Efficacy and Safety of Alirocumab 150 mg Every 4 Weeks in Patients With Hypercholesterolemia Not on Statin Therapy: The ODYSSEY CHOICE II Study

A rare case of alirocumab (PCSK9 inhibitor)-associated acute interstitial nephritis

Acute interstitial nephritis (AIN) is a common cause of hospital-acquired acute kidney injury (AKI) [1]. The most common cause of AIN is drug-induced AIN, which accounts for 60 - 70% of cases [2]. Alirocumab, a proprotein convertase subtilisin/kexin type 9 inhibitor (PCSK9 inhibitor) is a monoclonal antibody that lowers low-density lipoprotein-C levels by inhibiting the PCSK9 protein [3]. Common adverse events reported with alirocumab include injection-site reactions, myalgia, neurocognitive disorders, and ophthalmologic disorders [4]. There is paucity of data, with few reported cases of AKI, mostly in the form of acute tubular necrosis (ATN) associated with alirocumab [5]. In this article, we present a novel case of AIN associated with the use of alirocumab.

Efficacy and safety of ongericimab given by prefilled syringe or autoinjector in primary hypercholesterolemia and mixed hyperlipidemia

BACKGROUND AND AIMS

Limited evidence exist regarding the association between ongericimab, a novel recombinant humanized anti-PCSK9 monoclonal antibody, and primary hypercholesterolemia and mixed dyslipidemia. This study aimed to evaluate the efficacy and safety of ongericimab administered by prefilled syringe (PFS) or autoinjector (AI) in Chinese patients with primary hypercholesterolemia and mixed dyslipidemia on stable optimized lipid-lowering therapy.

METHODS AND RESULTS

A total of 255 patients on stable optimized lipid-lowering therapy were randomized in a 2:1:2:1 ratio to receive PFS for the subcutaneous injection of ongericimab 150 mg every 2 weeks (Q2W) or a matching placebo, or AI for the subcutaneous injection of ongericimab 150 mg Q2W or a matching placebo. The primary efficacy endpoint was the percent change in low-density lipoprotein cholesterol (LDL-C) levels from baseline to week 12. Safety was also evaluated. At week 12, the least squares mean percent changes were -72.7% (3.9%) for PFS and -71.1% (3.8%) for AI (all P < 0.001) compared to respective matching placebo groups. Beneficial effects were also seen for all secondary lipid parameters, notably with robust reduction in Lp (a). Treatment-emergent adverse events (TEAEs) and serious AEs with ongericimab were reported in 46.2% and 2.4% of patients, compared to 44.2% and 3.5% with placebo.

CONCLUSION

In Chinese patients with primary hypercholesterolemia and mixed dyslipidemia, a 12-week treatment regimen with ongericimab administered by PFS or AI significantly reduced LDL-C and other lipid parameters, proving to be safe and well tolerated. Patients experienced consistent effects from PFS or AI devices.

CLINICAL TRIAL REGISTRATION

CTR20220027; January 11, 2022; http://www.chinadrugtrials.org.cn/index.html.

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].

Postmarketing Reports of Incomplete Dosing-Related Complications with Self-Injected PCSK9 Inhibitors: A Descriptive Study and Disproportionality Analysis

BACKGROUND

Evolocumab and alirocumab are self-injected proprotein convertase subtilisin kexin type 9 (PCSK9) inhibitors indicated for low-density lipoprotein cholesterol reduction. Complications in the use or functionality of self-injection devices may precipitate incomplete dosing.

OBJECTIVE

This study sought to characterize postmarketing dosing failure reports involving self-injected PCSK9 inhibitors.

METHODS

US Food and Drug Administration Adverse Event Reporting System (FAERS) [2016-second quarter of 2023] data were utilized for a disproportionality analysis. Eight self-injected comparator medications served as referents. Medical Dictionary for Regulatory Activities preferred terms indicating explicit or probable failure to administer a complete dose classified cases. Proportional reporting ratios (PRRs) > 2.0 and lower 95% confidence intervals (CIs) > 1.0 indicated disproportionality signals. US FDA Manufacturer and User Facility Device Experience (MAUDE) [2013-2023] data underwent a narrative review.

RESULTS

During the study period, 194,781 (evolocumab, n = 152,831; alirocumab, n = 41,950) drug-event pairs and 43,725 (evolocumab, n = 38,489; alirocumab, n = 5236) cases reported to FAERS identified PCSK9 inhibitors. MAUDE contained six evolocumab reports, half describing dose omission, and no alirocumab reports. A potential dosing failure signal was detected for evolocumab (PRR 2.01; 95% CI 1.98-2.03), but not alirocumab (PRR 0.99; 95% CI 0.97-1.02), relative to pooled comparator reports. Across three case term subcategories, incomplete dosing disproportionality signals were further identified for evolocumab patient usage complication terms (PRR 3.44; 95% CI 3.38-3.50) and alirocumab device malfunction terms (PRR 2.09; 95% CI 1.98-2.22).

CONCLUSIONS

Proprotein convertase subtilisin kexin type 9 inhibitor incomplete dosing-related complications are frequently reported in the postmarketing setting. Systematic efforts to understand the incidence and mechanisms of dosing failure and associated patient burdens are needed.

Quantitative assessment of baseline imbalances in evolocumab and alirocumab trials: a meta-epidemiological study

BACKGROUND

Baseline imbalances have been identified in randomized trials of evolocumab and alirocumab. Our aim was to quantitatively assess (1) the presence of systematic baseline differences, and (2) the relationship of baseline differences with effects on low-density lipoprotein-cholesterol (LDL-c) and clinical outcomes in the trials.

METHODS

We performed a meta-epidemiological study. PubMed, Embase, regulatory reports, ClinicalTrials.gov and company websites were searched for trials. Seven baseline characteristics (mean age, LDL-c, BMI, percentage males, diabetics, smokers, and hypertensives) and five outcomes (LDL-c, major adverse cardiac events, serious adverse events, any adverse events, all-cause mortality) were extracted. We calculated (1) range and distribution of baseline imbalances (sign-test), (2) pooled baseline differences and heterogeneity (meta-analysis), (3) differences in SDs around continuous variables (sign-test and pooling), and (4) the relationship of baseline differences with outcomes (meta-regression). The comparisons of PCSK9-inhibitor groups with either placebo or ezetimibe were analysed separately and combined.

RESULTS

We identified 43 trials with 63,193 participants. Baseline characteristics were frequently missing. Many trials showed small baseline imbalances, but some large imbalances. Only baseline BMI showed a statistically significant lower pooled mean for the drug versus placebo groups (MD -0.16; 95% CI -0.24 to -0.09). Heterogeneity in baseline imbalances was present in six placebo- and five ezetimibe-comparisons. Heterogeneity was statistically significant for BMI, males, diabetics and hypertensives in the combined comparisons. There was a statistically significant preponderance for larger SDs in the PCSK9-inhibitor versus control groups (sign-test age 0.014; LDL-c 0.014; BMI 0.049). Meta-regression showed clinically relevant relationships of baseline imbalances in age, BMI and diabetics with the risk of any adverse events and the risk of mortality. Two relationships were statistically significant: A higher mean BMI in the drug versus control group with a decreased risk of mortality (beta - 0.56; 95% CI -1.10 to -0.02), and a higher proportion of diabetics with an increased risk of any adverse events (beta 0.02; 95% 0.01 to 0.04).

CONCLUSIONS

Heterogeneous baseline imbalances and systematically different SDs were present in evolocumab and alirocumab trials, so study groups cannot be assumed to be comparable. These findings raise concerns about the design and conduct of the randomization procedures.

Sex Differences in Cardiovascular Outcomes and Cholesterol-Lowering Efficacy of PCSK9 Inhibitors: Systematic Review and Meta-Analysis

Background

Guideline-recommended low-density lipoprotein cholesterol (LDL-C) thresholds are often not achieved in women. The proprotein convertase subtilisin/kexin type-9 inhibitor (PCSK9i) monoclonal antibodies can help further reduce LDL-C and major adverse cardiovascular events (MACE) although differences in efficacy by sex and type are less understood.

