Effect of Alirocumab on Lipoprotein(a) Over ≥1.5 Years (from the Phase 3 ODYSSEY Program)

Role of lipoprotein(a) in atherosclerotic cardiovascular disease: A review of current and emerging therapies

Lipoprotein(a), or Lp(a), is structurally like low-density lipoprotein (LDL) but differs in that it contains glycoprotein apolipoprotein(a) [apo(a)]. Due to its prothrombotic and proinflammatory properties, Lp(a) is an independent risk factor for atherosclerotic cardiovascular disease (ASCVD) and aortic valve stenosis. Lp(a) levels are genetically determined, and it is estimated that 20%-25% of the global population has an Lp(a) level ≥50 mg/dL (or ≥125 nmol/L). Diet and lifestyle interventions have little to no effect on Lp(a) levels. Lipoprotein apheresis is the only approved treatment for elevated Lp(a) but is time-intensive for the patient and only modestly effective. Pharmacological approaches to reduce Lp(a) levels and its associated risks are of significant interest; however, currently available lipid-lowering therapies have limited effectiveness in reducing Lp(a) levels. Although statins are first-line agents to reduce LDL cholesterol levels, they modestly increase Lp(a) levels and have not been shown to change Lp(a)-mediated ASCVD risk. Alirocumab, evolocumab, and inclisiran reduce Lp(a) levels by 20-25%, yet the clinical implications of this reduction for Lp(a)-mediated ASCVD risk are uncertain. Niacin also lowers Lp(a) levels; however, its effectiveness in mitigating Lp(a)-mediated ASCVD risk remains unclear, and its side effects have limited its utilization. Recommendations for when to screen and how to manage individuals with elevated Lp(a) vary widely between national and international guidelines and scientific statements. Three investigational compounds targeting Lp(a), including small interfering RNA (siRNA) agents (olpasiran, SLN360) and an antisense oligonucleotide (pelacarsen), are in various stages of development. These compounds block the translation of messenger RNA (mRNA) into apo(a), a key structural component of Lp(a), thereby substantially reducing Lp(a) synthesis in the liver. The purpose of this review is to describe current recommendations for screening and managing elevated Lp(a), describe the effects of currently available lipid-lowering therapies on Lp(a) levels, and provide insight into emerging therapies targeting Lp(a).

Lipoprotein(a) and the Effect of Alirocumab on Revascularization After Acute Coronary Syndrome

BACKGROUND

Many patients require revascularization after index acute coronary syndrome (ACS). Lipoprotein(a) is thought to play a pathogenic role in atherothrombosis. In ODYSSEY OUTCOMES, alirocumab reduced major adverse cardiovascular events after ACS, with greater reduction among those with higher lipoprotein(a) levels. We explored whether risk of revascularization after ACS was modified by the level of lipoprotein(a) and treatment with alirocumab or placebo.

METHODS

In ODYSSEY OUTCOMES alirocumab was compared with placebo in 18,924 patients with ACS and elevated atherogenic lipoprotein levels despite optimized statin treatment. In this post hoc analysis, treatment effects are summarized using competing risks proportional hazard models.

RESULTS

A total of 1559 (8.2%) patients had coronary, 204 (1.1%) had limb, and 40 (0.2%) had carotid revascularization. Alirocumab reduced coronary revascularization (2.8 vs 3.2 events per 100 patient-years; hazard ratio [HR], 0.88 [95% confidence interval (CI), 0.80-0.97]; P = 0.01) and any revascularization (3.2 vs 3.7 events per 100 patient-years; HR, 0.85 [95% CI, 0.78-0.94]; P = 0.001). Baseline lipoprotein(a) quartile was directly associated with risk of coronary or any revascularization in the placebo arm and inversely related to treatment HRs (all P for trend < 0.01). Alirocumab produced the greatest reduction of coronary revascularization in patients with baseline lipoprotein(a) in the top quartile (≥ 59.6 mg/dL; HR, 0.69 [95% CI, 0.57-0.84]), but no apparent reduction in the bottom quartile (HR, 1.00 [95% CI, 0.82-1.22]). Findings were similar for the effect of alirocumab on any revascularization.

CONCLUSIONS

Alirocumab reduced revascularization rates after ACS. The risk of revascularization and reduction in that risk with alirocumab were greatest in patients with elevated lipoprotein(a) at baseline.

Lipoprotein(a) as a Risk Factor for Cardiovascular Diseases: Pathophysiology and Treatment Perspectives

Cardiovascular disease (CVD) is still a leading cause of morbidity and mortality, despite all the progress achieved as regards to both prevention and treatment. Having high levels of lipoprotein(a) [Lp(a)] is a risk factor for cardiovascular disease that operates independently. It can increase the risk of developing cardiovascular disease even when LDL cholesterol (LDL-C) levels are within the recommended range, which is referred to as residual cardiovascular risk. Lp(a) is an LDL-like particle present in human plasma, in which a large plasminogen-like glycoprotein, apolipoprotein(a) [Apo(a)], is covalently bound to Apo B100 via one disulfide bridge. Apo(a) contains one plasminogen-like kringle V structure, a variable number of plasminogen-like kringle IV structures (types 1-10), and one inactive protease region. There is a large inter-individual variation of plasma concentrations of Lp(a), mainly ascribable to genetic variants in the Lp(a) gene: in the general po-pulation, Lp(a) levels can range from <1 mg/dL to >1000 mg/dL. Concentrations also vary between different ethnicities. Lp(a) has been established as one of the risk factors that play an important role in the development of atherosclerotic plaque. Indeed, high concentrations of Lp(a) have been related to a greater risk of ischemic CVD, aortic valve stenosis, and heart failure. The threshold value has been set at 50 mg/dL, but the risk may increase already at levels above 30 mg/dL. Although there is a well-established and strong link between high Lp(a) levels and coronary as well as cerebrovascular disease, the evidence regarding incident peripheral arterial disease and carotid atherosclerosis is not as conclusive. Because lifestyle changes and standard lipid-lowering treatments, such as statins, niacin, and cholesteryl ester transfer protein inhibitors, are not highly effective in reducing Lp(a) levels, there is increased interest in developing new drugs that can address this issue. PCSK9 inhibitors seem to be capable of reducing Lp(a) levels by 25-30%. Mipomersen decreases Lp(a) levels by 25-40%, but its use is burdened with important side effects. At the current time, the most effective and tolerated treatment for patients with a high Lp(a) plasma level is apheresis, while antisense oligonucleotides, small interfering RNAs, and microRNAs, which reduce Lp(a) levels by targeting RNA molecules and regulating gene expression as well as protein production levels, are the most widely explored and promising perspectives. The aim of this review is to provide an update on the current state of the art with regard to Lp(a) pathophysiological mechanisms, focusing on the most effective strategies for lowering Lp(a), including new emerging alternative therapies. The purpose of this manuscript is to improve the management of hyperlipoproteinemia(a) in order to achieve better control of the residual cardiovascular risk, which remains unacceptably high.

Novel and future lipid-modulating therapies for the prevention of cardiovascular disease

Lowering the levels of LDL cholesterol in the plasma has been shown to reduce the risk of atherosclerotic cardiovascular disease (ASCVD). Several other lipoproteins, such as triglyceride-rich lipoproteins, HDL and lipoprotein(a) are associated with atherosclerosis and ASCVD, with strong evidence supporting causality for some. In this Review, we discuss novel and upcoming therapeutic strategies targeting different pathways in lipid metabolism to potentially attenuate the risk of cardiovascular events. Key proteins involved in lipoprotein metabolism, such as PCSK9, angiopoietin-related protein 3, cholesteryl ester transfer protein and apolipoprotein(a), have been identified as viable targets for therapeutic intervention through observational and genetic studies. These proteins can be targeted using a variety of approaches, such as protein inhibition or interference, inhibition of translation at the mRNA level (with the use of antisense oligonucleotides or small interfering RNA), and the introduction of loss-of-function mutations through base editing. These novel and upcoming strategies are complementary to and could work synergistically with existing therapies, or in some cases could potentially replace therapies, offering unprecedented opportunities to prevent ASCVD. Moreover, a major challenge in the prevention and treatment of non-communicable diseases is how to achieve safe, long-lasting reductions in causal exposures. This challenge might be overcome with approaches such as small interfering RNAs or genome editing, which shows how far the field has advanced from when the burden of achieving this goal was placed upon patients through rigorous adherence to daily small-molecule drug regimens.

