Cost-effectiveness of PCSK9 inhibition in addition to standard lipid-lowering therapy in patients at high risk for vascular disease

PCSK9 inhibitors on the management of primary and secondary cardiovascular prevention

BACKGROUND

Proprotein convertase subtilisin/kexin type 9 inhibitors (PCSK9i) have represented an important change in the management of hypercholesterolemia, although, until now, they have barely been used. Without PCSK9i, many patients with atherosclerotic cardiovascular disease (CVD) or those at very high risk do not reach their therapeutic LDLc objectives.

OBJECTIVE

The analysis aimed to examine the clinical and biochemical characteristics of subjects receiving PCSK9i treatment in the Dyslipidemia Registry of the Spanish Atherosclerosis Society.

METHODS

All consecutive subjects aged ≥ 18 years from different Lipid Units included in the Dyslipidemia Registry of the SEA were analyzed. Inclusion criteria consisted of unrelated patients aged ≥ 18 at the time of inclusion with hypercholesterolemia (LDL-C ≥ 130 mg/dL or non-HDL-C ≥ 160 mg/dL after the exclusion of secondary causes) who were studied for at least two years after inclusion. Participants' baseline and final visit clinical and biochemical characteristics were analyzed based on whether they were on primary or secondary prevention and whether they were taking PCSK9i at the end of follow-up.

RESULTS

Eight hundred twenty-nine patients were analyzed, 7014 patients in primary prevention and 1281 in secondary prevention at baseline. 4127 subjects completed the required follow-up for the final analysis. The median follow-up duration was 7 years (IQR 3.0-10.0). Five hundred patients (12.1%) were taking PCSK9i at the end of the follow-up. The percentage of PCSK9i use reached 35.6% (n = 201) and 8.7% (n = 318) in subjects with and without CVD, respectively. Subjects on PCSK9i and oral lipid-lowering agents with and without CVD achieved LDLc reductions of 80.3% and 75.1%, respectively, concerning concentrations without lipid-lowering drugs. Factors associated with PCSK9i use included increasing age, LDLc without lipid-lowering drugs and the Dutch Lipid Clinic Network (DLCN) score. However, hypertension, diabetes, smoking, and LDLc after oral lipid-lowering drugs were not independent factors associated with PCSK9i prescription. In subjects with CVD, the use of PCSK9i was higher in men than in women (an odds ratio of 1.613, P = 0.048).

CONCLUSIONS

Approximately one-third of CVD patients received PCSK9i at the end of follow-up. The use of PCSK9i was more focused on baseline LDLc concentrations rather than on CVD risk. Women received less PCSK9i in secondary prevention compared to men.

Comparison of Evolocumab and Ezetimibe, Both Combined with Statin Therapy, for Patients with Recent Acute Coronary Syndrome: A Cost-Effectiveness Analysis from the Chinese Healthcare Perspective

PURPOSE

To assess the cost-effectiveness of evolocumab, a PCSK9 (proprotein convertase subtilisin/kexin type 9) inhibitor, compared with ezetimibe, both added to background statin therapy in patients with recent acute coronary syndrome (ACS) events (in the past 12 months) and low-density lipoprotein cholesterol (LDL-C) levels ≥ 100 mg/dL in China.

METHODS

A health economic evaluation was performed from a Chinese healthcare perspective, using a Markov model over a lifetime horizon based on a baseline cardiovascular (CV) event rate from claims database data and efficacy from the FOURIER trial. The health benefit was reflected in the decrease of LDL-C level, which led to a decrease of cardiovascular events. The costs of cardiovascular events and the utility value of each health state were derived from the published literature. Sensitivity analyses were conducted to evaluate the effects of uncertainty in parameters and the robustness of the model. The cost-effectiveness of evolocumab was also explored in patients with recent myocardial infarction (MI), at very high risk (VHR) of atherosclerotic cardiovascular disease (ASCVD), and homozygous familiar hypercholesterolemia (HoFH).

RESULTS

In patients with recent ACS, evolocumab was associated with incremental quality-adjusted life-years (QALYs) of 1.33 and incremental costs of 115,782 yuan versus ezetimibe, both with background statin therapy, resulting in an incremental cost-effectiveness ratio (ICER) of 87,050 yuan per QALY gained. The probability of evolocumab + statins being cost-effective at a threshold of 217,341 yuan (three times per capita GDP, 2020), compared with ezetimibe + statins, was 100% in patients with recent ACS, recent MI, VHR ASCVD, and HoFH.

