumab (50 mg/kg) or vehicle was administered weekly for six weeks in 32 male rats subjected to a 35 % ethanol liquid diet or a control liquid diet (n = 8 per group). The study evaluated PCSK9 expression, LDL receptor (LDLR) expression, oxidative stress, and neuroinflammatory markers in brain tissues. Chronic ethanol exposure increased PCSK9 expression in the brain, while alirocumab treatment significantly upregulated neuronal LDLR and reduced oxidative stress in neurons and brain vasculature (3-NT, p22phox). Alirocumab also mitigated ethanol-induced microglia recruitment in the cortex and hippocampus (Iba1). Additionally, alirocumab decreased the expression of pro-inflammatory cytokines and chemokines (TNF, CCL2, CXCL3) in whole brain tissue and attenuated the upregulation of adhesion molecules in brain vasculature (ICAM1, VCAM1, eSelectin). This study presents novel evidence that alirocumab diminishes oxidative stress and modifies neuroimmune interactions in the brain elicited by chronic ethanol exposure. Further investigation is needed to elucidate the mechanisms by which PCSK9 signaling influences the brain in the context of chronic ethanol exposure.

Safety of Monoclonal Antibodies Inhibiting PCSK9 in Pregnancy: Disproportionality Analysis in VigiBase®.

Safety data on the use of monoclonal antibodies inhibiting proprotein convertase subtilisin/kexin type 9 in pregnancy are scarce. This study queried VigiBase®, the World Health Organization global pharmacovigilance database, to search for signals of disproportionate reporting for pregnancy outcomes with alirocumab and evolocumab. As of November 22, 2023, there were 45 safety reports of exposure to evolocumab (N = 31) and alirocumab (N = 14) in pregnancy. Most of them originated from Europe (N = 25, 55.6%) and were more frequently reported by healthcare professionals (N = 35, 77.8%). Median patient age was 37 years (25th-75th percentiles; 32-41 years). Drug exposure occurred during pregnancy in 36 (80.0%) safety reports, via paternal exposure during pregnancy in four (8.9%), during lactation in three (6.7%), and in two safety reports the time of drug exposure remained unknown. Twenty safety reports (57.8%) merely reported drug exposure, while 19 (42.2%) also reported pregnancy outcomes, however, without specific maternal toxicities or patterns of birth defects. Spontaneous abortion was reported in eight safety reports without representing a signal of disproportionate reporting compared with either the full database (reporting odds ratio, ROR, 0.06 95% confidence interval, CI 0.03-0.12) or statins (ROR 0.16, 95% CI 0.08-0.32). In conclusion, this study showed that, currently, there are no signals of increased reporting of spontaneous abortion with alirocumab and evolocumab compared with the full database and statins in VigiBase®. Notwithstanding, lack of disproportionality is not synonymous with safety and, as disproportionality analyses depend on the number of safety reports that progressively accumulate in VigiBase®, they should be repeated at regular intervals to confirm the results of the present study.

Granulocyte pro-myeloperoxidase is redundantly processed by proprotein convertase furin and PC7 in HL-60 cells.

Neutrophil myeloperoxidase/H2O2/chloride system is a key mechanism to control pathogen infection. This enzyme, myeloperoxidase, plays a pivotal role in the arsenal of azurophilic granules that are released through degranulation upon neutrophil activation, which trigger local hypochlorous acid production. Myeloperoxidase gene encodes a protein precursor named promyeloperoxidase that arbors a propeptide that gets cleaved later during secretory routing in post-endoplasmic reticulum compartments. Although evidence suggested that this processing event was performed by one or different enzymes from the proprotein convertases family, the identity of this enzyme was never investigated. In this work, the naturally producing myeloperoxidase promyelocytic cell line HL-60 was used to investigate promyeloperoxidase cleavage during granulocytic differentiation in response to proprotein convertase inhibitors decanoyl-RVKR-chloromethylketone and hexa-d-arginine. Stable PC knockdown of endogenously expressed proprotein convertases, furin and PC7, was achieved using lentiviral delivery of shRNAs. None of the knockdown cell line could reproduce the effect of the pan-proprotein convertases inhibitor decanoyl-RVKR-chloromethylketone that accumulated intracellular promyeloperoxidase stores in HL-60 cells, therefore illustrating that both furin and PC7 redundantly process this proprotein.