Daring to dream: Targeting lipoprotein(a) as a causal and risk-enhancing factor

Lipoprotein(a) [Lp(a)], a distinct lipoprotein class, has become a major focus for cardiovascular research. This review is written in light of the recent guideline and consensus statements on Lp(a) and focuses on 1) the causal association between Lp(a) and cardiovascular outcomes, 2) the potential mechanisms by which elevated Lp(a) contributes to cardiovascular diseases, 3) the metabolic insights on the production and clearance of Lp(a) and 4) the current and future therapeutic approaches to lower Lp(a) concentrations. The concentrations of Lp(a) are under strict genetic control. There exists a continuous relationship between the Lp(a) concentrations and risk for various endpoints of atherosclerotic cardiovascular disease (ASCVD). One in five people in the Caucasian population is considered to have increased Lp(a) concentrations; the prevalence of elevated Lp(a) is even higher in black populations. This makes Lp(a) a cardiovascular risk factor of major public health relevance. Besides the association between Lp(a) and myocardial infarction, the relationship with aortic valve stenosis has become a major focus of research during the last decade. Genetic studies provided strong support for a causal association between Lp(a) and cardiovascular outcomes: carriers of genetic variants associated with lifelong increased Lp(a) concentration are significantly more frequent in patients with ASCVD. This has triggered the development of drugs that can specifically lower Lp(a) concentrations: mRNA-targeting therapies such as anti-sense oligonucleotide (ASO) therapies and short interfering RNA (siRNA) therapies have opened new avenues to lower Lp(a) concentrations more than 95%. Ongoing Phase II and III clinical trials of these compounds are discussed in this review.

Lipoprotein(a) Does Not Predict Thrombotic Events and In-Hospital Outcomes in Patients with COVID-19

The prothrombotic and proinflammatory properties of lipoprotein(a) (Lp(a)) have been hypothesized to play a role in the pathogenesis of severe COVID-19; however, the prognostic impact of Lp(a) on the clinical course of COVID-19 remains controversial. This study aimed to investigate whether Lp(a) may be associated with biomarkers of thrombo-inflammation and the occurrence of thrombotic events or adverse clinical outcomes in patients hospitalized for COVID-19. We consecutively enrolled a cohort of patients hospitalized for COVID-19 and collected blood samples for Lp(a) assessment at hospital admission. A prothrombotic state was evaluated through D-dimer levels, whereas a proinflammatory state was evaluated through C-reactive protein (CRP), procalcitonin, and white blood cell (WBC) levels. Thrombotic events were marked by the diagnosis of deep or superficial vein thrombosis (DVT or SVT), pulmonary embolism (PE), stroke, transient ischemic attack (TIA), acute coronary syndrome (ACS), and critical limb ischemia (CLI). The composite clinical end point of intensive care unit (ICU) admission/in-hospital death was used to evaluate adverse clinical outcomes. Among 564 patients (290 (51%) men, mean age of 74 ± 17 years) the median Lp(a) value at hospital admission was 13 (10-27) mg/dL. During hospitalization, 64 (11%) patients were diagnosed with at least one thrombotic event and 83 (15%) patients met the composite clinical end point. Lp(a), as either a continuous or categorical variable, was not associated with D-dimer, CRP, procalcitonin, and WBC levels (p > 0.05 for all correlation analyses). In addition, Lp(a) was not associated with a risk of thrombotic events (p > 0.05 for multi-adjusted odds ratios) nor with a risk of adverse clinical outcomes (p > 0.05 for multi-adjusted hazard ratios). In conclusion, Lp(a) does not influence biomarkers of plasma thrombotic activity and systemic inflammation nor has any impact on thrombotic events and adverse clinical outcomes in patients hospitalized for COVID-19.

Interplay between microRNAs, Serum Proprotein Convertase Subtilisin/Kexin Type 9 (PCSK9), and Lipid Parameters in Patients with Very High Lipoprotein(a) Treated with PCSK9 Inhibitors

Proprotein convertase subtilisin/kexin type 9 (PCSK9) has an important function in the regulation of lipid metabolism. PCSK9 reduces hepatic low-density lipoprotein receptors, thereby increasing low-density lipoprotein cholesterol levels. However, its regulation remains to be elucidated, including post-transcriptional regulation by microRNAs (miRNAs). We aimed to explore the interplay between miRNAs, total serum PCSK9, and lipids during treatment with PCSK9 inhibitors. A total of 64 patients with stable coronary artery disease and very high lipoprotein(a) levels and 16 sex- and age-matched control subjects were enrolled. Patients received a PCSK9 inhibitor (evolocumab or alirocumab). Total serum PCSK9 levels were measured by immunoassay. RNA was isolated from plasma using magnetic beads, and expression of selected miRNAs was analyzed by quantitative PCR. Total serum PCSK9 levels were significantly higher in control subjects compared with patients. After 6 months of treatment with PCSK9 inhibitors, total serum PCSK9 levels increased significantly. The expression of miR-191-5p was significantly lower, and the expression of miR-224-5p and miR-483-5p was significantly higher in patients compared with control subjects. Using linear regression, the expression of miR-483-5p significantly predicted the serum PCSK9 level at baseline. After the 6-month period of therapy, the expression of miR-191-5p and miR-483-5p significantly increased. Our results support a role for miR-483-5p in regulating circulating PCSK9 in vivo. The difference in expression of miR-191-5p, miR-224-5p, and miR-337-3p between patients and control subjects suggests their possible role in the pathogenesis of coronary artery disease.

Lipoprotein(a): a risk factor for atherosclerosis and an emerging therapeutic target

Lipoprotein(a) (Lp(a)) is a complex circulating lipoprotein, and increasing evidence has demonstrated its role as a risk factor for atherosclerotic cardiovascular disease (ASCVD) and as a possible therapeutic target. Lp(a) atherogenic effects are attributed to several potential mechanisms in addition to cholesterol accumulation in the arterial wall, including proinflammatory effects mainly mediated by oxidised phospholipids. Several studies have found a causal and independent relationship between Lp(a) levels and cardiovascular risk. Furthermore, several studies also suggest a causal association between Lp(a) levels and calcific aortic valve stenosis. Available lipid-lowering agents have at best moderate impact on Lp(a) levels. Among available therapies, antibody proprotein convertase subtilisin/kexin type 9 inhibitors are the most effective in reducing Lp(a). Potent Lp(a)-lowering treatments that target LPA expression are under development. Lp(a) level measurement poses some challenges due to the absence of a definitive reference method and the reporting of Lp(a) values as molar (nanomoles per litre (nmol/L)) or mass concentrations (milligrams per decilitre (mg/dL)) by different assays. Currently, Lp(a) measurement is recommended to refine cardiovascular risk in specific clinical settings, that is, in individuals with a family history of premature ASCVD, in patients with ASCVD not explained by standard risk factors or in those with recurrent events despite optimal management of traditional risk factors. Patients with high Lp(a) levels should be managed with more intensive approaches to treat other modifiable cardiovascular risk factors. Overall, this review focuses on Lp(a) as an ASCVD risk factor and therapeutic target. Furthermore, it reports practical recommendations for Lp(a) measurement and interpretation and updated evidence on Lp(a)-lowering approaches.

Lipoprotein(a) and Cardiovascular Disease in Chinese Population

Elevated concentration of lipoprotein(a) [Lp(a)] is an independent risk factor for atherosclerotic cardiovascular disease, including coronary artery disease, stroke, peripheral artery disease, and so on. Emerging data suggest that Lp(a) contributes to the increased risk for cardiovascular events even in the setting of effective reduction of plasma low-density lipoprotein cholesterol. Nevertheless, puzzling issues exist covering potential genetic factors, Lp(a) assay, possible individuals for analysis, a cutoff point of increased risk, and clinical interventions. In the Chinese population, Lp(a) exhibited a distinctive prevalence and regulated various cardiovascular diseases in specific ways. Hence, it is valuable to clarify the role of Lp(a) in cardiovascular diseases and explore prevention and control measures for the increase in Lp(a) prevalence in the Chinese population. This Beijing Heart Society experts' scientific statement will present the detailed knowledge concerning Lp(a)-related studies combined with Chinese population observations to provide the key points of reference.

The associations between exercise and lipid biomarkers

Cardiovascular diseases (CVD) remain the leading cause of death globally, and further efforts are being undertaken to understand and modify CVD risk factors, such as dyslipidemia (DLD), hypertension, and diabetes. The sedentary lifestyle of most individuals today contributes to the prevalence of these conditions. Uncontrolled dyslipidemia serves as a fertile ground for atherosclerotic plaque formation, while lipoproteins (Lp) act as cofactors for inflammatory processes that cause plaque destabilization leading to subsequent CVD events. As such, many health experts and institutions continue to emphasize the importance of cardiorespiratory fitness (CRF) and muscular strength (MusS) with the intent to reduce atherogenic lipoproteins and proprotein convertase subtilisin kexin type 9 (PCSK-9) expression. Concordantly, the two modes of exercise training (ET), such as aerobic ET (aET) and resistance ET (rET) have both demonstrated to improve CRF and MusS, respectively. Although both modes of ET were shown to independently reduce mortality, participation in both forms resulted in a more pronounced improvement in cholesterol levels and CVD-related mortality. Though reduction of adiposity is not a pre-requisite to achieve better control of DLD through increased CRF and MusS, the beneficial effects of physical activity on the inflammatory processes linked to atherosclerosis are almost always associated with a simultaneous decrease in overall adiposity. It is therefore essential to promote both aET and rET, including weight loss in order to attenuate the risks stemming from atherosclerosis and its proinflammatory components.

