PCSK9 inhibitors in clinical practice: Expectations and reality

Evaluating the Efficacy of a Pre-Established Lipid-Lowering Algorithm in Managing Hypercholesterolemia in Patients at Very High Cardiovascular Risk

BACKGROUND

Recent data from European studies (EUROASPIRE V, DA VINCI, SANTORINI) indicate that achieving the LDL cholesterol (LDL-C) target in patients at very high cardiovascular risk is uncommon. Additionally, using a combination therapy involving statins and ezetimibe remains infrequent.

METHODS

A single-center assessment of a pre-defined lipid lowering treatment algorithm's effectiveness at achieving the LDL-C target in patients at very high cardiovascular risk one month and one year after hospitalization.

RESULTS

81 patients were included, all in secondary prevention. The average age of the patient was 66.9 years, and the main cardiovascular risk factors included hypertension, diabetes mellitus, and smoking history. Following the predefined lipid-lowering algorithm specific to our study, which involves initiating high-intensity statin therapy or a combination of statin and ezetimibe depending on initial LDL-C levels and patient history; 30 (37%) patients initiated high-intensity statin therapy (Atorvastatin (40 mg, 80 mg) or Rosuvastatin (20 mg, 40 mg)), while 51 (63%) started combination therapy with high-intensity statin and ezetimibe 10 mg. After one year, 57 (70.4%) remained adherent to their initial treatment, achieving a mean LDL-C of 49.5 ± 16.9 mg/dL, with 36 (63.2%) of them reaching the LDL-C target of <55 mg/dL. A total of 13 patients discontinued treatment, and 9 were lost to follow-up, withdrew from the study, or died.

CONCLUSION

Initiating dual statin and ezetimibe therapy or high-intensity statin therapy early, based on the expected treatment efficacy, holds the potential to more rapidly and effectively achieve LDL-C targets in a larger proportion of very high-risk cardiovascular patients.

PCSK9 inhibitors and inclisiran with or without statin therapy on incident muscle symptoms and creatine kinase: a systematic review and network meta-analysis

Background

Atherosclerotic cardiovascular disease (ASCVD), a leading cause of global fatalities, has inconsistent findings regarding the impact of muscle symptoms despite promising clinical trials involving PCSK9 inhibitors (PCSK9i) and siRNA as potential therapeutic options.

Methods

The databases EMBASE, PubMed, Web of Science, Cochrane, and ClinicalTrials.gov were thoroughly searched without any restrictions on language. Review Manager 5.3 software was utilized to calculate relative risks with 95% confidence intervals (CIs) for dichotomous data and mean differences or standardized mean differences with 95%CIs for continuous data. To evaluate publication bias, Egger's test was employed using Stata/SE software.

Results

This analysis included 26 studies comprising 28 randomized controlled trials (RCTs) involving a total of 100,193 patients, and 4 different lipid-lowering therapy combinations. For events with creatine kinase >3ULN, evolocumab and alirocumab demonstrated significant advantages compared to inclisiran. Evolocumab showed the best results in terms of both new muscle symptom events and creatine kinase >3ULN.

Conclusions

Based on this network meta-analysis (NMA) results, evolocumab has emerged as a promising treatment option for patients with hyperlipidemia and muscle disorders compared to other PCSK9 inhibitors and inclisiran.

Systematic Review Registration

PROSPERO [CRD42023459558].

MicroRNA-mediated Regulation of LDL Receptor: Biological and Pharmacological Implications

One of the main causes of atherosclerosis is a disruption in cellular cholesterol hemostasis. The low-density lipoprotein receptor (LDLR) is an important factor in maintaining cholesterol homeostasis by the receptor-mediated endocytosis of LDL particles. Defective hepatic LDLR activity and uptake of LDL particles lead to elevated blood levels of low-density lipoprotein cholesterol (LDL-C), which is associated with a higher risk of atherosclerotic cardiovascular disease. LDLR expression can be affected by microRNAs (miRNAs). Some miRNAs, like miR-148a, miR-185, miR-224, miR-520, miR-128-1, miR-27a/b, miR-130b, and miR-301 seem to be important post-transcriptional regulators of LDLR related genes. These findings indicate the critical role of miRNAs in regulating LDL metabolism. The aim of this review was to provide insight into the miRNAs involved in LDLR activity and their potential roles in the treatment of cardiovascular disease.

Effect of evolocumab on the progression of intraplaque neovascularization of the carotid based on contrast-enhanced ultrasonography (EPIC study): A prospective single-arm, open-label study

Background and Purpose: The aim of this study was to explore the effect of half a year of evolocumab plus moderate-intensity statin treatment on carotid intraplaque neovascularization (IPN) and blood lipid levels. Methods: A total of 31 patients with 33 carotid plaques who received evolocumab plus statin treatment were included. Blood lipid levels, B-mode ultrasound and contrast-enhanced ultrasonography (CEUS) at baseline and after half a year of evolocumab plus statin therapy were collected. The area under the curve (AUC) reflected the total amount of acoustic developer entering the plaque or lumen within the 180 s measurement period. The enhanced intensity reflected the peak blood flow intensity during the monitoring period, and the contrast agent area reflected the area of vessels in the plaques. Results: Except for high-density lipoprotein cholesterol (HDL-c), all other lipid indices decreased. Compared with baseline, low-density lipoprotein cholesterol (LDL-c) decreased by approximately 57% (p < 0.001); total cholesterol (TC) decreased by approximately 34% (p < 0.001); small dense low-density lipoprotein (sd-LDL) decreased by approximately 52% (p < 0.001); and HDL-c increased by approximately 20% (p < 0.001). B-mode ultrasonography showed that the length and thickness of the plaque and the hypoechoic area ratio were reduced (p < 0.05). The plaque area, calcified area ratio, and lumen cross-sectional area changed little (p > 0.05). CEUS revealed that the area under the curve of plaque/lumen [AUC (P/L)] decreased from 0.27 ± 0.13 to 0.19 ± 0.11 (p < 0.001). The enhanced intensity ratio of plaque/lumen [intensity ratio (P/L)] decreased from 0.37 ± 0.16 to 0.31 ± 0.14 (p = 0.009). The contrast agent area in plaque/area of plaque decreased from 19.20 ± 13.23 to 12.66 ± 9.59 (p = 0.003). The neovascularization score decreased from 2.64 ± 0.54 to 2.06 ± 0.86 (p < 0.001). Subgroup analysis based on statin duration (<6 months and ≥6 months) showed that there was no significant difference in the AUC (P/L) or intensity ratio (P/L) at baseline or after half a year of evolocumab treatment. Conclusion: This study found that evolocumab combined with moderate-intensity statins significantly improved the blood lipid profile and reduced carotid IPN. Clinical Trial Registration: https://www.clinicaltrials.gov; identifier: NCT04423406.