Objectives

The authors sought to determine if there are differences in the efficacy of LDL-C lowering and reduction in the risk of MACE by sex and type of PCSK9i.

Methods

A comprehensive literature search was done through October 17, 2022, for published trials comparing PCSK9i vs control. Outcomes assessed were LDL-C reduction and incidence of MACE following the use of PCSK9i vs placebo, stratified by sex and type of PCSK9i used.

Results

We identified 16 trials with 54,996 adults, and 15,143 (27.5%) of them were female. PCSK9i significantly reduced MACE compared to placebo in both women (HR: 0.86, 95% CI: 0.74-0.97, P < 0.001) and men (HR: 0.85, 95% CI: 0.79-0.91, P < 0.001) with no significant sex difference (MD -0.01, 95% CI: -0.14 to -0.13, P = 0.930). PCSK9i also significantly reduced LDL-C levels in both sexes at 12 weeks (females: MD -62.57, 95% CI: -70.24 to -54.91, P < 0.001; males: MD -66.19, 95% CI: -72.03 to -60.34, P < 0.001) and 24 weeks (females: MD -47.52, 95% CI: -52.94 to -42.09, P < 0.001; males: MD -54.07, 95% CI: -59.46 to -48.68, P < 0.001). Significant sex difference was seen in the LDL reduction of PCSK9i for both 12 weeks (males vs females: MD -4.55, 95% CI: -7.34 to -1.75, P < 0.01) and 24 weeks (males vs females: MD -7.11, 95% CI: -9.99 to -4.23, P < 0.001).

Conclusions

The use of PCSK9i results in significant LDL-C and MACE reduction in both males and females. While there is no significant sex difference in MACE reduction, LDL-C reduction is greater in males than in females. Our data support the equal use of PCSK9i in all eligible patients, regardless of sex.

PCSK-9 Inhibitors and Cardiovascular Outcomes: A Systematic Review With Meta-Analysis

Proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors have been approved to treat dyslipidaemia. However, there is a lack of knowledge on the most efficient PCSK9 therapies that target PCSK9 for secondary prevention in subjects at high risk for cardiovascular (CV) events. Thus, this study aimed to assess the efficacy and safety of anti-PCSK9 antibodies in randomized controlled trials (RCTs). A comprehensive review of the available literature was done to identify RCTs that compared the use of PCSK9 inhibitors coupled with placebo or ezetimibe for the secondary prevention of CV events in patients on statin-background therapy. All-cause mortality was the major efficacy endpoint, while severe adverse events were the key safety outcome. A random effects model was used, and data were presented as risk ratio (RR) or risk difference with their corresponding 95% confidence intervals (CI). The heterogeneity of the publications was determined using Cochran's Q test, and publication bias was visually examined using funnel plots. All the chosen studies' quality was assessed using the Critical Appraisal Checklists for Studies created by the Joanna Briggs Institute (JBI). Forty-one studies (76,304 patients: 49,086 on evolocumab, and 27,218 on alirocumab) were included, and their years of publication spanned from 2010 to 2023. Overall, no significant differences were observed in CV and all-cause mortality between PCSK9 inhibitors and controls. However, alirocumab use was linked to a reduced risk of all-cause death compared to control, but not evolocumab. Each of the drugs, evolocumab and alirocumab, significantly reduced the risk of myocardial infarction (MI), coronary revascularization, and ischemic stroke. In comparison to the control therapy, the risk of major detrimental sequelae was significantly reduced by alirocumab therapy in the subgroup analysis of each PCSK9 inhibitor, whereas evolocumab treatment did not demonstrate significant differences (RR = 0.88; 95% CI = 0.72-1.04; evolocumab: RR = 0.99; 95% CI = 0.87-1.11). Both evolocumab and alirocumab are well-tolerated, safe medications that significantly lower low-density lipoprotein (LDL) levels.

Effect of Different Types and Dosages of Proprotein Convertase Subtilisin/Kexin Type 9 Inhibitors on Lipoprotein(a) Levels: A Network Meta-analysis

ABSTRACT

Lipoprotein(a) [Lp(a)] has become an important component of the residual risk of cardiovascular diseases. Proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors display promising effects in controlling Lp(a) levels. However, the effects of different types and dosages of PCSK9 inhibitors on Lp(a) have not been studied in detail. These include 2 monoclonal antibodies, alirocumab and evolocumab, and inclisiran, a small interfering RNA. We searched PubMed, Web of Science, Embase, and Cochrane Library for randomized controlled trials to investigate the efficacy of PCSK9 inhibitors at the Lp(a) level. Although changes in Lp(a) levels were not the primary endpoint in any of these studies, they all described these valuable data. Forty-one randomized controlled trials with 17,601 participants were included, involving 23 unduplicated interventions. Most PCSK9 inhibitors significantly reduced Lp(a) levels compared with placebo. The pairwise comparison demonstrated no significant difference among most PCSK9 inhibitors. However, in the comparison among different dosages of alirocumab, the dosage of 150 mg Q2W showed a significant reduction in Lp(a) levels compared with the dosages of 150, 200, and 300 mg Q4W. In addition, the comparison results demonstrated the significant efficacy of evolocumab 140 mg Q2W compared with alirocumab at a dosage of 150 mg Q4W. The cumulative rank probabilities demonstrated that evolocumab 140 mg Q2W showed the highest efficacy. This study showed that PCSK9 inhibitors reduced Lp(a) levels by up to 25.1%. A biweekly dose of either 140 mg evolocumab or 150 mg alirocumab was the best treatment option. However, the reduction in Lp(a) levels with a single kind of PCSK9 inhibitor alone did not demonstrate sufficient clinical benefit. Therefore, for patients with very high Lp(a) levels who remain at high residual risk in the context of statin administration, it may be acceptable to use a kind of PCSK9 inhibitor, but the clinical benefit needs further investigation.

Soluble PCSK9 Inhibition: Indications, Clinical Impact, New Molecular Insights and Practical Approach-Where Do We Stand?

Current research on cardiovascular prevention predominantly focuses on risk-stratification and management of patients with coronary artery disease (CAD) to optimize their prognosis. Several basic, translational and clinical research efforts aim to determine the etiological mechanisms underlying CAD pathogenesis and to identify lifestyle-dependent metabolic risk factors or genetic and epigenetic parameters responsible for CAD occurrence and/or progression. A log-linear association between the absolute exposure of LDL cholesterol (LDL-C) and the risk of atherosclerotic cardio-vascular disease (ASCVD) was well documented over the year. LDL-C was identified as the principal enemy to fight against, and soluble proprotein convertase subtilisin kexin type 9 (PCSK9) was attributed the role of a powerful regulator of blood LDL-C levels. The two currently available antibodies (alirocumab and evolocumab) against PCSK9 are fully human engineered IgG that bind to soluble PCSK9 and avoid its interaction with the LDLR. As documented by modern and dedicated "game-changer" trials, antibodies against soluble PCSK9 reduce LDL-C levels by at least 60 percent when used alone and up to 85 percent when used in combination with high-intensity statins and/or other hypolipidemic therapies, including ezetimibe. Their clinical indications are well established, but new areas of use are advocated. Several clues suggest that regulation of PCSK9 represents a cornerstone of cardiovascular prevention, partly because of some pleiotropic effects attributed to these newly developed drugs. New mechanisms of PCSK9 regulation are being explored, and further efforts need to be put in place to reach patients with these new therapies. The aim of this manuscript is to perform a narrative review of the literature on soluble PCSK9 inhibitor drugs, with a focus on their indications and clinical impact.

Atherogenic Dyslipidemias: Unmet Needs and the Therapeutic Potential of Emerging and Novel Approaches and Drugs

Innovative lipid-modifying agents are valuable resources to improve the control of atherogenic dyslipidemias and reduce the lipid-related residual cardiovascular risk of patients with intolerance or who are not fully responsive to a consolidated standard of care (statins plus ezetimibe). Moreover, some of the upcoming compounds potently affect lipid targets that are thus far considered "unmodifiable". The present paper is a viewpoint aimed at presenting the incremental metabolic and cardiovascular benefits of the emerging lipid-modulating agents and real-life barriers, hindering their prescription by physicians and their assumption by patients, which need to be worked out for a more diffuse and appropriate drug utilization.

