Assessment of the 1% of Patients with Consistent < 15% Reduction in Low-Density Lipoprotein Cholesterol: Pooled Analysis of 10 Phase 3 ODYSSEY Alirocumab Trials

Gene Mutation in Patients with Familial Hypercholesterolemia and Response to Alirocumab Treatment-A Single-Centre Analysis

Background: Familial hypercholesterolemia (FH) is an autosomal dominant genetic disorder characterized by significantly elevated levels of low-density lipoprotein (LDL) cholesterol, which plays a major role in the progression of atherosclerosis and leads to a heightened risk of premature atherosclerotic cardiovascular disease. Methods: We have carried out an observational study on a group of 17 patients treated at the Outpatient Lipid Clinic from 2019 to 2024. Result: The most frequent mutation observed was found in the LDL receptor (LDLR) gene, which was identified in ten patients (58.8%). Five patients were identified to have a mutation in the apolipoprotein B (APOB) gene, whereas two patients had two points mutations, one in the LDLR, and the other in the APOB gene. The average age of patients with LDLR mutation was 54.8 (12.3); for APOB mutation it was 61.4 (9.3) and for patients with two points mutation it was 61.5 (14.8). The study results showed that at Week 12, individuals with LDLR-defective heterozygotes who were given alirocumab 150 mg every two weeks experienced a 63.0% reduction in LDL cholesterol levels. On the other hand, individuals with APOB heterozygotes experienced a 59% reduction in LDL cholesterol levels. However, in patients with double heterozygous for mutations in LDLR and APOB genes, there was a hyporesponsiveness to alirocumab, and the reduction in LDL-C was only by 23% in two individuals. Conclusions: In patients with a single mutation, there was a greater response to treatment with alirocumab in contrast to patients with double heterozygous mutation, who did not respond to treatment with PCSK9 inhibitors.

Challenges in the management of familial hypercholesterolemia: a case report

Background

Familial hypercholesterolemia (FH) is a serious genetic condition that results in abnormally high levels of low-density lipoprotein cholesterol (LDL-C) in the bloodstream, significantly increasing the risk of early onset of cardiovascular disease. The heterozygous form of FH (HeFH) is widespread, affecting around 1 in 500 people worldwide.

Case report

In this clinical report, we present the case of a patient who suffers from HeFH due to a mutation in the LDL receptor (LDLR) gene. A woman exhibited intolerance to statin therapy and did not attain adequate reduction in low-density lipoprotein cholesterol (LDL-C) levels on ezetimibe monotherapy. Genetic testing confirmed the presence of a pathogenic variant for FH with the deletion of exons 7-14. The administration of alirocumab (a dose of 150 mg sc) as the primary therapy did not exhibit the desired therapeutic outcome. Consequently, the patient was given inclisiran therapy (a dose of 284 mg sc), which significantly reduced LDL cholesterol levels after 3 months of treatment and during the 1-year follow-up.

Conclusion

Inclisiran therapy has shown promising results for individuals with HeFH who experience statin intolerance. This therapy works by using a small interfering RNA (siRNA) to target the mRNA of proprotein convertase subtilisin/kexin type 9 (PCSK9), which leads to a significant reduction of LDL-C levels. This approach can be an alternative for patients without significant reductions in LDL-C levels with PCSK9 inhibitor therapy. For HeFH patients with limited treatment options due to statin intolerance and genetic mutations, inclisiran can represent a promising therapeutic option.

Walking the VLDL tightrope in cardiometabolic diseases

Very-low-density lipoprotein (VLDL), a triglyceride-rich lipoprotein secreted by hepatocytes, is pivotal for supplying peripheral tissues with fatty acids for energy production. As if walking on a tightrope, perturbations in the balance of VLDL metabolism contribute to cardiometabolic dysfunction, promoting pathologies such as cardiovascular disease (CVD) or metabolic dysfunction-associated steatotic liver disease (MASLD). Despite the advent of lipid-lowering therapies, including statins and proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors, risks for cardiovascular events persist. With limitations to currently available CVD therapeutics and no US Food and Drug Administration (FDA)-approved treatment for MASLD, this review summarizes the current understanding of VLDL metabolism that sheds light on novel therapeutic avenues to pursue for cardiometabolic disorders.

