Effects of Evolocumab on Vitamin E and Steroid Hormone Levels

Prognostic Value of PCSK9 Levels in Premenopausal Women at Risk of Breast Cancer-Evidence from a 17-Year Follow-Up Study

BACKGROUND AND AIM

The involvement of cholesterol in cancer development remains a topic of debate, and its association with breast cancer has yet to be consistently demonstrated. Considering that circulating cholesterol levels depend on several concomitant processes, we tested the liability of plasma levels of proprotein convertase subtilisin/kexin type 9 (PCSK9), one of the key regulators of cholesterol levels, as a prognostic biomarker in the context of breast neoplastic events.

METHODS

Within a prospective randomized breast cancer prevention trial we measured baseline plasma levels of PCSK9. A total of 235 at-risk premenopausal women were randomized and followed up for 17 years. Participants enrolled in this placebo-controlled, phase II, double-blind trial were randomly assigned to receive either tamoxifen 5 mg/d or fenretinide 200 mg/d, both agents, or placebo for 2 years. The associations with breast cancer events were evaluated through competing risk and Cox regression survival models, adjusted for randomization strata (5-year Gail risk ≥ 1.3% vs. intraepithelial neoplasia or small invasive breast cancer of favorable prognosis), age, and treatment allocation. PCSK9 associations with biomarkers linked to breast cancer risk were assessed on blood samples collected at baseline.

RESULTS

The plasmatic PCSK9 median and interquartile range were 207 ng/mL and 170-252 ng/mL, respectively. Over a median follow-up period of 17 years and 89 breast neoplastic events, disease-free survival curves showed a hazard ratio of 1.002 (95% CI: 0.999-1.005, p = 0.22) for women with PCSK9 plasma levels ≥ 207 ng/mL compared to women with levels below 207 ng/mL. No differences between randomization strata were observed. We found a negative correlation between PCSK9 and estradiol (r = -0.305), maintained even after partial adjustment for BMI and age (r = -0.287). Cholesterol (r = 0.266), LDL-C (r = 0.207), non-HDL-C (r = 0.246), remnant cholesterol (r = 0.233), and triglycerides (r = 0.233) also correlated with PCSK9.

CONCLUSIONS

In premenopausal women at risk of early-stage breast cancer, PCSK9 did not appear to have a role as a prognostic biomarker of breast neoplastic events. Larger studies are warranted investigating patients in different settings.

Efficacy and Safety of an Investigational Single-Course CRISPR Base-Editing Therapy Targeting PCSK9 in Nonhuman Primate and Mouse Models

BACKGROUND

VERVE-101 is an investigational in vivo CRISPR base-editing medicine designed to alter a single DNA base in the PCSK9 gene, permanently turn off hepatic protein production, and thereby durably lower low-density lipoprotein cholesterol. We test the efficacy, durability, tolerability, and potential for germline editing of VERVE-101 in studies of nonhuman primates and a murine F1 progeny study.

METHODS

Cynomolgus monkeys were given a single intravenous infusion of a vehicle control (n=10) or VERVE-101 at a dose of 0.75 mg/kg (n=4) or 1.5 mg/kg (n=22) with subsequent follow-up up to 476 days. Two studies assessed the potential for germline editing, including sequencing sperm samples from sexually mature male nonhuman primates treated with VERVE-101 and genotyping offspring from female mice treated with the murine surrogate of VERVE-101 (VERVE-101mu).

RESULTS

Liver biopsies 14 days after dosing noted mean PCSK9 editing of 46% and 70% in monkeys treated with VERVE-101 at 0.75 and 1.5 mg/kg, respectively. This translated into mean reductions in blood PCSK9 (proprotein convertase subtilisin/kexin type 9) of 67% and 83% and reductions of low-density lipoprotein cholesterol of 49% and 69% at the 0.75 and 1.5 mg/kg doses, respectively, assessed as time-weighted average change from baseline between day 28 and up to 476 days after dosing. Liver safety monitoring noted a transient rise in alanine aminotransferase and aspartate aminotransferase concentrations after infusion that fully resolved by day 14 with no accompanying change in total bilirubin. In a subset of monkeys necropsied 1 year after dosing, no findings related to VERVE-101 were identified on macroscopic and histopathologic assessment of the liver and other organs. In the study to assess potential germline editing of male nonhuman primates, sperm samples collected after VERVE-101 dosing showed no evidence of PCSK9 editing. Among 436 offspring of female mice treated with a saturating dose of VERVE-101mu, the PCSK9 edit was transmitted in 0 of 436 animals.

CONCLUSIONS

VERVE-101 was well tolerated in nonhuman primates and led to 83% lower blood PCSK9 protein and 69% lower low-density lipoprotein cholesterol with durable effects up to 476 days after dosing. These results have supported the initiation of a first-in-human clinical trial in patients with heterozygous familial hypercholesterolemia and atherosclerotic cardiovascular disease.

Genetics, Safety, Cost-Effectiveness, and Accessibility of Injectable Lipid-Lowering Agents: A Narrative Review

Cardiovascular disease causes significant personal, financial, and societal burden and is a major cause of mortality and morbidity globally. Dyslipidemia has proven to be a major factor that contributes to its increased incidence; thus, since a long time, low-density lipoprotein cholesterol-lowering therapies have been employed to reduce coronary artery disease-associated mortality. The first-line therapy for hyperlipidemia and dyslipidemia is statins. Evidence showed that statins decrease the level of LDL-C resulting in a lower risk of CVD (20-25% for every decrease of 1 mmol/L). However, due to statin intolerance in some patients and despite using maximal doses, they have not been successful in lowering cardiovascular-associated mortality. Moreover, bococizumab was recently suspended due to its higher immunogenicity with time, resulting in less efficacy with long-term use. Alternatives to statins are PCSK9 inhibitors which are administered subcutaneously every two or four weeks. They are injectables with considerable lipid-lowering properties. This narrative review discusses their genetics, safety, tolerability, and cost-effectiveness. It also quantifies their benefit in certain subgroups by analyzing the findings from recent randomized clinical trials. Current data from phase 2 and 3 trials (ORION, ODYSSEY, and FOURIER) suggest a favorable profile for evolocumab, alirocumab, and inclisiran with minimal tolerable side effects and superior efficacy in statin-intolerant patients. Their cost-effectiveness has not yet been established clearly, but future outcomes seem promising.

The role of proprotein convertase subtilisin/kexin type 9 (PCSK9) in the pathophysiology of psoriasis and systemic lupus erythematosus

Inflammation and atherogenic dyslipidaemia are often observed in skin diseases and represent an increased risk of cardiovascular disorders. Proprotein convertase subtilisin/kexin type 9 plays an important role in the regulation of serum low-density lipoprotein cholesterol levels. Its biological role, however, seems to go much beyond the regulation of cholesterol metabolism. The article presents potential pathophysiological links between inflammatory process and lipid disorders based on the example of psoriasis and systemic lupus erythematosus.