An Updated Meta-Analysis for Safety Evaluation of Alirocumab and Evolocumab as PCSK9 Inhibitors

Background

Alirocumab and evolocumab, as protein convertase subtilisin kexin type 9 (PCSK9) inhibitors, have been reported to reduce cardiovascular risk. This meta-analysis is aimed at updating the safety data of PCSK9 inhibitors.

Methods

We assessed the relative risk for all treatment-related adverse events, serious adverse events, diabetes-related adverse events, and neurocognitive and neurologic adverse events with PCSK9 inhibitors compared to controls (placebo or ezetimibe). In addition, we conducted a meta-analysis to quantitatively integrate and estimate the adverse event rates in long-term studies.

Results

There were no significant differences between PCSK9 inhibitors and controls in the relative risk analysis. In a subgroup analysis of each PCSK9 inhibitor, alirocumab treatment significantly reduced the risk of serious adverse events compared to control treatment (risk ratio (RR) = 0.937; 95% confidence interval (CI), 0.896-0.980), but no significant difference was observed with evolocumab treatment (RR = 1.003; 95% CI, 0.963-1.054). Moreover, alirocumab treatment afforded a significant reduction in the risk of diabetes-related adverse events compared to control treatment (RR = 0.9137; 95% CI, 0.845-0.987). The overall incidence (event rate) of long-term adverse events was 75.1% (95% CI, 71.2%-78.7%), and the incidence of serious long-term event rate was 16.2% (95% CI, 11.6%-22.3%).

Conclusions

We suggest that alirocumab and evolocumab are generally safe and well tolerated and that their addition to background lipid-lowering therapy is not associated with an increased risk of adverse events or toxicity.

A cVLP-Based Vaccine Displaying Full-Length PCSK9 Elicits a Higher Reduction in Plasma PCSK9 Than Similar Peptide-Based cVLP Vaccines

Administration of PCSK9-specific monoclonal antibodies, as well as peptide-based PCSK9 vaccines, can lower plasma LDL cholesterol by blocking PCSK9. However, these treatments also cause an increase in plasma PCSK9 levels, presumably due to the formation of immune complexes. Here, we utilize a versatile capsid virus-like particle (cVLP)-based vaccine platform to deliver both full-length (FL) PCSK9 and PCSK9-derived peptide antigens, to investigate whether induction of a broader polyclonal anti-PCSK9 antibody response would mediate more efficient clearance of plasma PCSK9. This head-to-head immunization study reveals a significantly increased capacity of the FL PCSK9 cVLP vaccine to opsonize and clear plasma PCSK9. These findings may have implications for the design of PCSK9 and other vaccines that should effectively mediate opsonization and immune clearance of target antigens.

Network Meta-Analysis of Randomized Trials Evaluating the Comparative Efficacy of Lipid-Lowering Therapies Added to Maximally Tolerated Statins for the Reduction of Low-Density Lipoprotein Cholesterol

Background Lowering low-density lipoprotein cholesterol (LDL-C) levels decreases major cardiovascular events and is recommended for patients at elevated cardiovascular risk. However, appropriate doses of statin therapy are often insufficient to reduce LDL-C in accordance with current guidelines. In such cases, treatment could be supplemented with nonstatin lipid-lowering therapy. Methods and Results A systematic literature review and network meta-analysis were conducted on randomized controlled trials of nonstatin lipid-lowering therapy added to maximally tolerated statins, including statin-intolerant patients. The primary objective was to assess relative efficacy of nonstatin lipid-lowering therapy in reducing LDL-C levels at week 12. Secondary objectives included the following: LDL-C level reduction at week 24 and change in non-high-density lipoprotein cholesterol and apolipoprotein B at week 12. There were 48 randomized controlled trials included in the primary network meta-analysis. All nonstatin agents significantly reduced LDL-C from baseline versus placebo, regardless of background therapy. At week 12, evolocumab, 140 mg every 2 weeks (Q2W)/420 mg once a month, and alirocumab, 150 mg Q2W, were the most efficacious regimens, followed by alirocumab, 75 mg Q2W, alirocumab, 300 mg once a month, inclisiran, bempedoic acid/ezetimibe fixed-dose combination, and ezetimibe and bempedoic acid used as monotherapies. Primary end point results were generally consistent at week 24, and for other lipid end points at week 12. Conclusions Evolocumab, 140 mg Q2W/420 mg once a month, and alirocumab, 150 mg Q2W, were consistently the most efficacious nonstatin regimens when added to maximally tolerated statins to lower LDL-C, non-high-density lipoprotein cholesterol, and apolipoprotein B levels and facilitate attainment of guideline-recommended risk-stratified lipoprotein levels.

PCSK9 Inhibitors in the Management of Cardiovascular Risk: A Practical Guidance

Proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors are potent medications in the toolkit for treatment of atherosclerotic cardiovascular disease. These agents have been well studied in clinical trials supporting their efficacy in dramatically reducing low-density lipoprotein cholesterol (LDL-C) and impact on cardiovascular outcomes. Since the approval of commercial use for PCSK9 inhibitors in 2015, we have also gained significant experience in the use of these therapeutics in the real-world setting. In this article, we review current guideline recommendations, clinical trial evidence on efficacy and safety as well as data on cost-effectiveness, prescription and adherence. We focus primarily on the monoclonal antibody class of PCSK9 inhibitors in this review while also touching on other types of therapeutics that are under development.

LDL-C calculated by Friedewald, Martin-Hopkins, or NIH equation 2 versus beta-quantification: pooled alirocumab trials

Accurate assessment of LDL-C levels is important, as they are often used for treatment recommendations. For many years, plasma LDL-C levels were calculated using the Friedewald equation, but there are limitations to this method compared with direct measurement via beta-quantification (BQ). Here, we assessed differences between the Friedewald, Martin-Hopkins, and NIH equation 2 methods of calculating LDL-C and the "gold standard" BQ method using pooled phase 3 data with alirocumab. All randomized patients were included irrespective of the treatment arm (n = 6,122). We compared pairs of LDL-C values (n = 17,077) determined by each equation and BQ. We found that BQ-derived LDL-C values ranged from 1 to 397 mg/dl (mean 90.68 mg/dl). There were strong correlations between Friedewald-calculated, Martin-Hopkins-calculated, and NIH equation 2-calculated LDL-C with BQ-determined LDL-C values (Pearson's correlation coefficient = 0.985, 0.981, and 0.985, respectively). Importantly, for BQ-derived LDL-C values ≥70 mg/dl, only 3.2%, 1.4%, and 1.8% of Friedewald-calculated, Martin-Hopkins-calculated, and NIH equation 2-calculated values were <70 mg/dl, respectively. When triglyceride (TG) levels were <150 mg/dl, differences between calculated and BQ-derived LDL-C values were minimal, regardless of the LDL-C level (<40, <55, or <70 mg/dl). However, when TG levels were >150 mg/dl, NIH equation 2 provided greater accuracy than Friedewald or Martin-Hopkins. When TGs were >250 mg/dl, inaccuracies were seen with all three methods, although NIH equation 2 remained the most accurate. In conclusion, LDL-C calculated by any of the three methods can guide treatment decisions for most patients, including those treated with proprotein convertase subtilisin/kexin type 9 inhibitors.

Efficacy and Safety of PCSK9 Inhibitors in Stroke Prevention

Proprotein convertase subtilisin/kexin type 9 (PCSK9) interacts with the low-density lipoprotein (LDL) receptor and, by enhancing its degradation, has a pivotal role in the regulation of cholesterol homeostasis. Two fully humanized monoclonal antibodies targeting PCSK9, evolocumab and alirocumab, are available for clinical use. PCSK9 inhibitors reduce LDL-C 30% more than ezetimibe and 60% more than placebo when added to statins. This reduction in LDL-C is accompanied by a decrease in the risk of major cardiovascular and cerebrovascular events. However, questions have been raised in relation to the cost-effectiveness of these medications. In this article, we review the clinical evidence on the use of PCSK9 inhibitors in lowering LDL-C and their effect on cerebrovascular health.

