Cardiovascular Efficacy and Safety of Bococizumab in High-Risk Patients

LDL-C: The Only Causal Risk Factor for ASCVD. Why Is It Still Overlooked and Underestimated?

PURPOSE OF REVIEW

Low-density lipoprotein cholesterol (LDL-C) is the most important causal risk factor for atherosclerotic cardiovascular disease (ASCVD). This article reviews why LDL-C remains overlooked and underestimated despite numerous studies that have proved its role.

RECENT FINDINGS

Recently published EAS/ESC Guidelines for dyslipidemia and EAS Guidelines for prevention set new targets for LDL-C levels in primary and secondary prevention of ASCVD. These guidelines are based on data from large studies and meta-analyzes that have shown that lower LDL-C also means lower cardiovascular event rates. Real-life experience published in registries worldwide has shown us that the guidelines have not been translated to everyday clinical practice, meaning that a significant number of patients are undertreated and have LDL-C levels well above target. Potential reasons for the abovementioned are poor adherence and education of the patient and physician and health care system related factors. Implementation of the latest version of guidelines will require continuous patient and physicians education, as well as a shared decision-making process between physician and patient.

Introducing dendritic cell antibody internalization as an immunogenicity risk assessment tool

Aim: Immunogenicity risk assessment assays are powerful tools that assess the relative immunogenicity of potential biotherapeutics. We detail here the development of a novel assay that measures the degree of antibody internalization by antigen-presenting cells as a predictor of immunogenicity. Results & methodology: The assay uses the fluorescence signal from the antibody bound to the outside of the cell as well as inside the cell to determine internalization. To calculate the amount of internalized antibody, the fluorescent signal from the outside was subtracted from the fluorescent signal from the inside, which is referred to as the internalization index. Conclusion: This assay format demonstrated that antibody-based biotherapeutics with higher clinical immunogenicity internalized to a higher degree than therapeutic antibodies with lower clinical immunogenicity.

PCSK9 inhibitors and ezetimibe with or without statin therapy for cardiovascular risk reduction: a systematic review and network meta-analysis

OBJECTIVE

To compare the impact of ezetimibe and proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors on cardiovascular outcomes in adults taking maximally tolerated statin therapy or who are statin intolerant.

DESIGN

Network meta-analysis.

DATA SOURCES

Medline, EMBASE, and Cochrane Library up to 31 December 2020.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

Randomised controlled trials of ezetimibe and PCSK9 inhibitors with ≥500 patients and follow-up of ≥6 months.

MAIN OUTCOME MEASURES

We performed frequentist fixed-effects network meta-analysis and GRADE (grading of recommendations, assessment, development, and evaluation) to assess certainty of evidence. Results included relative risks (RR) and absolute risks per 1000 patients treated for five years for non-fatal myocardial infarction (MI), non-fatal stroke, all-cause mortality, and cardiovascular mortality. We estimated absolute risk differences assuming constant RR (estimated from network meta-analysis) across different baseline therapies and cardiovascular risk thresholds; the PREDICT risk calculator estimated cardiovascular risk in primary and secondary prevention. Patients were categorised at low to very high cardiovascular risk. A guideline panel and systematic review authors established the minimal important differences (MID) of 12 per 1000 for MI and 10 per 1000 for stroke.

RESULTS

We identified 14 trials assessing ezetimibe and PCSK9 inhibitors among 83 660 adults using statins. Adding ezetimibe to statins reduced MI (RR 0.87 (95% confidence interval 0.80 to 0.94)) and stroke (RR 0.82 (0.71 to 0.96)) but not all-cause mortality (RR 0.99 (0.92 to 1.06)) or cardiovascular mortality (RR 0.97 (0.87 to 1.09)). Similarly, adding PCSK9 inhibitor to statins reduced MI (0.81 (0.76 to 0.87)) and stroke (0.74 (0.64 to 0.85)) but not all-cause (0.95 (0.87 to 1.03)) or cardiovascular mortality (0.95 (0.87 to 1.03)). Among adults with very high cardiovascular risk, adding PCSK9 inhibitor was likely to reduce MI (16 per 1000) and stroke (21 per 1000) (moderate to high certainty); whereas adding ezetimibe was likely to reduce stroke (14 per 1000), but the reduction of MI (11 per 1000) (moderate certainty) did not reach MID. Adding ezetimibe to PCSK9 inhibitor and statin may reduce stroke (11 per 1000), but the reduction of MI (9 per 1000) (low certainty) did not reach MID. Adding PCSK9 inhibitors to statins and ezetimibe may reduce MI (14 per 1000) and stroke (17 per 1000) (low certainty). Among adults with high cardiovascular risk, adding PCSK9 inhibitor probably reduced MI (12 per 1000) and stroke (16 per 1000) (moderate certainty); adding ezetimibe probably reduced stroke (11 per 1000), but the reduction in MI did not achieve MID (8 per 1000) (moderate certainty). Adding ezetimibe to PCSK9 inhibitor and statins did not reduce outcomes beyond MID, while adding PCSK9 inhibitor to ezetimibe and statins may reduce stroke (13 per 1000). These effects were consistent in statin-intolerant patients. Among moderate and low cardiovascular risk groups, adding PCSK9 inhibitor or ezetimibe to statins yielded little or no benefit for MI and stroke.

CONCLUSIONS

Ezetimibe or PCSK9 inhibitors may reduce non-fatal MI and stroke in adults at very high or high cardiovascular risk who are receiving maximally tolerated statin therapy or are statin-intolerant, but not in those with moderate and low cardiovascular risk.

Smad3 regulates smooth muscle cell fate and mediates adverse remodeling and calcification of the atherosclerotic plaque

Atherosclerotic plaques consist mostly of smooth muscle cells (SMC), and genes that influence SMC phenotype can modulate coronary artery disease (CAD) risk. Allelic variation at 15q22.33 has been identified by genome-wide association studies to modify the risk of CAD and is associated with the expression of SMAD3 in SMC. However, the mechanism by which this gene modifies CAD risk remains poorly understood. Here we show that SMC-specific deletion of Smad3 in a murine atherosclerosis model resulted in greater plaque burden, more outward remodelling and increased vascular calcification. Single-cell transcriptomic analyses revealed that loss of Smad3 altered SMC transition cell state toward two fates: a SMC phenotype that governs both vascular remodelling and recruitment of inflammatory cells, as well as a chondromyocyte fate. Together, the findings reveal that Smad3 expression in SMC inhibits the emergence of specific SMC phenotypic transition cells that mediate adverse plaque features, including outward remodelling, monocyte recruitment, and vascular calcification.

Drug Treatment of Hypercholesterolemia in Older Adults: Focus on Newer Agents

There is increasing research interest in cholesterol-lowering therapy in older patients. The newer lipid-lowering agents (the proprotein convertase subtilisin/kexin type 9 [PCSK9] inhibitors evolocumab and alirocumab; the PCSK9 synthesis inhibitor inclisiran, and the adenosine triphosphate–citrate lyase inhibitor bempedoic acid) might also provide more options for the future treatment of older patients. Data analyses of the phase III outcome trials of the PCSK9 inhibitors suggest that their clinical benefits are maintained at older ages and that there is no increased relative risk of adverse events in older patients; however, data from patients aged ≥ 75 years and particularly aged ≥ 85 years are limited, and the trials did not collect information on the frailty status of patients. Frailty is a predictor of adverse outcomes, including mortality, and might help guide therapy decisions. To date, no outcome data are available for cardiovascular endpoints for the low-density lipoprotein cholesterol-lowering drugs inclisiran and bempedoic acid. Except for the risk of gout and tendon rupture with bempedoic acid, which remains to be further characterized in larger populations, the safety profile of the novel lipid-lowering agents in older patients seems favorable. The newer lipid-lowering agents could be added to other lipid-lowering medication or used as an alternative treatment in older patients with documented statin intolerance (as is already recommended in guidelines for the PCSK9 inhibitors), such as myopathy. Especially in older patients needing high-intensity therapy despite polypharmacy or certain comedications, the absence of clinically relevant drug–drug interactions with the PCSK9 inhibitors and inclisiran might be an advantage.