Use of Lipoprotein(a) in clinical practice: A biomarker whose time has come. A scientific statement from the National Lipid Association

Lipoprotein(a) [Lp(a)] is a well-recognized, independent risk factor for atherosclerotic cardiovascular disease, with elevated levels estimated to be prevalent in 20% of the population. Observational and genetic evidence strongly support a causal relationship between high plasma concentrations of Lp(a) and increased risk of atherosclerotic cardiovascular disease-related events, such as myocardial infarction and stroke, and valvular aortic stenosis. In this scientific statement, we review an array of evidence-based considerations for testing of Lp(a) in clinical practice and the utilization of Lp(a) levels to inform treatment strategies in primary and secondary prevention.

Smoking and diabetes attenuate beneficial effects of PSCK9 inhibitors on arterial wall properties in patients with very high lipoprotein (a) levels

Background and aims

Elevated lipoprotein (a) (Lp(a)) and low-density lipoprotein cholesterol levels (LDL-C) are significant residual risk factors for cardiovascular events. Treatment with protein convertase subtilisin kexin type 9 (PCSK9) inhibitors reduces the levels of both. Less is known about effects of PCSK9 inhibitors on functional and morphological properties of the arterial wall. The aim of the present study was to determine whether other factors besides decreased LDL-C and Lp(a) are associated with functional (flow-mediated dilation [FMD]) and morphological (carotid intima-media thickness [c-IMT], pulse-wave velocity [PWV]) changes of the arterial wall properties in patients with coronary artery disease (CAD) treated with alirocumab and evolocumab.

Methods

One hundred patients with CAD after myocardial infarction before 55 years and with high Lp(a) were randomised to lipid-lowering therapies without PCSK9 inhibitors (control; N = 31), or with alirocumab 150 mg SC (N = 35) or evolocumab 140 mg SC (N = 34), every 2 weeks. All patients underwent blood sampling for biochemical analyses and ultrasound measurements for FMD, c-IMT and PWV.

Results

There were no significant changes in FMD for the control (10.7% ± 6.6%-11.1% ± 4.4%, p = 0.716) and alirocumab (10.7% ± 5.9%-11.2% ± 5.3%, p = 0.547) groups, while evolocumab promoted significant increase (11.2% ± 6.8%-14.1% ± 6.6%, p < 0.0001). Only in non-smokers and non-diabetics significant improvements in FMD (p < 0.0001) after treatment with PCSK9 inhibitors were observed.

Conclusion

These data show that for patients with CAD and high Lp(a) levels, beneficial effects of PCSK9 inhibitors on the arterial wall properties can be attenuated by specific risk factors, such as smoking and diabetes.

Apo(a) and ApoB Interact Noncovalently Within Hepatocytes: Implications for Regulation of Lp(a) Levels by Modulation of ApoB Secretion

BACKGROUND

Elevated plasma Lp(a) (lipoprotein(a)) levels are associated with increased risk for atherosclerotic cardiovascular disease and aortic valve stenosis. However, the cell biology of Lp(a) biosynthesis remains poorly understood, with the locations of the noncovalent and covalent steps of Lp(a) assembly unclear and the nature of the apoB-containing particle destined for Lp(a) unknown. We, therefore, asked if apo(a) and apoB interact noncovalently within hepatocytes and if this impacts Lp(a) biosynthesis.

METHODS

Using human hepatocellular carcinoma cells expressing 17K (17 kringle) apo(a), or a 17KΔLBS7,8 variant with a reduced ability to bind noncovalently to apoB, we performed coimmunoprecipitation, coimmunofluorescence, and proximity ligation assays to document intracellular apo(a):apoB interactions. We used a pulse-chase metabolic labeling approach to measure apo(a) and apoB secretion rates.

RESULTS

Noncovalent complexes containing apo(a)/apoB are present in lysates from cells expressing 17K but not 17KΔLBS7,8, whereas covalent apo(a)/apoB complexes are absent from lysates. 17K and apoB colocalized intracellularly, overlapping with staining for markers of endoplasmic reticulum trans-Golgi, and early endosomes, and less so with lysosomes. The 17KΔLBS7,8 had lower colocalization with apoB. Proximity ligation assays directly documented intracellular 17K/apoB interactions, which were dramatically reduced for 17KΔLBS7,8. Treatment of cells with PCSK9 (proprotein convertase subtilisin/kexin type 9) enhanced, and lomitapide reduced, apo(a) secretion in a manner dependent on the noncovalent interaction between apo(a) and apoB. Apo(a) secretion was also reduced by siRNA-mediated knockdown of APOB.

CONCLUSIONS

Our findings explain the coupling of apo(a) and Lp(a)-apoB production observed in human metabolic studies using stable isotopes as well as the ability of agents that inhibit apoB biosynthesis to lower Lp(a) levels.

Combination of High-Density Lipoprotein Cholesterol and Lipoprotein(a) as a Predictor of Collateral Circulation in Patients With Severe Unilateral Internal Carotid Artery Stenosis or Occlusion

BACKGROUND AND PURPOSE

Collateral circulation is considered an important factor affecting the risk of stroke, but the factors that affect collateral circulation remain unclear. This study was performed to identify the factors associated with collateral circulation, especially blood lipids.

METHODS

The study involved patients who had undergone digital subtraction angiography and were confirmed as having severe unilateral stenosis or occlusion of the internal carotid artery (ICA). We classified the collateral circulation status of each patient as good (Grade 3 or 4) or poor (Grade 0, 1, or 2) according to the grading system of the American Society of Interventional and Therapeutic Neuroradiology/American Society of Interventional Radiology. We collected data on patients' characteristics and identified the factors that affect collateral circulation.

RESULTS

This study included 212 patients. The multivariate logistic regression analysis showed that the high-density lipoprotein cholesterol (HDL-C) concentration and a complete anterior half of the circle of Willis were independent protective factors for good collateral circulation, whereas elevated lipoprotein(a) [Lp(a)] and serum creatinine concentrations were independent risk factors for good collateral circulation. The area under the receiver operating characteristics curve (AUC) was 0.68 (95% confidence interval [CI], 0.61-0.76) for HDL-C and 0.69 (95% CI, 0.62-0.76) for Lp(a). A binary logistic regression model analysis of the joint factor of HDL-C and Lp(a) yielded an AUC of 0.77 (95% CI, 0.71-0.84).

CONCLUSIONS

In patients with severe unilateral ICA stenosis or occlusion, the combination of HDL-C and Lp(a) is a useful predictor of collateral circulation.

PCSK9 Inhibitors in Clinical Practice: Experience of a Specialized Lipid Center

Aim. To characterize patients receiving PCSK9 inhibitors, and assess the efficiency of their treatment in a specialized lipid center.

Material and methods. A retrospective analysis of the medical records of patients who visited the Lipid clinic of the National Medical Research Center for Therapy and Preventive Medicine (Moscow, Russia), receiving PCSK9 inhibitor and having lipid profile in dynamics, was carried out (n=77). Cardiovascular risk (CVR) and low-density lipoprotein cholesterol (LDL-C) target levels were evaluated in accordance with the Russian guidelines for the diagnostics and correction of dyslipidemias 2020.

Results. Of 77 patients taking PCSK9 inhibitors (44.2% males, the median of age 56 [47; 66] years), the majority (64.0%) had a probable or definite familial hypercholesterolemia (FH). The proportion of other lipid metabolism disorders, pure hypercholesterolemia and combined hyperlipidemia was 21% and 15%. More than half of the patients (68.8%) had a very high CVR, mainly due to the presence of coronary heart disease (84.9%). The proportion of patients receiving PCSK9 inhibitors as monotherapy was 7.8%, in combination with high-intensity statin therapy – 33.8%, as part of triple lipid-lowering therapy (high-intensity statin, ezetimibe, PCSK9 inhibitors) – 50.6%. Addition of PCSK9 inhibitors to combined lipid-lowering therapy enabled to reduce the LDL-C level to 1.02 [0.62; 1.39] mmol/l with its total decrease from the baseline by 87.3%. While taking PCSK9 inhibitors, LDL-C <1.8 mmol/l and <1.4 mmol/l achieved at 78.3% and 57.7% FH patients with high and very high CVR, respectively. Among patients with other hyperlipidemias, 74.1% of patients with very high CVR was achieved the target LDL-C level <1.4 mmol/l.

Conclusion: In a specialized lipid center, PCSK9 inhibitors are prescribed to patients with high or very high CVR, most of whom are FH patients. The effectiveness of the use of PCSK9 inhibitors in real-world practice is comparable to the results of clinical trials.

