Cardiovascular Efficacy and Safety of Bococizumab in High-Risk Patients

Advances in Clinical Cardiology 2017: A Summary of Key Clinical Trials

INTRODUCTION

Numerous important cardiology clinical trials have been published or presented at major international meetings during 2017. This paper aims to summarize these trials and place them in clinical context.

METHODS

The authors reviewed clinical trials presented at major cardiology conferences during 2017 including the American College of Cardiology, European Association for Percutaneous Cardiovascular Interventions, European Society of Cardiology, European Association for the Study of Diabetes, Transcatheter Cardiovascular Therapeutics, and the American Heart Association. Selection criteria were trials with a broad relevance to the cardiology community and those with potential to change current practice.

RESULTS

A total of 75 key cardiology clinical trials were identified for inclusion. New interventional and structural cardiology data include left main bifurcation treatment strategy, multivessel disease management in cardiogenic shock, drug-eluting balloons for in-stent restenosis, instantaneous wave-free physiological assessment, new-generation stents (COMBO, Orsiro), transcatheter aortic valve implantation, and closure devices. New preventative cardiology data include trials of liraglutide, empagliflozin, PCSK9 inhibitors (evolocumab and bococizumab), inclisiran, and anacetrapib. Antiplatelet data include the role of uninterrupted aspirin therapy during non-cardiac surgery and dual antiplatelet therapy following coronary artery bypass grafting. New data are also included from fields of heart failure (levosimendan, spironolactone), atrial fibrillation (apixaban in DC cardioversion), cardiac devices (closed loop stimulation pacing for neuromediated syncope), and electrophysiology (catheter ablation for atrial fibrillation).

CONCLUSION

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

Navigating the Future of Cardiovascular Drug Development-Leveraging Novel Approaches to Drive Innovation and Drug Discovery: Summary of Findings from the Novel Cardiovascular Therapeutics Conference

PURPOSE

The need for novel approaches to cardiovascular drug development served as the impetus to convene an open meeting of experts from the pharmaceutical industry and academia to assess the challenges and develop solutions for drug discovery in cardiovascular disease.

METHODS

The Novel Cardiovascular Therapeutics Summit first reviewed recent examples of ongoing or recently completed programs translating basic science observations to targeted drug development, highlighting successes (protein convertase sutilisin/kexin type 9 [PCSK9] and neprilysin inhibition) and targets still under evaluation (cholesteryl ester transfer protein [CETP] inhibition), with the hope of gleaning key lessons to successful drug development in the current era. Participants then reviewed the use of innovative approaches being explored to facilitate rapid and more cost-efficient evaluations of drug candidates in a short timeframe.

RESULTS

We summarize observations gleaned from this summit and offer insight into future cardiovascular drug development.

CONCLUSIONS

The rapid development in genetic and high-throughput drug evaluation technologies, coupled with new approaches to rapidly evaluate potential cardiovascular therapies with in vitro techniques, offer opportunities to identify new drug targets for cardiovascular disease, study new therapies with better efficiency and higher throughput in the preclinical setting, and more rapidly bring the most promising therapies to human testing. However, there must be a critical interface between industry and academia to guide the future of cardiovascular drug development. The shared interest among academic institutions and pharmaceutical companies in developing promising therapies to address unmet clinical needs for patients with cardiovascular disease underlies and guides innovation and discovery platforms that are significantly altering the landscape of cardiovascular drug development.

Lipid-lowering therapy with PCSK9-inhibitors in the real-world setting: Two-year experience of a regional lipid clinic

AIM

PCSK9 inhibitors (PCSK9i) effectively lower cholesterol levels in randomized trials with reduction in cardiovascular outcomes and favorable safety profile. However, the access to PCSK9i is limited due to high cost and data regarding the use of PCSK9i in real-world practice is limited.

METHODS

Data on all patients submitted for approval of PCSK9i at a regional lipid clinic, outside of clinical trials. Patients' profile, approval rates, low-density lipoprotein cholesterol (LDL-C) reduction rates, and adverse events were evaluated.

RESULTS

Recommendation for PCSK9i was given to 133 patients; 16 did not receive insurance approval and additional 16 were approved but did not initiate therapy. Of the 101 treated patients (47% females; mean age 61 ± 11 years), 52 had probable/definite familial hypercholesterolemia (FH) (peak LDL-C level 305 ± 87 mg/dL vs non-FH 204 ± 39 mg/dL) and 62% had an established cardiovascular disease. Statin intolerance was reported by 77%. Follow-up lipid panel was available in 66/101 patients: mean LDL-C reduction was 59% ± 19. Subjects with heterozygous FH had similar LDL-C decrease than those with non-FH (59% ± 22 vs 60% ± 14, P = .792). LDL-C < 100 mg/dL was achieved by 76%, LDL-C < 70 mg/dL by 58% and LDL-C < 40 mg/dL by 18% of those with follow-up data. Side effects were reported by 10%, mainly musculoskeletal complaints and flu-like symptoms, and 15% have discontinued treatment.

CONCLUSIONS

Patient selection by a regional lipid clinic resulted in a high real-world PCSK9i insurance approval, with efficacy and safety comparable to randomized clinical trials. Cost and medication nonadherence are potential barriers to successful implementation of therapy in routine clinical care.

Lipid management in ACS: Should we go lower faster?