Genome-wide pharmacogenetics of anti-drug antibody response to bococizumab highlights key residues in HLA DRB1 and DQB1

In this largest to-date genetic analysis of anti-drug antibody (ADA) response to a therapeutic monoclonal antibody (MAb), genome-wide association was performed for five measures of ADA status among 8844 individuals randomized to bococizumab, which targets PCSK9 for LDL-C lowering and cardiovascular protection. Index associations prioritized specific amino acid substitutions at the DRB1 and DQB1 MHC class II genes rather than canonical haplotypes. Two clusters of missense variants at DRB1 were associated with general ADA measures (residues 9, 11, 13; and 96, 112, 120, 180) and a third cluster of missense variants in DQB1 was associated with ADA measures including neutralizing antibody (NAb) titers (residues 66, 67, 71, 74, 75). The structural disposition of the missense substitutions implicates peptide antigen binding and CD4 effector function, mechanisms that are potentially generalizable to other therapeutic mAbs.

Clinicaltrials.gov: NCT01968954, NCT01968967, NCT01968980, NCT01975376, NCT01975389, NCT02100514.

Efficacy and Safety of PCSK9 Monoclonal Antibodies in Patients With Diabetes

PURPOSE

Proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors are novel drugs that have proven efficacy in improving cardiovascular outcomes. Roles for the PCSK9 molecule in metabolic pathways beyond LDL receptor processing and cholesterol homeostasis are well established. PCSK9 genetic variants associated with lower LDL-C levels correlate with a higher incidence of type 2 diabetes (T2DM), calling into question the appropriateness of these drugs in patients with T2DM and those at high risk of developing diabetes, and whether cardiovascular benefit seen with PCSK9 inhibitors might be offset by resultant dysglycemia. The purpose of this review was to examine the role of PCSK9 protein in glucose homeostasis, the impact of PCSK9 inhibition in relation to glucose homeostasis, and whether some of the cardiovascular benefit seen with PCSK9 inhibitors and statins might be offset by resultant dysglycemia.

METHODS

Comprehensive literature searches of electronic databases of PubMed, EMBASE, and OVID were conducted by using the search terms hyperlipidaemia, PCSK9, diabetes, and glucose as well as other relevant papers of interest collected by the authors. The retrieved papers were reviewed and shortlisted most relevant ones.

FINDINGS

Genetically determined lower circulating LDL-C and PCSK9 concentrations may have an incremental effect in increasing T2DM incidence, but any perceived harm is outweighed by the reduced risk of atherosclerotic cardiovascular disease achieved through lower lifetime exposure to LDL-C. PCSK9 monoclonal antibodies are effective and safe in patients with T2DM and those at high risk of developing it. The number-needed-to-treat to prevent one atherosclerotic cardiovascular disease event in the FOURIER (Further Cardiovascular Outcomes Research with PCSK9 Inhibition in Subjects with Elevated Risk) study in the subgroup with diabetes is significantly lower than for those without. Therefore, T2DM or being at high risk to develop it should not be a reason to avoid these agents. The safety of PCSK9 inhibition in relation to glucose homeostasis may depend on the method of inhibition and whether it occurs in circulation or the cells. Data from experimental studies and randomized controlled trials suggest no detrimental effect of PCSK9 monoclonal antibodies on glucose homeostasis. More data and large randomized controlled studies are needed to assess the impact of other methods of PCSK9 inhibition on glucose homeostasis.

IMPLICATIONS

PCSK9monoclonal antibodies markedly reduce LDL-C and consistently reduce cardiovascular mortality in patients with and without diabetes. Current evidence does not suggest an adverse effect of PCSK9 monoclonal antibodies on glycemic parameters.

What is the Optimal Low-Density Lipoprotein Cholesterol?

One's total atherosclerotic plaque burden is related to his or her cumulative exposure to low-density lipoprotein cholesterol (LDL-C) and other apoB-containing lipoproteins. Long-term exposure to lower LDL-C levels is associated with a lower risk of cardiovascular events compared with shorter term exposure to lower LDL-C. New lipid-reducing agents have been able to reduce LDL-C to previously unseen levels, showing efficacy in safely decreasing rates of atherosclerotic cardiovascular disease in primary and secondary prevention populations. To date, an LDL-C level less than which there is no clinical benefit has not yet been identified.

Efficacy and safety of alirocumab and evolocumab: a systematic review and meta-analysis of randomized controlled trials

AIMS

The effect of low-density lipoprotein cholesterol-lowering therapy with alirocumab or evolocumab on individual clinical efficacy and safety endpoints remains unclear. We aimed to evaluate the efficacy and safety of alirocumab and evolocumab in patients with dyslipidaemia or atherosclerotic cardiovascular disease.

METHODS AND RESULTS

We performed a review of randomized controlled trials (RCTs) comparing treatment with alirocumab or evolocumab vs. placebo or other lipid-lowering therapies up to March 2018. Primary efficacy endpoints were all-cause death, cardiovascular death, myocardial infarction (MI), and stroke. We estimated risk ratios (RR) and 95% confidence intervals (CI) using random effect models. We included 39 RCTs comprising 66 478 patients of whom 35 896 were treated with proprotein convertase subtilisin-kexin type 9 (PCSK9) inhibitors (14 639 with alirocumab and 21 257 with evolocumab) and 30 582 with controls. Mean weighted follow-up time across trials was 2.3 years with an exposure time of 150 617 patient-years. Overall, the effects of PCSK9 inhibition on all-cause death and cardiovascular death were not statistically significant (P = 0.15 and P = 0.34, respectively). Proprotein convertase subtilisin-kexin type 9 inhibitors were associated with lower risk of MI (1.49 vs. 1.93 per 100 patient-year; RR 0.80, 95% CI 0.74-0.86; I  2 = 0%; P < 0.0001), ischaemic stroke (0.44 vs. 0.58 per 100 patient-year; RR 0.78, 95% CI 0.67-0.89; I  2 = 0%; P = 0.0005), and coronary revascularization (2.16 vs. 2.64 per 100 patient-year; RR 0.83, 95% CI 0.78-0.89; I  2 = 0%; P < 0.0001), compared with the control group. Use of these PCSK9 inhibitors was not associated with increased risk of neurocognitive adverse events (P = 0.91), liver enzymes elevations (P = 0.34), rhabdomyolysis (P = 0.58), or new-onset diabetes mellitus (P = 0.97).

CONCLUSION

Proprotein convertase subtilisin-kexin type 9 inhibition with alirocumab or evolocumab was associated with lower risk of MI, stroke, and coronary revascularization, with favourable safety profile.

Implementing a Clinical Immunogenicity Strategy using Preclinical Risk Assessment Outputs

Immunogenicity to biologics is often observed following dosing in human subjects during clinical trials. Both product and host specific factors may be implicated in contributing to a potential immune response. However, even if such risk factors are identified and eliminated as part of the rational quality by design approaches, the outcome in clinic can be uncertain and challenging to predict. Several tools have been employed to identify these risk factors and consequent mitigation approaches implemented prior to dosing in humans. However, the complexity of the immune system with an interplay of network of immune cells involved in driving a long- term immune response as well as patient characteristics, can make it challenging to predict the outcome in clinic. This perspective will provide an insight into recent advances in the risk assessment approaches that are utilized during preclinical stage of development of a biologic. The outputs from such tools can help to rank order and select the most optimal candidate with the least likelihood of an immune response and can further drive the development of a clinical bioanalytical and immunogenicity monitoring strategy. Such a strategy can be proactively shared with the regulators along with the proposal to streamline clinical immunogenicity and personalizing the outcome based on pharmacogenomics and other patient-related factors. This paper provides a roadmap on performing risk assessments through a systematic identification of risks and their mitigations wherever possible. Recommendations on incorporating the key components of such risk assessments as part of the new regulatory submissions are also provided. Shorter abstract Immunogenicity to biologics is common during clinical trials. Both product and host specific factors have been implicated. Several risk assessment tools can be used to identify and mitigate the risk factors responsible for immunogenicity. An insight into recent advances in the risk assessment approaches will be presented. The outputs can define a risk score and guide the clinical bioanalytical and immunogenicity monitoring strategy. A roadmap on performing risk assessments through a systematic identification of risks and their mitigations wherever possible is provided. Best practices for a risk assessment strategy and recommendations on the content for IND and the Integrated summary of Immunogenicity are also provided.