A bibliometric analysis of PCSK9 inhibitors from 2007 to 2022

Background

Since the approval of the proprotein convertase subtilisin/kexin type 9 (PCSK9) monoclonal antibodies for marketing in 2015, PCSK9 inhibitors have attracted significant interest in the field of cardiovascular endocrinology. A large number of clinical trials have confirmed the efficacy and safety of PCSK9 inhibitors in reducing cholesterol and the risk of cardiovascular events. No bibliometric analysis of PCSK9 inhibitors has been performed as of yet. This study aims to analyze the research trends and hotspots of PCSK9 inhibitors through bibliometric analysis.

Methods

We searched the Web of Science Core Collection (WoSCC) database for PCSK9 inhibitor-related publications from 2007 to 2022. Data visualization analysis was performed using CiteSpace software. Microsoft Excel and Graphpad software were used for the drawing of some tables and figures.

Results

A total of 1072 pieces of literature were retrieved between 2007 and 2022. The number of publications concerning PCSK9 inhibitors is growing annually. The top five countries with the most articles published were the United States, England, Canada, Italy, and France. Harvard University, Amgen, Brigham & Women's Hospital, Harvard Medical School, and Imperial College London are the five institutions with the highest output. The Journal of Clinical Lipidology is the most popular journal in this field. The most frequently cited journal is the New England Journal of Medicine. As for authors, Sabatine MS and Giugliano RP from Brigham & Women's Hospital have the highest number of published articles. Amgen is the funding agency for most of the research. According to keyword analysis, "low density lipoprotein", "familial hypercholesterolemia", "PCSK9 inhibitor", "PCSK9", and "efficacy" are the five keywords with the highest frequency of co-occurrence.

Conclusion

The past 15 years have witnessed a rapid and fruitful development of PCSK9 inhibitors. The research trend and focus for PCSK9 inhibitors are from the mechanism of reducing low-density lipoprotein cholesterol to related clinical trials. Developed countries such as the United States have contributed prominently in this area. Coronary artery and inflammation are currently at the forefront of research in the field and are in an explosion period.

Under-representation of ethnic and regional minorities in lipid-lowering randomized clinical trials: a systematic review and meta-analysis

AIMS

The efficacy of lipid-lowering therapies (LLT) amongst different ethnicities and regions remains unclear. We aimed to assess cardiovascular event reductions associated with LLT according to ethnicity and region in previously published randomized clinical trials (RCTs).

METHODS AND RESULTS

Medline, EMBASE, and Cochrane CENTRAL were searched for RCTs of statins, ezetimibe, or proprotein convertase subtilisin/kexin type 9 inhibitors comparing intensive vs. less-intensive low-density lipoprotein cholesterol (LDL-C) lowering. The primary endpoint was major adverse cardiovascular events (MACE) defined as the composite of cardiovascular mortality, myocardial infarction, stroke, and revascularization. Random-effects meta-analysis was used to pool risk ratios (RRs) with 95% confidence intervals (CI) adjusted per mmol/L reduction in LDL-C. Fifty-three trials with 329 897 participants were included. Amongst participants, 39.5% were from Europe, 16.0% from North America, 9.0% from Japan, 2.8% from Australasia, 1.8% from South America, 1.1% from Asia, 0.6% from South Africa, and 29.2% were unspecified. Amongst trials reporting ethnicities, there were 60.3% White, 20.2% Japanese, 9.4% Asian, 5.5% Black, and 4.7% Latin American. There was reduction in MACE with LLT in regions including Australasia (RR 0.75, 95% CI 0.67-0.85), North America (RR 0.75, 95% CI 0.69-0.83), Europe (RR 0.78, 95% CI 0.71-0.86), and Japan (RR 0.73, 95% CI 0.63-0.85) and in Black ethnicity (RR 0.55, 95% CI 0.37-0.82). Head-to-head comparisons between regions and ethnicities revealed no significant differences in MACE reduction.

CONCLUSION

Despite under-representation in clinical trials, regional and ethnic minority groups such as Australasia and Blacks appear to derive at least as much cardiovascular benefit from LLT.