Cellular and Molecular Aspects of Managing Familial Hypercholesterolemia: Recent and Emerging Therapeutic Approaches

Familial hypercholesterolemia (FH) as a high-frequency genetic disorder is diagnosed based on family and/or patient's history of coronary heart disease (CHD) or some other atherosclerotic disease, LDL-C levels and/or clinical signs such as tendonous xantomata, arcus cornealis before age 45 years as well as functional mutation in the LDLR, apoB or PCSK9 gene. Its clinical features are detectable since early childhood. Early diagnosis and timely treatment increase life expectancy in most patients with FH. Current FH therapies decrease the level of low-density lipoprotein up to ≥50% from baseline with diet, pharmacotherapeutic treatment, lipid apheresis, and liver transplantation. The cornerstone of medical therapy is the use of more potent statins in higher doses, to which often ezetimibe has to be added, but some FH patients do not achieve the target LDL-C with this therapy Therefore, besides these and the most recent but already established therapeutic approaches including PCSK9 inhibitors, inclisiran, and bempedoic acid, new therapies are on the horizon such as gene therapy, CRISPR/Cas9 strategy etc. This paper focuses on cellular and molecular potential strategies for the treatment of FH.

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

As dyslipidemias remain one of the main risk factors for developing cardiovascular disease, the question of maintaining optimal lipid levels with pharmacotherapy remains a subject of interest worldwide. In contrast to conventional pharmacotherapy, human monoclonal antibodies directed against proprotein convertase subtilisin/kexin type 9 (PSCK9) and small interfering RNA- (siRNA-) based drug targeting PCSK9 represent a new strategy for managing lipid disorders and reducing cardiovascular risk. Inclisiran is a long-acting, synthetic siRNA that targets hepatic production of PCSK9 and consequently causes a reduction in LDL-C concentrations by approximately 50% compared to placebo. The structural modification of inclisiran has led to better stability and prolonged biological activity of the drug. The main advantage over conventional pharmacotherapy and anti-PCSK9 monoclonal antibodies is its favorable administration regimen (0–90–180 days), which should lead to much better compliance. Clinical trials conducted so far have confirmed the tolerability and efficacy of inclisiran in long-term PCSK9 and LDL-C level reductions. Moreover, a short-term follow-up on the safety of inclisiran showed a relatively good safety profile of the drug. However, it is still of great importance for ongoing and forthcoming clinical trials to be continued on a larger group of patients in order to assess long-term tolerability, efficacy, and safety of inclisiran.

Efficacy and Safety of Lipid-Lowering Drugs of Different Intensity on Clinical Outcomes: A Systematic Review and Network Meta-Analysis

There have been many meta-analyses for statins, ezetimibe and proprotein convertase subtilisin/kexin type 9 inhibitors (PCSK9i) to evaluate clinical outcomes, but the efficacy and safety of different intensity of these three drugs on clinical outcomes was absent. PCSK9i, ezetimibe, and statins were divided into seven interventions as follows: including PCSK9i + high-intensity statins (P9i+HT), PCSK9i + moderate-intensity statins (P9i+MT), ezetimibe + high-intensity statins (Eze+HT), ezetimibe + moderate-intensity statins (Eze+MT), high-intensity statins (HT), moderate-intensity statins (MT), and low-intensity statins (LT). The risk ratios (RR) and 95% confidence intervals (CI) were calculated to evaluate the clinical outcomes in all randomized controlled trials included. In traditional meta-analysis, the more intensive treatment had a lower risk of all-cause mortality (RR 0.91, 95% CI 0.88-0.95), cardiovascular mortality (RR 0.89, 95% CI 0.86-0.92), myocardial infarction (RR 0.79, 95% CI 0.77-0.81), coronary revascularization (RR 0.80, 95% CI 0.76-0.84), and cerebrovascular events (RR 0.84, 95% CI 0.80-0.88) compared with the less intensive treatment. However, the more intensive treatment had a higher risk of new-onset diabetes (RR 1.08, 95% CI 1.04-1.12). The network meta-analysis demonstrated that P9i+HT, P9i+MT, HT, and MT were significantly associated with a risk reduction in coronary revascularization and cerebrovascular events compared with PLBO. LT could effectively reduce the risk of cardiovascular mortality (RR 0.71, 95% CI 0.54-0.92), MI (RR 0.67, 95% CI 0.54-0.82), and coronary revascularization (RR 0.77, 95% CI 0.65-0.91) compared with PLBO. P9i+HT was superior to HT in reducing the risk of MI (RR 0.78, 95% CI 0.68-0.90), coronary revascularization (RR 0.84, 95% CI 0.73-0.96), and cerebrovascular events (RR 0.78, 95% CI 0.64-0.95). However, compared with PLBO, P9i+HT, HT, and MT could increase the risk of new-onset diabetes (RR 1.23, 95% CI 1.11-1.37; RR 1.23, 95% CI 1.14-1.33; RR 1.09, 95% CI 1.02-1.15, respectively). In conclusion, PCSK9i added to background statins may be recommended as preferred lipid-lowering therapy, and did not increase the additional risk of new-onset diabetes. The safety and efficacy of ezetimibe was not superior to that of statins. LT can be recommended as the initial therapy.