PCSK9 Inhibitors and Cardiovascular Disease: Impact on Cardiovascular Outcomes

Cardiovascular Disease (CVD) remains the leading cause of morbidity and mortality in the western world. Hypolipidemic drugs have long been used for the primary and secondary prevention of heart disease. However, the high frequency of recurrent events in patients despite hypolipidemic therapy has increased the need for new more targeted therapeutic approaches. Proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors are monoclonal antibodies to the PCSK9 gene and represent a new class of drugs that have been shown to further decrease LDL-C when administered as a monotherapy or in combination with statins. In addition to LDL reduction, PCSK9 inhibitors are shown to decrease apolipoprotein B and lipoprotein (a) levels without major adverse effects. Whether or not PCSK9 inhibitors can actually reduce the incidence of cardiovascular events and ameliorate CVD prognosis is yet to be clarified. This review summarizes recent literature on the safety and efficacy of PCSK9 inhibitors on CVD outcome and its potential role in the management of patients with high-risk cardiovascular disease.

Meta-analysis of randomized clinical trials comparing PCSK9 monoclonal antibody versus ezetimibe/placebo in patients at high cardiovascular risk

BACKGROUND AND AIMS

Proprotein convertase subtilisin/kexin type 9 monoclonal antibodies (PCSK9 mAbs) reduce circulating low-density lipoprotein cholesterol (LDL-C) by controlling the expression of LDL-receptor on the surface of hepatocytes. This meta-analysis aimed at evaluating the efficacy of PCSK9 mAbs on clinical and lipid-lowering outcomes.

METHODS

PubMed, Embase, and ClinicalTrials.gov were searched from inception until November 2020 for randomized controlled trials (RCTs) that compared PCSK9 mAbs with ezetimibe or placebo in patients at high cardiovascular risk.

RESULTS

Twenty eight RCTs with a total of 89,115 participants were included. Compared with placebo, PCSK9 mAbs significantly reduced the risk of major adverse cardiac events (MACEs) (RR 0.83, 95% CI 0.79 to 0.88, p < 0.00001). However, no difference was observed in occurring MACEs between PCSK9 mAbs and ezetimibe (RR 0.70, 95% CI 0.40 to 1.20, p = 0.20). Secondary analyses show that PCSK9 mAbs were not superior to ezetimibe in preventing stroke (RR 0.38, 95% CI 0.09 to 1.69, p = 0.20), myocardial infarction (RR 0.95, 95% CI 0.47 to 1.90, p = 0.88), and cardiovascular death (RR 0.44, 95% CI 0.14 to 1.43, p = 0.17). Compared with placebo, PCSK9 mAbs significantly reduced the incidence of stroke (RR 0.75, 95% CI 0.66 to 0.86, p < 0.0001) and myocardial infarction (RR 0.81, 95% CI 0.76 to 0.87, p < 0.00001), but not the risk of cardiovascular death (RR 0.96, 95% CI 0.86 to 1.07, p = 0.45). As for lipid-lowering efficacy, PCSK9 mAbs markedly reduced percent change of LDL-C from baseline to week 12 and 24 compared to ezetimibe or placebo.

CONCLUSIONS

In patients at high cardiovascular risk, PCSK9 mAbs could effectively reduce MACEs, stroke, and myocardial infarction compared with placebo. However, PCSK9 mAbs were not superior to ezetimibe in preventing adverse cardiovascular events in our study; RCTs with long-term follow-up and cardiovascular events as the research endpoint are still needed.

Proprotein Convertase Subtilisin/Kexin Type 9 (PCSK9) inhibitors and the risk for neurocognitive adverse events: A systematic review, meta-analysis and meta-regression

BACKGROUND

It has been suggested that lipid lowering therapy causes impaired cognitive changes. The association between the use of Proprotein Convertase Subtilisin/Kexin Type 9 (PCSK9) inhibitors and the risk of neurocognitive adverse events remains unclear. This meta-analysis aims to assess neurocognitive safety of PCSK9 inhibitors in randomized controlled trials (RCTs).

METHODS AND RESULTS

The research was conducted according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). PubMed (MEDLINE), Embase and Cochrane library were searched through September 2019. Selection criteria included RCTs that addressed to neurocognitive adverse events of participants using Alirocumab, Evolocumab or Bococizumab, with a follow up duration of at least 6 months. The search results were screened by two independent reviewers. Safety data from included papers were extracted. Random effects meta-analysis was used to pool results, and meta-regression was utilized when applicable. Twenty-one studies were included. Among 59,733 patients, 31,611 were treated with PCSK9 inhibitors. The follow-up period ranged from 24 weeks to 48 months. No significant difference in the incidence of neurocognitive adverse effects between the groups was identified (RR = 1.01, 95% CI: 0.86-1.19, I² = 3%). Similar results were seen in subgroup analysis for each of the medications (alirocumab- RR = 0.88, 95% CI: 0.72-1.08, I² = 0%, evolocumab- RR = 1.42, 95% CI: 0.74-2.73, I² = 55%). A meta-regression analysis for evolocumab revealed that prolonged study duration was associated with decreased risk for neurocognitive adverse events (β_week = -0.0037, p-value = 0.03).

CONCLUSIONS

Pooled results of our meta-analysis and meta-regression show that exposure to PCSK9 inhibitors is not associated with an increased risk of neurocognitive adverse effects.

Lipoprotein(a) Reduction With Proprotein Convertase Subtilisin/Kexin Type 9 Inhibitors: A Systematic Review and Meta-analysis

ABSTRACT

Lipoprotein(a) [Lp(a)] is a cardiovascular factor, for which there is no approved specific lowering treatment. Proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors have been shown to have lowering effects on Lp(a). Aim of this systematic review is to synthesize the current literature and quantify the effects of PCSK9 inhibitors on the serum Lp(a) levels in human subjects. Double-blind, phase 2 or 3, randomized-controlled trials comparing PCSK9 inhibitors (alirocumab or evolocumab) to placebo and/or ezetimibe and/or other lipid-lowering therapy were deemed eligible for inclusion. We searched MEDLINE (via PubMed), CENTRAL, Scopus, and Web of Science as of 17 June 2020. Quality assessment was performed using the Revised Cochrane risk-of-bias tool for randomized trials. Forty-three studies were identified (64,107 patients randomized) and 41 studies were included in the quantitative analysis. PCSK9 inhibitors reduced Lp(a) levels by -26.7% (95% CI, -29.5% to -23.9%) with a significant heterogeneity within studies. There was significant difference in Lp(a) change from baseline according to comparator (placebo: mean -27.9%; 95% CI, -31.1% to -24.6% vs. ezetimibe: mean, -22.2%; 95% CI, -27.2% to -17.2%; P = 0.04) and duration of treatment (≤12 weeks: mean, -30.9%; 95% CI, -34.7% to -27.1% vs. >12 weeks: mean, -21.9%; 95% CI, -25.2% to -18.6%; P < 0.01). Meta-regression analysis showed that only the mean percentage change from baseline low-density lipoprotein cholesterol due to the intervention is significantly associated with the effect size difference (P < 0.0001). PCSK9 inhibitors reduced low-density lipoprotein cholesterol by -54% (95% CI -57.6% to -50.6%). There is substantial efficacy of the currently approved PCSK9 inhibitors in the lowering of Lp(a) levels. Dedicated randomized controlled trials are needed to establish the benefit of this intervention.

PCSK9 monoclonal antibodies for the primary and secondary prevention of cardiovascular disease

BACKGROUND

Despite the availability of effective drug therapies that reduce low-density lipoprotein (LDL)-cholesterol (LDL-C), cardiovascular disease (CVD) remains an important cause of mortality and morbidity. Therefore, additional LDL-C reduction may be warranted, especially for people who are unresponsive to, or unable to take, existing LDL-C-reducing therapies. By inhibiting the proprotein convertase subtilisin/kexin type 9 (PCSK9) enzyme, monoclonal antibodies (PCSK9 inhibitors) reduce LDL-C and CVD risk.