CONCLUSION

Compared with ezetimibe + statins, the combination of evolocumab + statins was found to be cost-effective at a threshold of 217,341 yuan (three times per capita GDP, 2020) in patients with recent ACS events in China.

Cost-effectiveness of Ezetimibe plus statin lipid-lowering therapy: A systematic review and meta-analysis of cost-utility studies

In addition to statin therapy, Ezetimibe, a non-statin lipid-modifying agent, is increasingly used to reduce low-density lipoprotein cholesterol and atherosclerotic cardiovascular disease risk. Literature suggests the clinical effectiveness of Ezetimibe plus statin (EPS) therapy; however, primary evidence on its economic effectiveness is inconsistent. Hence, we pooled incremental net benefit to synthesise the cost-effectiveness of EPS therapy. We identified economic evaluation studies reporting outcomes of EPS therapy compared with other lipid-lowering therapeutic agents or placebo by searching PubMed, Embase, Scopus, and Tufts Cost-Effective Analysis registry. Using random-effects meta-analysis, we pooled Incremental Net Benefit (INB) in the US $ with a 95% confidence interval (CI). We used the modified economic evaluations bias checklist and GRADE quality assessment for quality appraisal. The pooled INB from twenty-one eligible studies showed that EPS therapy was significantly cost-effective compared to other lipid-lowering therapeutic agents or placebo. The pooled INB (95% CI) was $4,274 (621 to 7,927), but there was considerable heterogeneity (I² = 84.21). On subgroup analysis EPS therapy is significantly cost-effective in high-income countries [$4,356 (621 to 8,092)], for primary prevention [$4,814 (2,523 to 7,106)], and for payers’ perspective [$3,255 (571 to 5,939)], and from lifetime horizon [$4,571 (746 to 8,395)]. EPS therapy is cost-effective compared to other lipid-lowering therapeutic agents or placebo in high-income countries and for primary prevention. However, there is a dearth of evidence from lower-middle-income countries and the societal perspective.

A Systematic Review of Cost-Effectiveness of Non-Statin Lipid-Lowering Drugs for Primary and Secondary Prevention of Cardiovascular Disease in Patients with Type 2 Diabetes Mellitus

Although studies of non-statin lipid-lowering therapies (NSLLTs) have demonstrated cardiovascular benefits; whether these benefits provide good value has not been evaluated in type 2 diabetes mellitus (T2DM) patients. A systematic review was performed to include studies on the cost-effectiveness of NSLLTs in T2DM patients with/without cardiovascular disease (CVD). Thirteen studies were included; ezetimibe (n=8), proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors (n=4), fenofibrate (n=2), nicotinic acid (n=1), extended-release niacin/laropiprant (ER- ERN/LRPT) (n=1), and icosapent ethyl (n=1). Six studies considered ezetimibe+statin to be a cost-effective compared to statins monotherapy, three studies suggested that PCSK9 inhibitors+statins were not cost-effective compared to statin+ezetimibe. Fenofibrate was a cost-effective either as monotherapy or combined with a statin compared to statin or fenofibrate monotherapy. Nicotinic acid and ER- ERN/LRPT compared to statin monotherapy were also cost-effective. Icosapent ethyl using the solid-state relay was cost-effective compared to standard care but not using the wholesale acquisition cost.

Dyslipidaemia management in the cardiac rehabilitation clinic of a tertiary referral centre: analysis of the impact of new ESC guidance on LDL-C target achievement

BACKGROUND

Optimisation of low-density lipoprotein cholesterol (LDL-C) targets is one component of cardiac rehabilitation (CR). The 2019 European Society of Cardiology (ESC) guidelines recommend lower LDL-C targets than those released in 2016.

AIMS

To determine the proportion of patients who met 2019 LDL-C targets and compare these to international standards; examine the effect of the introduction of the recent ESC guidelines on target achievement. Examine the choice of lipid lowering therapy (LLT) used in our cohort.

METHODS

Retrospective chart review of 163 patients who attended CR in 2019. Baseline LDL-C levels were calculated where applicable. Targets achieved were compared with the contemporary ESC guidance. Required LLT was estimated for those who were unable to meet their LDL-C target.

RESULTS

Overall, 96/163 (59%) patients met their absolute LDL-C targets, which was favourable when compared to international standards. Fewer patients treated using the 2019 ESC guidelines met their absolute, (63% (70/112) vs. 51% (26/51)), or relative LDL-C 43% (22/51) targets. A high intensity statin was prescribed in 63% (89/163) of patients and only 9% (5/163) patients were prescribed ezetimibe therapy; increased use of these agents may have led to a further 20% (33/162) of patients meeting their LDL-C targets. 13% (22/163) of patients likely require PCSK9i therapy.