Calcific aortic valve disease: from molecular and cellular mechanisms to medical therapy

Calcific aortic valve disease (CAVD) is a highly prevalent condition that comprises a disease continuum, ranging from microscopic changes to profound fibro-calcific leaflet remodelling, culminating in aortic stenosis, heart failure, and ultimately premature death. Traditional risk factors, such as hypercholesterolaemia and (systolic) hypertension, are shared among atherosclerotic cardiovascular disease and CAVD, yet the molecular and cellular mechanisms differ markedly. Statin-induced low-density lipoprotein cholesterol lowering, a remedy highly effective for secondary prevention of atherosclerotic cardiovascular disease, consistently failed to impact CAVD progression or to improve patient outcomes. However, recently completed phase II trials provide hope that pharmaceutical tactics directed at other targets implicated in CAVD pathogenesis offer an avenue to alter the course of the disease non-invasively. Herein, we delineate key players of CAVD pathobiology, outline mechanisms that entail compromised endothelial barrier function, and promote lipid homing, immune-cell infiltration, and deranged phospho-calcium metabolism that collectively perpetuate a pro-inflammatory/pro-osteogenic milieu in which valvular interstitial cells increasingly adopt myofibro-/osteoblast-like properties, thereby fostering fibro-calcific leaflet remodelling and eventually resulting in left ventricular outflow obstruction. We provide a glimpse into the most promising targets on the horizon, including lipoprotein(a), mineral-binding matrix Gla protein, soluble guanylate cyclase, dipeptidyl peptidase-4 as well as candidates involved in regulating phospho-calcium metabolism and valvular angiotensin II synthesis and ultimately discuss their potential for a future therapy of this insidious disease.

Plasma lipoprotein(a) measured in the routine clinical care is associated to atherosclerotic cardiovascular disease during a 14-year follow-up

AIMS

To investigate plasma lipoprotein(a) [Lp(a)] levels measured in routine clinical care and their association with mortality and cardiovascular disease.

METHODS AND RESULTS

This retrospective registry-based observational cohort study includes all individuals with plasma Lp(a) results measured at the Karolinska University Laboratory 2003-17. Outcome data were captured in national outcome registries. Levels of Lp(a) expressed in mass or molar units were examined separately. In adjusted Cox regression models, association between deciles of plasma Lp(a) concentrations, mortality, and cardiovascular outcomes were assessed. A total of 23 398 individuals [52% females, mean (standard deviation) age 55.5 (17.2) years, median Lp(a) levels 17 mg/dL or 19.5 nmol/L] were included. Individuals with an Lp(a) level >90th decile (>90 mg/dL or >180 nmol/L) had hazard ratios (95% confidence interval) of 1.25 (1.05-1.50) for major adverse cardiovascular events (P = 0.013), 1.37 (1.14-1.64) for atherosclerotic cardiovascular disease (P = 0.001), and 1.62 (1.28-2.05) for coronary artery disease (P ≤ 0.001), compared to individuals with Lp(a) ≤50th decile. No association between Lp(a) and mortality, peripheral artery disease, or ischaemic stroke was observed.

CONCLUSION

High Lp(a) levels are associated with adverse cardiovascular disease outcomes also in individuals with Lp(a) measured in routine clinical care. This supports the 2019 ESC/EAS recommendation to measure Lp(a) at least once during lifetime to assess cardiovascular risk and implies the need for intensive preventive therapy in patients with elevated Lp(a).

The size of apolipoprotein (a) is an independent determinant of the reduction in lipoprotein (a) induced by PCSK9 inhibitors

AIMS

Lipoprotein (a) [Lp(a)] is a lipoprotein species causatively associated with atherosclerosis. Unlike statins, PCSK9 inhibitors (PCSK9i) reduce Lp(a), but this reduction is highly variable. Levels of Lp(a) are chiefly governed by the size of its signature protein, apolipoprotein (a) [apo(a)]. Whether this parameter determines some of the reduction in Lp(a) induced by PCSK9i remains unknown. We aimed to investigate if the Lp(a) lowering efficacy of PCSK9i is modulated by the size of apo(a), which is genetically determined by the variable number of KIV domains present on that protein.

METHODS AND RESULTS

The levels of Lp(a) and the size of apo(a) were assessed in plasma samples from 268 patients before and after treatment with PCSK9i. Patients were recruited at the Outpatient Lipid Clinic of the Charité Hospital (Berlin) between 2015 and 2020. They were hypercholesterolemic at very high CVD risk with LDL-cholesterol levels above therapeutic targets despite maximally tolerated lipid-lowering therapy. Patients received either Alirocumab (75 or 150 mg) or Evolocumab (140 mg) every 2 weeks. Apo(a), apoB100, and apoE concentrations as well as apoE major isoforms were determined by liquid chromatography high-resolution mass spectrometry. Apo(a) isoforms sizes were determined by Western Blot. PCSK9i sharply reduced LDL-cholesterol (-57%), apoB100 (-47%) and Lp(a) (-36%). There was a positive correlation between the size of apo(a) and the relative reduction in Lp(a) induced by PCSK9i (r = 0.363, p = 0.0001). The strength of this association remained unaltered after adjustment for baseline Lp(a) levels and all other potential confounding factors. In patients with two detectable apo(a) isoforms, there was also a positive correlation between the size of apo(a) and the reduction in Lp(a), separately for the smaller (r = 0.350, p = 0.0001) and larger (r = 0.324, p = 0.0003) isoforms. The relative contribution of the larger isoform to the total concentration of apo(a) was reduced from 29% to 15% (p < 0.0001).

CONCLUSIONS

The size of apo(a) is an independent determinant of the response to PCSK9i. Each additional kringle domain is associated with a 3% additional reduction in Lp(a). This explains in part the variable efficacy of PCSK9i and allows to identify patients who will benefit most from these therapies in terms of Lp(a) lowering.

TRANSLATIONAL PERSPECTIVE

Unlike statins, PCSK9 inhibitors reduce the circulating levels of the highly atherogenic Lipoprotein (a). The underlying mechanism remains a matter of considerable debate. The size of apo(a), the signature protein of Lp(a), is extremely variable (300 to more than 800 kDa) and depends on its number of kringle domains. We now show that each increase in apo(a) size by one kringle domain is associated with a 3% additional reduction in Lp(a) following PCSK9i treatment and that apo(a) size polymorphism is an independent predictor of the reduction in Lp(a) induced by these drugs. In an era of personalized medicine, this allows to identify patients who will benefit most from PCSK9i in terms of Lp(a) lowering.

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.

The association of lipoprotein(a) and intraplaque neovascularization in patients with carotid stenosis: a retrospective study

Background

Lipoprotein(a) is genetically determined and increasingly recognized as a major risk factor for arteriosclerotic cardiovascular disease. We examined whether plasma lipoprotein(a) concentrations were associated with intraplaque neovascularization (IPN) grade in patients with carotid stenosis and in terms of increasing plaque susceptibility to haemorrhage and rupture.

Methods

We included 85 patients diagnosed with carotid stenosis as confirmed using carotid ultrasound who were treated at Guangdong General Hospital. Baseline data, including demographics, comorbid conditions and carotid ultrasonography, were recorded. The IPN grade was determined using contrast-enhanced ultrasound through the movement of the microbubbles. Univariate and multivariate binary logistic regression analyses were used to evaluate the association between lipoprotein(a) and IPN grade, with stepwise adjustment for covariates including age, sex, comorbid conditions and statin therapy (model 1), total cholesterol, triglyceride, low-density lipoprotein cholesterol calculated by Friedwald's formula, high-density lipoprotein cholesterol, apolipoprotein A and apolipoprotein B (model 2), maximum plaque thickness and total carotid maximum plaque thickness, degree of carotid stenosis and internal carotid artery (ICA) occlusion (model 3).

Results

Lipoprotein(a) was a significant predictor of higher IPN grade in binary logistic regression before adjusting for other risk factors (odds ratio [OR] 1.238, 95% confidence interval [CI] (1.020, 1.503), P = 0.031). After adjusting for other risk factors, lipoprotein(a) still remained statistically significant in predicting IPN grade in all model. (Model 1: OR 1.333, 95% CI 1.074, 1.655, P = 0.009; Model 2: OR 1.321, 95% CI 1.059, 1.648, P = 0.014; Model 3: OR 1.305, 95% CI 1.045, 1.628, P = 0.019). Lp(a) ≥ 300 mg/L is also significantly related to IPN compare to < 300 mg/L (OR 2.828, 95% CI 1.055, 7.580, P = 0.039) as well as in model 1, while in model 2 and model 3 there are not significant difference.

Conclusions

Plasma lipoprotein(a) concentrations were found to be independently associated with higher IPN grade in patients with carotid stenosis. Lowering plasma lipoprotein(a) levels may result in plaque stabilization by avoiding IPN formation.

Low-density lipoproteins cause atherosclerotic cardiovascular disease: pathophysiological, genetic, and therapeutic insights: a consensus statement from the European Atherosclerosis Society Consensus Panel

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Effectiveness of proprotein convertase subtilisin/kexin-9 monoclonal antibody treatment on plasma lipoprotein(a) concentrations in patients with elevated lipoprotein(a) attending a clinic

Background

Lipoprotein(a) (Lp[a]) is a causal risk factor for atherosclerotic cardiovascular disease (ASCVD). Proprotein convertase subtilisin/kexin‐9 monoclonal antibodies (PCSK9mAbs) can lower Lp(a) levels in clinical trials, but their effects in patients with elevated Lp(a) in clinical practice remain unclear.

Aims

To investigate the effectiveness and safety of PCSK9mAbs in lowering plasma Lp(a) in patients with elevated Lp(a) concentrations in a lipid clinic.

Methods

This was an open‐label study of 53 adult patients with elevated Lp(a) concentration (≥0.5 g/L). Clinical, biochemical, and safety data were collected before and on treatment with evolocumab or alirocumab over a mean period of 11 months.