Proprotein convertase subtilisin/kexin type 9 inhibitors treatment in dyslipidemic patients: a real world prescription

AIM

Dyslipidemia is recognized as one of the major risk factors for cardiovascular diseases. This retrospective observational study was aimed to assess the effect of proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors in dyslipidemic patients with a lipid profile not well controlled by maximally tolerated statin therapy or intolerant to these lipid-lowering drugs. We enrolled 151 patients, of whom, 119 were taking evolocumab and 32 alirocumab.

RESULTS

Total cholesterol significantly decreased progressively until the fourth year; after 4 years there was a significant reduction (-125.5 mg/dl, -51.5%, P < 0.0001 vs baseline, and P < 0.05 vs 1 year and P < 0.05 vs 2 years) and -2.8 mg/dl (-2.3%) compared with the third year. Low-density lipoprotein-cholesterol (LDL-C) also decreased significantly until the fourth year. After 3 years, there was a significant reduction (-117.8 mg/dl, -71.5%, P < 0.0001 vs baseline, and P < 0.05 vs 1 year) and -13.9 mg/dl (-22.8%) compared with the second year; after 4 years there was a significant reduction (-121.4 mg/dl, -73.7%, P < 0.0001 vs baseline, and P < 0.05 vs 1 year and P < 0.05 vs 2 years) and -3.6 mg/dl (-7.7%) compared with the third year. High-density lipoprotein-cholesterol increased significantly only during the fourth year of detection. After 3 years, there was a nonsignificant increase (4.9 mg/dl, 10.0%, P = 0.061 vs baseline) and 1.6 mg/dl (3.1%) compared with the second year; after 4 years, there was a significant increase (5.2 mg/dl, 10.6%, P < 0.05 vs baseline) and 0.3 mg/dl (0.6%) compared with the third year. The value of Tg was significantly reduced progressively until the second year and then stabilized in the third and fourth years. After 3 years, the value of Tg stabilized (-48.6 mg/dl, -32.4%, P < 0.01 vs baseline, and P < 0.05 vs 1 year) and -4.8 mg/dl (-4.5%) compared with the second year; after 4 years (-46.4 mg/dl, -31.0%, P < 0.01 vs baseline, and P < 0.05 vs 1 year) there was a slight and nonsignificant increase of 2.2 mg/dl (2.2%) compared with the third year. Regarding adverse events, both drugs were well tolerated.

CONCLUSIONS

We showed that PCSK9 inhibitors are well tolerated and provide long-term significant LDL-C lowering in individuals with hyperlipidemia.

PCSK9 as a Target for Development of a New Generation of Hypolipidemic Drugs

PCSK9 has now become an important target to create new classes of lipid-lowering drugs. The prevention of its interaction with LDL receptors allows an increase in the number of these receptors on the surface of the cell membrane of hepatocytes, which leads to an increase in the uptake of cholesterol-rich atherogenic LDL from the bloodstream. The PCSK9 antagonists described in this review belong to different classes of compounds, may have a low molecular weight or belong to macromolecular structures, and also demonstrate different mechanisms of action. The mechanisms of action include preventing the effective binding of PCSK9 to LDLR, stimulating the degradation of PCSK9, and even blocking its transcription or transport to the plasma membrane/cell surface. Although several types of antihyperlipidemic drugs have been introduced on the market and are actively used in clinical practice, they are not without disadvantages, such as well-known side effects (statins) or high costs (monoclonal antibodies). Thus, there is still a need for effective cholesterol-lowering drugs with minimal side effects, preferably orally bioavailable. Low-molecular-weight PCSK9 inhibitors could be a worthy alternative for this purpose.

The role of PCSK9 in inflammation, immunity, and autoimmune diseases

INTRODUCTION

Statins have pleiotropic effects, being both anti-inflammatory and immunomodulatory. Proprotein convertase subtilisin kexin 9 (PCSK9) targets the low-density lipoprotein receptor (LDLR), which increases LDL levels due to the lower expression of LDLR.

AREAS COVERED

Inhibition of PCSK9 by the use of antibodies represents a novel principle to lower LDL levels. LDL may have other properties than being a cholesterol carrier but is well established as a risk factor for cardiovascular disease and atherosclerosis. In atherosclerosis, the plaques are characterized by activated T cells and dendritic cells (DCs), dead cells, and OxLDL. The latter may be an important cause of the inflammation typical of atherosclerosis, by promoting a proinflammatory immune activation. This is inhibited by PCSK9 inhibition, and an anti-inflammatory type of immune activation is induced. OxLDL is raised in systemic lupus erythematosus (SLE), where both CVD and atherosclerosis are much increased compared to the general population. PCSK9 is reported to be associated with disease activity and complications in SLE. Also in other rheumatoid arthritis, PCSK9 may play a role.

EXPERT OPINION

PCSK9 has pleiotropic effects, being implicated in inflammation and immunity. Inhibition of PCSK9 is therefore interesting to study further as a potential therapy against inflammation and autoimmunity.

Hit or miss: the new cholesterol targets

Drug treatment to reduce cholesterol to new target levels is now recommended in four moderate- to high-risk patient populations: patients who have already sustained a cardiovascular event, adult diabetic patients, individuals with low density lipoprotein cholesterol levels ≥190 mg/dL and individuals with an estimated 10-year cardiovascular risk ≥7.5%. Achieving these cholesterol target levels did not confer any additional benefit in a systematic review of 35 randomised controlled trials. Recommending cholesterol lowering treatment based on estimated cardiovascular risk fails to identify many high-risk patients and may lead to unnecessary treatment of low-risk individuals. The negative results of numerous cholesterol lowering randomised controlled trials call into question the validity of using low density lipoprotein cholesterol as a surrogate target for the prevention of cardiovascular disease.

An update on emerging drugs for the treatment of hypercholesterolemia

INTRODUCTION

Elevated levels of low-density lipoprotein (LDL) cholesterol have been unequivocally demonstrated to play a causal role in atherosclerotic cardiovascular disease. The last thirty years have witnessed a generation of clinical trials that have demonstrated a reduction in cardiovascular risk with the use of increasing intensive lipid lowering regimens involving statin therapy in combination with other agents. However, many patients fail to achieve treatment mandated LDL cholesterol goals. This highlights the need to develop additional approaches to lower LDL cholesterol levels.

AREAS COVERED

(i) Contemporary data highlighting the atherogenicity of LDL cholesterol and cardiovascular benefits of current lipid lowering therapies. (ii) Importance of statin intolerance and inability to achieve LDL cholesterol goals in driving ongoing cardiovascular risk. (iii) Emergence of new therapeutic agents designed to achieve more effective lowering of LDL cholesterol.

EXPERT OPINION

Effective lowering of LDL cholesterol plays a critical role in approaches to the prevention of cardiovascular disease. A greater number of patients will require combinations of agents to achieve optimal lipid control. Accordingly, new agents will be required to provide sufficient choice for patients at high cardiovascular risk.