Mechanisms of unusual response to lipid-lowering therapy: PCSK9 inhibition

The efficacy of proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibition has broadened lipid-lowering therapy thus providing decreased risk in atherosclerotic cardiovascular disease. Unfortunately, the widespread use of PCSK9 inhibitors (PCSK9i), ie, monoclonal antibodies, has led to the findings of unusual responsiveness, ie, a phenomenon defined as an LDL-C reduction of <30% vs the average LDL-C reduction efficacy of 50-60%. This unusual responsiveness to PCSK9i is attributable to several factors, ie, lack of adherence, impaired absorption, poor distribution or early elimination as well as abnormal effects of PCSK9i in the presence of anti-antibodies or mutations in PCSK9 and LDLR. Unexpectedly increased lipoprotein (Lp)(a) also appear to contribute to the unusual responsiveness scenario. Identification of these responses and mechanisms underlying them are essential for effective management of LDL-C and cardiovascular risk. In this review, we describe plausible reasons underlying this phenomenon supported by findings of clinical trials. We also elaborate on the need for education and regular follow-up to improve adherence. Collectively, the review provides a summary of the past, present, and future of mechanisms and countermeasures revolving around unusual responses to PCSK9i therapy.

Inter-Individual Variability in Lipid Response: A Narrative Review

Lipid-lowering guidelines emphasize shared decision-making between clinicians and patients, resulting in patients anticipating the degree of response from diet or drug therapy. Challenging for physicians is understanding the sources of variability complicating their management decisions, which include non-adherence, genetic considerations, additional lipid parameters including lipoprotein (a) levels, and rare systemic responses limiting benefits that result in non-responsiveness to monoclonal antibody injection. In this narrative review, we focus on the variability of low-density lipoprotein cholesterol (LDL-C) response to guideline-directed interventions such as statins, ezetimibe, bile acid sequestrants, fibrates, proprotein/convertase subtilisin-kexin type 9 inhibitors, and LDL-C-lowering diets. We hypothesize that the variability in individual lipid responses is multifactorial. We provide an illustrative model with a check list that can be used to identify factors that may be present in the individual patient.

PCSK9 Inhibitor Wars: How Does Inclisiran Fit in with Current Monoclonal Antibody Inhibitor Therapy? Considerations for Patient Selection

PURPOSE OF REVIEW

Treatment of dyslipidemia represents one of the most crucial strategies to reduce risk of atherosclerotic cardiovascular (CV) disease (ASCVD). In this review, we critically summarize our knowledge on emerging cholesterol-lowering therapy, targeting PCSK9, paying particular attention on treatment allocation of two drug groups, currently available for clinical use, namely, anti-PCSK9 monoclonal antibodies (mAbs) and inclisiran, a first-in-class small interfering RNA against PCSK9.

RECENT FINDINGS

Although both drug classes show a pronounced, but fairly similar reduction in LDL-cholesterol, their long-term safety is still unknown. Compared to mAbs, inclisiran has a more favorable dosing regimen with biannual application that might improve therapeutic adherence significantly. However, a CV outcome trial (CVOT) for inclisiran is still missing. If inclisiran will be safe and effective in ongoing/future CVOTs, it has a huge potential to overcome medication non-compliance, thereby providing a powerful therapeutic option to decrease the burden of ASCVD.

Factors Associated With Enhanced Low-Density Lipoprotein Cholesterol Lowering With Bempedoic Acid

Background

Bempedoic acid (BA) inhibits ATP‐citrate lyase in the cholesterol synthesis pathway and lowers low‐density lipoprotein cholesterol (LDL‐C). As with other lipid‐lowering therapies, interindividual variation in response to BA was observed in clinical trials. We characterized LDL‐C response to BA using guideline‐defined statin intensity categories and identified clinical factors associated with enhanced LDL‐C lowering with BA.

Methods and Results

This post hoc analysis used pooled data from 4 phase 3 studies. Patients were randomized 2:1 to once‐daily BA 180 mg (n=2321) or placebo (n=1167) for 12 to 52 weeks and grouped based on percent change in LDL‐C from baseline to week 12 according to guideline‐established statin intensity categories. Factors associated with ≥30% reduction in LDL‐C were identified using logistic regression analyses. From baseline to week 12, BA lowered LDL‐C levels comparable to a moderate‐ or high‐intensity statin (≥30%) in 28.9% of patients; this degree of LDL‐C lowering was observed in 50.9% of patients not receiving background statin therapy. In a multivariable analysis, the absence of statins, female sex, a history of diabetes, ezetimibe use, and higher high‐sensitivity C‐reactive protein level were associated with increased rates of achieving ≥30% LDL‐C reduction with BA (P<0.01 for each).

Conclusions

A large percentage of patients receiving BA achieved LDL‐C reductions comparable to a moderate‐ or high‐intensity statin. Factors including statin absence, female sex, diabetes history, ezetimibe use, and a higher high‐sensitivity C‐reactive protein level may be useful to identify patients who may have a greater LDL‐C reduction with BA.