Low-density lipoprotein-cholesterol (LDL-C) is a well-accepted causal risk factor for athero-thrombotic cardiovascular disease, as demonstrated in large epidemiological studies, including Mendelian randomization data. Several randomized controlled trials and meta-analyzes have shown that lipid lowering therapies, such as statins and more recently the non-statin agents ezetimibe and Proprotein Convertase Subtilisin Kexin type 9 (PCSK9) monoclonal antibodies (mAb), reduce cardiovascular events across a broad range of baseline LDL-C levels. Over time, the recommended target for LDL-C has become more stringent, moving from 2.6 mmol/l to 1.8 mmol/l in very high-risk patients. It is currently recommended to start high intensity statin treatment immediately after acute coronary syndromes (ACS) to maximally and rapidly reduce LDL-C. The novel treatment options enable the achievement of very low LDL-C levels below 1 mmol/l, with no reported safety issues, in particular with regard to neurocognitive events. However, current evidence supports the use of PCSK9 mAb treatment in ACS patients only after an initial 2-3 month run-up treatment adaptation period with maximally tolerated statin. The use of PCSK9 mAb immediately in the acute phase of ACS (<1 month) remains to be studied. Some data suggest that circulating PCSK9 increases coronary plaque vulnerability, inflammation as well as platelet aggregation in the acute phase of ACS, potentially justifying earlier PSCK9 mAb treatment initiation. As the use of novel treatment combinations in ACS is further explored to widen the perspectives of a more personalized approach for the management of ACS based on individual patient risk profile and baseline LDL-C values, their relative cost-effectiveness will also need to be assessed.

The emerging role of proprotein convertase subtilisin/kexin type-9 inhibition in secondary prevention: from clinical trials to real-world experience

PURPOSE OF REVIEW

The recent advent of a highly efficacious class of low-density lipoprotein cholesterol (LDL-C) lowering agents, the proprotein convertase subtilisin/kexin type-9 (PCSK9) inhibitors, has transformed dyslipidaemia management in patients with cardiovascular disease as well as those with familial hypercholesterolemia.

RECENT FINDINGS

Recent positive results of the landmark Further Cardiovascular Outcomes Research with PCSK9 Inhibition in Subjects with Elevated Risk cardiovascular outcome trial with evolocumab as an add-on to statin therapy demonstrate further reduction of cardiovascular events. Additional safety outcomes from this large randomized trial, as well as the EBBINGHAUS substudy, allay fears of neurocognitive disorder as an adverse effect of achieving very low LDL-C levels with these agents.

SUMMARY AND IMPLICATIONS

Widespread clinical adoption of PCSK9 inhibitors will depend on the results from ongoing and planned cardiovascular efficacy and safety trials with PCSK9 inhibitors. In addition, understanding the practical challenges and barriers to usage of these injectable agents by high cardiovascular risk patients will also affect clinical adoption of this class of agents. Analysis of cost-benefit models, along with anticipated updates to practice guidelines for dyslipidaemia management are likely to strengthen the clinical utility of PCSK9 inhibitors. Importantly, the potency of this new class of agents provides a huge opportunity to extend further the 'lower LDL-C is better' hypothesis in an effort to reduce rates of cardiovascular morbidity and mortality on a population level.

Alirocumab vs usual lipid-lowering care as add-on to statin therapy in individuals with type 2 diabetes and mixed dyslipidaemia: The ODYSSEY DM-DYSLIPIDEMIA randomized trial

AIM

To compare alirocumab, a proprotein convertase subtilisin-kexin type 9 inhibitor, with usual care (UC) in individuals with type 2 diabetes (T2DM) and mixed dyslipidaemia not optimally managed by maximally tolerated statins in the ODYSSEY DM-DYSLIPIDEMIA trial (NCT02642159).

MATERIALS AND METHODS

The UC options (no additional lipid-lowering therapy; fenofibrate; ezetimibe; omega-3 fatty acid; nicotinic acid) were selected prior to stratified randomization to open-label alirocumab 75 mg every 2 weeks (with increase to 150 mg every 2 weeks at week 12 if week 8 non-HDL cholesterol concentration was ≥2.59 mmol/L [100 mg/dL]) or UC for 24 weeks. The primary efficacy endpoint was percentage change in non-HDL cholesterol from baseline to week 24.

RESULTS

The randomized population comprised 413 individuals (intention-to-treat population, n = 409; safety population, n = 412). At week 24, the mean non-HDL cholesterol reductions were superior with alirocumab (-32.5% difference vs UC, 97.5% confidence interval -38.1 to -27.0; P < .0001). Overall, 63.6% of alirocumab-treated individuals were maintained on 75 mg every 2 weeks. Alirocumab also reduced LDL cholesterol (-43.0%), apolipoprotein B (-32.3%), total cholesterol (-24.6%) and LDL particle number (-37.8%) at week 24 vs UC (all P < .0001). Consistent with the overall trial comparison, alirocumab reduced non-HDL cholesterol to a greater degree within each UC stratum at week 24. The incidence of treatment-emergent adverse events was 68.4% (alirocumab) and 66.4% (UC). No clinically meaningful effect on glycated haemoglobin, or change in number of glucose-lowering agents, was seen.

CONCLUSIONS

In individuals with T2DM and mixed dyslipidaemia on maximally tolerated statin, alirocumab showed superiority to UC in non-HDL cholesterol reduction and was generally well tolerated.

Effect of proprotein convertase subtilisin/kexin type 9 (PCSK9) monoclonal antibodies on new-onset diabetes mellitus and glucose metabolism: A systematic review and meta-analysis

AIMS

To investigate the effect of two clinically applied proprotein convertase subtilisin/kexin type 9 monoclonal antibodies (PCSK9-mAbs) on glycaemia and new-onset diabetes mellitus (NODM).