Immunometabolic Markers in a Small Patient Cohort Undergoing Immunotherapy

Although the discovery of immune checkpoints was hailed as a major breakthrough in cancer therapy, generating a sufficient response to immunotherapy is still limited. Thus, the objective of this exploratory, hypothesis-generating study was to identify potentially novel peripheral biomarkers and discuss the possible predictive relevance of combining scarcely investigated metabolic and hormonal markers with immune subsets. Sixteen markers that differed significantly between responders and non-responders were identified. In a further step, the correlation with progression-free survival (PFS) and false discovery correction (Benjamini and Hochberg) revealed potential predictive roles for the immune subset absolute lymphocyte count (rs = 0.51; p = 0.0224 *), absolute basophil count (rs = 0.43; p = 0.04 *), PD-1+ monocytes (rs = −0.49; p = 0.04 *), hemoglobin (rs = 0.44; p = 0.04 *), metabolic markers LDL (rs = 0.53; p = 0.0224 *), free androgen index (rs = 0.57; p = 0.0224 *) and CRP (rs = −0.46; p = 0.0352 *). The absolute lymphocyte count, LDL and free androgen index were the most significant individual markers, and combining the immune subsets with the metabolic markers into a biomarker ratio enhanced correlation with PFS (rs = −0.74; p ≤ 0.0001 ****). In summary, in addition to well-established markers, we identified PD-1+ monocytes and the free androgen index as potentially novel peripheral markers in the context of immunotherapy. Furthermore, the combination of immune subsets with metabolic and hormonal markers may have the potential to enhance the power of future predictive scores and should, therefore, be investigated further in larger trials.

Insight into the Evolving Role of PCSK9

Proprotein convertase subtilisin/kexin type 9 (PCSK9) is the last discovered member of the family of proprotein convertases (PCs), mainly synthetized in hepatic cells. This serine protease plays a pivotal role in the reduction of the number of low-density lipoprotein receptors (LDLRs) on the surface of hepatocytes, which leads to an increase in the level of cholesterol in the blood. This mechanism and the fact that gain of function (GOF) mutations in PCSK9 are responsible for causing familial hypercholesterolemia whereas loss-of-function (LOF) mutations are associated with hypocholesterolemia, prompted the invention of drugs that block PCSK9 action. The high efficiency of PCSK9 inhibitors (e.g., alirocumab, evolocumab) in decreasing cardiovascular risk, pleiotropic effects of other lipid-lowering drugs (e.g., statins) and the multifunctional character of other proprotein convertases, were the cause for proceeding studies on functions of PCSK9 beyond cholesterol metabolism. In this article, we summarize the current knowledge on the roles that PCSK9 plays in different tissues and perspectives for its clinical use.

Proprotein convertase subtilisin/kexin type 9 in the dyslipidaemia of patients with axial spondyloarthritis is related to disease activity

OBJECTIVE

Proprotein convertase subtilisin/kexin type 9 (PCSK9) is a serine protease that regulates cholesterol metabolism and has been linked to cardiovascular (CV) risk. The purpose of the present study was to examine whether PCSK9 levels are related to abnormalities in the lipid profile and the development of atherosclerosis that occurs in patients with axial SpA (axSpA).

METHODS

We performed a cross-sectional study that encompassed 545 individuals; 299 patients with axSpA and 246 statin use-matched controls. PCSK9 and standard lipid profiles were analysed in patients and controls. Carotid intima-media thickness (cIMT) and carotid plaques were assessed in patients. A multivariable analysis, adjusted for standard CV risk factors, was performed to evaluate the influence of PCSK9 on axSpA-related dyslipidaemia and subclinical carotid atherosclerosis.

RESULTS

Total cholesterol, high-density lipoprotein and low density lipoprotein cholesterol, lipoprotein (a) and apolipoprotein A1 were significantly lower in axSpA patients than controls. PCSK9 serum levels [β coefficient -44 ng/dl (95% CI -60, -27), P = 0.000] were also downregulated in axSpA patients after fully multivariable adjustment. ASDAS-CRP was found to be independently and significantly related to PCSK9 [β coefficient 10 ng/dl (95% CI 1, 18), P = 0.023] after analysing fully adjusted models that took age, sex and the rest of the lipid profile molecules into account. Whereas patients taking prednisone showed higher serum levels of PCSK9 [55 ng/ml (95% CI 24, 8), P = 0.001], those under anti-TNF-α therapies exhibited lower levels [β coefficient -26 ng/ml (95% CI -43, -9], P = 0.003].

CONCLUSION

PCSK9 is downregulated in patients with axSpA. Disease activity is positive and significantly related to PSCK9. Anti-TNF-therapy yields a reduction in PCSK9 serum levels.

[Real-life efficacy and safety of PCSK9 inhibitors treatment: Experience in three hospitals in Asturias]

BACKGROUND

Inhibitors of proprotein convertase subtilisin/kexin type9 (PCSK9 inhibitors) are a treatment option for those patients with familial hypercholesterolemia or in secondary prevention who do not reach the LDL-C target with other therapeutic measures. The aim of this study is to assess the effectiveness and safety of these drugs.

METHODS

Retrospective, multicentric, descriptive study. We collected data from all patients that have started PCSK9 inhibitors treatment in three hospitals in Asturias since the beginning of its use in 2016. We analysed changes in lipid profile with PCSK9 inhibitors and its side effects.

RESULTS

We registered 98 patients, 75 of them affected by familial hypercholesterolemia (FH) and 23 unaffected. Two months after the beginning of PCSK9 inhibitors treatment, a 61% reduction rate in LDL-C in patients with FH and 52% in those without this condition was observed. This statistically significant reduction remained stable during follow-up. A significant decrease in total cholesterol was observed, without significant changes in HDL-C and triglycerides. 96% of patients had no complications.

CONCLUSIONS

PCSK9 inhibitors are safe drugs that rapidly achieve significant reductions in LDL-C after the beginning of treatment, which are maintained over time. Hence, the use of PCSK9 inhibitors is an alternative for the control of LDL-C in those patients in which the LDL-C target is not reached with other therapeutic measures.

The Effect of the PCSK9 Inhibitor Evolocumab on Aldosterone Secretion among High Cardiovascular Risk Patients: A Pilot Study

Elevated low-density lipoprotein (LDL) cholesterol is one of the leading causes of cardiovascular disease. Proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors reduce LDL cholesterol levels with subsequent reductions in cardiovascular morbidity. Elevated aldosterone levels are also associated with a greater risk of cardiovascular morbidity. There are currently no published data on the impact of PCSK9 inhibitor monotherapy on the secretion of aldosterone. The aim of this study was to examine the effect of monotherapy with the PSCK9 inhibitor evolocumab on the lipid profile and aldosterone secretion level in high-risk cardiovascular patients. Lipid profile, sodium, potassium, aldosterone, cortisol, plasma renin activity, and adrenocorticotropic hormone (ACTH) levels were analyzed at baseline and after 3 months of evolocumab therapy. Each participant underwent a 250 mcg ACTH stimulation test upon study entry. Eight women and seven men were included in the study. Their median total cholesterol, LDL cholesterol, lipoprotein (a), apolipoprotein B100, and baseline and stimulated aldosterone levels were significantly lower after 3 months of evolocumab therapy. These heretofore unreported findings indicate that reductions in unstimulated and stimulated aldosterone secretion under evolocumab therapy could be associated with reductions in cardiovascular events, a possibility that warrants further investigation.