New Oral PCSK9 Inhibitor: "MK-0616".

MK-0616, a novel oral macrocyclic peptide inhibitor of proprotein convertase subtilisin/kexin type 9 (PCSK9), represents a significant advancement in the treatment of hypercholesterolemia. Unlike current PCSK9 inhibitors, which are injectable monoclonal antibodies and siRNA molecules, MK-0616 offers a patient-friendly alternative. The development of MK-0616 involved innovative synthetic chemistry and in vitro mRNA display technology. This cutting-edge approach led to the creation of an orally administered peptide with the ability to cover a larger portion of PCSK9 compared to smaller, linear peptides. Phase 1 and 2b clinical trials have demonstrated MK-0616's safety, efficacy, and pharmacokinetics. These trials indicate the drug's dose-dependent systemic absorption and long half-life. Notably, MK-0616 has exhibited comparable low-density lipoprotein cholesterol-lowering effects to currently available PCSK9 inhibitors, all while maintaining good tolerability in diverse patient populations, including those concurrently on statin therapy. As MK-0616 advances to Phase 3 trials, its lipid-lowering potential for heterozygous familial hypercholesterolemia and its impact on reducing the time to adverse cardiac events will be evaluated in a broad and diverse population, including underrepresented groups. The results achieved so far are promising for individuals with hypercholesterolemia, as they offer a potential solution for effectively lowering low-density lipoprotein cholesterol in patients on statin therapy and mitigating the risk of cardiovascular events. Ongoing research and monitoring will be critical to establish its long-term safety and efficacy, but MK-0616 may emerge as a valuable addition to the array of lipid-lowering therapies available to patients.

Inhibition of proprotein convertases activity results in repressed stemness and invasiveness of cancer stem cells in gastric cancer.

Gastric cancer (GC), the fourth leading cause of cancer-related death worldwide, with most deaths caused by advanced and metastatic disease, has limited curative options. Here, we revealed the importance of proprotein convertases (PCs) in the malignant and metastatic potential of GC cells through the regulation of the YAP/TAZ/TEAD pathway and epithelial-to-mesenchymal transition (EMT) in cancer stem cells (CSC). The general PCs inhibitor, decanoyl-RVKR-chloromethyl-ketone (CMK), was used to repress PCs activity in CSCs of various GC cell lines. Their tumorigenic properties, drug resistance, YAP/TAZ/TEAD pathway activity, and invasive properties were then investigated in vitro, and their metastatic properties were explored in a mouse xenograft model. The prognostic value of PCs in GC patients was also explored in molecular databases of GC. Inhibition of PCs activity in CSCs in all GC cell lines reduced tumorsphere formation and growth, drug efflux, EMT phenotype, and invasive properties that are associated with repressed YAP/TAZ/TEAD pathway activity in vitro. In vivo, PCs' inhibition in GC cells reduced their metastatic spread. Molecular analysis of tumors from GC patients has highlighted the prognostic value of PCs. PCs are overexpressed in GC and associated with poor prognosis. PCs are involved in the malignant and metastatic potential of CSCs via the regulation of EMT, the YAP/TAZ/TEAD oncogenic pathway, and their stemness and invasive properties. Their repression represents a new strategy to target CSCs and impair metastatic spreading in GC.

The Application of Peptide Nucleic Acids (PNA) in the Inhibition of Proprotein Convertase Subtilisin/Kexin 9 (PCSK9) Gene Expression in a Cell-Free Transcription/Translation System.