MATERIALS AND METHODS

PubMed, MEDLINE, Embase, Cochrane databases and ClinicalTrials.gov websites were systematically searched for randomized controlled trials that reported data on fasting plasma glucose (FPG), glycated haemoglobin (HbA1c) or NODM incidence. Risk ratios (RRs) for NODM and mean difference (MD) for FPG and HbA1c with 95% confidence intervals (CIs) were calculated using a fixed-effect model. Heterogeneity was examined using the I2 statistic and potential publication bias was assessed using funnel plots and Egger's test.

RESULTS

A total of 18 studies including 26 123 participants without diabetes were identified. No significant difference was observed in the PCSK9-mAb treatment groups in terms of NODM (RR 1.05, 95% CI 0.95-1.16), FPG (MD 0.00 mmol/L, 95% CI -0.02 to 0.02) or HbA1c (MD 0.00% [0 mmol/L], 95% CI -0.01 to 0.01) compared with control groups. Subgroup (PCSK9-mAb type, participant characteristics, treatment duration, treatment method and differences in control treatment) and sensitivity analyses did not significantly alter the results. Meta-regression analyses showed that risk of NODM was not associated with baseline age, baseline body mass index (BMI), proportion of men, treatment duration or percent LDL cholesterol reduction.

CONCLUSIONS

Alirocumab and evolocumab, two types of PCSK9-mAb approved by the US Food and Drug Administration and the European Medicines Agency, had no significant impact on NODM and glucose homeostasis, regardless of PCSK9-mAb type, participant characteristics, treatment duration, treatment method and differences in control treatment. Baseline age, BMI, proportion of men, treatment duration, and percent change of LDL cholesterol did not influence diabetes risk.

Unexplained reciprocal regulation of diabetes and lipoproteins

PURPOSE OF REVIEW

Type 2 diabetes is associated with a characteristic dyslipidemia that may exacerbate cardiovascular risk. The causes of, and the effects of new antihyperglycemia medications on, this dyslipidemia, are under investigation. In an unexpected reciprocal manner, lowering LDL-cholesterol with statins slightly increases the risk of diabetes. Here we review the latest findings.

RECENT FINDINGS

The inverse relationship between LDL-cholesterol and diabetes has now been confirmed by multiple lines of evidence. This includes clinical trials, genetic instruments using aggregate single nucleotide polymorphisms, as well as at least eight individual genes - HMGCR, NPC1L1, HNF4A, GCKR, APOE, PCKS9, TM6SF2, and PNPLA3 - support this inverse association. Genetic and pharmacologic evidence suggest that HDL-cholesterol may also be inversely associated with diabetes risk. Regarding the effects of diabetes on lipoproteins, new evidence suggests that insulin resistance but not diabetes per se may explain impaired secretion and clearance of VLDL-triglycerides. Weight loss, bariatric surgery, and incretin-based therapies all lower triglycerides, whereas SGLT2 inhibitors may slightly increase HDL-cholesterol and LDL-cholesterol.

SUMMARY

Diabetes and lipoproteins are highly interregulated. Further research is expected to uncover new mechanisms governing the metabolism of glucose, fat, and cholesterol. This topic has important implications for treating type 2 diabetes and cardiovascular disease.

CVD Risk Stratification in the PCSK9 Era: Is There a Role for LDL Subfractions?

Proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors reduce the risk of cardiovascular events and all-cause mortality in patients at high risk of cardiovascular disease (CVD). Due to high costs and unknown long-term adverse effects, critical evaluation of patients considered for PCSK9 inhibitors is important. It has been proposed that measuring low-density lipoprotein (LDL) subfractions, or LDL particle numbers (LDL-P), could be of value in CVD risk assessment and may identify patients at high risk of CVD. This review evaluates the evidence for the use of LDL subfractions, or LDL-P, when assessing CVD risk in patients for whom PCSK9 inhibitors are considered as a lipid-lowering therapy. Numerous methods for measuring LDL subfractions and LDL-P are available, but several factors limit their availability. A lack of standardization makes comparison between the different methods challenging. Longitudinal population-based studies have found an independent association between different LDL subfractions, LDL-P, and an increased risk of cardiovascular events, but definitive evidence that these measurements add predictive value to the standard risk markers is lacking. No studies have proven that these measurements improve clinical outcomes. PCSK9 inhibitors seem to be effective at lowering all LDL subfractions and LDL-P, but any evidence that measuring LDL subfractions and LDL-P yield clinically useful information is lacking. Such analyses are currently not recommended when considering whether to initiate PCKS9 inhibitors in patients at risk of CVD.

Pharmacokinetics and pharmacodynamics of bococizumab, a monoclonal antibody to PCSK9, after single subcutaneous injection at three sites [NCT 02043301]

AIM

To characterize the single-dose pharmacokinetics (PK) and pharmacodynamics (PD) of bococizumab, a monoclonal antibody inhibiting proprotein convertase subtilisin/kexin type 9 (PCSK9), administered subcutaneously (s.c.) to the abdomen, thigh, or upper arm (NCT02043301).

METHODS

Seventy-five adults with low-density lipoprotein cholesterol (LDL-C) ≥130 mg/dL and not on background lipid-lowering therapy were randomized (1:1:1) to a single 150-mg s.c. dose of bococizumab administered to the abdomen, thigh, or upper arm. Blood samples for bococizumab and lipids were collected for 12 weeks postdose.