OBJECTIVES

Primary To quantify the effects of PCSK9 inhibitors on CVD, all-cause mortality, myocardial infarction, and stroke, compared to placebo or active treatment(s) for primary and secondary prevention. Secondary To quantify the safety of PCSK9 inhibitors, with specific focus on the incidence of influenza, hypertension, type 2 diabetes, and cancer, compared to placebo or active treatment(s) for primary and secondary prevention.

SEARCH METHODS

We identified studies by systematically searching CENTRAL, MEDLINE, Embase, and Web of Science in December 2019. We also searched ClinicalTrials.gov and the International Clinical Trials Registry Platform in August 2020 and screened the reference lists of included studies. This is an update of the review first published in 2017.

SELECTION CRITERIA

All parallel-group and factorial randomised controlled trials (RCTs) with a follow-up of at least 24 weeks were eligible.

DATA COLLECTION AND ANALYSIS

Two review authors independently reviewed and extracted data. Where data were available, we calculated pooled effect estimates. We used GRADE to assess certainty of evidence and in 'Summary of findings' tables.

MAIN RESULTS

We included 24 studies with data on 60,997 participants. Eighteen trials randomised participants to alirocumab and six to evolocumab. All participants received background lipid-lowering treatment or lifestyle counselling. Six alirocumab studies used  an active treatment comparison group (the remaining used placebo), compared to three evolocumab active comparison trials. Alirocumab compared with placebo decreased the risk of CVD events, with an absolute risk difference (RD) of -2% (odds ratio (OR) 0.87, 95% confidence interval (CI) 0.80 to 0.94; 10 studies, 23,868 participants; high-certainty evidence), decreased the risk of mortality (RD -1%; OR 0.83, 95% CI 0.72 to 0.96; 12 studies, 24,797 participants; high-certainty evidence), and MI (RD -2%; OR 0.86, 95% CI 0.79 to 0.94; 9 studies, 23,352 participants; high-certainty evidence) and for any stroke (RD 0%; OR 0.73, 95% CI 0.58 to 0.91; 8 studies, 22,835 participants; high-certainty evidence). Compared to active treatment the alirocumab effects, for CVD, the RD was 1% (OR 1.37, 95% CI 0.65 to 2.87; 3 studies, 1379 participants; low-certainty evidence); for mortality, RD was -1% (OR 0.51, 95% CI 0.18 to 1.40; 5 studies, 1333 participants; low-certainty evidence); for MI, RD was 1% (OR 1.45, 95% CI 0.64 to 3.28, 5 studies, 1734 participants; low-certainty evidence); and for any stroke, RD was less than 1% (OR 0.85, 95% CI 0.13 to 5.61; 5 studies, 1734 participants; low-certainty evidence). Compared to placebo the evolocumab, for CVD, the RD was -2% (OR 0.84, 95% CI 0.78 to 0.91; 3 studies, 29,432 participants; high-certainty evidence); for mortality, RD was less than 1% (OR 1.04, 95% CI 0.91 to 1.19; 3 studies, 29,432 participants; high-certainty evidence); for MI, RD was -1% (OR 0.72, 95% CI 0.64 to 0.82; 3 studies, 29,432 participants; high-certainty evidence); and for any stroke RD was less than -1% (OR 0.79, 95% CI 0.65 to 0.94; 2 studies, 28,531 participants; high-certainty evidence).  Compared to active treatment, the evolocumab effects, for any CVD event RD was less than -1% (OR 0.66, 95% CI 0.14 to 3.04; 1 study, 218 participants; very low-certainty evidence); for all-cause mortality, the RD was less than 1% (OR 0.43, 95% CI 0.14 to 1.30; 3 studies, 5223 participants; very low-certainty evidence); and for MI, RD was less than 1% (OR 0.66, 95% CI 0.23 to 1.85; 3 studies, 5003 participants; very low-certainty evidence). There were insufficient data on any stroke.  AUTHORS' CONCLUSIONS: The evidence for the clinical endpoint effects of  evolocumab and alirocumab were graded as high. There is a strong evidence base to prescribe PCSK9 monoclonal antibodies to people who might not be eligible for other lipid-lowering drugs, or to people who cannot meet their lipid goals on more traditional therapies, which was the main patient population of the available trials.  The evidence base of PCSK9 inhibitors compared with active treatment is much weaker (low very- to low-certainty evidence) and it is unclear whether evolocumab or alirocumab might be effectively used as replacement therapies. Related, most of the available studies preferentially enrolled people with either established CVD or at a high risk already, and evidence in low- to medium-risk settings is minimal. Finally, there is very limited evidence on any potential safety issues of both evolocumab and alirocumab. While the current evidence synthesis does not reveal any adverse signals, neither does it provide evidence against such signals. This suggests careful consideration of alternative lipid lowering treatments before prescribing PCSK9 inhibitors.

Dyslipidaemias and Cardiovascular Disease: Focus on the Role of PCSK9 Inhibitors

Genetic, experimental and clinical studies have consistently confirmed that inhibition of Proprotein Convertase Subtilisin/Kexin type 9 (PCSK9) can result in significant lowering of LDL-C and two fully human PCSK9 monoclonal antibodies have received regulatory approval for use in highrisk patients. Co-administration of PCSK9 with statins has resulted in extremely low LDL-C levels with excellent short-term safety profiles. While results from Phase III clinical trials provided significant evidence about the role of PCSK9 inhibitors in reducing cardiovascular event rates, their impact on mortality remains less clear. PCSK9 inhibitor therapy can be considered for high-risk patients who are likely to experience significant cardiovascular risk reduction.

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.

Impact of Lowering Low-Density Lipoprotein Cholesterol with Contemporary Lipid-Lowering Medicines on Cognitive Function: A Systematic Review and Meta-Analysis

PURPOSE

To evaluate the potential association between the lowering of low-density lipoprotein cholesterol (LDL-C) with contemporary lipid-lowering medicines and cognitive function.

METHODS

Randomized controlled trials (RCTs) in databases including PubMed, Embase, and the Web of Science and all databases in the Cochrane Library and ClinicalTrials.gov were collected from inception to January 1, 2020. The cognitive function of patients receiving proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors, statins and ezetimibe was evaluated using meta-analysis.

RESULTS

A total of 2910 studies were obtained from databases and other sources. Thirty-three studies were selected by screening, including 11 studies on alirocumab, 9 studies on evolocumab, 11 studies on statins and 2 studies on ezetimibe. In our study, a total of 128,691 patients with no cognitive impairment were divided into an intervention group (66,330 patients) and a control group (62,361 patients). The data were subjected to a random-effects model or a fixed-effects model for meta-analysis. The contemporary lipid-lowering medicines significantly reduced LDL-C in terms of both percentage (WMD: -45.06%, 95% CI -50.12% to -40.00%, P < 0.001) and absolute value (WMD: -64.01 mg/dL, 95% CI -72.25 to -55.78, P < 0.001). Compared with the control group, patients receiving treatment with contemporary lipid-lowering medicines did not show a significant difference in the rate of neurocognitive disorder (RR: 1.02, 95% CI 0.90 to 1.16, I² = 0.0%, p = 0.696). Subgroup analysis was performed according to the intervention and LDL-C stratification. The result of this subgroup analysis was consistent with the main findings. Regarding global cognitive performance, no difference in major cognition was found among the pooled data (SMD: 0.02, 95% CI -0.01 to 0.04, P = 0.002), except for psychomotor speed (SMD: 0.09, 95% CI 0.02 to 0.16, P = 0.0024).

CONCLUSIONS

Contemporary lipid-lowering medicines were not associated with cognitive impairment in RCTs. A low LDL-C level did not influence the incidence of cognitive disorder or global cognitive performance.