Registration

URL: https://www.clinicaltrials.gov; Unique identifiers: NCT02666664, NCT02991118, NCT02988115, NCT03001076.

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

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

PCSK9 inhibitors revisited: Effectiveness and safety of PCSK9 inhibitors in a real-life Spanish cohort

INTRODUCTION

Proprotein convertase subtilisin/kexin type 9 inhibitors (PCSK9i) have emerged as a therapeutic option for patients with hypercholesterolemia who do not attain low-density lipoprotein cholesterol (LDL-C) goals and/or are intolerant to other lipid-lowering drugs. Our aim was to analyze the effectiveness and safety of PCSK9i in routine clinical practice and factors related to poor outcomes.

MATERIALS AND METHODS

We conducted an ambispective study in 115 patients who recieved alirocumab or evolocumab, in a tertiary level hospital. From February 2017 to April 2020, patients were recruited and followed up for a median of 20.4 months. The main outcomes were relative reduction in LDL-C, percentage of patients achieving the therapeutic goals established by 2016 ESC/EAS guidelines, incidence of major cardiovascular events (MACEs) and drug-related adverse events (ADRs).

RESULTS

The median LDL-C achieved was 57.0 mg/dL (relative reduction of 59.9% from baseline, p< 0.001). After adjusting for confounders, smaller LDL-C reductions were related to female sex, absence of concomitant lipid-lowering therapy and treatment with alirocumab. Overall, 84.6% of the patients achieved the therapeutic goals. During follow-up, 7 MACEs were detected. ADRs, generally considered mild, affected 38.1% of the participants (mainly mialgias and arthralgias) and triggered discontinuations in 8.7% of cases.

CONCLUSIONS

PCSK9i are effective and safe, although certain factors may influence their effectiveness. Interestingly, our results suggest that alirocumab and evolocumab may not be therapeutic equivalents, as initially suggested.

Association of PCSK9 Variants With the Risk of Atherosclerotic Cardiovascular Disease and Variable Responses to PCSK9 Inhibitor Therapy

Genetic polymorphisms or variations, randomly distributed in a population, may cause drug-gene response variations. Investigation into these polymorphisms may identify novel mechanisms contributing to a specific disease process. Such investigation necessitates the use of Mendelian randomization, an analytical method that uses genetic variants as instrumental variables for modifiable risk factors that affect population health.¹ In the past decade, advances in our understanding of genetic polymorphisms have enabled the identification of genetic variants in candidate genes that impact low-density lipoprotein cholesterol (LDL-C) regulating pathways and cardiovascular disease (CVD) outcomes. A specific candidate gene of interest is that of the LDL receptor degrading protein, PCSK9. In fact, loss-of-function genetic variants for the PCSK9 gene are what first highlighted this pathway as a candidate for pharmacologic inhibition. PCSK9 inhibitors (PCSK9i) are a class of cholesterol-lowering medications that provide significant reductions in LDL by inhibiting the degradation of LDL receptors (LDLR). These inhibitors have also been found to reduce production and enhance clearance of lipoprotein A (Lp[a]), an LDL-like particle currently under study as a separate risk factor for atherosclerotic CVD. Here, we discuss the promise of personalized medicine in developing a more efficacious and individualized pharmacogenomics-based approach for the use of PCSK9i that considers genetic variation and targets different patient populations. This review explores the pharmacogenomics of PCSK9i in the context of PCSK9 allele variants related to drug-metabolizing enzymes and responses since more studies are demonstrating that some patients are hyporesponsive or non-responsive to PCSK9i.² In summary, the pharmacogenomics of PCSK9 are a promising therapeutic target and genetic information from prospective randomized clinical trials is warranted to gain a full understanding of the efficacy and cost-effectiveness of such allele and/or gene-guided PCSK9i therapy.

Inclisiran: a small interfering RNA strategy targeting PCSK9 to treat hypercholesterolemia

INTRODUCTION

Inclisiran is a novel posttranscriptional gene silencing therapy that inhibits proprotein convertase subtilisin/kexin type 9 (PCSK9) synthesis by RNA interference and has a potent, dose-dependent, durable effect in lowering LDL-C, and therefore is an effective drug to treat dyslipidemia, reducing the risk for acute cardiovascular (CV) events. It is safe and well-tolerated.