The consequences of PCSK9 inhibition in selected tissues

Proprotein convertase subtilisin/kexin type 9 (PCSK9) is one of nine members of the proprotein convertase family. These serine proteases play a pivotal role in the post-translational modification of proteins and the activation of hormones, enzymes, transcription factors and growth factors. As a result, they participate in many physiological processes like embryogenesis, activity of central nervous system and lipid metabolism. Scientific studies show that the family of convertases is also involved in the pathogenesis of viral and bacterial infections, osteoporosis, hyperglycaemia, cardiovascular diseases, neurodegenerative disorders and cancer. The inhibition of PCSK9 by two currently approved for use monoclonal antibodies (alirocumab, evolocumab) slows down the degradation of low-density lipoprotein cholesterol receptors (LDLRs). This leads to increased density of LDLRs on the surface of hepatocytes, resulting in decreased level of low-density lipoprotein cholesterol (LDL-C) in the bloodstream, which is connected with the reduction of cardiovascular risk. PCSK9 inhibitors (PCSK9i) were created for the patients who could not achieve appropriate level of LDL-C using current statin and ezetimibe therapy. It seems that high therapeutic efficacy of PCSK9i will make them more common in the clinical use. The pleiotropic effects of previously mentioned lipid-lowering therapies were the reasons for literature review of possible positive and negative effects of PCSK9 inhibition beyond cholesterol metabolism.

Reduced adrenal stress response in patients on PCSK9 inhibitor therapy

BACKGROUND AND AIMS

Treatment with proprotein convertase subtilisin-kexin type 9 inhibitors (PCSK9i), in addition to statin therapy, reduces LDL-cholesterol (LDL-c) in some patients to extremely low levels (i.e.< 20 mg/dl or < 0.52 mmol/l). There is concern that at such low levels, the physiologic role of cholesterol may be impaired, e.g. the adrenal cortisol stress response might be compromised. We therefore evaluated the effect of PCSK9i therapy on the cortisol response to ACTH in patients with LDL-c down to extremely low levels.

METHODS

Nineteen patients on PCSK9i therapy and 18 controls matched for age, gender and comorbidities were included. The cortisol response to adrenocorticotropic hormone (ACTH) was tested after application of 250 μg ACTH.

RESULTS

LDL-c levels ranged from 0.42 to 3.32 mmol/l (mean 1.38 ± 0.84 mmol/l) in the PCSK9i group and 0.81-4.82 mmol/l (mean 2.10 ± 0.97) in the control group. By analysis of covariance (ANCOVA), the PCSK9i group had significantly lower cortisol response compared to the control group (- 97.26 nmol/l, -178.60 to -15.93, p = 0.02) after 60 min. There was a significant positive correlation between the duration of PCSK9i treatment and cortisol levels (r = 0.59, p = 0.009). Extremely low LDL-c levels down to 0.42 mmol/l were not associated with lower stimulated cortisol levels.

CONCLUSIONS

Patients on PCSK9i therapy showed a significantly lower cortisol response to ACTH. Stimulated cortisol levels were lower in the first months of PCSK9i treatment, suggesting an adaptive phenomenon. We conclude that the adrenal stress response in patients on PCSK9 inhibitor therapy is reduced.

Pleiotropic Effects of PCSK-9 Inhibitors

Proprotein convertase subtilisin/kexin type 9 (PCSK-9) inhibitors are a group of drugs whose main mechanism of action is binding to the PCSK-9 molecule, which reduces the degradation of the low-density lipoprotein receptor (LDL-R) and, hence, increases the uptake of low-density lipoprotein cholesterol (LDLc) from the bloodstream as well as reducing its concentration. The effectiveness of three monoclonal antibodies, namely, alirocumab (human IgG1/κ monoclonal antibody, genetically engineered in Chinese hamster ovary cells), evolocumab (the first fully human monoclonal antibody), and bococizumab (humanized mouse antibody), in inhibiting the action of PCSK-9 and reducing LDLc levels has been confirmed. The first two, after clinical trials, were approved by the Food and Drug Administration (FDA) and are used primarily in the treatment of autosomal familial hypercholesterolemia and in cases of statin intolerance. They are currently used both as monotherapy and in combination with statins and ezetimibe to intensify therapy and achieve therapeutic goals following the American Heart Association (AHA) and European Society of Cardiology (ESC) guidelines. However, the lipid-lowering effect is not the only effect of action described by researchers that PCSK-9 inhibitors have. This paper is a review of the literature describing the pleiotropic effects of PCSK-9 inhibitors, which belong to a group of drugs that are being increasingly used, especially when standard lipid-lowering therapy fails. The article focuses on activities other than lipid-lowering, such as the anti-atherosclerotic effect and stabilization of atherosclerotic plaque, the anti-aggregation effect, the anticoagulant effect, the antineoplastic effect, and the ability to influence the course of bacterial infections. In this publication, we try to systematically review the current scientific data, both from our own scientific work and knowledge from international publications.

PCSK9 immunization using nanoliposomes: preventive efficacy against hypercholesterolemia and atherosclerosis

INTRODUCTION

The aim of the study was to study a nanoliposomal anti-PCSK9 vaccine as a novel approach for cholesterol lowering via PCSK9 inhibition.

MATERIAL AND METHODS

An immunogenic peptide construct termed immunogenic fused PCSK9-tetanus (IFPT) was displayed on the surface of liposome nanoparticles (L-IFPT) and mixed into alum adjuvant (L-IFPTA+). The manufactured vaccine formulations IFPT, L-IFPT, L-IFPTA+, IFPTA+, and free nanoliposomes were subcutaneously injected four times with bi-weekly intervals in C57BL/6 mice on a severe atherogenic protocol.

RESULTS

Among the formulations, L-IFPTA+ vaccine was found to elicit the highest IgG response against PCSK9 peptide. The induced PCSK9 antibodies inhibited PCSK9-LDLR interaction through binding to PCSK9 in vaccinated mice. Liver low-density lipoprotein receptor (LDLR) protein was increased in vaccinated mice. L-IFPTA+, L-IFPT and IFPTA+ vaccines reduced total cholesterol by up to -38.13 ±3.8% (p = 0.006), -23 ±4.1% (p = 0.027) and -19.12 ±3% (p = 0.038), and low-density lipoprotein cholesterol (LDL-C) by up to -57 ±7.7% (p = 0.0003), -41.67 ±4.2% (p = 0.03) and -36.11 ±5% (p = 0.02) in hypercholesterolemic mice, respectively, versus control mice after 8 weeks. Long-term assessment indicated that the vaccine formulations could stimulate a long-lasting humoral immune response against PCSK9 peptide, which was associated with a marked reduction of total cholesterol in L-IFPTA+, L-IFPT and IFPTA+ vaccine groups by up to -82.5 ±7.3% (p = 0.002), -70.54 ±6.2% (p = 0.013) and -72.02 ±8.7% (p = 0.004), respectively, and LDL-C by up to -88.14 ±5.6% (p = 0.002), -55.92 ±8.3% (p = 0.003) and 54.81 ±9.3% (p = 0.003), respectively, versus the pre-vaccination time point adjusted to the control group. Anti-inflammatory Th2 cells and IL-4 cytokine were considerably increased in splenocytes of vaccinated mice.