Gene Therapy for Cardiovascular Disease: Basic Research and Clinical Prospects

In recent years, the vital role of genetic factors in human diseases have been widely recognized by scholars with the deepening of life science research, accompanied by the rapid development of gene-editing technology. In early years, scientists used homologous recombination technology to establish gene knock-out and gene knock-in animal models, and then appeared the second-generation gene-editing technology zinc-finger nucleases (ZFNs) and transcription activator-like effector nucleases (TALENs) that relied on nucleic acid binding proteins and endonucleases and the third-generation gene-editing technology that functioned through protein-nucleic acids complexes-CRISPR/Cas9 system. This holds another promise for refractory diseases and genetic diseases. Cardiovascular disease (CVD) has always been the focus of clinical and basic research because of its high incidence and high disability rate, which seriously affects the long-term survival and quality of life of patients. Because some inherited cardiovascular diseases do not respond well to drug and surgical treatment, researchers are trying to use rapidly developing genetic techniques to develop initial attempts. However, significant obstacles to clinical application of gene therapy still exists, such as insufficient understanding of the nature of cardiovascular disease, limitations of genetic technology, or ethical concerns. This review mainly introduces the types and mechanisms of gene-editing techniques, ethical concerns of gene therapy, the application of gene therapy in atherosclerosis and inheritable cardiovascular diseases, in-stent restenosis, and delivering systems.

Polyreactivity and polyspecificity in therapeutic antibody development: risk factors for failure in preclinical and clinical development campaigns

Antibody-based drugs, which now represent the dominant biologic therapeutic modality, are used to modulate disparate signaling pathways across diverse disease indications. One fundamental premise that has driven this therapeutic antibody revolution is the belief that each monoclonal antibody exhibits exquisitely specific binding to a single-drug target. Herein, we review emerging evidence in antibody off-target binding and relate current key findings to the risk of failure in therapeutic development. We further summarize the current state of understanding of structural mechanisms underpining the different phenomena that may drive polyreactivity and polyspecificity, and highlight current thinking on how de-risking studies may be best implemented in the screening triage. We conclude with a summary of what we believe to be key observations in the field to date, and a call for the wider antibody research community to work together to build the tools needed to maximize our understanding in this nascent area.

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

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

Emerging Anti-Atherosclerotic Therapies

Cardiovascular disease (CAD) is the main cause of morbidity and deaths in the western world. The development of atherosclerosis underlying CAD development begins early in human life. There are numerous genetic and environmental risk factors accelerating its progression which then leads to the occurrence of acute events. Despite considerable progress in determining risk factors, there is still a lot of work ahead since identified determinants are responsible only for a part of overall CAD risk. Current therapies are insufficient to successfully reduce the risk of atherosclerosis development. Therefore, there is a need for effective preventive measures of clinical manifestations of atherosclerosis since the currently available drugs cannot prevent the occurrence of even 70% of clinical events. The shift of the target from lipid metabolism has opened the door to many new therapeutic targets. Currently, the majority of known targets for anti-atherosclerotic drugs focus also on inflammation (a common mediator of many risk factors), mechanisms of innate and adaptive immunity in atherosclerosis, molecule scavengers, etc. The therapeutic potential of cyclodextrins, protein kinase inhibitors, colchicine, inhibitors of p38 mitogen-activated protein kinase (MAPK), lipid dicarbonyl scavengers, a monoclonal antibody targeting interleukin-1β, and P-selectin inhibitors is still not fully confirmed and requires confirmation in large clinical trials. The preliminary results look promising.

Relationship of serial hsCRP changes to long-term clinical outcomes in stabilized post myocardial infarction patients

BACKGROUND

Little is known about the association between serial hsCRP (high-sensitivity C-reactive protein) measurements and long-term outcomes in post-myocardial infarction(MI) patients. We aimed to investigate the usefulness of serial hsCRP measurements for risk stratification in stabilized post-MI patients following percutaneous coronary intervention (PCI).

METHODS

A total of 1,018 patients who had hsCRP values at both baseline and 1 year following MI were included. High inflammatory status was defined as an hsCRP>2 mg/L. Patients were classified into four groups: persistently low, falling (first high then low hsCRP), rising (first low then high hsCRP), or persistently high hsCRP. The primary outcome was major adverse cardiac and cerebrovascular events (MACCE: a composite of all-cause of death, MI, and cerebrovascular accident) within 4 years after the second hsCRP measurement.

RESULTS

At 1 year after MI, the number of patients in the persistently low, falling, rising, and persistently high hsCRP groups was 394(38.7%),358(35.2%),69(6.8%), and 197(19.4%), respectively. The incidence of MACCE was progressively elevated from the persistently low to the falling, rising, and persistently high hsCRP groups.(respectively,4.8%,8.1%,10.1%, and 13.2%; p=0.004). Persistently high hsCRP was an independent predictor of MACCE (adjusted hazard ratio:2.55; 95% confidence interval:1.35 to 4.81; p=0.004) and provided incremental prognostic value beyond that of the baseline clinical risk model (NRI=0.397, IDI=0.025, all p < 0.001).

CONCLUSIONS

Among stabilized post-MI patients who underwent PCI, persistently high hsCRP was frequently seen 1 year after MI and was strongly associated with long-term adverse clinical outcomes. Serial measurements of hsCRP during clinical follow-up after MI may help to identify patients at higher risk for mortality and morbidity.

Incremental net benefit of lipid-lowering therapy with PCSK9 inhibitors: a systematic review and meta-analysis of cost-utility studies

INTRODUCTION

Proprotein convertase subtilisin/kexin 9 inhibitors (PCSK9i) are monoclonal antibodies that lower lipid levels. Although several cardiovascular outcome trials reported the effectiveness of PCSK9i, the evidence on cost-effectiveness is mixed. We systematically reviewed the evidence and synthesized incremental net benefit (INB) to quantify pooled cost-effectiveness.

METHODS

We systematically searched for full economic evaluation studies reporting outcomes of PCSK9i compared with other lipid-lowering pharmacotherapies. We searched PubMed, Embase, Scopus, and Tufts Registry for eligible studies up to August 2021, adhering to preferred reporting items for systematic reviews and meta-analyses guidelines. We pooled INB in US$ with a 95% confidence interval using a random-effects model. We assessed heterogeneity using the Cochran Q test and I² statistics. We used the modified economic evaluations bias (ECOBIAS) checklist to evaluate the quality of selected studies.

RESULTS

Twenty-three studies were eligible, mainly from high-income countries (HIC). The pooled INB (INBp) of PCSK9i versus other lipid-lowering pharmacotherapies were estimated from n = 24 comparisons, with high heterogeneity (I² = 99.99). The INBp (95% CI) was $ - 78,207 (- 120,422; - 35,993) or € - 52,526 (- 80,879; - 24,174) (conversion factor 1 US$ = 0.67€) which shows that PCSK9i was not significantly cost-effective when compared to other standard therapies. On subgroup analysis PCSK9i was significantly not cost-effective [$ - 23,672 (- 24,061; - 23,282)] compared to other lipid-lowering pharmacotherapies in HICs, upper-middle-income countries [$ - 158,412 (- 241,738; - 75,086)] or when the target population was CVD [$ - 109,343 (- 158,968; - 59,717)]; and for treatment subgroup: against placebo or no treatment [$ - 79,018 (- 79,649; - 78,388 PCSK9)] and standard statin therapies [$ - 131,833 (- 173,449; - 90,216)]. The sensitivity analysis revealed that the findings are not robust for HICs and the treatment subgroups.

CONCLUSION

PCSK9 inhibitors are not cost-effective compared to other lipid-lowering pharmacotherapies in HICs. Further, current pieces of evidence are predominantly from HICs with largely lacking evidence from other economies.

PROSPERO REGISTRATION

ID CRD42020206043.