AREAS COVERED

This paper aims to review the mechanism of action of inclisiran while evaluating its efficacy and safety in the treatment of dyslipidemia from data of the clinical trials in the ORION program.

EXPERT OPINION

Data from the clinical trials in the ORION program demonstrated efficacy and safety of inclisiran in patients with dyslipidemia. Adverse events were similar in the inclisiran and placebo groups in the clinical trials, although injection-site reactions were more frequent with inclisiran than with placebo. Although the combination of efficacy and safety makes inclisiran a good option for the treatment of dyslipidemia compared to other PCSK9 targeting therapeutic strategies, however, further studies should exclude the possibility that inclisiran, through lower-affinity interactions, may influence other mRNAs in the physiological milieu.

Efficacy of PCSK9 inhibitors in the treatment of heterozygous familial hypercholesterolemia: A clinical practice experience

BACKGROUND

PCSK9 inhibitors are a treatment option for patients with familial hypercholesterolemia not on low-density lipoprotein cholesterol goals despite the use of maximally tolerated high intensity-statins dose.

OBJECTIVE

To evaluate the efficacy of alirocumab and evolocumab in LDL-C reduction and targets attainment in patients with heterozygous familial hypercholesterolemia in clinical practice setting.

METHODS

SAFEHEART is an open, long-term prospective study of a cohort of subjects with molecular diagnosis of familial hypercholesterolemia. This study analyze subjects ≥ 20 years of age on stable lipid-lowering therapy, who received PCSK9 inhibitors during the period 2016 to January 2020.

RESULTS

433 patients (mean age 55 years, 53% male, 39% with cardiovascular disease) were included and followed-up for a median of 2.5 years (IQR 1.6-3.0). Median LDL-C level prior to PCSK9 inhibitors was 145 mg/dL (IQR 125-173). The addition of PCSK9 inhibitors (211 alirocumab, 222 evolocumab) reduced LDL-C by 58% (IQR 41-70) p<0.001, in men and women, achieving a median LDL-C level of 62 mg/dL (IQR 44-87) without differences between both PCSK9 inhibitors. Out of them 67% with and 80% without cardiovascular disease reached 2016 ESC/EAS LDL-C targets, and 46% very high risk and 50% high risk patients achieved 2019 ESC/EAS LDL-C goals. Independent predictor factors for attainment of 2019 ESC/EAS LDL-C goals were to be male, smoking and the use of statins with ezetimibe. Both inhibitors were well tolerated.

CONCLUSIONS

PCSK9 inhibitors on top of maximum lipid-lowering treatment significantly reduced LDL-C levels in patients with familial hypercholesterolemia and improved the achievement of LDL-C targets.

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

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

Inhibitors of Protein Convertase Subtilisin/Kexin 9 (PCSK9) and Acute Coronary Syndrome (ACS): The State-of-the-Art

Acute Coronary Syndrome (ACS) remains one of the most frequent causes of morbidity and mortality in the world. Although the age- and gender-adjusted incidence of ACS is decreasing, the mortality associated with this condition remains high, especially 1-year after the acute event. Several studies demonstrated that PCSK9 inhibitors therapy determine a significant reduction of major adverse cardiovascular events (MACE) in post-ACS patients, through a process of plaque modification, by intervening in lipid metabolism and platelet aggregation and finally determining an improvement in endothelial function. In the EVACS (Evolocumab in Acute Coronary Syndrome) study, evolocumab allows >90% of patients to achieve LDL-C < 55 mg/dL according to ESC/EAS guidelines compared to 11% of patients who only receive statins. In the EVOPACS (EVOlocumab for Early Reduction of low-density lipoprotein (LDL)-cholesterol Levels in Patients With Acute Coronary Syndromes) study, evolocumab determined LDL levels reduction of 40.7% (95% CI: 45.2 to 36.2; p < 0.001) and allowed 95.7% of patients to achieve LDL levels <55 mg/dL. In ODYSSEY Outcome trial, alirocumab reduced the overall risk of MACE by 15% (HR = 0.85; CI: 0.78-0.93; p = 0.0003), with a reduced risk of all-cause mortality (HR = 0.85; CI: 0.73-0.98: nominal p = 0026), and fewer deaths for coronary heart disease (CHD) compared to the control group (HR = 0.92; CI: 0.76-1.11; p = 0.38). The present review aimed at describing the beneficial effect of PCSK9 inhibitors therapy early after ACS in reducing LDL circulating levels (LDL-C) and the risk of major adverse cardiovascular events, which was very high in the first year and persists higher later after the acute event.