RESULTS

Plasma bococizumab concentration-time profiles and PK parameters were generally similar across injection sites. Mean maximum observed concentration (C_max ) ranged from 8.14 to 11.9 μg/mL, and area under the concentration-time curve (AUC_inf ) ranged from 160.3 to 198.9 µg∙day/mL. The median time to C_max (T_max ) ranged from 4.25 to 6.93 days. Similar LDL-C concentration-time profiles were observed across injection sites, with mean (% coefficient of variation) maximum reductions in LDL-C of -57.5% (15.8), -57.0% (25.9), and -55.0% (24.1) for the abdomen, thigh, and upper arm, respectively. Adverse events (AEs) were mostly mild and generally similar across injection sites. Commonly reported AEs were upper respiratory tract infection (9.3%), headache (6.7%), and injection site reaction (6.7%). One serious AE was reported (ischemic colitis), which was not considered related to study drug.

CONCLUSIONS

Similar PK profiles and robust LDL-C reductions were observed following a single 150-mg s.c. injection of bococizumab administered to the abdomen, thigh, or upper arm in untreated subjects with LDL-C ≥130 mg/dL. Bococizumab was generally well tolerated following a single 150-mg s.c. administration in this subject population.

Prescribing Patterns of Proprotein Convertase Subtilisin-Kexin Type 9 Inhibitors in Eligible Patients With Clinical Atherosclerotic Cardiovascular Disease or Heterozygous Familial Hypercholesterolemia

Two proprotein convertase subtilisin-kexin type 9 (PCSK9) inhibitors are approved for patients with atherosclerotic cardiovascular disease or heterozygous familial hypercholesterolemia who require additional low-density lipoprotein cholesterol (LDL-C) lowering. This retrospective study sought to determine differences between eligible patients who were prescribed and those who were not prescribed a PCSK9 inhibitor. Patients from an electronic medical record database were included in the analysis, and their demographic, clinical, and treatment characteristics were evaluated. Of 368,624 PCSK9 inhibitor-eligible patients, 1,752 (<0.5%) received a PCSK9 inhibitor prescription. Patients who received a PCSK9 inhibitor were more frequently associated with a higher cardiovascular disease risk category and a higher baseline LDL-C level (139.4 vs 103.5 mg/dl; p <0.0001) compared with those who did not. Patients with a PCSK9 inhibitor prescription were significantly more likely to be on ezetimibe, alone or in combination with a statin, at baseline compared with those without (29% vs 5%; p <0.0001). The use of a PCSK9 inhibitor was very low in the 2 groups of patients identified as PCSK9 inhibitor-eligible based on the American College of Cardiology Expert Consensus Decision Pathway. In conclusion, this study demonstrates that most PCSK9 inhibitor-eligible patients do not receive a PCSK9 inhibitor prescription, highlighting that many high-risk patients could benefit from additional LDL-C lowering with a PCSK9 inhibitor.

PCSK9: From Basic Science Discoveries to Clinical Trials

Unknown 15 years ago, PCSK9 (proprotein convertase subtilisin/kexin type 9) is now common parlance among scientists and clinicians interested in prevention and treatment of atherosclerotic cardiovascular disease. What makes this story so special is not its recent discovery nor the fact that it uncovered previously unknown biology but rather that these important scientific insights have been translated into an effective medical therapy in record time. Indeed, the translation of this discovery to novel therapeutic serves as one of the best examples of how genetic insights can be leveraged into intelligent target drug discovery. The PCSK9 saga is unfolding quickly but is far from complete. Here, we review major scientific understandings as they relate to the role of PCSK9 in lipoprotein metabolism and atherosclerotic cardiovascular disease and the impact that therapies designed to inhibit its action are having in the clinical setting.

Residual Inflammatory Risk on Treatment With PCSK9 Inhibition and Statin Therapy

BACKGROUND

The combination of statin therapy and PCSK9 (proprotein convertase subtilisin/kexin type 9) inhibition markedly lowers low-density lipoprotein cholesterol (LDL-C) and reduces cardiovascular event rates. Whether residual inflammatory risk as measured by on-treatment high sensitivity C-reactive protein (hsCRP) remains an important clinical issue in such patients is uncertain.

METHODS

We evaluated residual inflammatory risk among 9738 patients participating in the SPIRE-1 and SPIRE-2 cardiovascular outcomes trials (Studies of PCSK9 Inhibition and the Reduction in Vascular Events), who were receiving both statin therapy and bococizumab, according to on-treatment levels of hsCRP (hsCRP_OT) and LDL-C_OT measured 14 weeks after drug initiation. The primary end point was nonfatal myocardial infarction, nonfatal stroke, hospitalization for unstable angina requiring urgent revascularization, or cardiovascular death.

RESULTS

At 14 weeks, the mean percentage change in LDL-C among statin-treated patients who additionally received bococizumab was -60.5% (95% confidence interval [CI], -61.2 to -59.8; P<0.001; median change, -65.4%) as compared to 6.6% (95% CI, -1.0 to 14.1; P=0.09; median change, 0.0%) for hsCRP. Incidence rates for future cardiovascular events for patients treated with both statin therapy and bococizumab according to hsCRP_OT <1, 1 to 3, and >3 mg/L were 1.96, 2.50, and 3.59 events per 100 person-years, respectively, corresponding to multivariable adjusted hazard ratios of 1.0, 1.16 (95% CI, 0.81-1.66), and 1.62 (95% CI, 1.14-2.30) (P-trend=0.001) after adjustment for traditional cardiovascular risk factors and LDL-C_OT. Comparable adjusted hazard ratios for LDL-C_OT (<30, 30-50, >50 mg/dL) were 1.0, 0.87, and 1.21, respectively (P-trend=0.16). Relative risk reductions with bococizumab were similar across hsCRP_OT groups (P-interaction=0.87).

CONCLUSIONS

In this post hoc analysis of the SPIRE trials of bococizumab in a stable outpatient population, evidence of residual inflammatory risk persisted among patients treated with both statin therapy and proprotein convertase subtilisin-kexin type 9 inhibition.