Inclisiran-Silencing the Cholesterol, Speaking up the Prognosis

The reduction of circulating low-density lipoprotein-cholesterol (LDL-C) is a primary target in cardiovascular risk reduction due to its well-established benefits in terms of decreased mortality. Despite the use of statin therapy, 10%-20% of high- and very-high-risk patients do not reach their LDL-C targets. There is an urgent need for improved strategies to manage dyslipidemia, especially among patients with homozygous familial hypercholesterolemia, but also in patients with established cardiovascular disease who fail to achieve LDL goals despite combined statin, ezetimibe, and PCSK9 inhibitor (PCSK9i) therapy. Inclisiran is a disruptive, first-in-class small interfering RNA (siRNA)-based therapeutic developed for the treatment of hypercholesterolemia that inhibits proprotein convertase subtilisin-kexin type 9 (PCSK9) synthesis, thereby upregulating the number of LDL receptors on the hepatocytes, thus lowering the plasma LDL-C concentration. Inclisiran decreases the LDL-C levels by over 50% with one dose every 6 months, making it a simple and well-tolerated treatment strategy. In this review, we summarize the general information regarding (i) the role of LDL-C in atherosclerotic cardiovascular disease, (ii) data regarding the role of PCSK9 in cholesterol metabolism, (iii) pleiotropic effects of PCSK9, and (iv) the effects of PCSK9 silencing. In addition, we focus on inclisiran, in terms of its (i) mechanism of action, (ii) biological efficacy and safety, (iii) results from the ORION trials, (iv) benefits of its combination with statins, and (v) its potential future role in atherosclerotic cardiovascular disease.

Based on Network Pharmacology and RNA Sequencing Techniques to Explore the Molecular Mechanism of Huatan Jiangzhuo Decoction for Treating Hyperlipidemia

Background

Hyperlipidemia, due to the practice of unhealthy lifestyles of modern people, has been a disturbance to a large portion of population worldwide. Recently, several scholars have turned their attention to Chinese medicine (CM) to seek out a lipid-lowering approach with high efficiency and low toxicity. This study aimed to explore the mechanism of Huatan Jiangzhuo decoction (HTJZD, a prescription of CM) in the treatment of hyperlipidemia and to determine the major regulation pathways and potential key targets involved in the treatment process.

Methods

Data on the compounds of HTJZD, compound-related targets (C-T), and known disease-related targets (D-T) were collected from databases. The intersection targets (I-T) between C-T and D-T were filtered again to acquire the selected targets (S-T) according to the specific index. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment, as well as network construction, were applied to predict the putative mechanisms of HTJZD in treating hyperlipidemia. Thereafter, an animal experiment was conducted to validate the therapeutic effect of HTJZD. In addition, regulated differentially expressed genes (DEGs) were processed from the RNA sequencing analysis results. Common genes found between regulated DEGs and S-T were analyzed by KEGG pathway enrichment to select the key targets. Lastly, key targets were validated by real-time quantitative reverse transcription PCR (qRT-PCR) analysis.

Results

A total of 210 S-T were filtered out for enrichment analysis and network construction. The enrichment results showed that HTJZD may exert an effect on hyperlipidemia through the regulation of lipid metabolism and insulin resistance. The networks predict that the therapeutic effect of HTJZD may be based on the composite pharmacological action of these active compounds. The animal experiment results verify that HTJZD can inhibit dyslipidemia in rats with hyperlipidemia, suppress lipid accumulation in the liver, and reverse the expression of 202 DEGs, which presented an opposite trend in the model and HTJZD groups. Six targets were selected from the common targets between 210 S-T and 202 regulated DEGs, and the qRT-PCR results showed that HTJZD could effectively reverse Srebp-1c, Cyp3a9, and Insr mRNA expression (P < 0.01).

Conclusion

In brief, network pharmacology predicted that HTJZD exerts a therapeutic effect on hyperlipidemia. The animal experimental results confirmed that HTJZD suppressed the pathological process induced by hyperlipidemia by regulating the expression of targets involved in lipid metabolism and insulin resistance.

Development of a novel, fully human, anti-PCSK9 antibody with potent hypolipidemic activity by utilizing phage display-based strategy

Background

Proprotein convertase subtilisin/kexin type 9 (PCSK9) regulates serum LDL cholesterol (LDL-C) levels by facilitating the degradation of the LDL receptor (LDLR) and is an attractive therapeutic target for hypercholesterolemia intervention. Herein, we generated a novel fully human antibody with favourable druggability by utilizing phage display-based strategy.

Methods

A potent single-chain variable fragment (scFv) named AP2M21 was obtained by screening a fully human scFv phage display library with hPCSK9, and performing two in vitro affinity maturation processes including CDR-targeted tailored mutagenesis and cross-cloning. Thereafter, it was transformed to a full-length Fc-silenced anti-PCSK9 antibody FAP2M21 by fusing to a modified human IgG1 Fc fragment with L234A/L235A/N297G mutations and C-terminal lysine deletion, thus eliminating its immune effector functions and mitigating mAb heterogeneity.

Findings

Our data showed that the generated full-length anti-PCSK9 antibody FAP2M21 binds to hPCSK9 with a K_D as low as 1.42 nM, and a dramatically slow dissociation rate (k_off, 4.68 × 10⁻⁶ s⁻¹), which could be attributed to its lower binding energy (-47.51 kcal/mol) than its parent counterpart FAP2 (-30.39 kcal/mol). We verified that FAP2M21 potently inhibited PCSK9-induced reduction of LDL-C uptake in HepG2 cells, with an EC₅₀ of 43.56 nM. Further, in hPCSK9 overexpressed C57BL/6 mice, a single tail i.v. injection of FAP2M21 at 1, 3 and 10 mg/kg, dose-dependently up-regulated hepatic LDLR levels, and concomitantly reduced serum LDL-C by 3.3% (P = 0.658, unpaired Student's t-test), 30.2% (P = 0.002, Mann-Whitney U-test) and 37.2% (P = 0.002, Mann-Whitney U-test), respectively.