Results

Treatment with a PCSK9mAb resulted in a significant reduction of 0.29 g/L (−22%) in plasma Lp(a) concentration (p<.001). There were also significant reductions in low‐density lipoprotein‐cholesterol (LDL‐C) (−53%), remnant‐cholesterol (−12%) and apolipoprotein B (−43%) concentrations. The change in Lp(a) concentration was significantly different from a comparable group of 35 patients with elevated Lp(a) who were not treated with a PCSK9mAb (−22% vs. −2%, p<.001). The reduction in Lp(a) concentration was not associated with the corresponding changes in LDL‐C, remnant‐cholesterol, and apolipoprotein B (p>.05 in all). 7.5% and 47% of the patients attained a target concentration of Lp(a) <0.5 g/L and LDL‐C <1.8 mmol/L, respectively. PCSK9mAbs were well tolerated, the common adverse effects being pharyngitis (9.4%), nasal congestion (7.6%), myalgia (9.4%), diarrhoea (7.6%), arthralgia (9.4%) and injection site reactions (11%).

Conclusion

PCSK9mAbs can effectively and safely lower plasma Lp(a) concentrations in patients with elevated Lp(a) in clinical practice; the impact of the fall in Lp(a) on ASCVD outcomes requires further investigation.

Coronary heart disease risk: Low-density lipoprotein and beyond

Coronary heart disease (CHD) is the leading cause of morbidity and mortality world-wide and has been characterized as a chronic immunoinflammatory, fibroproliferative disease fueled by lipids. Great advances have been made in elucidating the complex mechanistic interactions among risk factors associated with CHD, yielding abundant success towards preventive measures and the development of pharmaceuticals to prevent and treat CHD via attenuation of lipoprotein-mediated risk. However, significant residual risk remains. Several potentially modifiable CHD risk factors ostensibly contributing to this residual risk have since come to the fore, including systemic inflammation, diabetes mellitus, high-density lipoprotein, plasma triglycerides (TG) and remnant lipoproteins (RLP), lipoprotein(a) (Lp[a]), and vascular endothelial dysfunction (ED). Herein, we summarize the body of evidence implicating each of these risk factors in residual CHD risk.

PCSK9 promotes tumor growth by inhibiting tumor cell apoptosis in hepatocellular carcinoma

Background

Proprotein convertase subtilisin/kexin type 9 (PCSK9), one of the key enzymes in the process of lipid transport, is involved in the disease progression of various types of tumors. This article is to study the role of PCSK9 in the progression of hepatocellular carcinoma (HCC).

Methods

Immunohistochemistry was used to assess the expression of PCSK9 in tumor specimens from 105 HCC patients who underwent curative resection. Western blotting and quantitative real-time PCR were used to test the protein and mRNA expression levels in HCC cell lines. Cell Counting Kit-8 (CCK-8) and clone formation assays were performed to evaluate the proliferation ability of different kinds of cells in vitro. Flow cytometry was used to analyze cell cycle distribution and apoptosis rate. A xenograft model was established to study the effect of PCSK9 on HCC growth in vivo. TUNEL and immunofluorescence assays were used to detect cell apoptosis.

Results

High expression of PCSK9 in tumor tissues was related to microvascular invasion (p = 0.036) and large tumor size (p = 0.001) in HCC patients. Overall survival and disease-free survival after surgery were poor in patients with high expression of PCSK9 (p = 0.035 and p = 0.007, respectively). In vivo and in vitro experiments showed that PCSK9 promoted the growth of HCC by inhibiting cell apoptosis. A mechanistic study revealed that PCSK9 increases FASN expression, thereby inhibiting apoptosis of HCC cells via the Bax/Bcl-2/Caspase9/Caspase3 pathway.

Conclusions

PCSK9 expression level in HCC is an indicator of poor prognosis for patients with HCC. FASN-mediated anti-apoptosis plays an important role in PCSK9-induced HCC progression.

Lipoprotein(a): a genetic marker for cardiovascular disease and target for emerging therapies

Lipoprotein(a) [Lp(a)] is an established cardiovascular risk factor, and growing evidence indicates its causal association with atherosclerotic disease because of the proatherogenic low-density lipoprotein (LDL)-like properties and the prothrombotic plasminogen-like activity of apolipoprotein(a) [apo(a)]. As genetics significantly influences its plasma concentration, Lp(a) is considered an inherited risk factor of atherosclerotic cardiovascular disease (ASCVD), especially in young individuals. Moreover, it has been suggested that elevated Lp(a) may significantly contribute to residual cardiovascular risk in patients with coronary artery disease and optimal LDL-C levels. Nonetheless, the fascinating hypothesis that lowering Lp(a) could reduce the risk of cardiovascular events - in primary or secondary prevention - still needs to be demonstrated by randomized clinical trials. To date, no specific Lp(a)-lowering agent has been approved for reducing the lipoprotein levels, and current lipid-lowering drugs have limited effects. In the future, emerging therapies targeting Lp(a) may offer the possibility to further investigate the relation between Lp(a) levels and cardiovascular outcomes in randomized controlled trials, ultimately leading to a new era in cardiovascular prevention. In this review, we aim to provide an updated overview of current evidence on Lp(a) as well as currently investigated therapeutic strategies that specifically address the reduction of the lipoprotein.

Cardiovascular Outcomes and Proprotein Convertase Subtilisin/Kexin Type 9 Inhibitors: Current Data and Future Prospects

Cardiovascular (CV) disease remains the leading cause of morbidity and mortality worldwide and poses an ongoing challenge with the aging population. Elevated low-density lipoprotein cholesterol (LDL-C) is an established risk factor for atherosclerotic cardiovascular disease (ASCVD), and the expert consensus is the use of statin therapy (if tolerated) as first line for LDL-C reduction. However, patients with ASCVD may experience recurrent ischemic events despite receiving maximally tolerated statin therapy, including those whose on-treatment LDL-C remains ≥70 mg/dL, patients with familial hypercholesterolemia, high-risk subgroups with comorbidities such as diabetes mellitus, and those who have an intolerance to statin therapy. Optimal therapeutic strategies for this unmet need should deploy aggressive lipid lowering to minimize the contribution of dyslipidemia to their CV risk, particularly for very high-risk populations with additional risk factors beyond hypercholesterolemia and established ASCVD. To understand the current clinical climate and guidelines regarding ASCVD, we primarily searched PubMed for articles published in English regarding lipid-lowering therapies and CV risk reduction, including emerging therapies, and CV outcomes trials with proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors. This review discusses the findings of recent clinical trial evidence for CV risk reduction with cholesterol-lowering therapies, with a focus on CV outcomes trials with PCSK9 inhibitors, and considers the impact of the study results for secondary prevention and future strategies in patients with hypercholesterolemia and CV risk despite maximally tolerated statin therapy.

Safety, Tolerability, Pharmacokinetics, and Pharmacodynamics of Alirocumab in Healthy Chinese Subjects: A Randomized, Double-Blind, Placebo-Controlled, Ascending Single-Dose Study

BACKGROUND

The addition of alirocumab (a fully human monoclonal antibody to proprotein convertase subtilisin/kexin type 9 [PCSK9]) to background statin therapy provides significant incremental low-density lipoprotein cholesterol (LDL-C) lowering and cardiovascular event risk reduction.

OBJECTIVES

Our objectives were to assess the safety, tolerability, pharmacokinetics, and pharmacodynamics of single ascending doses of alirocumab in healthy Chinese subjects.

METHODS

In this double-blind, placebo-controlled, phase I study, 35 Chinese subjects (aged 21-45 years) with baseline LDL-C > 100 mg/dL (2.59 mmol/L) were randomized to receive a single 1 mL subcutaneous injection of alirocumab 75, 150, or 300 mg, or placebo, and followed up for ~ 12 weeks.

RESULTS

Treatment-emergent adverse events, most frequently nasal congestion and dry throat, were reported in three of seven or eight subjects in each alirocumab dose group (two of seven in the placebo group). One patient receiving alirocumab 300 mg had a mild local injection-site reaction. No alirocumab recipients demonstrated antidrug antibodies. Maximum alirocumab serum concentrations (6-34 mg/dL) occurred at a median of 3-7 days across the dose groups. Maximum mean LDL-C reductions from baseline were observed on days 8, 15, and 22 with alirocumab 75 (55.3%), 150 (63.7%), and 300 mg (73.7%), respectively. Mean free PCSK9 levels were reduced to below the lower limit of quantification within 4 h of dosing. Total cholesterol, non-high-density lipoprotein cholesterol, and apolipoprotein B were reduced with alirocumab.

CONCLUSIONS

In Chinese subjects, alirocumab 75, 150, and 300 mg was safe and well-tolerated. Pharmacokinetic/pharmacodynamic parameters, including clinically meaningful reductions in LDL-C and other lipids/lipoproteins, were consistent with data from Japanese and Western populations. Clinicaltrials.gov identifier: NCT02979015.