CLINICAL TRIAL REGISTRATION

URL: https://www.clinicaltrials.gov. Unique identifiers: NCT01975376, NCT01975389.

Nutraceuticals as therapeutic agents for atherosclerosis

Atherosclerosis, a chronic inflammatory disorder of medium and large arteries and an underlying cause of cardiovascular disease (CVD), is responsible for a third of all global deaths. Current treatments for CVD, such as optimized statin therapy, are associated with considerable residual risk and several side effects in some patients. The outcome of research on the identification of alternative pharmaceutical agents for the treatment of CVD has been relatively disappointing with many promising leads failing at the clinical level. Nutraceuticals, products from food sources with health benefits beyond their nutritional value, represent promising agents in the prevention of CVD or as an add-on therapy with current treatments. This review will highlight the potential of several nutraceuticals, including polyunsaturated fatty acids, flavonoids and other polyphenols, as anti-CVD therapies based on clinical and pre-clinical mechanism-based studies.

RNA-guided transcriptional silencing in vivo with S. aureus CRISPR-Cas9 repressors

CRISPR-Cas9 transcriptional repressors have emerged as robust tools for disrupting gene regulation in vitro but have not yet been adapted for systemic delivery in adult animal models. Here we describe a Staphylococcus aureus Cas9-based repressor (dSaCas9KRAB) compatible with adeno-associated viral (AAV) delivery. To evaluate dSaCas9KRAB efficacy for gene silencing in vivo, we silenced transcription of Pcsk9, a regulator of cholesterol levels, in the liver of adult mice. Systemic administration of a dual-vector AAV8 system expressing dSaCas9KRAB and a Pcsk9-targeting guide RNA (gRNA) results in significant reductions of serum Pcsk9 and cholesterol levels. Despite a moderate host response to dSaCas9KRAB expression, Pcsk9 repression is maintained for 24 weeks after a single treatment, demonstrating the potential for long-term gene silencing in post-mitotic tissues with dSaCas9KRAB. In vivo programmable gene silencing enables studies that link gene regulation to complex phenotypes and expands the CRISPR-Cas9 perturbation toolbox for basic research and gene therapy applications.

Comparative Pharmacokinetics and Pharmacodynamics of Bococizumab Following a Single Subcutaneous Injection Using Drug Substance Manufactured at Two Sites or Administration via Two Different Devices

The pharmacokinetics (PK) and pharmacodynamics (PD) of bococizumab, a proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitor, were compared following a single 150-mg subcutaneous dose administered to healthy subjects (n = 156-158/arm) via: (1) a prefilled syringe (PFS) using drug substance (DS) manufactured by Pfizer, (2) a PFS using DS manufactured by Boehringer Ingelheim Pharma, (3) a prefilled pen using DS manufactured by Pfizer (NCT02458209). Blood samples were collected for 12 weeks postdose. Safety was monitored throughout. Mean maximum plasma concentration (C_max ) ranged between 11.0 and 11.3 μg/mL, and area under the plasma concentration-time curve (AUC_inf ) ranged between 177.6 and 185.0 μg·day/mL across treatments. The 90% confidence intervals for the ratios of adjusted geometric means for C_max and AUC_inf fell within the 80%-125% range for both DS and delivery device comparisons. Comparable low-density lipoprotein cholesterol profiles were observed, with nadir values of 54.3-56.1 mg/dL across treatments. Similar PCSK9 responses were also observed. Safety profiles were similar across treatments, and the majority of adverse events (AEs) were mild. Three subjects reported serious AEs. The most frequently reported AEs were headache, injection-site reaction, and upper respiratory tract infection, with no clear differences across treatments. Comparable PK, PD, and safety were observed following a single bococizumab 150-mg subcutaneous injection regardless of site of DS manufacture or delivery device used.

Safety and Efficacy of Extremely Low LDL-Cholesterol Levels and Its Prospects in Hyperlipidemia Management

The risk of cardiovascular disease has been reported to have a linear relationship with LDL levels. Additionally, the currently recommended LDL target goal of 70 mg/dl does not diminish the CV risk entirely leaving behind some residual risk. Previous attempts to maximally lower the LDL levels with statin monotherapy have met dejection due to the increased side effects associated with the treatment. Nevertheless, with the new advancements in clinical medicine, it has now become possible to bring down the LDL levels to as low as 15 mg/dl using PCSK9 monoclonal antibodies alone or in combination with statins. The development of inclisiran, siRNA silencer targeting PCSK9 gene, is a one step forward in these endeavors. Moreover, various studies aiming to lower the CV risk and mortality by lowering LDL levels have demonstrated encouraging results. The current challenge is to explore this arena to redefine the target LDL levels, if required, to avoid any suboptimal treatment. After thorough literature search in the PubMed, Embase, Scopus, and Google Scholar, we present this article to provide a brief overview of the safety and efficacy of lowering LDL below the current goal.

Association Between Baseline LDL-C Level and Total and Cardiovascular Mortality After LDL-C Lowering: A Systematic Review and Meta-analysis

IMPORTANCE

Effects on specific fatal and nonfatal end points appear to vary for low-density lipoprotein cholesterol (LDL-C)-lowering drug trials.

OBJECTIVE

To evaluate whether baseline LDL-C level is associated with total and cardiovascular mortality risk reductions.

DATA SOURCESAND STUDY SELECTION

Electronic databases (Cochrane, MEDLINE, EMBASE, TCTMD, ClinicalTrials.gov, major congress proceedings) were searched through February 2, 2018, to identify randomized clinical trials of statins, ezetimibe, and PCSK9-inhibiting monoclonal antibodies.