Interpretation

FAP2M21 with potent inhibitory effect on PCSK9 may serve as a promising therapeutic agent for treating hypercholesterolemia and associated cardiovascular diseases.

Associations of serially measured PCSK9, LDLR and MPO with clinical outcomes in heart failure

Aim: To investigate the temporal evolution of plasma proprotein convertase subtilisin/kexin type 9 (PCSK9), low-density lipoprotein receptor (LDLR) and myeloperoxidase (MPO) in relation to clinical outcome in chronic heart failure (CHF). Methodology & results: Trimonthly blood sampling was performed during a median follow-up of 2.2 (IQR 1.4-2.5) years in 263 CHF patients. Seventy patients reached the primary end point (PE) (cardiovascular death, heart transplantation, left ventricular assist device implantation or HF-hospitalization). MPO level was independently associated with the PE; the adjusted (for clinical factors) hazard ratio (aHR) per standard deviation difference in MPO was 1.71 (95% CI: 1.23-2.43) at any time during follow-up. PCSK9 level (HR: 1.45 [1.04-2.06]) and LDLR (HR: 0.66 [0.49-0.87]) were statistical significantly associated with the PE but only in unadjusted analyses. Slope of temporal MPO evolution (aHR: 1.34 [1.12-1.76] per 0.1 standard deviation/year difference in slope) and LDLR (aHR: 0.78 [0.61-0.90]) however, were associated with PE. Conclusion: Temporal patterns of MPO and LDLR are independently associated with clinical outcome in CHF, which illustrates the importance of assessing temporal evolutions. Clinical trial registration information: registered in ClinicalTrials.gov, number NCT01851538. https://clinicaltrials.gov/ct2/show/NCT01851538.

Novel Experimental Agents for the Treatment of Hypercholesterolemia

Atherosclerotic cardiovascular diseases (ASCVD) are still the leading cause of morbidity and mortality in most developed countries and even more in developing countries. Dyslipidemia is a well known main risk factor for ASCVD. Lipid-lowering treatment, particularly lowering LDL-cholesterol (LDL-C), can decrease the risk for ASCVD. New data and guidelines based upon them suggest that we should go with LDL-C levels as low as we can. Therefore, conventional lipid lowering agents (statins and statins+ezetimibe) are not enough mainly because of poor compliance and statin intolerance which is in the real world mostly pseudo-intolerance. PCSK9 inhibitors provided a new hope to further decrease LDL-C but are still expensive, they have to be injected subcutaneously twice a month and their long-lasting adverse effects are not known. Therefore, there is a constant need to develop novel, more potent, more safe, less expensive, more user friendly regimens of hypolipemic agents (bempedoic acid, selective PPAR alpha receptor modulators etc). One of the ways to overcome poor compliance and increase the potency of therapy with less adverse effects are fixed combinations of established drugs (statin+ezetimibe). The future of hypolipemic agents is based on antisense therapy, ie. the use of specific oligonucleotide sequences blocking the translation of the selected protein (targeting apolipoprotein CIII, lipoprotein (a), apolipoprotein B) or RNA silencing technique (PCSK9 mRNA) and are in various stages of clinical trials. Some of them are almost ready to use in everyday clinical practice. High risk and very high risk patients (eg. familial hypercholesterolemia, familial severe chylomicronemia syndrome) will benefit most. The aim of this review is to inform about novel hypolipemic agents – potent and safe drugs for dyslipidemia which should reduce the risk of ASCVD.

PCSK9 inhibition in clinical practice: Treatment patterns and attainment of lipid goals in a large health maintenance organization

BACKGROUND

Proprotein convertase subtilisin/kexin type-9 inhibitors (PCSK9i) effectively reduce low-density lipoprotein cholesterol (LDL-C), improving cardiovascular outcomes in clinical trials when added to statin therapy.

OBJECTIVES

As real-world evidence is lacking, we aimed to evaluate treatment and adherence patterns using PCSK9i in clinical practice.

METHODS

We investigated 1600 patients initiating PCSK9i between January 2016 and December 2019 in a large health maintenance organization. Treatment discontinuation was defined as a gap ≥60 days between last days' supply of one prescription and the start of the next. Re-initiation rates as well as proportion of days covered (PDC) over 1-year period and attainment of lipid goals under PCSK9i, were analyzed.

RESULTS

Evolocumab 140 mg was initiated by 50.7%, alirocumab 75 mg by 29.5% and 150 mg by 19.8%. Cumulative discontinuation rates were 28.1% after 6-months and 49.9% after 3-years. Overall, 58% of the patients that discontinued therapy have re-initiated PCSK9i (31% after 3-months from discontinuation). Mean PDC over 1-year of therapy was 56% ± 29, with PDC ≥80% evident in 29%. Of those with established cardiovascular disease (n = 991), 55% achieved LDL-C<70 mg/dL and 38% LDL-C<55 mg/dL. Attainment rates were lower in patients with PDC<80%, baseline LDL-C>190 mg/dL and in those not treated with concurrent statin therapy.

CONCLUSIONS

In real-world practice of patients treated by PCSK9i, high proportion of early treatment discontinuation was evident, with non-negligible re-initiation rates but overall low medication coverage over time. This have contributed to sub-optimal attainment of LDL-C treatment goals, particularly observed in patients with severe hypercholesterolemia, inadequate drug adherence, and those using PCSK9i as monotherapy.