Modern Approaches to Lower Lipoprotein(a) Concentrations and Consequences for Cardiovascular Diseases

Lipoprotein(a) (Lp(a)) is a low density lipoprotein particle that is associated with poor cardiovascular prognosis due to pro-atherogenic, pro-thrombotic, pro-inflammatory and pro-oxidative properties. Traditional lipid-lowering therapy does not provide a sufficient Lp(a) reduction. For PCSK9 inhibitors a small reduction of Lp(a) levels could be shown, which was associated with a reduction in cardiovascular events, independently of the effect on LDL cholesterol. Another option is inclisiran, for which no outcome data are available yet. Lipoprotein apheresis acutely and in the long run decreases Lp(a) levels and effectively improves cardiovascular prognosis in high-risk patients who cannot be satisfactorily treated with drugs. New drugs inhibiting the synthesis of apolipoprotein(a) (an antisense oligonucleotide (Pelacarsen) and two siRNA drugs) are studied. Unlike LDL-cholesterol, for Lp(a) no target value has been defined up to now. This overview presents data of modern capabilities of cardiovascular risk reduction by lowering Lp(a) level.

Umbrella Review on Non-Statin Lipid-Lowering Therapy

OBJECTIVES

The main aim of this review was to summarize current evidence on approved and emerging non-statin lipid-lowering therapies.

METHODS AND MATERIALS

Recent literature on U.S. FDA approved non-statin lipid-lowering therapies and evolving lipid-lowering drugs currently under development was reviewed.

RESULTS AND DISCUSSION

In the past 20 years, the emergence of non-statin cholesterol-lowering drugs has changed the landscape of dyslipidemia management. Food and Drug Administration approval of non-statin lipid-lowering therapies such as ezetimibe, proprotein convertase subtilisin/Kexin type 9 (PCSK9) inhibitors (evolocumab, alirocumab), bempedoic acid and combination of bempedoic acid and ezetimibe, evinacumab and other triglyceride-lowering agents (eg, icosapent ethyl) has emerged. The European Commission has also recently approved inclisiran for treatment of hypercholesterolemia and mixed hypercholesterolemia even though FDA has put the approval of this drug on hold. Recent guidelines have incorporated PCSK9 inhibitors to treat patients with primary hyperlipidemia and patients with very high-risk ASCVD, who could not achieve adequate lipid-lowering with combination therapy of maximally tolerated statin and ezetimibe. Icosapent ethyl use as an adjunct therapy to statins is also recommended to reduce the risk of ASCVD in patients with hypertriglyceridemia.

CONCLUSION

Despite cost limitations, the uptake of PCSK9 inhibitors is increasing. Approval of bempedoic acid alone or in combination with ezetimibe has provided additional oral lipid-lowering drug alternatives to ezetimibe. Various lipid-lowering drug targets are under investigation.

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.

Coronary Artery Disease Genetics Enlightened by Genome-Wide Association Studies

Many cardiovascular diseases are facilitated by strong inheritance. For example, large-scale genetic studies identified hundreds of genomic loci that affect the risk of coronary artery disease. At each of these loci, common variants are associated with disease risk with robust statistical evidence but individually small effect sizes. Only a minority of candidate genes found at these loci are involved in the pathophysiology of traditional risk factors, but experimental research is making progress in identifying novel, and, in part, unexpected mechanisms. Targets identified by genome-wide association studies have already led to the development of novel treatments, specifically in lipid metabolism. This review summarizes recent genetic and experimental findings in this field. In addition, the development and possible clinical usefulness of polygenic risk scores in risk prediction and individualization of treatment, particularly in lipid metabolism, are discussed.

Achieved low-density lipoprotein cholesterol level and stroke risk: A meta-analysis of 23 randomised trials

AIMS

Lowering the low-density lipoprotein cholesterol level reduces the risk of stroke, but it has not been clear whether the stroke risk would continuously decrease by lowering low-density lipoprotein cholesterol to a very low level. The purpose of this study was to evaluate the association between achieved low-density lipoprotein cholesterol levels and stroke risk.

METHODS AND RESULTS

A systematic search of MEDLINE, EMBASE and Cochrane Library databases was conducted to identify randomised controlled trials that tested cholesterol-lowering pharmacological therapies and reported both achieved low-density lipoprotein cholesterol levels and stroke outcomes. A meta-regression analysis was conducted to assess the linear association between the achieved low-density lipoprotein cholesterol levels and stroke risk. In addition, we evaluated pooled estimates of low-density lipoprotein cholesterol-lowering effect stratified by achieved low-density lipoprotein cholesterol levels of active arms. A total of 222,149 participants in 23 trials (52 arms of 26 studies) were included. The meta-regression analysis showed that each 1 mmol/L decrease in the achieved low-density lipoprotein cholesterol level (down to 0.78 mmol/L) was associated with a significant reduction of 23.5% (slope 0.235, 95% confidence interval 0.007-0.464, P = 0.044) in stroke risk. Irrespective of achieved low-density lipoprotein cholesterol levels in the active arms, the effects of lowering the low-density lipoprotein cholesterol level on stroke risk were significant and consistent (test for subgroup difference, P = 0.23, I2 = 31%). However, there was no significant increase in haemorrhagic stroke risk with lower achieved low-density lipoprotein cholesterol levels.

CONCLUSION

In this meta-analysis of randomised controlled trials, the stroke risk monotonically reduced with lowering of low-density lipoprotein cholesterol to very low levels.

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.

Lipid-Lowering Therapy and Hemorrhagic Stroke Risk: Comparative Meta-Analysis of Statins and PCSK9 Inhibitors

BACKGROUND AND PURPOSE

Statins were shown to increase hemorrhagic stroke (HS) in patients with a first cerebrovascular event in 2006 (SPARCL), likely due to off-target antithrombotic effects, but continued to sometimes be used in patients with elevated HS risk due to absence of alternative medications. Recently, the PCSK9Is (proprotein convertase subtilisin kexin 9 inhibitors) have become available as a potent lipid-lowering class with potentially less hemorrhagic propensity.

METHODS

We performed a systematic comparative meta-analysis assessing HS rates across all completed statin and PCSK9I randomized clinical trials with treatment >3 months, following PRISMA guidelines. In addition to HS rates across all trials, causal relation was probed by evaluating for dose-response relationships by medication (low versus high medication dose/potency) and by presence and type of preceding brain vascular events at inception (none versus ischemic stroke/transient ischemic attack versus HS).

RESULTS

The systematic review identified 36 statin randomized clinical trials (204 918 patients) and 5 PCSK9I randomized clinical trials (76 140 patients). Across all patient types and all medication doses/potencies, statins were associated with increased HS: relative risk 1.15, P=0.04; PCSK9Is were not (P=0.77). In the medication dose/potency analysis, higher dose/potency statins (7 trials, 62 204 patients) were associated with magnified HS risk: relative risk, 1.53; P=0.002; higher dose/potency PCSK9Is (1 trial, 27 564 patients) were not (P=0.99). In the type of index brain vascular injury analysis for statins (5 trials, 9772 patients), prior ischemic stroke/transient ischemic attack was associated with a magnified risk of HS: relative risk, 1.43; P=0.04; and index intracerebral hemorrhage was associated with an extremely high effect estimate of risk of recurrent HS: hazard ratio, 4.06. For PCSK9Is, prior ischemic stroke/transient ischemic attack (1 trial, 5337 patients) was not associated with increased HS risk (P=0.97).

CONCLUSIONS

Statins increase the risk of HS in a medication dose- and type of index brain vascular injury-dependent manner; PCSK9Is do not increase HS risk. PCSK9Is may be a preferred lipid-lowering medication class in patients with elevated HS risk, including patients with prior HS.