Indirect comparison of the efficacy and safety of alirocumab and evolocumab: a systematic review and network meta-analysis

AIMS

Although alirocumab and evolocumab have both been associated with improved outcomes in patients with dyslipidaemia or established atherosclerotic cardiovascular disease, data on their respective performances are scarce. This study aimed at providing an indirect comparison of the efficacy and safety of alirocumab vs. evolocumab.

METHODS AND RESULTS

We conducted a systematic review and network meta-analysis of randomized trials comparing alirocumab or evolocumab to placebo with consistent background lipid-lowering therapy up to November 2018. We estimated the relative risk (RR) and the 95% confidence intervals (CIs) using fixed-effect model in a frequentist pairwise and network meta-analytic approach. A total of 30 trials, enrolling 59 026 patients were included. Eligibility criteria varied significantly across trials evaluating alirocumab and evolocumab. Compared with evolocumab, alirocumab was associated with a significant reduction in all-cause death (RR 0.80, 95% CI 0.66-0.97) but not in cardiovascular death (RR 0.83, 95% CI 0.65-1.05). This study did not find any significant differences in myocardial infarction (RR 1.15, 95% CI 0.99-1.34), stroke (RR 0.96, 95% CI 0.71-1.28), or coronary revascularization (RR 1.13, 95% CI 0.99-1.29) between the two agents. Alirocumab was associated with a 27% increased risk of injection site reaction compared to evolocumab; however, no significant differences were found in terms of treatment discontinuations, systemic allergic reaction, neurocognitive events, ophthalmologic events, or new-onset of or worsening of pre-existing diabetes.

CONCLUSION

Alirocumab and evolocumab share a similar safety profile except for injection site reaction. No significant differences were observed across the efficacy endpoints, except for all-cause death, which may be related to the heterogeneity of the studied populations treated with the two drugs.

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.

Meta-analysis of Randomized Controlled Trials Assessing the Impact of Proprotein Convertase Subtilisin/Kexin Type 9 Antibodies on Mortality and Cardiovascular Outcomes

Proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibition by monoclonal antibodies has been shown to reduce low density lipoprotein (LDL-C) but its effects on cardiovascular (CV) outcomes have not been fully described. The aim of this study is to assess the impact of PCSK9 inhibition on mortality and CV outcomes by pooling data from all available randomized clinical trials (RCT) of PCSK9 inhibitors. We conducted a comprehensive search of electronic databases, up to December 1, 2018, for all RCTs comparing PCSK9 inhibition to placebo or ezetimibe in patients with hypercholesterolemia or coronary artery disease receiving maximally tolerated statin for primary or secondary prevention of mortality and cardiovascular outcomes. We used random-effects meta-analyses to summarize the studies. We retained 23 RCTs having included 88,041 patients in primary and secondary prevention. The follow-up ranged from 6 to 36 months. PCSK9 inhibition was not significantly associated with reductions in total mortality (odds ratio [OR] 0.91, 95% confidence interval [CI] 078 to 1.06; p = 0.22) and CV mortality (OR 0.95, 95% CI 0.84 to 1.07; p = 0.37). In contrast, PCSK9 inhibition was associated with reductions in myocardial infarction (OR 0.80, 95% CI 0.71 to 0.91; p <0.0001), stroke (OR 0.75, 95% CI 0.65 to 0.85; p <0.0001), and coronary revascularization (OR 0.82, 95% CI 0.77 to 0.88; p <0.0001). In conclusion, PCSK9 inhibition was associated with reductions in myocardial infarction, stroke, and coronary revascularization. Future analyses may identify high-risk patients who may benefit more from these agents and longer follow-up of current or new trials may show a mortality benefit.

Fragment-based design of small molecule PCSK9 inhibitors using simulated annealing of chemical potential simulations

PCSK9 is a protein secreted by the liver that binds to the low-density lipoprotein receptor (LDLR), causing LDLR internalization, decreasing the clearance of circulating LDL particles. Mutations in PCSK9 that strengthen its interactions with LDLR result in familial hypercholesterolemia (FH) and early onset atherosclerosis, while nonsense mutations of PCSK9 result in cardio-protective hypocholesterolemia. These observations led to PCSK9 inhibition for cholesterol lowering becoming a high-interest therapeutic target, with antibody drugs reaching the market. An orally-available small molecule drug is highly desirable, but inhibiting the PCSK9/LDLR protein-protein interaction (PPI) has proven challenging. Alternate approaches to finding good lead candidates are needed. Motivated by the FH mutation data on PCSK9, we found that modeling the PCSK9/LDLR interface revealed extensive electron delocalization between and within the protein partners. Based on this, we hypothesized that compounds assembled from chemical fragments could achieve the affinity required to inhibit the PCSK9/LDLR PPI if they were selected to interact with PCSK9 in a way that, like LDLR, also involves significant fractional charge transfer to form partially covalent bonds. To identify such fragments, Simulated Annealing of Chemical Potential (SACP) fragment simulations were run on multiple PCSK9 structures, using optimized partial charges for the protein. We designed a small molecule, composed of several fragments, predicted to interact at two sites on the PCSK9. This compound inhibits the PPI with 1 μM affinity. Further, we designed two similar small molecules where one allows charge delocalization though a linker and the other doesn’t. The first inhibitor with charge delocalization enhances LDLR surface expression by 60% at 10 nM, two orders of magnitude more potent than the EGF domain of LDLR. The other enhances LDLR expression by only 50% at 1 μM. This supports our conjecture that fragments can have surprisingly outsized efficacy in breaking PPI’s by achieving fractional charge transfer leading to partially covalent bonding.

PCSK9 inhibitors and cardiovascular outcomes

Introduction: Dyslipidemia, particularly elevated low-density lipoprotein cholesterol (LDL-C), is a key risk factor for atherosclerotic cardiovascular disease (ASCVD), and lipid-lowering drugs are beneficial for the primary and secondary prevention of cardiovascular (CV) disease. While statins are clear first-line drugs, new drug developments such as proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors have been shown to improve cardiovascular outcomes when added to statins. Evolocumab reduced the risk of cardiovascular events in patients with ASCVD when added to maximally tolerated statin therapy (± ezetimibe), and recent data from the ODYSSEY OUTCOMES trial indicate that alirocumab added to maximally tolerated statin therapy (± other lipid-lowering drugs) reduces the risk of cardiovascular events in patients with a recent acute coronary syndrome. In this article the authors review the available data on the effect of PCSK9 inhibitors on cardiovascular outcomes.Areas covered: This article reviews the available data on the effect of PCSK9 inhibitors on CV outcomes. Relevant papers were identified from a search of PubMed/Medline and the Cochrane Central Register of Controlled Trials (CENTRAL).Expert opinion: The authors conclude that PCSK9 inhibitors provide substantial and durable reductions in LDL-C levels and improve cardiovascular outcomes.

Comparative quantitative systems pharmacology modeling of anti-PCSK9 therapeutic modalities in hypercholesterolemia

Since the discovery of proprotein convertase subtilisin/kexin type 9 (PCSK9) as an attractive target in the treatment of hypercholesterolemia, multiple anti-PCSK9 therapeutic modalities have been pursued in drug development. The objective of this research is to set the stage for the quantitative benchmarking of two anti-PCSK9 pharmacological modality classes, monoclonal antibodies (mAbs) and small interfering RNA (siRNA). To this end, we developed an integrative mathematical model of lipoprotein homeostasis describing the dynamic interplay between PCSK9, LDL-cholesterol (LDL-C), VLDL-cholesterol, HDL-cholesterol (HDL-C), apoB, lipoprotein a [Lp(a)], and triglycerides (TGs). We demonstrate that LDL-C decreased proportionally to PCSK9 reduction for both mAb and siRNA modalities. At marketed doses, however, treatment with mAbs resulted in an additional ∼20% LDL-C reduction compared with siRNA. We further used the model as an evaluation tool and determined that no quantitative differences were observed in HDL-C, Lp(a), TG, or apoB responses, suggesting that the disruption of PCSK9 synthesis would provide no additional effects on lipoprotein-related biomarkers in the patient segment investigated. Predictive model simulations further indicate that siRNA therapies may reach reductions in LDL-C levels comparable to those achieved with mAbs if the current threshold of 80% PCSK9 inhibition via siRNA could be overcome.