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

Objective

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

Methods

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

Results

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

Conclusions

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

Effect of Alirocumab on Lipoprotein(a) and Cardiovascular Risk After Acute Coronary Syndrome

BACKGROUND

Lipoprotein(a) concentration is associated with cardiovascular events. Alirocumab, a proprotein convertase subtilisin/kexin type 9 inhibitor, lowers lipoprotein(a) and low-density lipoprotein cholesterol (LDL-C).

OBJECTIVES

A pre-specified analysis of the placebo-controlled ODYSSEY Outcomes trial in patients with recent acute coronary syndrome (ACS) determined whether alirocumab-induced changes in lipoprotein(a) and LDL-C independently predicted major adverse cardiovascular events (MACE).

METHODS

One to 12 months after ACS, 18,924 patients on high-intensity statin therapy were randomized to alirocumab or placebo and followed for 2.8 years (median). Lipoprotein(a) was measured at randomization and 4 and 12 months thereafter. The primary MACE outcome was coronary heart disease death, nonfatal myocardial infarction, ischemic stroke, or hospitalization for unstable angina.

RESULTS

Baseline lipoprotein(a) levels (median: 21.2 mg/dl; interquartile range [IQR]: 6.7 to 59.6 mg/dl) and LDL-C [corrected for cholesterol content in lipoprotein(a)] predicted MACE. Alirocumab reduced lipoprotein(a) by 5.0 mg/dl (IQR: 0 to 13.5 mg/dl), corrected LDL-C by 51.1 mg/dl (IQR: 33.7 to 67.2 mg/dl), and reduced the risk of MACE (hazard ratio [HR]: 0.85; 95% confidence interval [CI]: 0.78 to 0.93). Alirocumab-induced reductions of lipoprotein(a) and corrected LDL-C independently predicted lower risk of MACE, after adjustment for baseline concentrations of both lipoproteins and demographic and clinical characteristics. A 1-mg/dl reduction in lipoprotein(a) with alirocumab was associated with a HR of 0.994 (95% CI: 0.990 to 0.999; p = 0.0081).

CONCLUSIONS

Baseline lipoprotein(a) and corrected LDL-C levels and their reductions by alirocumab predicted the risk of MACE after recent ACS. Lipoprotein(a) lowering by alirocumab is an independent contributor to MACE reduction, which suggests that lipoprotein(a) should be an independent treatment target after ACS. (ODYSSEY Outcomes: Evaluation of Cardiovascular Outcomes After an Acute Coronary Syndrome During Treatment With Alirocumab; NCT01663402).

Lipoprotein (a): An Update on a Marker of Residual Risk and Associated Clinical Manifestations

Lipoprotein (a) [Lp(a)] is a low-density, cholesterol-containing lipoprotein that differs from other low-density lipoproteins due to the presence of apolipoprotein(a) bound to its surface apolipoprotein B100. Multiple epidemiologic studies, including Mendelian Randomization studies, have demonstrated that increasing Lp(a) levels are associated with increased risk of heart disease, including atherosclerotic cardiovascular disease and calcific aortic stenosis. The risk associated with elevations in Lp(a) appears to be independent of other lipid markers. While the current treatment options for elevated Lp(a) are limited, promising new therapies are under development, leading to renewed interest in Lp(a). This review provides an overview of the biology and epidemiology of Lp(a), available outcome studies, and insights into future therapies.

Long-Term Efficacy and Safety of Evolocumab in Patients With Hypercholesterolemia

BACKGROUND

Evolocumab and other anti-PCSK9 antibodies reduced adverse cardiovascular outcomes in clinical trials of high-risk patients over <3 years median treatment duration.

OBJECTIVES

The OSLER-1 trial (Open Label Study of Long Term Evaluation Against LDL-C Trial) evaluated longer-term effects of evolocumab during open-label hypercholesterolemia treatment for up to 5 years.

METHODS

Patients randomized to standard of care (SOC) or evolocumab 420 mg monthly (evolocumab + SOC) for year 1. After year 1, patients could enter the all-evolocumab period and receive evolocumab + SOC for an additional 4 years. The authors analyzed the persistence of lipid effects and exposure-dependent safety focusing on yearly rates of adverse events (AEs) and anti-drug antibodies over 4.951 patient-years of observation.

RESULTS

A total of 1,255 patients (safety analysis population) randomized into the year 1 SOC-controlled period and received ≥1 evolocumab dose (mean ± SD age 57 ± 12 years; 53% female). A total of 1,151 patients (efficacy analysis population) progressed to the all-evolocumab period (year 2 and beyond). Evolocumab + SOC persistently lowered mean ± SE low-density lipoprotein cholesterol (LDL-C) by 56% ± 0.6% (n = 1,071), 57% ± 0.8% (n = 1,001), 56% ± 0.8% (n = 943), and 56% ± 0.8% (n = 803) after approximately 2, 3, 4, and 5 years, respectively, from randomization. Mean baseline LDL-C decreased from 140 to 61 mg/dl on treatment. Yearly serious AE rates during evolocumab + SOC ranged from 6.9% to 7.9%, comparable to the 6.8% rate in SOC patients during year 1. Evolocumab discontinuation due to AEs occurred in 5.7% of patients. Two SOC and 2 evolocumab + SOC patients developed new, transient, binding anti-drug antibodies; no neutralizing antibodies were observed.

CONCLUSIONS

The OSLER-1 trial demonstrated consistently excellent LDL-C-lowering efficacy, tolerance, and safety of evolocumab, with no neutralizing antibodies detected, throughout the longest-duration study of a PCSK9 inhibitor reported to date. (Open Label Study of Long Term Evaluation Against LDL-C Trial [OSLER-1]; NCT01439880).

Lipoprotein(a) and Atherosclerotic Cardiovascular Disease: Current Understanding and Future Perspectives

PURPOSE

To review current knowledge of elevated lipoprotein(a) [Lp(a)] levels in relation to atherosclerotic cardiovascular disease (ASCVD) and discuss their potential use as biomarkers and therapeutic approaches in clinical practice.

METHODS

We summarized the current understanding and recent advances in the structure, metabolism, atherogenic mechanisms, standardized laboratory measurement, recommended screening populations, and prognostic value of Lp(a), with a special focus on the current potential treatment approaches for hyperlipoprotein(a)emia in patients with ASCVD.

RESULTS

Lp(a) is composed of LDL-like particle and characteristic apolipoprotein(a) [apo(a)] connected by a disulfide bond. Substantial evidence shows that elevated plasma Lp(a) level is a heritable, independent, and possibly causal risk factor for ASCVD through its proatherogenic, proinflammatory, and potentially prothrombotic properties. Current guidelines recommend Lp(a) measurement for patients with an intermediate-high risk of ASCVD, familial hypercholesterolemia, a family history of early ASCVD or elevated Lp(a), and progressive ASCVD despite receiving optimal therapy. Traditional Lp(a)-lowering approaches such as niacin, PCSK9 inhibitors, mipomersen, lomitapide, and lipoprotein apheresis were associated with a non-specific and limited reduction of Lp(a), intolerable side effects, invasive procedure, and high expense. The phase 2 randomized controlled trial of antisense oligonucleotide against the apo(a) encoding gene LPA mRNA showed that IONIS-APO(a)-L_RX could specifically reduce the level of Lp(a) by 90% with good tolerance, which may become a promising candidate for the prevention and treatment of ASCVD in the future.

CONCLUSIONS

It is reasonable to measure Lp(a) levels to reclassify ASCVD risk and manage individuals with elevated Lp(a) to further reduce the residual risk of ASCVD, especially with IONIS-APO(a)-L_RX.

PCSK9 Inhibition with alirocumab increases the catabolism of lipoprotein(a) particles in statin-treated patients with elevated lipoprotein(a)

BACKGROUND

Lipoprotein(a) (Lp(a)) is a low-density lipoprotein (LDL) particle containing apolipoprotein(a) (apo(a)) covalently linked to apolipoprotein B-100 (apoB). Statin-treated patients with elevated Lp(a) have an increased risk of atherosclerotic cardiovascular disease (ASCVD). Recent trials show that proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibition decreases Lp(a) and cardiovascular events, particularly in high risk patients with elevated Lp(a). We investigated the kinetic mechanism whereby alirocumab, a PCSK9 inhibitor, lowers Lp(a) in statin-treated patients with high Lp(a) and ASCVD.

METHODS

The effects of 12-week alirocumab treatment (150 mg every 2 weeks) on apo(a) kinetics were studied in 21 patients with elevated Lp(a) concentration (>0.5 g/L). Apo(a) fractional catabolic rate (FCR) and production rate (PR) were determined using intravenous D3-leucine administration, mass spectrometry and compartmental modelling. All patients were on long-term statin treatment.

RESULTS

Alirocumab significantly decreased plasma concentrations of total cholesterol (-39%), LDL-cholesterol (-67%), apoB (-56%), apo(a) (-25%) and Lp(a) (-22%) (P< 0.001 for all). Alirocumab also significantly lowered plasma apo(a) pool size (-26%, P <0.001) and increased the FCR of apo(a) (+28%, P< 0.001), but did not alter apo(a) PR, which remained significantly higher relative to a reference group of patients on statins with normal Lp(a) (P< 0.001).