CONCLUSIONS

L-IFPTA+ vaccine can induce long-lasting, functional and safe PCSK9-specific antibodies in hypercholesterolemic C57BL/6 mice, providing a long-term protective impact on dyslipidemia and atherosclerosis.

Safety and Tolerability of PCSK9 Inhibitors: Current Insights

The current era of preventive cardiology continues to emphasize on low-density lipoprotein cholesterol (LDL-C) reduction to alleviate the burden of atherosclerotic cardiovascular disease (ASCVD). In this regard, the pharmacological inhibition of proprotein convertase subtilisin/kexin type 9 (PCSK9) enzyme via monoclonal antibodies has emerged as a novel lipid-lowering therapy, leading to a marked reduction in circulating LDL-C levels and subsequent improvement of cardiovascular outcomes. As these agents are increasingly used in current clinical practice, mounting scientific and clinical evidence supports that PCSK9 inhibitors offer an excellent safety and tolerability profile with a low incidence of adverse events. Notably, the most frequently reported side effects are injection-site reactions. In contrast to statins, PCSK9 inhibitors do not appear to exert a detrimental effect on glycemic control or to increase the incidence of new-onset diabetes mellitus. Accumulating evidence also indicates that PCSK9 inhibitors are a safe, well-tolerated and effective therapeutic strategy for patients with statin intolerance. On the other hand, as PCSK9 inhibitors reduce LDL-C to unprecedented low levels, a large body of current research has examined the effects of their long-term administration on neurocognition and on levels of vitamin E and other fat-soluble vitamins, providing encouraging results. This review aims to present and discuss the current clinical and scientific evidence pertaining to the safety and tolerability of PCSK9 inhibitors.

Lipid Management in Patients with Endocrine Disorders: An Endocrine Society Clinical Practice Guideline

OBJECTIVE

This guideline will provide the practicing endocrinologist with an approach to the assessment and treatment of dyslipidemia in patients with endocrine diseases, with the objective of preventing cardiovascular (CV) events and triglyceride-induced pancreatitis. The guideline reviews data on dyslipidemia and atherosclerotic cardiovascular disease (ASCVD) risk in patients with endocrine disorders and discusses the evidence for the correction of dyslipidemia by treatment of the endocrine disease. The guideline also addresses whether treatment of the endocrine disease reduces ASCVD risk.

CONCLUSION

This guideline focuses on lipid and lipoprotein abnormalities associated with endocrine diseases, including diabetes mellitus, and whether treatment of the endocrine disorder improves not only the lipid abnormalities, but also CV outcomes. Based on the available evidence, recommendations are made for the assessment and management of dyslipidemia in patients with endocrine diseases.

Cardiovascular and Metabolic Protection by Vitamin E: A Matter of Treatment Strategy?

Cardiovascular diseases (CVD) cause about 1/3 of global deaths. Therefore, new strategies for the prevention and treatment of cardiovascular events are highly sought-after. Vitamin E is known for significant antioxidative and anti-inflammatory properties, and has been studied in the prevention of CVD, supported by findings that vitamin E deficiency is associated with increased risk of cardiovascular events. However, randomized controlled trials in humans reveal conflicting and ultimately disappointing results regarding the reduction of cardiovascular events with vitamin E supplementation. As we discuss in detail, this outcome is strongly affected by study design, cohort selection, co-morbidities, genetic variations, age, and gender. For effective chronic primary and secondary prevention by vitamin E, oxidative and inflammatory status might not have been sufficiently antagonized. In contrast, acute administration of vitamin E may be more translatable into positive clinical outcomes. In patients with myocardial infarction (MI), which is associated with severe oxidative and inflammatory reactions, decreased plasma levels of vitamin E have been found. The offsetting of this acute vitamin E deficiency via short-term treatment in MI has shown promising results, and, thus, acute medication, rather than chronic supplementation, with vitamin E might revitalize vitamin E therapy and even provide positive clinical outcomes.

Proprotein convertase subtilisin/kexin type 9 inhibition in cardiovascular disease: current status and future perspectives

Proprotein convertase subtilisin/kexin type 9 (PCSK9) targets the degradation of low-density lipoprotein (LDL) receptors; it has been proved that its inhibition improves cardiovascular outcomes in patients with established atherosclerotic cardiovascular disease (ASCVD). Herein, we review the current status of PCSK9 inhibitors in clinical practice and the future scope of PCSK9 inhibition. The results of two recent large clinical trials reveal that two PCSK9 monoclonal antibodies evolocumab and alirocumab reduce the risk of a cardiovascular event on top of background statin therapy in patients with stable ASCVD and those with recent acute coronary syndrome, respectively. However, there are several ongoing concerns regarding the efficacy in reducing mortality, cost-effectiveness, and long-term safety of extremely low LDL cholesterol levels with PCSK9 inhibition. The results of ongoing cardiovascular outcomes trials with PCSK9 monoclonal antibodies for primary prevention and with small interfering RNA to PCSK9 for secondary prevention may help to shape the use of this new therapeutic class.

Efficacy and safety of PCSK9 monoclonal antibodies: an evidence-based review and update

Objective

Treatment of dyslipidemia lowers cardiovascular (CV) risk. Although statin use is a cornerstone therapy, many patients are not achieving their risk-specific low-density lipoprotein cholesterol (LDL-C) goals. The proprotein convertase subtilisin/kexin type 9 (PCSK9) monoclonal antibodies have been extensively studied as lipid-lowering therapy (LLT). Herein, we present an updated evidence-based review of the efficacy and safety of PCSK9 monoclonal antibodies in the treatment of familial and non-familial hypercholesterolemia.

Methods

PubMed database was searched to review Phase III studies on PCSK9 monoclonal antibodies. Then, the US National Institutes of Health Registry and the WHO International Clinical Trial Registry Platform were searched to identify and present the ongoing research.

Results

PCSK9 monoclonal antibodies were investigated for the treatment of dyslipidemia, as a single therapeutic agent or as an add-on therapy to the traditional LLT. They proved effective and safe in the treatment of familial and non-familial hypercholesterolemia, and in the prevention of adverse CV events.

Conclusions

The use of PCSK9 monoclonal antibodies in the treatment of dyslipidemia is currently recommended to achieve risk-specific LDL-C goal to reduce adverse CV events. Future results of the ongoing research might expand their clinical generalizability to broader patient populations.