Lipoprotein(a) Testing and Emerging Therapies

The study of lipoprotein(a) [Lp(a)] over the years has been a source of both enlightenment and frustration for the medical community. Accumulating evidence from large sample observational studies, Mendelian randomization studies, and genome-wide association studies has strengthened the association between Lp(a) and the development of atherosclerotic cardiovascular disease. This evidence supports the testing of Lp(a) in certain high-risk populations in order for clinicians to improve the risk profile of patients. Despite a variety of medical therapies that have been proven to reduce Lp(a) levels, the connection between the medical management of serum Lp(a) and improved cardiovascular outcomes remains elusive, due to the lack of specificity that current therapies have in targeting the Lp(a) production pathway. A new frontier in Lp(a) research has emerged with antisense-oligonucleotide therapy and RNA interference therapy, both of which target Lp(a) production at the level of mRNA translation. These therapies provide a pathway for investigating the effect of medical management of serum Lp(a) on cardiovascular outcomes.

Targeting the Cholesterol Paradigm in the Risk Reduction for Atherosclerotic Cardiovascular Disease: Does the Mechanism of Action of Pharmacotherapy Matter for Clinical Outcomes?

Hypercholesterolemia is a well-established risk factor for atherosclerotic cardiovascular disease (ASCVD). Low-density lipoprotein cholesterol (LDL-C) has been labeled as "bad" cholesterol and high-density lipoprotein cholesterol (HDL-C) as "good" cholesterol. The prevailing hypothesis is that lowering blood cholesterol levels, especially LDL-C, reduces vascular deposition and retention of cholesterol or apolipoprotein B (apoB)-containing lipoproteins which are atherogenic. We review herein the clinical trial data on different pharmacological approaches to lowering blood cholesterol and propose that the mechanism of action of cholesterol lowering, as well as the amplitude of cholesterol reduction, are critically important in leading to improved clinical outcomes in ASCVD. The effects of bile acid sequestrants, fibrates, niacin, cholesteryl ester transfer protein (CETP) inhibitors, apolipoprotein A-I and HDL mimetics, apoB regulators, acyl coenzyme A: cholesterol acyltransferase (ACAT) inhibitors, cholesterol absorption inhibitors, statins, and proprotein convertase subtilisin kexin 9 (PCSK9) inhibitors, among other strategies are reviewed. Clinical evidence supports that different classes of cholesterol lowering or lipoprotein regulating approaches yielded variable effects on ASCVD outcomes, especially in cardiovascular and all-cause mortality. Statins are the most widely used cholesterol lowering agents and have the best proven cardiovascular event and survival benefits. Manipulating cholesterol levels by specific targeting of apoproteins or lipoproteins has not yielded clinical benefit. Understanding why lowering LDL-C by different approaches varies in clinical outcomes of ASCVD, especially in survival benefit, may shed further light on our evolving understanding of how cholesterol and its carrier lipoproteins are involved in ASCVD and aid in developing effective pharmacological strategies to improve the clinical outcomes of ASCVD.

Antibody-Based Therapeutics for Atherosclerosis and Cardiovascular Diseases

Cardiovascular disease is the leading cause of death worldwide, and its prevalence is increasing due to the aging of societies. Atherosclerosis, a type of chronic inflammatory disease that occurs in arteries, is considered to be the main cause of cardiovascular diseases such as ischemic heart disease or stroke. In addition, the inflammatory response caused by atherosclerosis confers a significant effect on chronic inflammatory diseases such as psoriasis and rheumatic arthritis. Here, we review the mechanism of action of the main causes of atherosclerosis such as plasma LDL level and inflammation; furthermore, we review the recent findings on the preclinical and clinical effects of antibodies that reduce the LDL level and those that neutralize the cytokines involved in inflammation. The apolipoprotein B autoantibody and anti-PCSK9 antibody reduced the level of LDL and plaques in animal studies, but failed to significantly reduce carotid inflammation plaques in clinical trials. The monoclonal antibodies against PCSK9 (alirocumab, evolocumab), which are used as a treatment for hyperlipidemia, lowered cholesterol levels and the incidence of cardiovascular diseases. Antibodies that neutralize inflammatory cytokines (TNF-α, IL-1β, IL-6, IL-17, and IL-12/23) have shown promising but contradictory results and thus warrant further research.

Association Between Industry Marketing Payments and Prescriptions for PCSK9 (Proprotein Convertase Subtilisin/Kexin Type 9) Inhibitors in the United States

BACKGROUND

Marketing payments from the pharmaceutical industry to physicians have come under scrutiny due to their potential to influence clinical decision-making. Two proprotein convertase subtilisin/kexin type 9 inhibitors (PCSK9i) were approved by the US Food and Drug Administration in 2015 for reducing low-density lipoprotein cholesterol in high-risk patients, but their initial uptake was limited due to their high-cost and stringent prior authorization requirements. We sought to investigate the association between industry marketing and early adoption of PCSK9i among US physicians.

METHODS

We used nationwide databases of primary care physicians, cardiologists, and endocrinologists treating Medicare beneficiaries to examine the association between PCSK9i-related marketing payments in 2016 and the number of filled PCSK9i prescriptions in 2017, after adjusting for physician characteristics. In subgroup analyses, we stratified our analyses by physician specialty and prior experience with prescribing PCSK9i.

RESULTS

Among 209 840 physicians included in this analysis, 49 341 (24%) physicians received 292 941 PCSK9i-related marketing payments in 2016. The total value of these payments was $19 million, with a median payment of $61 per physician (interquartile range, $25-$132). Most payments (95%) were for meals, with a median of $14 per meal. The receipt of PCSK9i-related payments in 2016 was associated with increased PCSK9i prescription in 2017 (adjusted risk ratio, 3.18 [95% CI, 2.95-3.42]). This association was larger among primary care physicians (adjusted risk ratio, 6.67 [95% CI, 5.87-7.57]) than cardiologists (adjusted risk ratio, 2.00 [95% CI, 1.84-2.16]) and endocrinologists (adjusted risk ratio, 4.06 [95% CI, 2.95-5.59]). The association was observed across all types of payments.

CONCLUSIONS

At a time when few physicians had experience with prescribing PCSK9i under strict prior authorization requirements, industry marketing payments to physicians for PCSK9i, predominantly in the form of meals, were associated with increased PCSK9i prescription in the subsequent year.

Inclisiran: A Novel Agent for Lowering Apolipoprotein B-Containing Lipoproteins

ABSTRACT

Hypercholesterolemia is a leading cause of cardiovascular morbidity and mortality. Accordingly, efforts to lower apolipoprotein B-containing lipoproteins in plasma are the centerpiece of strategies for cardiovascular prevention and treatment in primary and secondary management. Despite the importance of this endeavor, many patients do not achieve appropriate low density lipoprotein cholesterol (LDL-C) and non-high density lipoprotein cholesterol (non-HDL-C) goals, even among those who have experienced atherosclerotic cardiovascular disease (ASCVD). The development of new LDL-C-lowering medications with alternative mechanisms of action will facilitate improved goal achievement in high risk patients. Inclisiran is a novel small interfering ribonucleic acid (siRNA)-based drug that is experimental in the US and approved for clinical use in the EU. It lowers LDL-C and other apolipoprotein B-containing lipoproteins by reducing production of Proprotein Convertase Subtilisin/Kexin Type 9 (PCSK9), a protein that normally contributes to LDL-receptor (LDLR) degradation, thereby increasing LDLR density and recycling in hepatocytes. Although the lipid-lowering efficacy of inclisiran is comparable to results achieved with PCSK9-blocking monoclonal antibodies (PCSK9i) (alirocumab and evolocumab), there are several important differences between the two drug classes. First, inclisiran reduces levels of PCSK9 both intracellularly and extracellularly by blocking translation of and degrading PCSK9 messenger RNA. Second, the long biological half-life of inclisiran produces sustained LDL-C-lowering with twice yearly dosing. Third, although PCSK9i drugs are proven to reduce ASCVD events, clinical outcomes trials with inclisiran are still in progress. In this manuscript, we review the clinical development of inclisiran, its mechanism of action, lipid-lowering efficacy, safety and tolerability, and potential clinical role of this promising new agent.