CONCLUSIONS

In statin-treated patients, alirocumab lowers elevated plasma Lp(a) concentrations by accelerating the catabolism of Lp(a) particles. This may be consequent on marked upregulation of hepatic receptors (principally for LDL) and/or reduced competition between Lp(a) and LDL particles for these receptors; the mechanism could contribute to the benefit of PCSK9 inhibition with alirocumab on cardiovascular outcomes.

Discordant responses of plasma low-density lipoprotein cholesterol and lipoprotein(a) to alirocumab: A pooled analysis from 10 ODYSSEY Phase 3 studies

AIMS

Proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors consistently reduce low-density lipoprotein cholesterol (LDL-C) by 50-60% and lipoprotein(a) (Lp(a)) by 20-30%, but the mechanism of Lp(a) lowering remains unclear. If Lp(a) is cleared by the LDL receptor, similar to LDL-C, then one would expect PCSK9 inhibition to induce a concordant LDL-C/Lp(a) response in an approximately 2:1 ratio. We aim to determine the prevalence of discordant plasma LDL-C/Lp(a) response to the PCSK9 inhibitor alirocumab.

METHODS

This is a post hoc, pooled analysis of 10 randomized controlled trials from the ODYSSEY Phase 3 clinical trial program for alirocumab. Patients enrolled in the trials were high cardiovascular risk and/or with heterozygous familial hypercholesterolemia. The primary end point was prevalence of discordant LDL-C/Lp(a) response to alirocumab at 24 weeks. Discordant response was defined as LDL-C reduction >35% and Lp(a) reduction ≤10%, or LDL-C reduction ≤35% and Lp(a) reduction >10%.

RESULTS

Of the 1709 patients in the pooled study cohort, 62.4% were male, and the mean age was 59.2 (SD: 11.0) years. Baseline mean LDL-C was 126.5 (SD: 46.3) mg/dL and baseline median Lp(a) was 46.9 (interquartile range: 21.8-89.0) mg/dL. Total prevalence of discordant LDL-C/Lp(a) response was 21.5% (12.6% with LDL-C >35% reduction and Lp(a) ≤10% reduction; 8.9% with LDL-C ≤35% reduction and Lp(a) >10% reduction). Baseline Lp(a) and familial hypercholesterolemia status did not affect discordance.

CONCLUSION

A high prevalence of discordant LDL-C/Lp(a) response was observed with alirocumab, further suggesting that PCSK9 inhibitor therapy with alirocumab reduces plasma Lp(a) through alternative pathways to LDL receptor clearance.

Relationship Between Low-Density Lipoprotein Cholesterol and Lipoprotein(a) Lowering in Response to PCSK9 Inhibition With Evolocumab

Background

Beyond their potent LDL (low‐density lipoprotein) cholesterol (LDL‐C)–lowering efficacy (50–60%), PCSK9 (proprotein convertase subtilisin/kexin type 9) inhibitors also reduce Lp(a) (lipoprotein[a]) levels by 25% to 30%, suggesting a 2:1 response ratio. We aimed to characterize the relationship between LDL‐C and Lp(a) lowering by evolocumab, a PCSK9 inhibitor, in a large clinical trial population and to determine the prevalence of concordant/discordant LDL‐C and Lp(a) responses to PCSK9 inhibition.

Methods and Results

Data were analyzed from 4 randomized, 12‐week, multicenter, phase 3 evolocumab trials. Patients with familial hypercholesterolemia, nonfamilial hypercholesterolemia, or statin intolerance participated in the trials. The main measure was the degree of concordance or discordance of LDL‐C and Lp(a) in response to PCSK9 inhibition; concordant response was defined as LDL‐C reduction >35% and Lp(a) reduction >10%. The study cohort comprised 895 patients (438 female; median age: 59.0 years [interquartile range: 51–66 years]). Baseline mean level of LDL‐C was 133.6 mg/dL (SE: 1.7) and median Lp(a) level was 46.4 mg/dL (interquartile range: 18.4–82.4 mg/dL). A discordant response was observed in 165 (19.7%) patients. With these cutoffs, the prevalence of discordance was higher when considering baseline Lp(a) concentrations >30 mg/dL (26.5%) or >50 mg/dL (28.6%).

Conclusions

We demonstrate high prevalence of discordance in LDL‐C and Lp(a) reduction in response to evolocumab, particularly when considering higher baseline Lp(a) concentrations, indicating the possibility of alternative pathways beyond LDLR (LDL receptor)–mediated clearance involved in Lp(a) reduction by evolocumab.

Clinical Trial Registration

URL: http://www.clinicaltrials.gov. Unique identifiers: NCT01763827, NCT01763866, NCT01763905, NCT01763918.

See Editorial by Nestel

Familial hypercholesterolemia and elevated lipoprotein(a): double heritable risk and new therapeutic opportunities

There is compelling evidence that the elevated plasma lipoprotein(a) [Lp(a)] levels increase the risk of atherosclerotic cardiovascular disease (ASCVD) in the general population. Like low-density lipoprotein (LDL) particles, Lp(a) particles contain cholesterol and promote atherosclerosis. In addition, Lp(a) particles contain strongly proinflammatory oxidized phospholipids and a unique apoprotein, apo(a), which promotes the growth of an arterial thrombus. At least one in 250 individuals worldwide suffer from the heterozygous form of familial hypercholesterolemia (HeFH), a condition in which LDL-cholesterol (LDL-C) is significantly elevated since birth. FH-causing mutations in the LDL receptor gene demonstrate a clear gene-dosage effect on Lp(a) plasma concentrations and elevated Lp(a) levels are present in 30-50% of patients with HeFH. The cumulative burden of two genetically determined pro-atherogenic lipoproteins, LDL and Lp(a), is a potent driver of ASCVD in HeFH patients. Statins are the cornerstone of treatment of HeFH, but they do not lower the plasma concentrations of Lp(a). Emerging therapies effectively lower Lp(a) by as much as 90% using RNA-based approaches that target the transcriptional product of the LPA gene. We are now approaching the dawn of an era, in which permanent and significant lowering of the high cholesterol burden of HeFH patients can be achieved. If outcome trials of novel Lp(a)-lowering therapies prove to be safe and cost-effective, they will provide additional risk reduction needed to effectively treat HeFH and potentially lower the CVD risk in these high-risk patients even more than currently achieved with LDL-C lowering alone.

Kappa-on-Heavy (KoH) bodies are a distinct class of fully-human antibody-like therapeutic agents with antigen-binding properties

We describe a Kappa-on-Heavy (KoH) mouse that produces a class of highly diverse, fully human, antibody-like agents. This mouse was made by replacing the germline variable sequences of both the Ig heavy-chain (IgH) and Ig kappa (IgK) loci with the human IgK germline variable sequences, producing antibody-like molecules with an antigen binding site made up of 2 kappa variable domains. These molecules, named KoH bodies, structurally mimic naturally existing Bence-Jones light-chain dimers in their variable domains and remain wild-type in their antibody constant domains. Unlike artificially diversified, nonimmunoglobulin alternative scaffolds (e.g., DARPins), KoH bodies consist of a configuration of normal Ig scaffolds that undergo natural diversification in B cells. Monoclonal KoH bodies have properties similar to those of conventional antibodies but exhibit an enhanced ability to bind small molecules such as the endogenous cardiotonic steroid marinobufagenin (MBG) and nicotine. A comparison of crystal structures of MBG bound to a KoH Fab versus a conventional Fab showed that the KoH body has a much deeper binding pocket, allowing MBG to be held 4 Å further down into the combining site between the 2 variable domains.

ODYSSEY EAST: Alirocumab efficacy and safety vs ezetimibe in high cardiovascular risk patients with hypercholesterolemia and on maximally tolerated statin in China, India, and Thailand

BACKGROUND

The proprotein convertase subtilisin/kexin type 9 inhibitor alirocumab significantly reduces low-density lipoprotein cholesterol (LDL-C).

OBJECTIVE

This study (ODYSSEY EAST) assessed the efficacy and safety of alirocumab vs ezetimibe in high cardiovascular risk patients from Asia.

METHODS

Patients (n = 615) from China, India, and Thailand with hypercholesterolemia at high cardiovascular risk on maximally tolerated statin were randomized (2:1) to alirocumab (75 mg every 2 weeks [Q2W]; with dose increase to 150 mg Q2W at week 12 if week 8 LDL-C was >1.81 mmol/L [>70 mg/dL]) or ezetimibe (10 mg daily) for 24 weeks. The primary efficacy endpoint was percentage change in calculated LDL-C from baseline to week 24. Safety was assessed throughout.

RESULTS

Baseline data were similar in both groups. LDL-C levels were reduced from baseline to week 24 by 56.0% and 20.3% in the alirocumab and ezetimibe groups, respectively (P < .0001 vs ezetimibe). Overall, 18.8% of alirocumab-treated patients received a dose increase to 150 mg Q2W. At week 24, 85.1% of alirocumab-treated and 40.5% of ezetimibe-treated patients reached LDL-C <1.81 mmol/L (<70 mg/dL, P < .0001 vs ezetimibe). Treatment-emergent adverse events occurred in 68.5% of alirocumab-treated and 63.1% of ezetimibe-treated patients, with upper respiratory tract infection the most common (alirocumab: 13.3%; ezetimibe: 14.1%). Injection-site reactions occurred more frequently in alirocumab-treated patients (2.7%) than in ezetimibe-treated patients (1.0%).