Proprotein convertase subtilisin/kexin 9 (PCSK9) is a protein that plays a key role in the metabolism of low-density lipoprotein (LDL) cholesterol. The gain-of-function mutations of the PCSK9 gene lead to a reduced number of surface LDL receptors by binding to them, eventually leading to endosomal degradation. This, in turn, is the culprit of hypercholesterolemia, resulting in accelerated atherogenesis. The modern treatment for hypercholesterolemia encompasses the use of biological drugs against PCSK9, like monoclonal antibodies and gene expression modulators such as inclisiran-a short, interfering RNA (siRNA). Peptide nucleic acid (PNA) is a synthetic analog of nucleic acid that possesses a synthetic peptide skeleton instead of a phosphate-sugar one. This different structure determines the unique properties of PNA (e.g., neutral charge, enzymatic resistance, and an enormously high affinity with complementary DNA and RNA). Therefore, it might be possible to use PNA against PCSK9 in the treatment of hypercholesterolemia. We sought to explore the impact of three selected PNA oligomers on PCSK9 gene expression. Using a cell-free transcription/translation system, we showed that one of the tested PNA strands was able to reduce the PCSK9 gene expression down to 74%, 64%, and 68%, as measured by RT-real-time PCR, Western blot, and HPLC, respectively. This preliminary study shows the high applicability of a cell-free enzymatic environment as an efficient tool in the initial evaluation of biologically active PNA molecules in the field of hypercholesterolemia research. This cell-free approach allows for the omission of the hurdles associated with transmembrane PNA transportation at the early stage of PNA selection.

Current Understanding of PCSK9 and Its Relevance to Cancer Prognosis and Immune Therapy: A Review.

The effectiveness of immunotherapy for most cancer patients remains low, with approximately 10-30% of those treated surviving. Thus, much effort is being put into finding new ways to improve immune checkpoint therapy. Our review concludes that inhibition of proprotein convertase subtilisin/Kexin type 9 (PCSK9), which plays a critical role in regulating cholesterol metabolism, can cause movement of T cells toward tumors, with increased sensitivity to immune checkpoint therapies. We searched PubMed, NCBI, Scopus, and Google Scholar for the published articles without limitations on publication dates. We used the following terms: "PCSK9", "Cancer", "Immune Checkpoint", and "Cancer Prognosis" in the title and/or abstract. Our search initially revealed 600 records on the subject and stored them in the used databases under EndNote X8 management software. A total of 161 articles were selected and through a careful review, 76 were included in our research. We concluded that PCSK9 reduces the number of LDL receptors (LDL-R) on the cell surface, which is linked to its ability to regulate cholesterol levels in the body. Also, we discuss how suppressing PCSK9 leads to the MHC-1 accumulation on the surface of cancer cells, which results in T lymphocyte invasion. Finally, we believe that inhibiting PCSK9 may be an effective strategy for improving cancer immunotherapy.

Rationale and design of the effect of evolocumab in patients at high cardiovascular risk without prior myocardial infarction or stroke (VESALIUS-CV) trial

The reduction of low-density lipoprotein cholesterol (LDL-C) with evolocumab, a fully human monoclonal antibody inhibitor of proprotein convertase subtilisin/kexin type 9 (PCSK9i), reduces the risk of major adverse cardiovascular events in patients with established atherosclerotic cardiovascular disease (ASCVD) with a prior MI, prior stroke, or symptomatic peripheral artery disease, with no offsetting safety concerns. The effect of evolocumab on CV outcomes in lower risk patients without a history of MI or stroke has not been explored. VESALIUS-CV is a randomized, double-blind, placebo-controlled, global clinical trial designed to evaluate the effect of evolocumab on the risk of major cardiovascular events in patients at high cardiovascular risk but without a prior ischemic event. The study population consists of 12,301 patients with atherosclerosis or high-risk diabetes mellitus without a prior MI or stroke; an LDL-C ≥ 90 mg/dL, or non-high-density lipoprotein cholesterol (non-HDL-C) ≥ 120 mg/dL, or apolipoprotein B ≥ 80 mg/dL; and treated with optimized lipid-lowering therapy. Patients were randomized in a 1:1 ratio to evolocumab 140 mg subcutaneously every 2 weeks or matching placebo. The primary efficacy objective is to assess whether evolocumab reduces the risk of the dual primary composite endpoints of coronary heart disease (CHD) death, myocardial infarction (MI), or ischemic stroke (triple primary endpoint) and of CHD death, MI, ischemic stroke, or ischemia-driven arterial revascularization (quadruple primary endpoint). Recruitment began in June 2019 and completed in November 2021. The trial is planned to continue until at least 751 patients experience an adjudicated triple endpoint, at least 1254 experience an adjudicated quadruple endpoint, and the median follow-up is ≥4.5 years. VESALIUS-CV will determine whether the addition of evolocumab to optimized lipid-lowering therapy reduces cardiovascular events in patients at high cardiovascular risk without a prior MI or stroke. NCT03872401.