DATA EXTRACTION AND SYNTHESIS

Two investigators abstracted data and appraised risks of bias. Intervention groups were categorized as "more intensive" (more potent pharmacologic intervention) or "less intensive" (less potent, placebo, or control group).

MAIN OUTCOMES AND MEASURES

The coprimary end points were total mortality and cardiovascular mortality. Random-effects meta-regression and meta-analyses evaluated associations between baseline LDL-C level and reductions in mortality end points and secondary end points including major adverse cardiac events (MACE).

RESULTS

In 34 trials, 136 299 patients received more intensive and 133 989 received less intensive LDL-C lowering. All-cause mortality was lower for more vs less intensive therapy (7.08% vs 7.70%; rate ratio [RR], 0.92 [95% CI, 0.88 to 0.96]), but varied by baseline LDL-C level. Meta-regression showed more intensive LDL-C lowering was associated with greater reductions in all-cause mortality with higher baseline LDL-C levels (change in RRs per 40-mg/dL increase in baseline LDL-C, 0.91 [95% CI, 0.86 to 0.96]; P = .001; absolute risk difference [ARD], -1.05 incident cases per 1000 person-years [95% CI, -1.59 to -0.51]), but only when baseline LDL-C levels were 100 mg/dL or greater (P < .001 for interaction) in a meta-analysis. Cardiovascular mortality was lower for more vs less intensive therapy (3.48% vs 4.07%; RR, 0.84 [95% CI, 0.79 to 0.89]) but varied by baseline LDL-C level. Meta-regression showed more intensive LDL-C lowering was associated with a greater reduction in cardiovascular mortality with higher baseline LDL-C levels (change in RRs per 40-mg/dL increase in baseline LDL-C, 0.86 [95% CI, 0.80 to 0.94]; P < .001; ARD, -1.0 incident cases per 1000 person-years [95% CI, -1.51 to -0.45]), but only when baseline LDL-C levels were 100 mg/dL or greater (P < .001 for interaction) in a meta-analysis. Trials with baseline LDL-C levels of 160 mg/dL or greater had the greatest reduction in all-cause mortality (RR, 0.72 [95% CI, 0.62 to 0.84]; P < .001; 4.3 fewer deaths per 1000 person-years) in a meta-analysis. More intensive LDL-C lowering was also associated with progressively greater risk reductions with higher baseline LDL-C level for myocardial infarction, revascularization, and MACE.

CONCLUSIONS AND RELEVANCE

In these meta-analyses and meta-regressions, more intensive compared with less intensive LDL-C lowering was associated with a greater reduction in risk of total and cardiovascular mortality in trials of patients with higher baseline LDL-C levels. This association was not present when baseline LDL-C level was less than 100 mg/dL, suggesting that the greatest benefit from LDL-C-lowering therapy may occur for patients with higher baseline LDL-C levels.

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

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

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.

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

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

The Emerging Role of Inflammation in Cardiovascular Disease

Objective: To review the role of inflammatory suppression in patients with atherosclerotic cardiovascular disease (ASCVD) with a focus on the interleukin-1β blocker canakinumab. Data Sources: An Ovid MEDLINE literature search (1946 to February 2018) was performed using search terms inflammation, ASCVD, atherosclerosis, C-reactive protein, canakinumab. Additional references were identified from a review of literature citations. Study Selection and Data Extraction: English-language studies assessing the impact of pharmacological agents, including canakinumab, on inflammation as measured by high-sensitivity C-reactive protein (hsCRP) and the association with reducing ASCVD events were evaluated. Data Synthesis: Nine studies were included to describe the effect of ASCVD drugs on hsCRP. Aspirin, angiotensin-converting enzyme inhibitors, gemfibrozil, and statins exhibit varying degrees of hsCRP reduction and are associated with a reduction of ASCVD events. The Canakinumab Antiinflammatory Thrombosis Outcome Study (CANTOS), showed a significant reduction of ASVCD events in patients with elevated baseline hsCRP levels without affecting cholesterol. Conclusions: Patients with elevated inflammatory markers such as hsCRP are at risk for ASVCD events. Several drug classes have shown the ability to decrease hsCRP levels, but the extent to which this reduces ASCVD events in lieu of other drug mechanisms was not clear. Canakinumab specifically targets the inflammatory process in ASCVD and was proven to be effective in preventing ASCVD events in patients with elevated hsCRP levels.

Lipid Target in Very High-Risk Cardiovascular Patients: Lesson from PCSK9 Monoclonal Antibodies

The role of low-density lipoproteins (LDLs) as a major risk factor for cardiovascular disease has been demonstrated by several epidemiological studies. The molecular basis for LDLs in atherosclerotic plaque formation and progression is not completely unraveled yet. Pharmacological modulation of plasma LDL-C concentrations and randomized clinical trials addressing the impact of lipid-lowering interventions on cardiovascular outcome have clearly shown that reducing plasma LDL-C concentrations results in a significant decrease in major cardiovascular events. For many years, statins have represented the most powerful pharmacological agents available to lower plasma LDL-C concentrations. In clinical trials, it has been shown that the greater the reduction in plasma LDL-C concentrations, the lower the rate of major cardiovascular events, especially in high-risk patients, because of multiple risk factors and recurrent events. However, in a substantial number of patients, the recommended LDL target is difficult to achieve because of different factors: genetic background (familial hypercholesterolemia), side effects (statin intolerance), or high baseline plasma LDL-C concentrations. In the last decade, our understanding of the molecular mechanisms involved in LDL metabolism has progressed significantly and the key role of proprotein convertase subtilisin/kexin type 9 (PCSK9) has emerged. This protein is an enzyme able to bind the LDL receptors (LDL-R) on hepatocytes, favoring their degradation. Blocking PCSK9 represents an intriguing new therapeutic approach to decrease plasma LDL-C concentrations, which in recent studies has been demonstrated to also result in a significant reduction in major cardiovascular events.