Eligibility for PCSK-9 inhibitors treatment in acute coronary syndrome, chronic coronary artery disease and outpatient dyslipidemic patients

BACKGROUND AND AIMS

We aimed to investigate potential eligibility for proprotein convertase subtilisin-kexin type 9 (PCSK9) inhibitors in patients with coronary artery disease and dyslipidaemia according to patient characteristics and variable criteria.

METHODS

We prospectively enrolled 2000 patients (acute coronary syndrome = 407, chronic coronary artery disease inpatients = 1087, outpatient Lipid's clinic = 506). To calculate PCSK-9 inhibitors real-world eligibility, a proprietary adjustable software was developed, which stores data and patient characteristics and can determine eligibility depending on different criteria. We tested four scenarios with different LDL thresholds according to ESC/EAS 2016 and 2019 Guidelines, 2017 American College of Cardiology Expert Consensus, and National criteria.

RESULTS

The eligible percentage was 18.85%, 9.75%, 8.55% and 2.15%, in the total population for the four classifications, respectively, and it varied according to clinical status. The increase toward more recent guidelines was mostly attributed to the increasing number of coronary patients who become eligible as our criteria become stricter.

CONCLUSIONS

For the first time, a realistic estimation of PCSK-9 eligibility is provided via an adjustable predictive model in a population of 2000 patients with acute coronary syndrome, chronic coronary artery disease and dyslipidaemia. This can be a valuable tool for the incorporation of PCSK-9 inhibitors in health care systems.

Egyptian Association of Vascular Biology and Atherosclerosis (EAVA) consensus on the usage of proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors

Background

The current expert view of the PCSK9 inhibitors’ use in Egypt is still ambiguous.

Main body

Hyperlipidemia is an important, if not the most important, risk factor for the occurrence of atherosclerosis worldwide. Egypt is the most populous country in the Middle East and North Africa and has > 15% of the cardiovascular deaths in the region. The burden of dyslipidemia as seen in the recently published CardioRisk project conducted throughout Egypt shows a high prevalence of dyslipidemia as a risk factor that is still reaching up to 71% in female participants. Reaching the targets for LDL lowering, and thus control of hyperlipidemia, is quite often very difficult especially with the update of the last ESC guidelines. With the advent of PCSK9 inhibitors, the control rate of patients, reduction of cardiac major adverse events, and mortality have been improved. However, Egypt is not considered a rich country on the grounds of annual income, and this raises a concern on which patients would benefit from these expensive medications. Revising the randomized control trials, we analyzed the data that would enable us to control LDL in those patients, at risk, to obtain simple clear indications for the use of these rather expensive medications.

Conclusion

We recommend the use of PCSK9 inhibitors in addition to statins ± ezetimibe in patients with ASCVD, by definition at very high risk; patients with ASCVD at very high risk who do not tolerate appropriate doses of at least three statins; and familial hypercholesterolaemia patients with clinically diagnosed ASCVD, at very high cardiovascular risk.

Low-density lipoprotein cholesterol lowering treatment: the current approach

In the last 50 years, several clinical and epidemiological studies during have shown that increased levels of low-density lipoprotein cholesterol (LDLc) are associated with the development and progression of atherosclerotic lesions. The discovery of β-Hydroxy β-methylglutaryl-CoA reductase inhibitors (statins), that possess LDLc-lowering effects, lead to a true revolution in the prevention and treatment of cardiovascular diseases. Statins remain the cornerstone of LDLc-lowering therapy. Lipid-lowering drugs, such as ezetimibe and bile acid sequestrants, are prescribed either in combination with statins or in monotherapy (in the setting of statin intolerance or contraindications to statins). Microsomal triglyceride transfer protein inhibitors and protein convertase subtilisin/kexin type 9 (PCSK9) inhibitors are other drug classes which have been investigated for their potential to decrease LDLc. PCSK9 have been approved for the treatment of hypercholesterolemia and for the secondary prevention of cardiovascular events. The present narrative review discusses the latest (2019) guidelines of the European Atherosclerosis Society/European Society of Cardiology for the management of dyslipidemia, focusing on LDLc-lowering drugs that are either already available on the market or under development. We also consider "whom, when and how" do we treat in terms of LDLc reduction in the daily clinical practice.

Inflammatory Biomarkers for Cardiovascular Risk Stratification in Familial Hypercholesterolemia

Familial hypercholesterolemia (FH) is a frequent autosomal genetic disease characterized by elevated concentrations of low-density lipoprotein cholesterol (LDL) from birth with increased risk of premature atherosclerotic complications. Accumulating evidence has shown enhanced inflammation in patients with FH. In vessels, the deposition of modified cholesterol lipoproteins triggers local inflammation. Then, inflammation facilitates fatty streak formation by activating the endothelium to produce chemokines and adhesion molecules. This process eventually results in the uptake of vascular oxidized LDL (OxLDL) by scavenger receptors in monocyte-derived macrophages and formation of foam cells. Further leukocyte recruitment into the sub-endothelial space leads to plaque progression and activation of smooth muscle cells proliferation. Several inflammatory biomarkers have been reported in this setting which can be directly synthetized by activated inflammatory/vascular cells or can be indirectly produced by organs other than vessels, e.g., liver. Of note, inflammation is boosted in FH patients. Inflammatory biomarkers might improve the risk stratification for coronary heart disease and predict atherosclerotic events in FH patients. This review aims at summarizing the current knowledge about the role of inflammation in FH and the potential application of inflammatory biomarkers for cardiovascular risk estimation in these patients.

Macrophage: A Key Therapeutic Target in Atherosclerosis?

Background:

Atherosclerosis is a chronic inflammatory disease and a leading cause of coronary artery disease, peripheral vascular disease and stroke. Lipid-laden macrophages are derived from circulating monocytes and form fatty streaks as the first step of atherogenesis.

Methods:

An electronic search in major databases was performed to review new therapeutic opportunities for influencing the inflammatory component of atherosclerosis based on monocytes/macrophages targeting.