Discovery of (2-(4-Substituted phenyl)quinolin-4-yl)(4-isopropylpiperazin-1-yl)methanone Derivatives as Potent Proprotein Convertase Subtilisin/Kexin Type 9 Inhibitors.

Inhibition of proprotein convertase subtilisin/kexin type 9 (PCSK9) plays an increasingly important role in the treatment of hyperlipidemia. In pursuit of potent small molecules that block the PCSK9/low-density lipoprotein receptor (LDLR) protein-protein interaction (PPI), a series of 2-phenylquinoline-4-carboxylic acid derivatives were designed and synthesized based on previously derived molecules. In the in vitro PPI inhibition test, compounds M1, M12, M14, M18 and M27 exhibited potent activities with IC50 values of 6.25 μM, 0.91 μM, 2.81 μM, 4.26 μM and 0.76 μM, respectively, compared with SBC-115337 (IC50 value of 9.24 μM). Molecular docking and molecular dynamics simulations revealed the importance of hydrophobic interactions in the binding of inhibitors to the PPI interface of PCSK9. In LDLR expression and LDL uptake assays, the tested compounds M1, M12 and M14 were found to restore LDLR expression levels and to increase the extracellular LDL uptake capacity of HepG2 cells in the presence of exogenous PCSK9. Collectively, novel small-molecule PCSK9/LDLR PPI inhibitors (especially M12) with in vitro lipid lowering ability, were discovered as lead compounds for further development of hypolipidemic drugs.

Abstract 11893: Efficacy and Safety of Ongericimab in Chinese Patients With Primary Hypercholesterolemia and Mixed Dyslipidemia

Background: Ongericimab, a monoclonal antibody that inhibits proprotein convertase subtilisin/kexin type 9 (PCSK9), significantly reduced low-density lipoprotein cholesterol (LDL-C) levels in the phase 2 trial. A phase 3 trial was conducted to evaluate the efficacy and safety of ongericimab in Chinese patients with primary hypercholesterolemia and mixed dyslipidemia on background lipid-lowering therapy (LLT). Methods: This was a randomized, double-blind, placebo-controlled, 52-week trial conducted in China (NCT02662569). Eligible patients receiving stable statin (±ezetimibe) therapy but not achieving LDL-C goals were enrolled. Patients were randomly assigned in a 2:1:2:1 ratio to receive either ongericimab 150 mg or placebo subcutaneously every 2 weeks (Q2W), or ongericimab 300 mg or placebo subcutaneously every 4 weeks (Q4W) for 52 weeks. The primary endpoint was percent change in LDL-C from baseline to week 24. Results: A total of 806 patients were randomized, 802 patients received at least one dose of ongericimab or placebo. The least-squares (LS) mean difference between ongericimab and placebo in LDL-C from baseline to week 24 was -67.7% (95% CI: -72.49%, -62.99%; p &lt; 0.0001) in Q2W group and -61.2% (95% CI: -67.09%, -55.21%; p &lt; 0.0001) in Q4W group. LDL-C reductions were maintained to Week 52. Ongericimab also favorably altered other lipid parameters (Table 1). The overall incidence of adverse events was similar between ongericimab and placebo. Conclusion: Ongericimab on stable background LLT significantly reduced LDL-C and was well tolerated in Chinese patients with primary hypercholesterolemia and mixed dyslipidemia.

Schisandrin A in Schisandra chinensis Upregulates the LDL Receptor by Inhibiting PCSK9 Protein Stabilization in Steatotic Model.