PCSK9 Inhibitors: From Nature’s Lessons to Clinical Utility

Background:

Proprotein convertase subtilisin-kexin type 9 (PCSK9) inhibitors are a novel class of non-statin lipid lowering therapy that reduce LDL-cholesterol by 50 - 60%. PCSK9 inhibitors decrease LDL-cholesterol by preventing intracellular degradation of LDL receptors; subsequently, a greater number of LDL-receptors are available on the cell surface to extract circulating LDL.

Objective:

To describe the origins of PCSK9 inhibitors and their current use in clinical practice.

Methods:

We performed a narrative review of the PCSK9 inhibitor class of drugs.

Results:

Current data indicate that PCSK9 inhibitors effectively reduce LDL-cholesterol and are well tolerated and safe. PCSK9 inhibitors have also been shown to reduce cardiovascular event rates in patients with stable atherosclerotic cardiovascular disease and in patients with a recent (up to one year) acute coronary syndrome. Given the costs, chronicity of the treatment and the potential budget impact, PCSK9 inhibitors are often limited to patients with the highest absolute risk for major adverse cardiovascular events despite optimal treatment with high-intensity statin and ezetimibe.

Conclusion:

PCSK9 inhibitors have a favorable safety, efficacy and tolerability profile. Postmarketing safety surveillance and real-world studies are needed to further support the long-term safety profile of this class of medicine.

Effects of evolocumab therapy and low LDL-C levels on vitamin E and steroid hormones in Chinese and global patients with type 2 diabetes

AIMS

We assessed the change from baseline in vitamin E, steroid hormones, adrenocorticotropic hormone (ACTH), and gonadotropins, overall and by lowest achieved low-density lipoprotein-cholesterol (LDL-C) level, in patients with type 2 diabetes and dyslipidaemia after 12 weeks of treatment with evolocumab.

MATERIALS AND METHODS

This was a prespecified analysis of vitamin E, cortisol, ACTH, gonadal hormones and gonadotropins in the 12-week, placebo-controlled BERSON trial of evolocumab in patients with type 2 diabetes and dyslipidaemia. In BERSON, 981 (451 in China) patients on daily atorvastatin 20 mg were randomized to placebo or one of two doses of evolocumab. We measured analyte levels at baseline and week 12 (vitamin E in all patients; steroid/gonadal hormones only in Chinese patients).

RESULTS

In both the global and Chinese populations, absolute vitamin E levels decreased from baseline to week 12 by approximately 6 μmol/L (P < .0001) among evolocumab-treated patients; however, when normalized for LDL-C, apoB or non-HDL-C, we observed no decrease in vitamin E levels. In Chinese patients, levels of cortisol and ACTH as well as the cortisol:ACTH ratio did not change significantly from baseline to week 12. No patient had a cortisol:ACTH ratio <3.0 (nmol/pmol), suggestive of adrenocortical deficiency. We did not observe clinically relevant changes for gonadal hormones and gonadotropins (oestradiol and testosterone in female and male patients, respectively, luteinizing and follicle-stimulating hormones for both).

CONCLUSIONS

In the BERSON study, evolocumab did not adversely affect vitamin E, steroid hormone or gonadotropin levels in the Chinese or global type 2 diabetic populations.ClinicalTrials.gov NCT02662569.

PCSK9 Monoclonal Antibodies: An Overview

PCSK9 monoclonal antibodies are novel lipid-lowering therapy that have been extensively studied in patients with hypercholesterolemia either as monotherapy or as an add-on to other LLTs. PCSK9 monoclonal antibodies have significantly reduced the low-density lipoprotein cholesterol (LDL-C) plasma level resulting in a better LDL-C goal attainment. The commercially available PCSK9 monoclonal antibodies, alirocumab and evolocumab, have demonstrated reductions in major adverse cardiovascular events such as myocardial infarction, stroke, unstable angina, and the need for coronary revascularization but not mortality. PCSK9 monoclonal antibodies have demonstrated a favorable safety profile. The most reported side effects are mild injection site with no causal relationship proven between the inhibition of PCSK9 and neurocognitive or glycemic adverse events. In this overview, the efficacy and safety of PCSK9 monoclonal antibodies in the treatment of primary and familial hypercholesterolemia will be discussed.

Short- and long-term effects of lipoprotein apheresis on plasma hormones in patients with therapy-resistant dyslipidemia

BACKGROUND AND AIMS

Lipoprotein apheresis (LA) is a highly effective method to improve the clinical and metabolic situation in patients with therapy-resistant disorders of lipid metabolism. Cholesterol is the substrate for the synthesis of all steroid hormones. If repeated massive reduction of LDL-cholesterol may interfere with human adrenal steroidogenesis, and could become clinically relevant is unknown, so far. Thus, the aim of this study was to determine possible short- and long-term effects of LA on blood plasma levels of ACTH, cortisol, aldosterone, DHEAS, renin and testosterone.

METHODS

In total, 39 patients, treated with one of four LA techniques were studied: 1. Lipid Filtration (LF; n = 7), 2. Dextran Sulfate Adsorption (DSA; n = 7), 3. Membrane Filtration Optimised Novel Extracorporeal Treatment (MONET; n = 8), and 4. Direct Absorption of Lipoproteins (DALI; n = 15). Hormone levels were analyzed before and after five LA sessions with an interval of 20 weeks covering a total observation time of two years. In addition patients were comprehensively characterized by clinical and laboratory data.

RESULTS

Patients treated with LA revealed an acute reduction of steroid hormones and ACTH, independent of apheresis technology but no long-term insufficiency in steroidogenesis was observed. Plasma renin levels were stable in LF patients and were highly elevated in patients under DSA, MONET and DALI apheresis throughout the observation period.

CONCLUSIONS

In summary, these data suggest that although different LA techniques considerably differ in their acute effects on hormone levels during LA, they did not alter long-term hormone levels sustainably.

Cholesterol-Lowering Agents

Loss-of-function variants in PCSK9 (proprotein convertase subtilisin-kexin type 9) are associated with lower lifetime risk of atherosclerotic cardiovascular disease) events. Confirmation of these genetic observations in large, prospective clinical trials in participants with atherosclerotic cardiovascular disease has provided guidance on risk stratification and enhanced our knowledge on hitherto unresolved and contentious issues concerning the efficacy and safety of markedly lowering LDL-C (low-density lipoprotein cholesterol). PCSK9 has a broad repertoire of molecular effects. Furthermore, clinical trials with PCSK9 inhibitors demonstrate that reductions in atherosclerotic cardiovascular disease events are more effective in patients with recent myocardial infarction, multiple myocardial infarctions, multivessel coronary artery disease, and lower extremity arterial disease. The potent LDL-C lowering efficacy of PCSK9 inhibitors provides the opportunity for more aggressive LDL-lowering strategies in high-risk patients with atherosclerotic cardiovascular disease and supports the notion that there is no lower limit for LDL-C. Aggressive LDL-C lowering with fully human PCSK9 monoclonal antibodies has been associated by a safety profile superior to that of other classes of LDL-lowering agents. These clinical trials provide evidence that LDL lowering with PCSK9 inhibitors is an effective therapy for lowering cardiovascular events in high-risk patients with LDL-C levels ≥70 mg/dL on maximally tolerated oral therapies, including statins and ezetimibe.