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.

Real-World Efficacy of Proprotein Convertase Subtilisin/Kexin Type 9 Inhibitors (PCSK9i) in Heterozygous Familial Hypercholesterolemia Patients Referred for Lipoprotein Apheresis

BACKGROUND A small proportion of familial hypercholesterolemia (FH) patients can adequately control this condition, although achieving the recommended targets for low-density lipoprotein cholesterol (LDL-c) levels remains a challenge. Proprotein convertase subtilisin/kexin type 9 inhibitors (PCSK9i) are new and potent lipid-lowering drugs. However, there is scarce literature on real-world data about their use in patients with FH. MATERIAL AND METHODS We examined the reduction in LDL-c levels from the baseline, after PCSK9i initiation in heterozygous familial hypercholesterolemia patients referred for lipoprotein apheresis in our regional lipid clinic. The study was conducted from March 2018 to September 2019, the period immediately after PCSK9i reimbursement was available in France. PCSK9i was added on top of the patients' maximal tolerated lipid-lowering regimens. RESULTS The study had 123 patients with heterozygous FH. The mean age of the patients was 59±11 years. The mean baseline LDL-c for all the participants was 277±78 mg/dl. It was 283±81 mg/dl in the PCSK9i monotherapy group (n=83), 247±68 mg/dl in the PCSK9i plus ezetimibe group (n=12), and 264±78 mg/dl in the PCSK9i plus statin and ezetimibe group (n=28). The mean decrease observed in the LDL-c level from baseline was 136±70 mg/dl (n=123), 125±60 mg/dl (n=83), 103±77 mg/dl (n=12), and 175±70 mg/dl (n=28), respectively. CONCLUSIONS An overall reduction of 49.1% from the baseline LDL-c was observed in the heterozygous FH population after PCSK9i initiation in a real-world experience. The group treated with PCSK9i ezetimibe plus statin showed further reduction of their LDL-c levels with a better responder rate, achieving the target 50% reduction in LDL-c from the baseline.

Advances in Clinical Cardiology 2020: A Summary of Key Clinical Trials

INTRODUCTION

Despite the challenge of a global pandemic, 2020 has been an invaluable year in cardiology research with numerous important clinical trials published or presented virtually at major international meetings. This article aims to summarise these trials and place them in clinical context.

METHODS

The authors reviewed clinical trials presented at major cardiology conferences during 2020 including the American College of Cardiology, European Association for Percutaneous Cardiovascular Interventions, European Society of Cardiology, Transcatheter Cardiovascular Therapeutics and the American Heart Association. Trials with a broad relevance to the cardiology community and those with potential to change current practice were included.

RESULTS

A total of 87 key cardiology clinical trials were identified for inclusion. New interventional and structural cardiology data included trials evaluating bifurcation percutaneous coronary intervention (PCI) techniques, intravascular ultrasound (IVUS)-guided PCI, instantaneous wave-free (iFR) physiological assessment, new generation stents (DynamX bioadaptor), transcatheter aortic valve implantation (TAVI) in low-risk patients, and percutaneous mitral or tricuspid valve interventions. Preventative cardiology data included new data with proprotein convertase subtilisin-kexin type 9 (PCSK9) inhibitors (evolocumab and alirocumab), omega-3 supplements, evinacumab and colchicine in the setting of chronic coronary artery disease. Antiplatelet data included trials evaluating both the optimal length of course following PCI and combination of antiplatelet agents and regimes including combination antithrombotic therapies for patients with atrial fibrillation (AF). Heart failure data included the use of sodium-glucose cotransporter 2 (SGLT2) inhibitors (sotagliflozin, empagliflozin and dapagliflozin) and mavacamten in hypertrophic cardiomyopathy. Electrophysiology trials included early rhythm control in AF and screening for AF.

CONCLUSION

This article presents a summary of key clinical cardiology trials during the past year and should be of relevance to both clinicians and cardiology researchers.

Therapeutic targets in the treatment of dyslipidaemias: From statins to PCSK9 inhibitors. Unmet needs

The use of low-density lipoprotein cholesterol (LDLc)-lowering medications has led to a significant reduction of cardiovascular risk in both primary and secondary prevention. Statins represent the cornerstone of lipid-lowering treatment and substantially decreases cardiovascular morbidity and mortality. However, there are still unmet clinical needs in the management of dyslipidaemia. Indeed, it is difficult to achieve LDLc targets in many patients, particularly in those at high/very high cardiovascular risk and in those with very high baseline LDLc concentrations. Moreover, a considerable proportion of patients are unable to tolerate maximum statin doses, mostly due to muscle-related adverse effects. In the present narrative review, a summary is presented on the current knowledge on the effects of the different cholesterol-lowering drugs, including those recently approved by European and American regulatory agencies, on lipid profile, and on cardiovascular risk. Since difficult-to-treat patients may benefit from new combination therapies as a result of the emergence of new drugs with clinical evidence, updates of the clinical guidelines would be recommended.

LDL-cholesterol reduction in chronic kidney disease: options beyond statins

PURPOSE OF REVIEW

Individuals with chronic kidney disease (CKD) are at increased risk of atherosclerotic cardiovascular disease (ASCVD) events. LDL cholesterol (LDL-C) is a key modifiable cause of ASCVD and lowering LDL-C with statins reduces the risk of ASCVD events in a wide range of populations, including those with CKD. This review considers the utility of recently developed nonstatin LDL-C-lowering therapies in CKD.

RECENT FINDINGS

The cholesterol absorption inhibitor, ezetimibe, reduces LDL-C by 15-20% and is well tolerated in CKD. Monoclonal antibodies (mAbs) targeting proprotein convertase subtilisin kexin type 9 (PCSK9) reduce LDL-C by 50-60% and reduce the risk of ASCVD events. However, these agents require self-administration by subcutaneous injection every 2-4 weeks. The PCSK9 synthesis inhibitor, inclisiran, is administered approximately 6 monthly and may be more suitable for widespread use, although outcome trials are awaited. These PCSK9 targeting therapies require no dose adjustment in CKD and have no drug interactions.

SUMMARY

Statins and ezetimibe are safe and reduce ASCVD risk in CKD populations. PCSK9 targeting agents may be useful in high-risk CKD patients, including those with prior ASCVD.

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.

Role of PCSK9 Inhibitors in Patients with Familial Hypercholesterolemia

Patients with familial hypercholesterolemia (FH) are at high or very high risk for cardiovascular disease. Those with heterozygous FH (HeFH) often do not reach low-density lipoprotein cholesterol (LDL-C) targets with statin and ezetimibe therapy, and those with homozygous FH (HoFH) usually require additional lipid-modifying therapies. Drugs that inhibit proprotein convertase subtilisin/kexin type 9 (PCSK9) offer a novel approach to reduce LDL-C. The monoclonal antibodies, alirocumab and evolocumab, given by subcutaneous injection every 2 or 4 weeks produce reductions in LDL-C of 50% to 60% in patients with HeFH, allowing many of them to achieve their LDL-C goals. Patients with HoFH show a reduced and more variable LDL-C response, which appears to depend on residual LDL receptor activity, and those with receptor-negative mutations may show no response. Inclisiran is a long-acting small interfering RNA therapeutic agent that inhibits the synthesis of PCSK9. Subcutaneous doses of 300 mg can reduce LDL-C by more than 50% for at least 6 months and the responses in HeFH and HoFH patients are similar to those achieved with monoclonal antibodies. These PCSK9 inhibitors are generally well tolerated and they provide a new opportunity for effective treatment for the majority of patients with FH.