CONCLUSIONS

Patients may be more likely to meet LDL-C targets while enrolled in CR compared to standard care. Following the introduction of lower absolute LDL-C targets and additional > 50% LDL-C reduction from baseline requirement, fewer patients are meeting the LDL-C targets set out in the 2019 ESC dyslipidaemia guidelines. Additionally, many patients are not on maximum statin therapy, ezetimibe is under-prescribed, and a guideline-reimbursement gap exists for those who require PCSK9i therapy.

Cost-effectiveness of proprotein convertase subtilisin/kexin type 9 inhibition with evolocumab in patients with a history of myocardial infarction in Sweden

Aims

To assess the cost-effectiveness of proprotein convertase subtilisin/kexin type 9 inhibition with evolocumab added to standard-of-care lipid-lowering treatment [maximum tolerated dose (MTD) of statin and ezetimibe] in Swedish patients with a history of myocardial infarction (MI).

Methods and results

Cost-effectiveness was evaluated using a Markov model based on Swedish observational data on cardiovascular event rates and efficacy from the FOURIER trial. Three risk profiles were considered: recent MI in the previous year; history of MI with a risk factor; and history of MI with a second event within 2 years. For each population, three minimum baseline low-density lipoprotein cholesterol (LDL-C) levels were considered: 2.5 mmol/L (≈100 mg/dL), based on the current reimbursement recommendation in Sweden; 1.8 mmol/L (≈70 mg/dL), based on 2016 ESC/EAS guidelines; and 1.4 mmol/L (≈55 mg/dL), or 1.0 mmol/L (≈40 mg/dL) for MI with a second event, based on 2019 ESC/EAS guidelines. Proprotein convertase subtilisin/kexin type 9 inhibition with evolocumab was associated with increased quality-adjusted life-years and costs vs. standard-of-care therapy. Incremental cost-effectiveness ratios (ICERs) were below SEK700 000 (∼€66 500), the generally accepted willingness-to-pay threshold in Sweden, for minimum LDL-C levels of 2.3 (recent MI), 1.7 (MI with a risk factor), and 1.7 mmol/L (MI with a second event). Sensitivity analyses demonstrated that base-case results were robust to changes in model parameters.

Conclusion

Proprotein convertase subtilisin/kexin type 9 inhibition with evolocumab added to MTD of statin and ezetimibe may be considered cost-effective at its list price for minimum LDL-C levels of 1.7–2.3 mmol/L, depending on risk profile, with ICERs below the accepted willingness-to-pay threshold in Sweden.

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.

Cost-Effectiveness of Evolocumab Therapy for Myocardial Infarction: The Chinese Healthcare Perspective

PURPOSE

Proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors are an indispensable lipid-lowering treatment option, but their cost-effectiveness has been questioned. This study aimed to perform a health economic evaluation of evolocumab versus placebo in patients with myocardial infarction (MI) in China.

METHODS

A Markov cohort state-transition model was developed in decision analysis software to estimate the incremental cost-effectiveness ratio (ICER), defined as cost per quality-adjusted life-year (QALY) saved. The simulation subjects could undergo non-fatal MI and/or stroke, or vascular or non-vascular death event. We integrated the Chinese population-specific demographics and event rates with the risk reduction of evolocumab based on the FOURIER trial and/or lowering of low-density lipoprotein cholesterol (LDL-C). Age-related change, event costs and utilities were included from published sources.

RESULTS

At its current list price [33,748 Chinese yuan (CNY) annually per person], the ICER for evolocumab therapy was 927,713 CNY per QALY gained when integrating the FOURIER trial with absolute reduction of LDL-C. The probability of cost-effectiveness of evolocumab versus placebo was 1.96%, with a generally accepted threshold of 212,676 CNY per QALY gained. A reduction in acquisition price by approximately 70% (to less than 10,255 CNY annually) was needed to be cost-effective. Alternative scenario analyses of therapeutic benefit showed that the ICER for evolocumab in MI patients with uncontrolled familial hypercholesterolemia (FH) was 187,736 CNY per QALY gained.

CONCLUSION

Evolocumab in patients with MI was not cost-effective based on the price in 2019 in China; however, treatment with evolocumab was more favorable in MI patients with FH.