PCSK9 Inhibitors in Hyperlipidemia: Current Status and Clinical Outlook

The clinical reality of residual risk despite statin (HMG-CoA reductase inhibitor) therapy and emergence of statin intolerance support the need to develop additional lipid-lowering strategies. Proprotein convertase subtilisin kexin type 9 (PCSK9) has received considerable attention by virtue of genetic and clinical studies that have revealed its pivotal role in the regulation of cholesterol homeostasis. Monoclonal antibodies have been developed targeting PCSK9, which have been demonstrated to produce profound low-density lipoprotein cholesterol (LDL-C) lowering when provided as monotherapy or in combination with statins. With the reports that the PCSK9 inhibitor evolocumab has a favorable impact on both plaque progression and cardiovascular outcomes, these findings begin to translate the benefits of PCSK9 inhibition from lipids to the vessel wall and ultimately to clinical outcomes. The clinical implications for the use of these agents are reviewed in this article.

Impact of Novel Low-Density Lipoprotein-Cholesterol Assessment on the Utility of Secondary Non-High-Density Lipoprotein-C and Apolipoprotein B Targets in Selected Worldwide Dyslipidemia Guidelines

BACKGROUND

Selected dyslipidemia guidelines recommend non-high-density lipoprotein-cholesterol (non-HDL-C) and apolipoprotein B (apoB) as secondary targets to the primary target of low-density lipoprotein-cholesterol (LDL-C). After considering 2 LDL-C estimates that differ in accuracy, we examined: (1) how frequently non-HDL-C guideline targets could change management; and (2) the utility of apoB targets after meeting LDL-C and non-HDL-C targets.

METHODS

We analyzed 2518 adults representative of the US population from the 2011 to 2012 National Health and Nutrition Examination Survey and 126 092 patients from the Very Large Database of Lipids study with apoB. We identified all individuals as well as those with high-risk clinical features, including coronary artery disease, diabetes mellitus, and metabolic syndrome who met very high- and high-risk guideline targets of LDL-C <70 and <100 mg/dL using Friedewald estimation (LDL-C_F) and a novel, more accurate method (LDL-C_N). Next, we examined those not meeting non-HDL-C (<100, <130 mg/dL) and apoB (<80, <100 mg/dL) guideline targets. In those meeting dual LDL-C and non-HDL-C targets (<70 and <100 mg/dL, respectively, or <100 and <130 mg/dL, respectively), we determined the proportion of individuals who did not meet guideline apoB targets (<80 or <100 mg/dL).

RESULTS

A total of 7% to 9% and 31% to 36% of individuals had LDL-C <70 and <100 mg/dL, respectively. Among those with LDL-C_F<70 mg/dL, 14% to 15% had non-HDL-C ≥100 mg/dL, and 7% to 8% had apoB ≥80 mg/dL. Among those with LDL-C_F<100 mg/dL, 8% to 10% had non-HDL-C ≥130 mg/dL and 2% to 3% had apoB ≥100 mg/dL. In comparison, among those with LDL-C_N<70 or 100 mg/dL, only ≈2% and ≈1% of individuals, respectively, had non-HDL-C and apoB values above guideline targets. Similar trends were upheld among those with high-risk clinical features: ≈0% to 3% of individuals with LDL-C_N<70 mg/dL had non-HDL-C ≥100 mg/dL or apoB ≥80 mg/dL compared with 13% to 38% and 9% to 25%, respectively, in those with LDL-C_F<70 mg/dL. With LDL-C_F or LDL-C_N<70 mg/dL and non-HDL-C <100 mg/dL, 0% to 1% had apoB ≥80 mg/dL. Among all dual LDL-C_F or LDL-C_N<100 mg/dL and non-HDL-C <130 mg/dL individuals, 0% to 0.4% had apoB ≥100 mg/dL. These findings were robust to sex, fasting status, and lipid-lowering therapy status.

CONCLUSIONS

After more accurately estimating LDL-C, guideline-suggested non-HDL-C targets could alter management in only a small fraction of individuals, including those with coronary artery disease and other high-risk clinical features. Furthermore, current guideline-suggested apoB targets provide modest utility after meeting cholesterol targets.

CLINICAL TRIAL REGISTRATION

URL: https://www.clinicaltrials.gov. Unique identifier: NCT01698489.

The Evolving Epidemiology of Atherosclerotic Cardiovascular Disease in People with Diabetes

Atherosclerotic cardiovascular disease (ASCVD) is a leading global cause of death and accounts for most deaths among individuals with diabetes. This article reviews the latest observational and trial data on changes in the relationship between diabetes and ASCVD risk, remaining gaps in how the role of each risk factor is understood, and current knowledge about specific interventions. Differences between high-income countries and low-income and middle-income countries are examined, barriers and facilitators are discussed, and a discussion around the concept of ideal cardiovascular health factors (Life's Simple 7) is focused on.