PEARL: A Non-interventional Study of Real-World Alirocumab Use in German Clinical Practice

BACKGROUND

Several lipid guidelines recommend that proprotein convertase subtilisin/kexin type 9 inhibitors should be considered for patients with atherosclerotic cardiovascular disease who are inadequately treated with maximally tolerated lipid-lowering treatment.

OBJECTIVES

The PEARL study assessed the efficacy and safety of the proprotein convertase subtilisin/kexin type 9 inhibitor alirocumab in patients with hypercholesterolemia in a real-world setting.

METHODS

PEARL was an open, prospective, multicenter, non-interventional study conducted in Germany. Patients (n = 619) for whom treating physicians decided to use alirocumab 75 or 150 mg every 2 weeks according to German guidelines (low-density lipoprotein cholesterol > 1.8/2.6 mmol/L [> 70/100 mg/dL], depending on cardiovascular risk, despite maximally tolerated statin therapy with/without other non-alirocumab lipid-lowering therapy) were enrolled and followed for 24 weeks. Physicians could adjust the alirocumab dose based on their clinical judgment. The primary efficacy endpoint was low-density lipoprotein cholesterol reduction from baseline (prior to alirocumab therapy) to week 24.

RESULTS

Overall, 72.8% of patients reported complete or partial statin intolerance. Mean low-density lipoprotein cholesterol was 4.7 mmol/L (180.5 mg/dL) and 2.3 mmol/L (89.8 mg/dL) at baseline and week 24, respectively. Least-squares mean percentage change from baseline to week 24 in low-density lipoprotein cholesterol was - 48.6%. Initial alirocumab dose was 75 mg in 72.9% of patients and 150 mg in 24.5% of patients; 19.6% of patients received an alirocumab dose increase (75 to 150 mg) and 1.6% of patients received a dose decrease. Adverse events were reported in 10.3% of patients, with myalgia being the most common.

CONCLUSIONS

In a real-world setting in Germany, alirocumab was used in patients who had high baseline low-density lipoprotein cholesterol levels with/without statin intolerance. Efficacy and safety were consistent with findings observed in the ODYSSEY Phase III program.

Anti-PCSK9 antibodies inhibit pro-atherogenic mechanisms in APOE*3Leiden.CETP mice

LDL-cholesterol (LDL-C) is a causal pathogenic factor in atherosclerosis. Monoclonal anti-proprotein convertase subtilisin/kexin type 9 (PCSK9) neutralizing antibodies are novel potent LDL-lowering drugs which reduce cardiovascular events. To characterize their effect on atherogenesis, APOE*3Leiden.CETP mice were fed a high cholesterol/high fat diet (WTD) or normal chow (NC) for 18 weeks. Mice on WTD were injected with the human anti-PCSK9 antibody mAb1 (PL-45134, 10 mg*kg^-1 s.c.) or 0.9% saline every 10 days. PCSK9 inhibition decreased total cholesterol in serum of APOE*3Leiden.CETP mice and prevented the development of atherosclerosis. The plaque area in the aortic root was reduced by half and macrophage infiltration determined by Ly6c and Mac-3 staining was ameliorated. PCSK9 inhibition decreased markers of inflammation in mononuclear cells (Il-6, Tnfa mRNA), and in serum (CXCL-1,-10,-13; complement factor C5a) compared to control WTD fed animals. The number of circulating Sca-1/VEGF-R2 positive endothelial progenitor cells of the peripheral blood and spleen-derived diLDL/lectin double positive circulating angiogenic cells was increased. To conclude, the PCSK9-mediated anti-atherosclerotic effect involves the upregulation of pro-regeneratory endothelial progenitor cells, a reduction of inflammation and change of plaque composition.

PCSK9: from molecular biology to clinical applications

Proprotein convertase subtilisin kexin 9 (PCSK9) is a serine protease with a key role in regulating plasma low-density lipoprotein (LDL) concentration. Since its discovery via parallel molecular biology and clinical genetics studies in 2003, work to characterize PCSK9 has shed new light on the life-cycle of the low-density lipoprotein receptor and the molecular basis of familial hypercholesterolaemia. These discoveries have also led to the advent of the PCSK9 inhibitors, a new generation of low-density lipoprotein cholesterol (LDL-C) lowering drugs. Clinical trials have shown these agents to be both safe and capable of unprecedented reductions in LDL-C, and it is hoped they may herald a new era of cardiovascular disease prevention. As such, the still evolving PCSK9 story serves as a particularly successful example of translational medicine. This review provides a summary of the principal PCSK9 research findings, which underpin our current understanding of its function and clinical relevance.

Proprotein Convertase Subtilisin/Kexin Type 9 (PCSK9) Inhibitors, Reality or Dream in Managing Patients with Cardiovascular Disease

BACKGROUND

Statins have been a major keystone in the management of patients with atherosclerotic cardiovascular disease. The benefits of inhibiting HMG CoA reductase, via statins, were translated into reduction in LDL-c with proportionate decrease in cardiovascular events in response to the magnitude of LDL-c reduction. Despite major advances in pharmacological treatments, including the use of high-dose statins, there are urgent need to further reduce future cardiovascular risk. This is in particularly important since 1 out of 5 high-risk atherosclerotic patients who achieve low LDL-c return with a second cardiovascular event within five years. Although this residual risk post-statin is largely heterogeneous, lowering LDL-c beyond 'normal' or guidelines-recommended level using novel therapies has resulted in further reduction in cardiovascular events.

OBJECTIVE

The current review will discuss the use of PCSK9 inhibitors in patients with atherosclerotic disease. PCSK9 inhibitors are a new class of lipid-lowering drugs that are either fully human monoclonal antibodies (evolocumab and alirocumab) or humanised monoclonal antibodies (bococizumab) that effectively reduce LDL-c to unprecedented level. By blocking circulating PCSK9, these drugs would preserve LDL receptors and prevent them from cellular degradation. This process promotes recycling of LDL receptors back to hepatocytes surface, leading into further reduction of LDL-c. Combining PCSK9 inhibitors with statin have led into lower LDL-c, reduction in plaque volume and more importantly reduction in future cardiovascular events.

CONCLUSION

These drugs are very promising, nonetheless, the unselective approach of applying these monoclonal antibodies may not prove to be cost-effective and potentially exposing some patients to unnecessary side effects.

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.

A Meta-Analysis of the Effect of PCSK9-Monoclonal Antibodies on Circulating Lipoprotein (a) Levels

BACKGROUND

Lipoprotein (a) [Lp(a)] is an atherogenic lipoprotein. While no effective therapy for Lp(a) is currently available, recently, several pooled analyses with small sample sizes have suggested that proprotein convertase subtilisin/kexin type 9 monoclonal antibodies (PCSK9-mAbs) could reduce circulating Lp(a) levels. This meta-analysis was performed to comprehensively investigate the efficacy of PCSK9-mAbs with respect to serum Lp(a) concentrations.

METHODS

PubMed, MEDLINE, Embase, ClinicalTrials.gov, Cochrane CENTRAL, Web of Science and recent conferences up to July 2018 were searched. Randomized clinical trials evaluating the effect of PCSK9-mAbs and control treatment on plasma Lp(a) concentrations were included. Mean differences and odds ratios with 95% confidence intervals (CIs) were used.

RESULTS

Twenty-seven randomized clinical trials with a total of 11,864 participants were included. PCSK9-mAbs showed a significant efficacy in reducing Lp(a) (- 21.9%, 95% CI - 24.3 to - 19.5), irrespective of PCSK9-mAb types, treatment duration, participant characteristics, treatment methods, differences of control treatment, baseline Lp(a) levels, and test methods. The greatest reduction was achieved with 150 mg alirocumab biweekly (- 24.6%, 95% CI - 28.0 to - 21.2) and  140 mg evolocumab monthly (- 26.8%, 95% CI - 31.6 to - 21.9). Meta-regression analyses found that the more intense low-density lipoprotein cholesterol levels declined during PCSK9-mAb treatment, the greater the reduction in Lp(a) levels. Safety was in accordance with previous reports.