PCSK9 Functions in Atherosclerosis Are Not Limited to Plasmatic LDL-Cholesterol Regulation

The relevance of PCSK9 in atherosclerosis progression is demonstrated by the benefits observed in patients that have followed PCSK9-targeted therapies. The impact of these therapies is attributed to the plasma lipid-lowering effect induced when LDLR hepatic expression levels are recovered after the suppression of soluble PCSK9. Different studies show that PCSK9 is involved in other mechanisms that take place at different stages during atherosclerosis development. Indeed, PCSK9 regulates the expression of key receptors expressed in macrophages that contribute to lipid-loading, foam cell formation and atherosclerotic plaque formation. PCSK9 is also a regulator of vascular inflammation and its expression correlates with pro-inflammatory cytokines release, inflammatory cell recruitment and plaque destabilization. Furthermore, anti-PCSK9 approaches have demonstrated that by inhibiting PCSK9 activity, the progression of atherosclerotic disease is diminished. PCSK9 also modulates thrombosis by modifying platelets steady-state, leukocyte recruitment and clot formation. In this review we evaluate recent findings on PCSK9 functions in cardiovascular diseases beyond LDL-cholesterol plasma levels regulation.

Association Between Circulating Proprotein Convertase Subtilisin/Kexin Type 9 and Major Adverse Cardiovascular Events, Stroke, and All-Cause Mortality: Systemic Review and Meta-Analysis

Background: Proprotein convertase subtilisin/kexin type 9 (PCSK9), a pivotal protein in low-density lipoprotein cholesterol metabolism, has been validated to be an established target for cardiovascular (CV) risk reduction. Nevertheless, prospective studies concerning the associations between circulating PCSK9 and the risk of CV events and mortality have yielded, so far, inconsistent results. Herein, we conducted a meta-analysis to evaluate the association systemically. Methods: Pertinent studies were identified from PubMed, EMBASE, and Cochrane Library database through July 2020. Longitudinal studies investigating the value of circulating PCSK9 for predicting major adverse cardiovascular events (MACEs) or stroke or all-cause mortally with risk estimates and 95% confidence intervals (CI) were included in the analyses. Dose-response meta-analysis was also applied to evaluate circulating PCSK9 and risk of MACEs in this study. Results: A total of 22 eligible cohorts comprising 28,319 participants from 20 eligible articles were finally included in the study. The pooled relative risk (RR) of MACEs for one standard deviation increase in baseline PCSK9 was 1.120 (95% CI, 1.056-1.189). When categorizing subjects into tertiles, the pooled RR for the highest tertile of baseline PCSK9 was 1.252 (95% CI, 1.104-1.420) compared with the lowest category. This positive association between PCSK9 level and risk of MACEs persisted in sensitivity and most of the subgroup analyses. Twelve studies were included in dose-response meta-analysis, and a linear association between PCSK9 concentration and risk of MACEs was observed (x2 test for non-linearity = 0.31, P non-linearity = 0.575). No significant correlation was found either on stroke or all-cause mortality. Conclusion: This meta-analysis added further evidence that high circulating PCSK9 concentration significantly associated with increased risk of MACEs, and a linear dose-response association was observed. However, available data did not suggest significant association either on stroke or all-cause mortality. Additional well-designed studies are warranted to further investigate the correlations between PCSK9 concentration and stroke and mortality.

Personalized medicine in lipid-modifying therapy

The choice of lipid-modifying treatment is largely based on the absolute level of cardiovascular risk and baseline lipid profile. Statins are the first-line treatment for most patients requiring reduction of low-density-lipoprotein cholesterol (LDL-C) and ezetimibe and proprotein convertase subtilisin/kexin type 9 inhibitors can be added to reach LDL-C targets. Statins have some adverse effects that are somewhat predictable based on phenotypic and genetic factors. Fibrates or omega-3 fatty acids can be added if triglyceride levels remain elevated. The RNA-targeted therapeutics in development offer the possibility of selective liver targeting for specific lipoproteins such as lipoprotein(a) and long-term reduction of LDL-C with infrequent administration of a small-interfering RNA may help to overcome the problem of adherence to therapy.

New and Emerging Therapies for Reduction of LDL-Cholesterol and Apolipoprotein B: JACC Focus Seminar 1/4

Adding to the foundation of statins, ezetimibe and proprotein convertase subtilisin-kexin type 9 inhibitors (PCSK9i), novel, emerging low-density lipoprotein cholesterol (LDL-C)-lowering therapies are under development for the prevention of cardiovascular disease. Inclisiran, a small interfering RNA molecule that inhibits PCSK9, only needs to be dosed twice a year and has the potential to help overcome current barriers to persistence and adherence to lipid-lowering therapies. Bempedoic acid, which lowers LDL-C upstream from statins, provides a novel alternative for patients with statin intolerance. Angiopoetin-like 3 protein (ANGPTL3) inhibitors have been shown to provide potent LDL-C lowering in patients with homozygous familial hypercholesterolemia without major adverse effects as seen with lomitapide and mipomersen, and may reduce the need for apheresis. Finally, CETP inhibitors may yet be effective with the development of obicetrapib. These novel agents provide the clinician the tools to effectively lower LDL-C across the entire range of LDL-C-induced elevation of cardiovascular risk, from primary prevention and secondary prevention to null-null homozygous familial hypercholesterolemia patients.

The neutrophil-lymphocyte ratio and incident atherosclerotic events: analyses from five contemporary randomized trials

AIMS

The neutrophil-lymphocyte ratio (NLR) is a readily available inflammatory biomarker that may associate with atherosclerosis and predict cardiovascular (CV) events. The aims of this study are to determine whether the NLR predicts incident major adverse cardiovascular events (MACE) and is modified by anti-inflammatory therapy.

METHODS AND RESULTS

Baseline and on-treatment NLRs were calculated from complete blood counts among 60 087 participants randomized in the CANTOS, JUPITER, SPIRE-1, SPIRE-2, and CIRT trials to receive placebo or canakinumab, rosuvastatin, bococizumab, or methotrexate, respectively, and followed up for MACE. All analyses were performed first in CANTOS, and then externally validated in the other four trials. For the five trials, hazard ratios for major CV events and mortality comparing NLR quartiles were computed using Cox proportional hazards models, and the effect of each randomized intervention on the NLR was evaluated in comparison to placebo. The NLR modestly correlated with interleukin-6, C-reactive protein, and fibrinogen levels but minimally with lipids. In all five randomized trials, baseline NLR predicted incident CV events and death; the per-quartile increase in risk of MACE was 20% in CANTOS [95% confidence interval (CI) 14-25%, P < 0.0001], 31% in SPIRE-1 (95% CI 14-49%, P = 0.00007), 27% in SPIRE-2 (95% CI 12-43%, P = 0.0002), 9% in CIRT (95% CI 0.2-20%, P = 0.045), and 11% in JUPITER (95% CI 1-22%, P = 0.03). While lipid-lowering agents had no significant impact on the NLR, anti-inflammatory therapy with canakinumab lowered the NLR (P < 0.0001).

CONCLUSION

The NLR, an easily obtained inflammatory biomarker, independently predicts CV risk and all-cause mortality, and is reduced by interleukin-1β blockade with canakinumab.

Advances in biological therapies for dyslipidemias and atherosclerosis

Atherosclerosis is a multifactorial disease influenced by genetics, lifestyle and environmental factors. Despite therapeutic advances that reduce the risk of cardiovascular events, atherosclerosis-related diseases remain the leading cause of mortality worldwide. Precise targeting of genes involved in lipoprotein metabolism is an emerging approach for atherosclerosis prevention and treatment. This article focuses on the latest developments, clinical potential and current challenges of monoclonal antibodies, vaccines and genome/transcriptome modification strategies, including antisense oligonucleotides, genome/base editing and gene therapy. Multiple lipid lowering biological therapies have already been approved by the FDA with impressive results to date, while many more promising targets are being pursued in clinical trials or pre-clinical animal models.