PCSK9 Inhibitors: From Nature’s Lessons to Clinical Utility

Background:

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

Objective:

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

Methods:

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

Results:

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

Conclusion:

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

Impact of preventive screening and lifestyle interventions in women with a history of preeclampsia: A micro-simulation study

BACKGROUND

Preeclampsia is a female-specific risk factor for the development of future cardiovascular disease. Whether early preventive cardiovascular disease risk screenings combined with risk-based lifestyle interventions in women with previous preeclampsia are beneficial and cost-effective is unknown.

METHODS

A micro-simulation model was developed to assess the life-long impact of preventive cardiovascular screening strategies initiated after women experienced preeclampsia during pregnancy. Screening was started at the age of 30 or 40 years and repeated every five years. Data (initial and follow-up) from women with a history of preeclampsia was used to calculate 10-year cardiovascular disease risk estimates according to Framingham Risk Score. An absolute risk threshold of 2% was evaluated for treatment selection, i.e. lifestyle interventions (e.g. increasing physical activity). Screening benefits were assessed in terms of costs and quality-adjusted-life-years, and incremental cost-effectiveness ratios compared with no screening.

RESULTS

Expected health outcomes for no screening are 27.35 quality-adjusted-life-years and increase to 27.43 quality-adjusted-life-years (screening at 30 years with 2% threshold). The expected costs for no screening are €9426 and around €13,881 for screening at 30 years (for a 2% threshold). Preventive screening at 40 years with a 2% threshold has the most favourable incremental cost-effectiveness ratio, i.e. €34,996/quality-adjusted-life-year, compared with other screening scenarios and no screening.

CONCLUSIONS

Early cardiovascular disease risk screening followed by risk-based lifestyle interventions may lead to small long-term health benefits in women with a history of preeclampsia. However, the cost-effectiveness of a lifelong cardiovascular prevention programme starting early after preeclampsia with risk-based lifestyle advice alone is relatively unfavourable. A combination of risk-based lifestyle advice plus medical therapy may be more beneficial.

Control of cardiovascular risk factors and health behaviors in patients post acute coronary syndromes eligible for protein convertase subtilisin/kexin-9 inhibitors

BACKGROUND

We aimed to examine cardiovascular risk factors and health behaviors in patients with acute coronary syndromes (ACS) according to potential extension of eligibility criteria for protein convertase subtilisin/kexin-9 inhibitors (PCSK9i) to all patients with low-density lipoprotein cholesterol (LDL-c) equal or above 1.8 mmol/l.

METHODS

In this prospective cross-sectional study, patients with ACS between 2009 and 2016 and with available LDL-c at one year were considered. We defined three mutually exclusive groups of patients according to eligibility for PCSK9i: "not eligible", "currently eligible", and "newly eligible". We explored the control of cardiovascular risk factors and health behaviors.

RESULTS

Out of 3025 patients who had an ACS one year ago, 1071 (35.4%) were not eligible for PCSK9i, 415 (13.7%) were currently eligible, and 1539 (50.9%) were newly eligible. The proportion of patients with uncontrolled hypertension in the not eligible group was lower than in the group currently eligible (27.6% vs 33.6%, p = 0.02), but similar to the group newly eligible (27.6% vs 28.2%, p = 0.73). The proportion of smokers in the not eligible group was lower than in the group currently eligible (21.2% vs 28.0%, p = 0.02), but similar to the group newly eligible (21.2% vs 22.5%, p = 0.51).

CONCLUSIONS

More than half of patients with ACS would be additionally eligible for PCSK9i if prescription is extended from current guidelines to all patients with LDL-c equal or above 1.8 mmol/l. Patients currently eligible for PCSK9i one year after an ACS had a worst control of cardiovascular risk factors than patients potentially newly eligible.