Diabetes and lipid metabolism

The authors review the association between diabetes mellitus (DM) and aberrations of lipid metabolism related to DM, diabetic dyslipidemia (DD). DM is considered as a major health burden worldwide and one of the most important modifiable cardiovascular disease (CVD) risk factors. This applies to both the developed and the developing countries, especially the latter. While patients with type 1 DM, 10% of all DM cases, usually do not have dyslipidemia, DD is frequent among patients with type 2 DM (T2DM) (prevalence > 75%) and is mainly a mixed dyslipidemia [increase in triglycerides (TGs), low high-density lipoprotein cholesterol (HDL-C), and small-dense (atherogenic), low-density lipoprotein cholesterol (LDL-C) particles]. The components of DD, which is characterized by quantitative (mentioned above), qualitative, and kinetic abnormalities all contributing to CVD risk, are mostly related to insulin resistance. Statins, ezetimibe, and PCSK9 inhibitors can be used in monotherapy or consecutively in combinations if needed. Statins compose the main drug. For the residual CVD risk after statin treatment, the use of statin-fibrate combinations is indicated only in patients with mixed dyslipidemia. In conclusion, DD is a major health problem worldwide. It is a significant CVD risk factor and should be treated according to current guidelines. The means today exist to normalize all quantitative, qualitative, and kinetic aberrations of DD, thereby reducing CVD risk.

Non-Native Conformational Isomers of the Catalytic Domain of PCSK9 Induce an Immune Response, Reduce Lipids and Increase LDL Receptor Levels

PCSK9 (Proprotein convertase subtilisin/kexin type 9) increases plasma cholesterol levels by promoting LDL receptor degradation. Current antibody inhibitors block the interaction between PCSK9 and LDL receptors, significantly decrease plasma cholesterol levels, and provide beneficial clinical outcomes. To reduce the action of PCSK9 in plasma, a novel strategy that will produce a panel of non-native, conformationally-altered isomers of PCSK9 (X-PCSK9) to develop active immunotherapy targeting of native PCSK9 and inhibiting/blocking the interaction of PCSK9 with LDL receptor, thus decreasing plasma cholesterol levels is proposed. The authors used the scrambled disulfide bond technique to generate conformationally-altered isomers of the catalytic domain of mouse PCSK9. The focus was on the immune response of four X-isomers and their effects on plasma cholesterol and triglyceride levels in both C57BL/6J and Apoe−/− mice. The authors showed that the four immunogens produced significant immunogenicity against native PCSK9 to day 120 after immunization of C57BL/6J and Apoe−/− mice. This resulted in significantly decreased plasma cholesterol levels in C57BL/6J mice, and to a lesser degree in Apoe−/− mice. The X-PCSK9-B1 treated mice had increased LDL receptor mRNA and protein levels at day 120 after treatment. Thus, this study provides a new, potentially promising approach that uses long-term immunotherapy for a treatment of hypercholesterolemia.

Advances in lipid-lowering therapy through gene-silencing technologies

New treatment opportunities are emerging in the field of lipid-lowering therapy through gene-silencing approaches. Both antisense oligonucleotide inhibition and small interfering RNA technology aim to degrade gene mRNA transcripts to reduce protein production and plasma lipoprotein levels. Elevated levels of LDL, remnant lipoproteins, and lipoprotein(a) all cause cardiovascular disease, whereas elevated levels of triglyceride-rich lipoproteins in some patients can cause acute pancreatitis. The levels of each of these lipoproteins can be reduced using gene-silencing therapies by targeting proteins that have an important role in lipoprotein production or removal (for example, the protein products of ANGPTL3, APOB, APOC3, LPA, and PCSK9). Using this technology, plasma levels of these lipoproteins can be reduced by 50-90% with 2-12 injections per year; such dramatic reductions are likely to reduce the incidence of cardiovascular disease or acute pancreatitis in at-risk patients. The reported adverse effects of these new therapies include injection-site reactions, flu-like symptoms, and low blood platelet counts. However, newer-generation drugs are more efficiently delivered to liver cells, requiring lower drug doses, which leads to fewer adverse effects. Although these findings are promising, robust evidence of cardiovascular disease reduction and long-term safety is needed before these gene-silencing technologies can have widespread implementation. Before the availability of such evidence, these drugs might have roles in patients with unmet medical needs through orphan indications.

Differential effects of PCSK9 variants on risk of coronary disease and ischaemic stroke

Aims

PCSK9 genetic variants that have large effects on low-density lipoprotein cholesterol (LDL-C) and coronary heart disease (CHD) have prompted the development of therapeutic PCSK9-inhibition. However, there is limited evidence that PCSK9 variants are associated with ischaemic stroke (IS).

Methods and results

Associations of the loss-of-function PCSK9 genetic variant (rs11591147; R46L), and five additional PCSK9 variants, with IS and IS subtypes (cardioembolic, large vessel, and small vessel) were estimated in a meta-analysis involving 10 307 IS cases and 19 326 controls of European ancestry. They were then compared with the associations of these variants with LDL-C levels (in up to 172 970 individuals) and CHD (in up to 60 801 CHD cases and 123 504 controls). The rs11591147 T allele was associated with 0.5 mmol/L lower LDL-C level (P = 9 × 10-143) and 23% lower CHD risk [odds ratio (OR): 0.77, 95% confidence interval (CI): 0.69-0.87, P = 7 × 10-6]. However, it was not associated with risk of IS (OR: 1.04, 95% CI: 0.84-1.28, P = 0.74) or IS subtypes. Information from additional PCSK9 variants also indicated consistently weaker effects on IS than on CHD.

Conclusion

PCSK9 genetic variants that confer life-long lower PCSK9 and LDL-C levels appear to have significantly weaker, if any, associations with risk of IS than with risk of CHD. By contrast, similar proportional reductions in risks of IS and CHD have been observed in randomized trials of therapeutic PCSK9-inhibition. These findings have implications for our understanding of when Mendelian randomization can be relied upon to predict the effects of therapeutic interventions.