PCSK9 Inhibition: New Treatment Options and Perspectives to Lower Atherogenic Lipoprotein Particles and Cardiovascular Risk

PURPOSE OF REVIEW

To summarize latest clinical studies and to put them into perspectives for clinical relevant subgroups and new therapeutic options.

RECENT FINDINGS

Have investigated PCSK9 inhibitors in patients with very high cardiovascular risk and insufficient LDL cholesterol lowering under current maximal tolerated lipid-lowering therapy, patients with statin intolerance, or genetic forms of familiar hypercholesterolemia, and patients on LDL apheresis. Purpose of recent cardiovascular endpoint trials has proven cardiovascular benefit of this new approach. PCSK9 inhibition with fully humanized antibodies has proven to be effective, safe, and well-tolerated in reducing cardiovascular risk by LDL cholesterol lowering. Therefore, research interests are to elucidate additional roles and effects of PCSK9 modulation on inflammation and cellular processes of the atherosclerotic plaque and to develop alternative therapeutic strategies addressing PCSK9 as a proven and therefore promising drug target.

Low Density Lipoprotein (LDL) Cholesterol as a Causal Role for Atherosclerotic Disease: Potential Role of PCSK9 Inhibitors

Proprotein convertase subtilisin/kexin type 9 (PCSK9)-related discoveries of the turn of the century have translated into substantial novelty in dyslipidemia treatment in the last 5 years. With chronic preventable atherosclerotic cardiovascular diseases (ASCVD) representing an epidemic of morbidity and mortality worldwide, low-density lipoprotein cholesterol (LDL-c) reduction represents a public health priority. By overcoming two major statin-related issues, namely intolerance and ineffectiveness, PCSK9 inhibitors have offered a safe and effective option in selected clinical settings where LDL-c reduction is required. Herein, we recapitulate recent findings, clinical applications, and ASCVD prevention potential of PCSK9 inhibition, with focus on anti-PCSK9 monoclonal antibodies, evolocumab and alirocumab.

How Low to Go With Lipid-Lowering Therapies in a Cost-effective and Prudent Manner

The 2013 American College of Cardiology/American Heart Association guideline on the treatment of blood cholesterol was a landmark document guiding health care professionals around the globe on how to administer lipid-lowering therapies. Those guidelines were primarily focused on statin therapy benefit groups. The writing committee found insufficient evidence for specific low-density lipoprotein cholesterol (LDL-C) treatment targets. There have been many important updates in the lipid literature since the publication of that document. Most importantly, clinical trials have provided definitive evidence for the pivotal role of LDL-C in atherogenesis and the improvement in clinical outcomes by means of aggressive LDL-C reduction. Ezetimibe, evolocumab, and alirocumab treatment resulted in substantial reductions in major adverse cardiovascular outcomes. These data encourage a discussion on whether LDL-C targets are warranted in primary and/or secondary prevention, and if so, how low should those targets be. In order to answer such questions, the costs and safety of such therapies, as well as the safety of very low levels of LDL-C need to be addressed. This review discusses the relationship between LDL-C lowering and cardiovascular risk reduction, the efficacy, safety, and cost-effectiveness of high-intensity lipid-lowering therapies, and the recommendations from the most recent lipid guidelines.

PCSK9 Inhibitors: Clinical Relevance, Molecular Mechanisms, and Safety in Clinical Practice

Coronary artery disease (CAD) is one of the leading causes of mortality. High circulating levels of low-density lipoprotein (LDL) in the blood are associated with cardiovascular mortality, whether through an etiological role or through its association with the progression of CAD per se. Randomized clinical trials have shown that, when LDL levels are reduced, cardiovascular risk is also reduced, which reinforces this association. The first major trial involving a hypolipidemic agent of the statin family, the Scandinavian Simvastatin Survival Study (4S), was published in 1994 and found a significant reduction in mortality in patients at high cardiovascular risk. However, even in subsequent studies with different statins, a residual risk persisted, and this seems not to have changed over time; it is speculated that this risk may be due to statin intolerance. In this scenario, the potential exists for novel hypolipidemic agents to drive a true revolution in the therapy of dyslipidemia. The recent discovery of PCSK9 inhibitors (PCSK9i), a class of hypolipidemic monoclonal antibodies, is extremely promising. PCSK9 inhibition is capable of promoting a mean LDL reduction of up to 60%, with potential for very significant clinical repercussions, as every 38 mg/dL reduction in LDL appears to be associated with a 22% reduction in cardiovascular risk. This review addresses a brief history of PCSK9i, major trials of these drugs, cardiovascular outcomes, and aspects related to their efficacy and safety. Finally, the molecular mechanisms and possible pleiotropic effects of PCSK9i are also discussed.

Persistent Safety and Efficacy of Evolocumab in Patients with Statin Intolerance: a Subset Analysis of the OSLER Open-Label Extension Studies

PURPOSE

Evolocumab reduced low-density lipoprotein cholesterol (LDL-C) in 12-week trials in statin-intolerant patients (GAUSS-1 and GAUSS-2); however, the persistence of efficacy during longer-term treatment is unknown. This subset analysis of the open-label extension studies (OSLER-1 and OSLER-2) aimed to evaluate the safety and efficacy of evolocumab up to 2 years in statin-intolerant patients.

METHODS

Patients who completed GAUSS-1 and GAUSS-2 were enrolled in the OSLER studies and rerandomized 2:1 to evolocumab (140 mg biweekly or 420 mg monthly) plus standard of care (SOC) or SOC during year 1, and thereafter, evolocumab plus SOC.

RESULTS

A total of 382 statin-intolerant patients who completed the GAUSS-1 and GAUSS-2 parent studies were enrolled and rerandomized into the OSLER studies. After year 1, 246 (98%) patients randomized to evolocumab plus SOC and 124 (95%) on SOC during year 1 remained in the OSLER studies; after year 2, 364 (95%) remained on study. Mean parent study baseline LDL-C concentration was 4.97-5.02 mmol/L (192-194 mg/dL). The median percentage reduction from baseline in LDL-C was 13% for SOC and 57% for evolocumab plus SOC at year 1, and 59% for evolocumab plus SOC at year 2. The patient incidence of muscle-related adverse events during year 1 in the SOC and evolocumab plus SOC groups was 16% and 14%, respectively, and 11% for evolocumab plus SOC at year 2. No patient discontinued the study due to adverse events.

CONCLUSION

Evolocumab plus SOC was persistently safe, tolerable, and efficacious for up to 2 years in statin-intolerant patients.