Results:

In the past two decades, macrophages have been recognized as the main players in atherogenesis but also in its thrombotic complications. There is a growing interest in immunometabolism and recent studies on metabolism of macrophages have created new therapeutic options to treat atherosclerosis. Targeting recruitment, polarization, cytokine profile extracellular matrix remodeling, cholesterol metabolism, oxidative stress, inflammatory activity and non-coding RNAs of monocyte/macrophage have been proposed as potential therapeutic approaches against atherosclerosis.

Conclusion:

Monocytes/macrophages have a crucial role in progression and pathogenesis of atherosclerosis. Therefore, targeting monocyte/macrophage therapy in order to achieve anti-inflammatory effects might be a good option for prevention of atherosclerosis.

Association of Serum PCSK9 Levels with Antibiotic Resistance and Severity of Disease in Patients with Bacterial Infections Admitted to Intensive Care Units

BACKGROUND

The results of several studies have suggested that infections and sepsis, either bacterial or viral, might be associated with elevated plasma proprotein convertase subtilisin/kexin type 9 (PCSK9) levels. Since there are no data on PCSK9 levels and antibiotic resistance or the severity of disease in patients with bacterial infections in intensive care units, the aim of this study was to investigate whether any such associations exist.

METHODS

100 patients (46 males, mean age 67.12 ± 1.34 years) with bacterial infections who were staying in an intensive care unit (ICU) longer than 48 h but less than 7 days and who were not receiving corticosteroids were analyzed. Their serum levels of albumin, C-reactive protein, glucose, lactate, blood urea nitrogen, prothrombin (international normalized ratio), total cholesterol, triglycerides, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, serum glutamic oxaloacetic transaminase, serum glutamic pyruvic transaminase, PCSK9, and procalcitonin were measured. The severity of the patients' condition was assessed by using the Glasgow Coma Scale (GCS), the Sequential Organ Failure Assessment (SOFA), and the Acute Physiology and Chronic Health Evaluation II (APACHE II) scales.

RESULTS

Using a hierarchical regression modeling approach, no significant association was found between PCSK9 levels and either the severity of disease (APACHE II, SOFA, and GCS) indices or resistance to antibiotics.

CONCLUSION

The results suggest that there is no association between PCSK9 levels and resistance to antibiotics or the condition of patients hospitalized in intensive care units.

PCSK9 inhibitors: A new improvement for health

It is a patient with heterozygous familial hypercholesterolemia and a personal history of acute myocardial infarction, which is referred to our lipid unit for hypocholesterolemic treatment adjustment. Since he does not reach therapeutic goals with oral medication, he starts a treatment with fortnightly sessions of LDL-apheresis, which he keeps for 8 years. With the introduction and availability of PCSK9 inhibitors, a new treatment option is possible for this patient.

Cardiovascular events with PCSK9 inhibitors: an updated meta-analysis of randomised controlled trials

The therapy with proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors efficiently reduces plasma cholesterol levels, which has been recently associated with improvement in cardiovascular outcomes. This meta-analysis aimed at investigating the safety and efficacy of treatment with the clinically available anti-PCSK9 monoclonal antibodies (mAbs) in all published randomized clinical trials (RCTs), updating the available results with the recently published ODYSSEY OUTCOMES trial. Data search was carried out using PubMed/MEDLINE and EMBASE (inception - January 2019). Inclusion criteria were: (1) phase 2 or 3 RCTs; (2) comparing anti-PCSK9 mAbs (specifically evolocumab and alirocumab) with placebo; (3) with effects on outcomes reported; (4) with treatment duration longer than 8 weeks. Odds ratios (ORs) with 95% CIs were used as summary statistics. We pooled the estimates by using both the DerSimonian & Laird method (random-effects model). Between-study heterogeneity was tested by Cochrane's Q test and measured with the I2 statistics. Twenty-eight RCTs comprising 62,281 participants (33,204 in the mAb arm, 29,077 in the placebo arm) were included in the meta-analysis. The treatment follow-up ranged from 8 weeks up to 208 weeks. Overall, no significant difference in all-cause mortality was observed between the two groups (OR 0.93 [95% CI, 0.85-1.03]). The treatment with an anti-PCSK9 mAb was associated with a significant reduction of CV events compared with placebo (OR 0.83 [95% CI, 0.78-0.87]), being the FOURIER and ODYSSEY OUTCOMES studies the major contributors. Both myocardial infarction and stroke were significantly reduced following the treatment with an anti-PCSK9 mAb. No significant difference was observed in cardiovascular mortality (OR 0.94 [95% CI, 0.83-1.07]). The incidence of serious adverse events was similar in the two groups (OR: 0.95, [95% CI, 0.91-0.99]). Thus, the pharmacological approach with anti-PCSK9 mAbs significantly and safely improves cardiovascular outcomes. Despite that, the pooled analysis failed to show a significant cardiovascular mortality benefit with anti-PCSK9 mAb treatment, suggesting that specific longer-term studies are warranted to address this issue. We suggest that the observed delay between the rapid effect on plasma cholesterol levels and the emergence of the clinical benefit, observed both in FOURIER and ODYSSEY OUTCOMES trials, might explain this finding.

Emerging drugs for the treatment of hypercholesterolemia

INTRODUCTION

Despite the consolidated role of statins and ezetimibe to treat hypercholesterolemia, often the desirable low-density lipoprotein cholesterol (LDL-C) values are not achieved, with a consequent increase of the residual cardiovascular (CV) risk. Areas covered: In this review, we summarize the main pharmacological characteristics of new lipid-lowering drugs, such as proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors, cholesteryl ester transfer protein inhibitors, microsomal triglyceride transfer protein inhibitors, ATP citrate lyase inhibitors, antisense oligonucleotides, small interfering RNA, and peroxisome proliferator-activated receptors type α agonists. The available clinical evidence of efficacy and safety as well as the prospects of application, based on the different mechanisms and targets of action, is critically discussed. Expert opinion: Some of these emerging agents represent an excellent therapeutic strategy to treat patients with LDL largely out of target, resistant or intolerant to statins, trying to minimize the residual CV risk, modulating different classes of lipoproteins, not just LDL. The main challenge for the large use of emerging drugs is their cost. Thus, the correct identification of the adequate target population for treatment is a priority. This is particularly true for safe, powerful, and fully developed drugs such as the PCSK9 inhibitors, for which a relatively large use is potentially expected.