CONCLUSIONS

Alirocumab significantly reduced LDL-C vs ezetimibe in high cardiovascular risk patients from Asia and was generally well tolerated. These findings are consistent with previous ODYSSEY studies.

Potential Causality and Emerging Medical Therapies for Lipoprotein(a) and Its Associated Oxidized Phospholipids in Calcific Aortic Valve Stenosis

The prevalence of calcific aortic valve disease is increasing with aging of the population. Current treatment options for advanced or symptomatic aortic stenosis are limited to traditional surgical or percutaneous aortic valve replacement. Medical therapies that impact the progression of calcific aortic valve disease do not currently exist. New pathophysiological insights suggest that the processes leading to calcific aortic valve disease are metabolically active for many years before and during the clinical expression of disease. The identification of genetic and potentially causal mediators of calcific aortic valve disease allows opportunities for therapies that may slow progression to the point where aortic valve replacement can be avoided. Recent studies suggest that approximately one-third of aortic stenosis cases are associated with highly elevated lipoprotein(a) [Lp(a)] and pathways related to the metabolism of procalcifying oxidized phospholipids. Oxidized phospholipids can be carried by Lp(a) into valve leaflets but can also be formed in situ from cell membranes, lipoproteins, and apoptotic cells. This review will summarize the clinical data implicating the potential causality of Lp(a)/oxidized phospholipids, describe emerging therapeutic agents, and propose clinical trial designs to test the hypothesis that lowering Lp(a) will reduce progression aortic stenosis and the need for aortic valve replacement.

Cholesterol-Lowering Agents

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

Apolipoprotein(a) phenotype determines the correlations of lipoprotein(a) and proprotein convertase subtilisin/kexin type 9 levels in patients with potential familial hypercholesterolemia

BACKGROUND AND AIMS

The aim of this study is to investigate the relation between lipoprotein(a) [Lp(a)] and proprotein convertase subtilisin/kexin type 9 (PCSK9) concentrations, and their complex, in patients with potential familial hypercholesterolemia (FH), depending on apo(a) phenotype.

METHODS

The study included 205 patients with total cholesterol (TC) > 7.5 mmol/L and/or low density lipoprotein cholesterol (LDL-C)>4.9 mmol/L, 32 (15%) patients suffered from ischemic heart disease (IHD), 64 were taking statins. The diagnosis of FH was estimated according to the Dutch Lipid Clinics Network criteria. Lipid parameters, apoB-containing lipoprotein subfractions, Lp(a), PCSK9, Lp(a)-PCSK9 complex levels and apo(a) phenotype were determined. Depending on the apo(a) phenotype, all patients were divided into 2 groups: with high molecular weight (HMW) (n = 145) and low molecular weight (LMW) (n = 60) apo(a) phenotype.

RESULTS

The groups were comparable by all major clinical characteristics and biochemical parameters. In the whole group, PCSK9 concentration correlated with age, statins intake, Lp(a), TC and TG levels. Correlation between Lp(a) and PCSK9 levels was found only in the LMW apo(a) phenotype group independently of statins intake (r = 0.46, p < 0.001). Associations between Lp(a)-PCSK9 complex and large subfractions of intermediate (r = 0.30) and low-density lipoproteins (r = 0.30, p < 0.05 for both) were observed, with more significance in group 2 (r = 0.59, p < 0.005 and r = 0.40, p < 0.05, respectively).

CONCLUSIONS

In patients with potential familial hypercholesterolemia, positive correlations between concentrations of Lp(a) and PCSK9, as well as of Lp(a)-PCSK9 plasma complex with large subfractions of intermediate and low-density lipoproteins (IDL-1 and LDL-C), were determined by the LMW apo(a) phenotype.

Efficacy and Safety of Alirocumab 300 mg Every 4 Weeks in Individuals With Type 2 Diabetes on Maximally Tolerated Statin

CONTEXT

In the ODYSSEY CHOICE I trial, alirocumab 300 mg every 4 weeks (Q4W) was assessed in patients with hypercholesterolemia. Alirocumab efficacy and safety were evaluated in a patient subgroup with type 2 diabetes mellitus (T2DM) and who were receiving maximally tolerated statins with or without other lipid-lowering therapies.

METHODS

Participants received either alirocumab 300 mg Q4W (n = 458, including 96 with T2DM) or placebo (n = 230, including 50 with T2DM) for 48 weeks, with alirocumab dose adjustment to 150 mg every 2 weeks at Week (W) 12 if W8 low-density lipoprotein cholesterol (LDL-C) levels were ≥70 mg/dL or ≥ 100 mg/dL, depending on cardiovascular risk, or if LDL-C reduction was <30% from baseline. Efficacy end points included percentage change from baseline to W24 for lipids, and time-averaged LDL-C over W21 to W24.

RESULTS

In individuals with T2DM, LDL-C reductions from baseline to W24 and the average of W21 to W24 were significantly greater with alirocumab (-61.6% and -68.8%, respectively) vs placebo. At W24, alirocumab significantly reduced levels of non-high-density lipoprotein cholesterol (HDL-C) and other lipids. At W24, 85.9% and 12.5% of individuals in the alirocumab and placebo groups, respectively, reached both non-HDL-C <100 mg/dL and LDL-C <70 mg/dL. At W12, In total, 18% of alirocumab-treated participants received dose adjustment. The most common treatment-emergent adverse events were upper respiratory tract infection and injection-site reaction. No clinically significant changes in fasting plasma glucose and glycated hemoglobin were observed.

CONCLUSION

In individuals with T2DM, alirocumab 300 mg Q4W was generally well tolerated and efficacious in reducing atherogenic lipoproteins.

Pharmacokinetic and pharmacodynamic assessment of alirocumab in patients with familial hypercholesterolemia associated with proprotein convertase subtilisin/kexin type 9 gain-of-function or apolipoprotein B loss-of-function mutations

BACKGROUND

Familial hypercholesterolemia is characterized by high levels of low-density lipoprotein cholesterol (LDL-C), and causes of familial hypercholesterolemia include apolipoprotein B (APOB) loss-of-function mutations (LOFm) and proprotein convertase subtilisin/kexin type 9 (PCSK9) gain-of-function mutations (GOFm).

OBJECTIVE

The aim of this study was to compare the pharmacokinetics and pharmacodynamics of alirocumab between patients with APOB LOFm vs PCSK9 GOFm.

METHODS

Patients (6 APOB LOFm and 17 PCSK9 GOFm carriers) with LDL-C ≥70 mg/dL on maximally tolerated lipid-lowering therapies received alirocumab 150 mg at Weeks 0, 2, 4, and 6, placebo at Week 8, alirocumab at Week 10, placebo at Weeks 12 and 14, then completed a follow-up period at Week 22.

RESULTS

At Week 8, mean ± standard error (SE) alirocumab concentration was lower in APOB LOFm carriers compared with PCSK9 GOFm carriers (12.12 ± 1.81 vs 16.74 ± 2.53 mg/L). APOB LOFm carriers had higher mean ± SE total PCSK9 (6.56 ± 0.73 mg/L) and lower mean ± SE free PCSK9 (0.025 ± 0.016 mg/L) at Week 8 compared with PCSK9 GOFm carriers (4.21 ± 0.35 and 0.11 ± 0.035 mg/L for total and free PCSK9, respectively). Despite this observed greater PCSK9 suppression, mean ± SE percent LDL-C reduction was lower in APOB LOFm (55.3 ± 1.0%) compared with PCSK9 GOFm carriers (73.1 ± 0.9%). Treatment-emergent adverse events occurred in 16 patients (94.1%) in the PCSK9 GOFm group and 5 patients (83.3%) in the APOB LOFm group.

CONCLUSIONS

Overall, PCSK9 inhibition with alirocumab results in clinically meaningful reductions in LDL-C in both APOB LOFm and PCSK9 GOFm carriers, although reductions were greater in the PCSK9 GOFm carriers. The results indicate a possible underlying contributor to hypercholesterolemia other than PCSK9 in patients with APOB LOFm.

CLINICAL TRIAL REGISTRATION

NCT01604824; clinicaltrials.gov.

New Therapeutic Approaches for Familial Hypercholesterolemia

Familial hypercholesterolemia (FH) is a common genetic condition characterized by elevated plasma levels of low-density lipoprotein cholesterol (LDL-C), premature atherosclerotic cardiovascular disease, and considerable unmet medical need with conventional LDL-C-lowering therapies. Between 2012 and 2015, the US Food and Drug Administration approved four novel LDL-C-lowering agents for use in patients with FH based on the pronounced LDL-C-lowering efficacy of these medicines. We review the four novel approved agents, as well as promising LDL-C-lowering agents in clinical development, with a focus on their mechanism of action, efficacy in FH cohorts, and safety.