Vascular Oxidative Stress: Impact and Therapeutic Approaches

Oxidative stress has been defined as an imbalance between oxidants and antioxidants and more recently as a disruption of redox signaling and control. It is generally accepted that oxidative stress can lead to cell and tissue injury having a fundamental role in vascular dysfunction. Physiologically, reactive oxygen species (ROS) control vascular function by modulating various redox-sensitive signaling pathways. In vascular disorders, oxidative stress instigates endothelial dysfunction and inflammation, affecting several cells in the vascular wall. Vascular ROS are derived from multiple sources herein discussed, which are prime targets for therapeutic development. This review focuses on oxidative stress in vascular physiopathology and highlights different strategies to inhibit ROS production.

Is lower low-density lipoprotein cholesterol associated with lower androgen and erectile dysfunction in men?

BACKGROUND AND AIMS

Therapeutic possibilities now exist to lower low-density lipoprotein cholesterol (LDL-C) to very low levels. However, substantial controversy remains in clinical practice with regard to its safety, and the question of whether low LDL-C levels per se may provoke adverse effects in humans arises. We aimed to explore the association of LDL-C with androgen and erectile dysfunction (ED) in a general population of men.

METHODS AND RESULTS

A total of 4203 men without hormone replacement therapy were enrolled from 22 sites in East China. Total testosterone (T) and Free T were assessed. Free androgen index (FAI) was calculated. The IIEF-5 questionnaire was used to assess ED. We found that free T and FAI gradually and markedly increased with increasing LDL-C levels. Using linear regression, after adjusting for age, educational level, economic status, smoking status, drinking status, BMI, diabetes, and use of lipid-lowering medication, LDL-C was positively associated with free T (B = 0.175, 95% CI: 0.084, 0.266) and FAI (B = 0.064, 95% CI: 0.016, 0.112). Meanwhile, there was a U-shaped curvilinear relationship between LDL-C and prevalence of ED. In the logistic regression analysis, compared to those with LDL-C among the 10th-90th percentile, the ORs of ED in men in the lowest and highest deciles were 1.938 (95% CI: 1.121, 3.349) and 1.804 (95% CI: 1.117, 2.916), respectively.

CONCLUSION

Lower LDL-C levels were significantly associated with lower free T and lower FAI in a general population of men. Moreover, both low and high levels of LDL-C might be risk factors for ED.

Inhibiting PCSK9 - biology beyond LDL control

Clinical trials have unequivocally shown that inhibition of proprotein convertase subtilisin/kexin type 9 (PCSK9) efficaciously and safely prevents cardiovascular events by lowering levels of LDL cholesterol. PCSK9 in the circulation is derived mainly from the liver, but the protein is also expressed in the pancreas, the kidney, the intestine and the central nervous system. Although PCSK9 modulates cholesterol metabolism by regulating LDL receptor expression in the liver, in vitro and in vivo studies have suggested that PCSK9 is involved in various other physiological processes. Although therapeutic PCSK9 inhibition could theoretically have undesired effects by interfering with these non-cholesterol-related processes, studies of individuals with genetically determined reduced PCSK9 function and clinical trials of PCSK9 inhibitors have not revealed clinically meaningful adverse consequences of almost completely eradicating PCSK9 from the circulation. The clinical implications of PCSK9 functions beyond lipid metabolism in terms of wanted or unwanted effects of therapeutic PCSK9 inhibition therefore appear to be limited. The objective of this Review is to describe the physiological role of PCSK9 beyond the LDL receptor to provide a rational basis for monitoring the effects of PCSK9 inhibition as these drugs gain traction in the clinic.

Adverse Events Associated With PCSK9 Inhibitors: A Real-World Experience

In randomized clinical trials (RCTs) proprotein convertase subtilisin/kexin 9 (PCSK9) inhibitors showed a favorable safety profile, however, “real‐world” data on adverse events (AEs) is scarce. Three datasets, a hospital registry (n = 164), and two Pharmacovigilance databases, Lareb (n = 149) and VigiLyze (n = 15,554), reporting AEs attributed to PCSK9 inhibitors (alirocumab or evolocumab) prescribed in clinical practice were analyzed. In the hospital registry, 41.5% of the patients reported any AE, most often injection‐site reactions (33.8%) and influenza‐like illness (27.9%). Twelve patients (7%) discontinued PCSK9 inhibitor treatment. Most common AE reported in the Lareb and VigiLyze database was myalgia (12.8% and 8.3%, respectively). No clinically relevant differences in gender or between drugs were observed. No specific subgroup of patients could be identified at risk of developing AEs. During follow‐up, AEs resolved in most patients (71.1%). In a real‐world setting, PCSK9 inhibitors are well tolerated with an overall safety profile comparable to RCTs.

Comparative Effects of PCSK9 (Proprotein Convertase Subtilisin/Kexin Type 9) Inhibition and Statins on Postprandial Triglyceride-Rich Lipoprotein Metabolism

Supplemental Digital Content is available in the text.

Objective—

Inhibition of PCSK9 (proprotein convertase subtilisin/kexin type 9) and statins are known to lower plasma LDL (low-density lipoprotein)-cholesterol concentrations. However, the comparative effects of these treatments on the postprandial metabolism of TRLs (triglyceride-rich lipoproteins) remain to be investigated.

Approach and Results—

We performed a 2-by-2 factorial trial of the effects of 8 weeks of subcutaneous evolocumab (420 mg every 2 weeks) and atorvastatin (80 mg daily) on postprandial TRL metabolism in 80 healthy, normolipidemic men after ingestion of an oral fat load. We evaluated plasma total and incremental area under the curves for triglycerides, apo (apolipoprotein)B-48, and VLDL (very-LDL)-apoB-100. We also examined the kinetics of apoB-48 using intravenous D3-leucine administration, mass spectrometry, and multicompartmental modeling. Atorvastatin and evolocumab independently lowered postprandial VLDL-apoB-100 total area under the curves (P<0.001). Atorvastatin, but not evolocumab, reduced fasting plasma apoB-48, apoC-III, and angiopoietin-like 3 concentrations (P<0.01), as well as postprandial triglyceride and apoB-48 total area under the curves (P<0.001) and the incremental area under the curves for plasma triglycerides, apoB-48, and VLDL-apoB-100 (P<0.01). Atorvastatin also independently increased TRL apoB-48 fractional catabolic rate (P<0.001) and reduced the number of apoB-48–containing particles secreted in response to the fat load (P<0.01). In contrast, evolocumab did not significantly alter the kinetics of apoB-48.

Conclusions—

In healthy, normolipidemic men, atorvastatin decreased fasting and postprandial apoB-48 concentration by accelerating the catabolism of apoB-48 particles and reducing apoB-48 particle secretion in response to a fat load. Inhibition of PCSK9 with evolocumab had no significant effect on apoB-48 metabolism.