Can Lp(a) Lowering Against Background Statin Therapy Really Reduce Cardiovascular Risk?

PURPOSE OF REVIEW

The association between elevated plasma levels of lipoprotein (a) [Lp(a)] and atherosclerotic cardiovascular disease (ASCVD) has been discussed for many years. Recent genetic findings have confirmed that elevated Lp(a) similar to elevated LDL-cholesterol (LDL-C) might be causally related to premature ASCVD. Lp(a) is relatively refractory to lifestyle interventions. The results of studies with statins and their possible effect on Lp(a) are conflicting. Specific Lp(a) apheresis is used as a treatment against background statin therapy and can decrease Lp(a). The purpose of this review is to discuss whether new drugs which decrease Lp(a) can prevent ASCVD and decrease ASCVD mortality when applied in addition to statins.

RECENT FINDINGS

Some new LDL-C-lowering drugs such as mipomersen and lomitapide decrease elevated Lp(a) in addition to statins but they have some unpleasant adverse effects. Recently, an antisense oligonucleotide against apo(a), AKCEA-APO(a)Rx, has been shown to selectively decrease Lp(a). The most recent advance in LDL-C lowering are PCSK9 inhibitors. Alirocumab and evolocumab do not only significantly reduce LDL-C on top of maximally tolerated statin therapy and prevent ASCVD events, but also further decrease Lp(a). There is no data to indicate whether mipomersen, lomitapide, or IONIS-APO(a)-LRx decrease ASCVD events and mortality. Conclusive evidence is still lacking as to whether the treatment with PCSK9 inhibitors against background statin therapy actually additionally reduces ASCVD risk due to the lowering of Lp(a) or simply due to lowering LDL-C to levels much lower than high-intensity statin treatment as monotherapy. Ongoing trials will probably provide an answer to these questions.

Changes in circulating pro-protein convertase subtilisin/kexin type 9 levels - experimental and clinical approaches with lipid-lowering agents

Regulation of pro-protein convertase subtilisin/kexin type 9 (PCSK9) by drugs has led to the development of a still small number of agents with powerful activity on low-density lipoprotein cholesterol levels, associated with a significant reduction of cardiovascular events in patients in secondary prevention. The Further Cardiovascular Outcomes Research with PCSK9 Inhibition in Subjects with Elevated Risk (FOURIER) and Evaluation of Cardiovascular Outcomes After an Acute Coronary Syndrome During Treatment With Alirocumab (ODYSSEY OUTCOMES) studies, with the two available PCSK9 antagonists, i.e. evolocumab and alirocumab, both reported a 15% reduction in major adverse cardiovascular events. Regulation of PCSK9 expression is dependent upon a number of factors, partly genetic and partly associated to a complex transcriptional system, mainly controlled by sterol regulatory element binding proteins. PCSK9 is further regulated by concomitant drug treatments, particularly by statins, enhancing PCSK9 secretion but decreasing its stimulatory phosphorylated form (S688). These complex transcriptional mechanisms lead to variable circulating levels making clinical measurements of plasma PCSK9 for cardiovascular risk assessment a debated matter. Determination of total PCSK9 levels may provide a diagnostic tool for explaining an apparent resistance to PCSK9 inhibitors, thus indicating the need for other approaches. Newer agents targeting PCSK9 are in clinical development with a major interest in those with a longer duration of action, e.g. RNA silencing, allowing optimal patient compliance. Interest has been expanded to areas not only limited to low-density lipoprotein cholesterol reduction but also investigating other non-lipid pathways raising cardiovascular risk, in particular inflammation associated to raised high-sensitivity C-reactive protein levels, not significantly affected by the present PCSK9 antagonists.

Treatment patterns and patient characteristics among early initiators of PCSK9 inhibitors

Purpose

To describe patient characteristics and treatment patterns among early initiators of proprotein convertase subtilisin/kexin type nine inhibitors (PCSK9is) who initiated treatment within the first 6 months of market availability.

Patients and methods

This retrospective cohort study used IQVIA’s longitudinal open-source point-of-sale pharmacy claims database (LRx) and PharMetrics Plus (P+) health plan claims database to identify patients initiating a PCSK9i between January 1, 2016 and June 30, 2016. The index date was defined as the date of the first PCSK9i prescription (index claim) during the enrollment window; patients were followed for ≥6 months postindex. Patient characteristics including use of baseline lipid-lowering therapy (LLT) and measures such as persistence and adherence to PCSK9i therapy were evaluated with respect to health plan type (commercial vs Medicare).

Results

Overall, patients initiating PCSK9i (n=13,151) had a mean age of 66 years, and 51% were male. Approximately 67.4% of patients used some form of LLT (statin and/or ezetimibe) in the 24 months prior to initiating PCSK9i therapy. The proportion of patients covered by a commercial health plan (51.2%) was similar to that covered by Medicare (48.8%). Persistence on PCSK9i was marginally longer for patients with commercial insurance than Medicare (mean days on therapy 202.2 vs 198.5). Overall, 42.6% of patients discontinued their PCSK9i during the 180 days of follow-up.

Conclusion

This study demonstrates that a large proportion of patients discontinue PCSK9i therapy at 30 and 90 days, which are the time frames for which many health plans require recertification to continue access to PCSK9i. Future studies looking at treatment patterns among patients who initiate PCSK9i therapy after the first 180 days once health plan formularies and utilization management criteria were finalized are needed to understand more comprehensively real-world PCSK9i usage patterns.