Schisandra chinensis extract (SCE) protects against hypocholesterolemia by inhibiting proprotein convertase subtilisin/kexin 9 (PCSK9) protein stabilization. We hypothesized that the hypocholesterolemic activity of SCE can be attributable to upregulation of the PCSK9 inhibition-associated low-density lipoprotein receptor (LDLR). Male mice were fed a low-fat diet or a Western diet (WD) containing SCE at 1% for 12 weeks. WD increased final body weight and blood LDL cholesterol levels as well as alanine transaminase and aspartate aminotransferase expression. However, SCE supplementation significantly attenuated the increase in blood markers caused by WD. SCE also attenuated WD-mediated increases in hepatic LDLR protein expression in the obese mice. In addition, SCE increased LDLR protein expression and attenuated cellular PCSK9 levels in HepG2 cells supplemented with delipidated serum (DLPS). Non-toxic concentrations of schisandrin A (SA), one of the active components of SCE, significantly increased LDLR expression and tended to decrease PCSK9 protein levels in DLPS-treated HepG2 cells. High levels of SA-mediated PCSK9 attenuation was not attributable to reduced PCSK9 gene expression, but was associated with free PCSK9 protein degradation in this cell model. Our findings show that PCSK9 secretion can be significantly reduced by SA treatment, contributing to reductions in free cholesterol levels.

A virus-like particle-based bivalent PCSK9 vaccine lowers LDL-cholesterol levels in non-human primates

Elevated low-density lipoprotein cholesterol (LDL-C) is an important risk factor in the development of atherosclerotic cardiovascular disease (ASCVD). Inhibitors of proprotein convertase subtilisin/kexin type 9 (PCSK9), a negative regulator of LDL-C metabolism, have emerged as promising approaches for reducing elevated LDL-C levels. Here, we evaluated the cholesterol-lowering efficacy of virus-like particle (VLP) based vaccines that target epitopes found within the LDL receptor (LDL-R) binding domain of PCSK9. In both mice and non-human primates, a bivalent VLP vaccine targeting two distinct epitopes on PCSK9 elicited strong and durable antibody responses and lowered cholesterol levels. In macaques, a VLP vaccine targeting a single PCSK9 epitope was only effective at lowering LDL-C levels in combination with statins, whereas immunization with the bivalent vaccine lowered LDL-C without requiring statin co-administration. These data highlight the efficacy of an alternative, vaccine-based approach for lowering LDL-C.

The Effects of Statins, Ezetimibe, PCSK9-Inhibitors, Inclisiran, and Icosapent Ethyl on Platelet Function.

This review aims to examine the complex interaction between dyslipidemia, platelet function, and related drug treatments. In particular, the manuscript provides an overview of the effects of major hypolipidemic drugs on platelet function. Indeed, growing evidence supports the view that statins, ezetimibe, PCSK9 inhibitors, inclisiran, and icosapent ethyl also act as antithrombotics. It is known that platelets play a key role not only in the acute phase of coronary syndromes but also in the early phase of atherosclerotic plaque formation. The goal of cholesterol-lowering therapy is to reduce cardiovascular events. The direct effects of cholesterol-lowering drugs are widely described in the literature. Lowering LDL-c (low-density lipoprotein cholesterol) by 1 mmol/L results in a 22-23% reduction in cardiovascular risk. Numerous studies have examined the direct antithrombotic effects of these drugs on platelets, endothelium, monocytes, and smooth muscle cells, and thus, potentially independent of blood LDL-cholesterol reduction. We reviewed in vitro and in vivo studies evaluating the complex interaction between hypercholesterolemia, hypertriglyceridemia, platelet function, and related drug treatments. First, we discussed the role of statins in modulating platelet activation. Discontinuation of statin therapy was associated with increased cardiovascular events with increased ox-LDL, P-selectin, and platelet aggregation. The effect of PCSK9-I (inhibitors of proprotein convertase subtilisin/kexin type 9, PCSK9 involved in the degradation of LDL receptors in the liver) was associated with a statistically significant reduction in platelet reactivity, calculated in P2Y12 reaction units (PRU), in the first 14 days and no difference at 30 days compared to placebo. Finally, in patients with hypertriglyceridemia, the REDUCE-IT study showed that icosapent ethyl (an ethyl ester of eicosapentaenoic acid that reduces triglyceride synthesis and improves triglyceride clearance) resulted in a 25% reduction in ischemic events and cardiovascular death. However, to date, there is not yet clear clinical evidence that the direct antithrombotic effects of the drugs may have a beneficial impact on outcomes independently from the reduction in LDL-C or triglycerides.