PCSK9 inhibitors and cardiovascular outcomes

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

Proprotein convertase subtilisin/kexin type 9 in kidney disease

Chronic kidney disease (CKD) is associated with a substantially increased risk for the development of atherosclerotic cardiovascular (CV) disease. Accordingly, CV mortality is increased even in the earliest stages of CKD. In the general population and in CKD patients, high plasma levels of low-density lipoprotein cholesterol (LDL-C) are crucially involved in the initiation and progression of atherosclerotic vascular lesions. Lowering LDL-C by use of statins and/or ezetimibe represents the gold standard of lipid-lowering therapy, with a great body of evidence from several large clinical trials. Statin therapy reduces CV events in patients with normal and impaired kidney function alike, while the evidence for patients on maintenance haemodialysis is weaker. The inhibition of proprotein convertase subtilisin/kexin type 9 (PCSK9) serine protease represents a novel lipid-lowering tool. Currently the monoclonal antibodies evolocumab and alirocumab are the approved PCSK9 inhibitors. Despite maximum-tolerated statin therapy, they efficiently further reduce LDL-C plasma levels without any major adverse effects. Moreover, in large clinical outcome trials, both antibodies have been proven to lower CV events. Notably, the LDL-lowering capacity was independent of baseline kidney function and also efficient in patients with moderate CKD. However, patients with severely impaired kidney function, that is, the population at the highest CV risk, have been excluded from those trials. The relevance of the LDL-independent effects of PCSK9 inhibitors, such as lowering lipoprotein(a) or ameliorating dyslipidaemia in patients with nephrotic syndrome, has to be determined. Therefore further specific studies assessing the effects and outcomes of PCSK9-inhibiting treatment in CKD patients are warranted.

Alirocumab in Patients With Polyvascular Disease and Recent Acute Coronary Syndrome: ODYSSEY OUTCOMES Trial

BACKGROUND

Patients with acute coronary syndrome (ACS) and concomitant noncoronary atherosclerosis have a high risk of major adverse cardiovascular events (MACEs) and death. The impact of lipid lowering by proprotein convertase subtilisin-kexin type 9 inhibition in such patients is undetermined.

OBJECTIVES

This pre-specified analysis from ODYSSEY OUTCOMES (Evaluation of Cardiovascular Outcomes After an Acute Coronary Syndrome During Treatment With Alirocumab) determined whether polyvascular disease influenced risks of MACEs and death and their modification by alirocumab in patients with recent ACS and dyslipidemia despite intensive statin therapy.

METHODS

Patients were randomized to alirocumab or placebo 1 to 12 months after ACS. The primary MACEs endpoint was the composite of coronary heart disease death, nonfatal myocardial infarction, fatal or nonfatal ischemic stroke, or unstable angina requiring hospitalization. All-cause death was a secondary endpoint.

RESULTS

Median follow-up was 2.8 years. Of 18,924 patients, 17,370 had monovascular (coronary) disease, 1,405 had polyvascular disease in 2 beds (coronary and peripheral artery or cerebrovascular), and 149 had polyvascular disease in 3 beds (coronary, peripheral artery, cerebrovascular). With placebo, the incidence of MACEs by respective vascular categories was 10.0%, 22.2%, and 39.7%. With alirocumab, the corresponding absolute risk reduction was 1.4% (95% confidence interval [CI]: 0.6% to 2.3%), 1.9% (95% CI: -2.4% to 6.2%), and 13.0% (95% CI: -2.0% to 28.0%). With placebo, the incidence of death by respective vascular categories was 3.5%, 10.0%, and 21.8%; the absolute risk reduction with alirocumab was 0.4% (95% CI: -0.1% to 1.0%), 1.3% (95% CI: -1.8% to 4.3%), and 16.2% (95% CI: 5.5% to 26.8%).

CONCLUSIONS

In patients with recent ACS and dyslipidemia despite intensive statin therapy, polyvascular disease is associated with high risks of MACEs and death. The large absolute reductions in those risks with alirocumab are a potential benefit for these patients. (Evaluation of Cardiovascular Outcomes After an Acute Coronary Syndrome During Treatment With Alirocumab [ODYSSEY OUTCOMES]: NCT01663402).

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

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

Small molecules as inhibitors of PCSK9: Current status and future challenges

Proprotein convertase subtilisin/kexin type 9 (PCSK9) plays an important role in regulating lipoprotein metabolism by binding to low-density lipoprotein receptors (LDLRs), leading to their degradation. LDL cholesterol (LDL-C) lowering drugs that operate through the inhibition of PCSK9 are being pursued for the management of hypercholesterolemia and reducing its associated atherosclerotic cardiovascular disease (CVD) risk. Two PCSK9-blocking monoclonal antibodies (mAbs), alirocumab and evolocumab, were approved in 2015. However, the high costs of PCSK9 antibody drugs impede their prior authorization practices and reduce their long-term adherence. Given the potential of small-molecule drugs, the development of small-molecule PCSK9 inhibitors has attracted considerable attention. This article provides an overview of the recent development of small-molecule PCSK9 inhibitors disclosed in the literature and patent applications, and different approaches that have been pursued to modulate the functional activity of PCSK9 using small molecules are described. Challenges and potential strategies in developing small-molecule PCSK9 inhibitors are also discussed.