Strategies to achieve low-density lipoprotein cholesterol targets in high-risk patients

Several options exist in very-high risk patients who do not achieve low-density lipoprotein cholesterol (LDL-C) targets despite treatment with atorvastatin 80 mg, including switching to rosuvastatin 40 mg, adding ezetimibe or adding a proprotein convertase subtilisin/kexin type 9 inhibitor. Taking into account the safety, LDL-C lowering capacity, effect on cardiovascular events and cost of these available options, switching to rosuvastatin 40 mg appears to represent the most attractive strategy. Nevertheless, more studies are needed to confirm the effects of this strategy on LDL-C levels given the limited available data.

Lipid lowering drugs and inflammatory changes: an impact on cardiovascular outcomes?

Inflammatory changes are responsible for maintenance of the atherosclerotic process and may underlie some of the most feared vascular complications. Among the multiple mechanisms of inflammation, the arterial deposition of lipids and particularly of cholesterol crystals is the one responsible for the activation of inflammasome NLRP3, followed by the rise of circulating markers, mainly C-reactive protein (CRP). Elevation of lipoproteins, LDL but also VLDL and remnants, associates with increased inflammatory changes and coronary risk. Lipid lowering medications can reduce cholesterolemia and CRP: patients with elevations of both are at greatest cardiovascular (CV) risk and receive maximum benefit from therapy. Evaluation of the major drug series indicates that statins exert the largest LDL and CRP reduction, accompanied by reduced CV events. Other drugs, mainly active on the triglyceride/HDL axis, for example, PPAR agonists, may improve CRP and the lipid pattern, especially in patients with metabolic syndrome. PCSK9 antagonists, the newest most potent medications, do not induce significant changes in inflammatory markers, but patients with the highest baseline CRP levels show the best CV risk reduction. Parallel evaluation of lipids and inflammatory changes clearly indicates a significant link, both guiding to patients at highest risk, and to the best pharmacological approach. Key messages Lipid lowering agents with "pleiotropic" effects provide a more effective approach to CV prevention In CANTOS study, patients achieving on-treatment hsCRP concentrations ≤2 mg/L had a higher benefit in terms of reduction in major CV events The anti-inflammatory activity of PCSK9 antagonists appears to be of a minimal extent.

PCSK9 in cholesterol metabolism: from bench to bedside

Dyslipidemia, and specifically elevated low-density lipoprotein (LDL) cholesterol, is one of the most important cardiovascular risk factors. Statins are considered first line therapy for the primary and secondary prevention of cardiovascular disease. However, statins may not be adequate treatment for elevated circulating LDL levels and are ineffective in certain familial hypercholesterolemias. The discovery of proprotein convertase subtilisin/kexin type 9 (PCSK9), a regulatory protein that affects LDL receptors, offers a new alternative for these patients. Moreover, gain-of-function PCSK9 mutations were discovered to be the root cause of familial autosomal dominant hypercholesterolemia. Inhibition of PSCK9 reduces plasma LDL levels, even in patients for whom statins are ineffective or not tolerated. Alirocumab and evolocumab, human monoclonal antibodies that inhibit PCSK9, have been approved to lower LDL levels. While there are drawbacks to these treatments, including adverse events, administration by subcutaneous injection, and high cost, these drugs are indicated for the treatment of atherosclerotic cardiovascular disease and familial hypercholesterolemia as adjunct to diet and maximally tolerated statin therapy. PCSK9 inhibitors may work synergistically with statins to lower LDL. Novel approaches to PCSK9 inhibition are currently in development with the aim of providing safe and effective treatment options to decrease cardiovascular event burden, ideally at lower cost and with oral bioavailability.

The Pharmacologic Role and Clinical Utility of PCSK9 Inhibitors for the Treatment of Hypercholesterolemia

In addition to monoclonal antibodies against proprotein convertase subtilisin-kexin type 9 (PCSK9), vaccines against PCSK9 and smaller molecule inhibitors as well as RNA inhibitors of PCSK9 production have been created. The monoclonal antibodies against PCSK9 and the PCSK9 RNA inhibitors can reduce low-density lipoproteins (LDLs) by over 50%, non-high-density lipoprotein (HDL) cholesterol and triglycerides, and increasing HDL. Although effective in several homozygous familial hypercholesterolemia patient types, PCSK9 inhibitors does not work in all patient types. Outcome trials show no effects on mortality but do show reductions in atherosclerotic events such as myocardial infarctions, strokes, and need for coronary revascularization. PCSK9 inhibitors have a very attractive safety profile with no significant elevations in measures of muscle or liver damage. The current and more advanced experimental agents all require subcutaneous dosing, and injection site reactions are among the most common adverse events. Therapy for the Food and Drug Administration (FDA) approved agents is markedly expensive, and this is the primary barrier to utilization. However, it is possible to identify patients with a number needed to treat to prevent an atherosclerotic event low enough to render it cost-effective and one such factor is whether or not you require a 50% reduction in LDL in order to achieve your LDL goal.

Patient adherence, compliance, and perspectives on evolocumab for the management of resistant hypercholesterolemia

Evolocumab is a PCSK9 inhibitor which is administered subcutaneously, and when added to statin therapy it has been shown to cause a significant incremental LDL-C reduction, leading to a reduction of cardiovascular risk. Evolocumab has a favorable side effect profile, and its self-administration at home appears to be safe and effective with the appropriate training and instructions from a health care provider. Current studies are showing encouraging results regarding adherence to evolocumab in real-life settings, and adherence rates to evolocumab appear to be better than those to statins. However, further larger studies are needed for a more definitive assessment of the short- and long-term patient adherence rates to evolocumab. In addition, reductions in the price of evolocumab may also be necessary to improve cost-effectiveness of the drug.