Role of PCSK9 in lipid metabolism and atherosclerosis

Elevated plasma low-density lipoprotein cholesterol (LDL-C) is an important risk factor for cardiovascular diseases. Statins are the most widely used therapy for patients with hyperlipidemia. However, a significant residual cardiovascular risk remains in some patients even after maximally tolerated statin therapy. Proprotein convertase subtilisin/kexin type 9 (PCSK9) is a new pharmacologically therapeutic target for decreasing LDL-C. PCSK9 reduces LDL intake from circulation by enhancing LDLR degradation and preventing LDLR recirculation to the cell surface. Moreover, PCSK9 inhibitors have been approved for patients with either familial hypercholesterolemia or atherosclerotic cardiovascular disease, who require additional reduction of LDL-C. In addition, PCSK9 inhibition combined with statins has been used as a new approach to help reduce LDL-C levels in patients with either statin intolerance or unattainable LDL goal. This review will discuss the emerging anti-PCSK9 therapies in the regulation of cholesterol metabolism and atherosclerosis.

Population pharmacokinetics and exposure-response modeling and simulation for evolocumab in healthy volunteers and patients with hypercholesterolemia

Evolocumab, a novel human monoclonal antibody, inhibits proprotein convertase subtilisin/kexin type 9, a protein that targets low-density lipoprotein-cholesterol (LDL-C) receptors for the treatment of hyperlipidemia. The primary objective of this analysis was to characterize the population pharmacokinetics (popPK) and exposure-response relationship of evolocumab to assess if dose adjustment is needed across differing patient populations. Data were pooled for 5474 patients in 11 clinical studies who received evolocumab doses of 7-420 mg at various frequencies, either intravenously or subcutaneously. Evolocumab area under concentration-time curve from 8 to 12 weeks (AUC_wk8-12) was simulated for individuals using the popPK model and was used to predict the LDL-C response in relation to AUC_wk8-12. Evolocumab was eliminated through nonspecific (linear) and target-mediated (nonlinear) clearance. PopPK parameters and associated variabilities of evolocumab were similar to those of other monoclonal antibodies. The exposure-response model predicted a maximal 66% reduction in LDL-C from baseline to the mean of weeks 10 and 12 for doses of evolocumab 140 mg subcutaneously every 2 weeks or 420 mg subcutaneously once monthly. After inclusion of statistically significant covariates in an uncertainty-based simulation, LDL-C reduction from baseline at the mean of weeks 10 and 12 was predicted to be within 74% to 126% of the reference patient for all simulated patient groups. Evolocumab had nonlinear pharmacokinetics. The range of responses based on intrinsic and extrinsic factors was not predicted to be sufficiently different from the reference patient to warrant evolocumab dose adjustment.

Cardiovascular Outcomes of PCSK9 Inhibitors: With Special Emphasis on Its Effect beyond LDL-Cholesterol Lowering

PCSK9 inhibitors, monoclonal antibodies, are novel antihypercholesterolemic drugs. FDA first approved them in July 2015. PCSK9 protein (692-amino acids) was discovered in 2003. It plays a major role in LDL receptor degradation and is a prominent modulator in low-density lipoprotein cholesterol (LDL-C) metabolism. PCSK9 inhibitors are monoclonal antibodies that target PCSK9 protein in liver and inhibiting this protein leads to drastically lowering harmful LDL-C level in the bloodstream. Despite widespread use of the statin, not all the high-risk patients were able to achieve targeted level of LDL-C. Using PCSK9 inhibitors could lead to a substantial decrement in LDL-C plasma level ranging from 50% to 70%, either as a monotherapy or on top of statins. A large number of trials have shown robust reduction of LDL-C plasma level with the use of PCSK9 inhibitors as a monotherapy or in combination with statins in familial and nonfamilial forms of hypercholesterolemia. Moreover, PCSK9 inhibitors do not appear to increase the risk of hepatic and muscle-related side effects. PCSK9 inhibitors proved to be a highly potent and promising antihypercholesterolemic drug by decreasing LDL-R lysosomal degradation by PCSK9 protein. Statin drugs are known to have some pleiotropic effects. In this article, we are also focusing on the effects of PCSK9 inhibitor beyond LDL-C reduction like endothelial inflammation, atherosclerosis, its safety in patients with diabetes, obesity, and chronic kidney disease, and its influence on neurocognition and stroke.

Evolocumab: Considerations for the Management of Hyperlipidemia

PURPOSE OF REVIEW

To review the efficacy, safety, pharmacology, and pharmacokinetics of evolocumab, a proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitor.

RECENT FINDINGS

PCSK9 inhibitors are a class of lipid-lowering agents that significantly reduce low-density lipoprotein cholesterol (LDL-C) levels in patients with atherosclerotic cardiovascular disease and hyperlipidemia. Evolocumab is a monoclonal antibody that inhibits PCSK9 and has been evaluated in phase II and III studies as monotherapy, in combination with statins and other lipid-lowering therapies, in patients who are statin intolerant, and in patients with heterozygous and homozygous familial hypercholesterolemia. Data from these studies show that evolocumab significantly reduces LDL-C levels. Treatment with evolocumab also significantly improves levels of other lipid parameters (e.g., apolipoproteins A1 and B, lipoprotein(a), non-high-density lipoprotein cholesterol, and triglycerides). Recent results indicate that LDL-C reduction with evolocumab significantly reduces the risk of cardiovascular events and is also associated with atherosclerotic plaque regression. From a safety standpoint, rates of adverse events (AEs), serious AEs, and AEs leading to discontinuation were similar between evolocumab and controls in clinical trials, and no increase in AEs was observed when evolocumab was used in combination with statins. Patients with elevated LDL-C benefit from evolocumab treatment, suggesting that evolocumab could help meet an unmet medical need in high-risk patient populations with atherosclerotic cardiovascular disease and hyperlipidemia that are unable to reduce LDL-C levels sufficiently with statin therapy alone.

Clinical and pathophysiological evidence supporting the safety of extremely low LDL levels-The zero-LDL hypothesis

While the impact of very low concentrations of low-density lipoprotein cholesterol (LDL-C) on cardiovascular prevention is very reassuring, it is intriguing to know what effect these extremely low LDL-C concentrations have on lipid homoeostasis. The evidence supporting the safety of extremely low LDL levels comes from genetic studies and clinical drug trials. Individuals with lifelong low LDL levels due to mutations in genes associated with increased LDL-LDL receptor (LDLR) activity reveal no safety issues. Patients achieving extremely low LDL levels in the IMPROVE-IT and FOURIER, and the PROFICIO and ODYSSEY programs seem not to have an increased prevalence of adverse effects. The main concern regarding extremely low LDL-C plasma concentrations is the adequacy of the supply of cholesterol, and other molecules, to peripheral tissues. However, LDL proteomic and kinetic studies reaffirm that LDL is the final product of endogenous lipoprotein metabolism. Four of 5 LDL particles are cleared through the LDL-LDLR pathway in the liver. Given that mammalian cells have no enzymatic systems to degrade cholesterol, the LDL-LDLR pathway is the main mechanism for removal of cholesterol from the body. Our focus, therefore, is to review, from a physiological perspective, why such extremely low LDL-C concentrations do not appear to be detrimental. We suggest that extremely low LDL-C levels due to increased LDLR activity may be a surrogate of adequate LDL-LDLR pathway function.