CONCLUSIONS

The results of this analysis suggested that PCSK9-mAbs could significantly reduce circulating Lp(a) levels. Long-term studies may be needed to confirm the effect of PCSK9-mAbs on Lp(a) in the future.

The Role of PCSK9 Inhibitors in the Improvement of Outcomes in Patients after Acute Coronary Syndrome: Results of ODYSSEY OUTCOMES Trial

The aim of this review was to present the recently published results of ODYSSEY OUTCOMES trial and discuss the clinical perspective of these data. Patients with acute coronary syndrome are at very high risk of recurrent ischemic cardiovascular complications, especially during the first year after the event. The use of high-intensity statin therapy in this group of patients does not always lead to the achievement of target levels of atherogenic lipoproteins. PCSK9 inhibitors, administered in addition to statins, can provide additional reduction of low-density lipoprotein cholesterol, which leads to further improvements of outcomes in patients with atherosclerotic cardiovascular disease. According to the latest results from ODYSSEY OUTCOMES trial, among patients with recent acute coronary syndrome, who were receiving high-intensity statin therapy, the risk of recurrent ischemic cardiovascular events was lower among those who were treated with alirocumab then among those who received placebo. The treatment with alirocumab in patients with recent acute coronary syndrome was associated with reduction in death from any causes. The absolute risk reduction with alirocumab was the most prominent in the subpopulation of patients with low-density lipoprotein cholesterol ≥2,6 mmol/l at baseline. These results have implication for clinical practice and may play an important role for the improvement of outcomes in patients at highest cardiovascular risk after acute cardiovascular syndrome.

Alirocumab for low-density lipoprotein cholesterol lowering

Ischemic heart disease and stroke are the leading causes of death in the world currently. Both of these conditions are primarily caused by atherosclerosis, the underlying pathophysiology of which is the deposition of lipid, specifically low-density lipoprotein cholesterol (LDL-C) within the arterial bed. PCSK9, is a proteolytic enzyme, which indirectly increases LDL-C levels by causing the destruction of LDL receptors, the main way that humans regulate their serum LDL-C levels. Inhibitors of PCSK9 in conjunction with statins have allowed achievement of very low LDL-C levels. This review will provide an in-depth efficacy and safety review of alirocumab, a monoclonal antibody inhibitor of PCSK9, including the ODYSSEY OUTCOMES trial.

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.

PCSK9 inhibition for LDL lowering and beyond – implications for patients with peripheral artery disease

Abstract. Low-density lipoprotein cholesterol (LDL-C) has been proven to be a causal factor of atherosclerosis and, along with other triggers like inflammation, the most frequent reason for peripheral arterial disease. Moreover, a linear correlation between LDL-C concentration and cardiovascular outcome in high-risk patients could be established during the past century. After the development of statins, numerous randomized trials have shown the superiority for LDL-C reduction and hence the decrease in cardiovascular outcomes including mortality. Over the past decades it became evident that more intense LDL-C lowering, by either the use of highly potent statin supplements or by additional cholesterol absorption inhibitor application, accounted for an even more profound cardiovascular risk reduction. Proprotein convertase subtilisin/kexin type 9 (PCSK9), a serin protease with effect on the LDL receptor cycle leading to its degradation and therefore preventing continuing LDL-C clearance from the blood, is the target of a newly developed monoclonal antibody facilitating astounding LDL-C reduction far below to what has been set as target level by recent ESC/EAS guidelines in management of dyslipidaemias. Large randomized outcome trials including subjects with PAD so far have been able to prove significant and even more intense cardiovascular risk reduction via further LDL-C debasement on top of high-intensity statin medication. Another approach for LDL-C reduction is a silencing interfering RNA muting the translation of PCSK9 intracellularly. Moreover, PCSK9 concentrations are elevated in cells involved in plaque composition, so the potency of intracellular PCSK9 inhibition and therefore prevention or reversal of plaques may provide this mechanism of action on PCSK9 with additional beneficial effects on cells involved in plaque formation. Thus, simultaneous application of statins and PCSK9 inhibitors promise to reduce cardiovascular event burden by both LDL-C reduction and pleiotropic effects of both agents.

PCSK9 inhibitors: a non-statin cholesterol-lowering treatment option

Elevated low-density lipoprotein cholesterol (LDL-C) plays a major role in the development of atherosclerotic cardiovascular disease. Statins are the first-line treatment to lower LDL-C in patients with hypercholesterolemia; however, some high cardiovascular risk patients may have inadequate responses to statin therapy or are intolerant to statins, and may need additional and/or alternative non-statin therapies to further reduce their LDL-C levels. Monoclonal antibodies that inhibit proprotein convertase subtilisin/kexin type 9 (PCSK9), a key regulator of circulating LDL-C levels, have received considerable attention as promising non-statin therapeutic options for the management of hypercholesterolemia. This review provides a brief overview of the history and science of PCSK9 inhibitors, focusing on two PCSK9 monoclonal antibodies that have been approved by the US Food and Drug Administration: alirocumab and evolocumab. Recently released and forthcoming clinical trial data will be discussed, as well as the practical application of patient populations that may benefit from PCSK9 inhibitors. Finally, the recent expert recommendations regarding the use of PCSK9 inhibitors and other non-statin therapies to treat patients with inadequate LDL-C-lowering on statin therapy will be summarized.

Neurological effects of proprotein convertase subtilisin/kexin type 9 inhibitors: direct comparisons

Aims

Proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors considerably alter the lipid profile. We sought to examine the rates of ischaemic stroke and neurocognitive deficits in patients treated with and without PCSK9 inhibitors.

Methods and results

Randomized controlled trials (RCTs) reporting rates of ischaemic stroke and neurocognitive deficits in patients using PCSK9 inhibitors were identified. Standard meta-analysis techniques were used to compare these outcomes among patients treated with and without PCSK9 inhibitors and the two US Food and Drug Administration-approved PCSK9 inhibitors, evolocumab and alirocumab. The results were presented in terms of risk ratio (RR) with 95% confidence intervals (CIs). Sixteen RCTs with 39 104 patients were included. Evolocumab was used in six RCTs with 33 450 patients, whereas alirocumab was used in 10 RCTs with 5654 patients. We observed a significantly lower risk of ischaemic stroke among those treated with PCSK9 inhibitors (RR 0.77, 95% CI 0.64-0.93) when compared with those without. We did not observe any difference in the risk of neurocognitive deficits between the aforementioned groups (RR 1.11, 95% CI 0.93-1.32). The lower stroke risk in the PCSK9 inhibitors group was driven by evolocumab studies. We observed no difference in the risk of neurocognitive deficits among evolocumab and alirocumab when compared with no PCSK9 inhibitors group.

Conclusion

Treatment with PCSK9 inhibitors significantly lowers the risk of ischaemic stroke, without any increased risk of neurocognitive deficits. PCSK9 inhibitors are neuroprotective due to the decrease in ischaemic-mediated neurovascular events and should be considered cognitively innocuous medications.

Recent Advances in Treatment of Coronary Artery Disease: Role of Science and Technology

Coronary artery disease (CAD) is one of the most common causes of death worldwide. In the last decade, significant advancements in CAD treatment have been made. The existing treatment is medical, surgical or a combination of both depending on the extent, severity and clinical presentation of CAD. The collaboration between different science disciplines such as biotechnology and tissue engineering has led to the development of novel therapeutic strategies such as stem cells, nanotechnology, robotic surgery and other advancements (3-D printing and drugs). These treatment modalities show promising effects in managing CAD and associated conditions. Research on stem cells focuses on studying the potential for cardiac regeneration, while nanotechnology research investigates nano-drug delivery and percutaneous coronary interventions including stent modifications and coatings. This article aims to provide an update on the literature (in vitro, translational, animal and clinical) related to these novel strategies and to elucidate the rationale behind their potential treatment of CAD. Through the extensive and continued efforts of researchers and clinicians worldwide, these novel strategies hold the promise to be effective alternatives to existing treatment modalities.