Clinical Efficacy and Safety of Alirocumab After Acute Coronary Syndrome According to Achieved Level of Low-Density Lipoprotein Cholesterol: A Propensity Score-Matched Analysis of the ODYSSEY OUTCOMES Trial

Supplemental Digital Content is available in the text.

Recent international guidelines have lowered recommended target levels of low-density lipoprotein cholesterol (LDL-C) for patients at very high risk for major adverse cardiovascular events (MACE). However, uncertainty persists whether additional benefit results from achieved LDL-C levels below the conventional targets. Inferences from previous analyses are limited because patients who achieve lower versus higher LDL-C on lipid-lowering therapy differ in other characteristics prognostic for MACE and because few achieved very low LDL-C levels. To overcome these limitations, we performed a propensity score–matching analysis of the ODYSSEY OUTCOMES trial (Evaluation of Cardiovascular Outcomes After an Acute Coronary Syndrome During Treatment With Alirocumab) which compared alirocumab with placebo in 18 924 patients with recent acute coronary syndrome receiving intensive or maximum-tolerated statin treatment.

Unusual responses to PCSK9 inhibitors in a clinical cohort utilizing a structured follow-up protocol

Objective

To characterize unusual responses to PCSK9 inhibitor (PCSK9i) therapy in a real-world setting, given their extremely low prevalence in clinical trials.

Methods

A retrospective study of patients seen in a structured academic PCSK9i clinic who had LDL-C measurements before and after initiation of PCSK9i (up to 12 months). Unusual response was defined as: (1) no response: no changes in LDL-C level at all time points; (2) delayed response: <30% LDL-C reduction by the third dose, but achieving this threshold at a later time; (3) reduced response: <30% LDL-C reduction at all time points; and (4) lost response: ≥30% LDL-C reduction by the third dose, but displaying <30% reduction at a later time.

Results

Of the 411 patients meeting inclusion criteria, 54 were initially classified as unusual responders. After excluding those not adherent to prescribed interventions, 31 patients (7.5%) were classified as true unusual responders. These included: 2 with no response, 12 with delayed response, 3 with reduced response, 6 with delayed or reduced response, 4 with lost response, and 4 with delayed and lost response. Response to PCSK9i therapy at all time points revealed higher on-treatment LDL-C values (94–100 vs. 47–51 ​mg/dL, p ​< ​0.001) and lower degree of percent reduction in LDL-C (23.3–34% vs. 61.1–64.5%, p ​< ​0.001) in the unusual versus usual responders. Lipoprotein (a) (Lp[a]) values were consistently higher in the unusual responders (81–92.5 vs. 28.5–52 ​mg/dL, p ​< ​0.01). Fold change in post-versus pre-treatment PCSK9 plasma results was similar between the two cohorts (p ​> ​0.05), suggesting that unusual responses were not due to insufficient plasma PCSK9 blockade. Multiple logistic regression analysis identified clinical FH (OR 2.9, 95% CI 1.27-7.24) and no ezetimibe therapy (OR 0.334, 95% CI 0.150-0.728) as factors related to true unusual response.

Conclusions

Unusual responses to PCSK9i in a clinical cohort are more common than reported in clinical trials. Of the suspected unusual responders, nearly half were the result of adherence issues, and thus careful medication reconciliation should be the first step in diagnosing an unusual response.

PCSK9 inhibitors in clinical practice: Novel directions and new experiences

BACKGROUND

In randomized clinical trials, proprotein convertase subtilisin/kexin type 9 inhibitors (PCSK9i) effectively reduce low-density lipoprotein-cholesterol (LDL-C) with a favorable tolerability and safety profile. Our purpose is to provide real-world data regarding the indications, efficacy and safety of PCSK9i.

METHODS

The cohort comprised 141 patients who attended the lipid clinic of 3 hospitals in Greece and started using PCSK9i. Patients were requested to attend the lipid clinic at 3 months and at 1 year.

RESULTS

Ninety percent of patients had heterozygous familial hypercholesterolaemia (heFH) and 75% had cardiovascular disease (CVD). A PCSK9i [evolocumab 140 mg/2 weeks (n = 82), alirocumab 75 mg/2 weeks (n = 46) and alirocumab 150 mg/2 weeks (n = 13)] was prescribed due to failure to achieve LDL-C targets despite maximum lipid-lowering therapy (LLT) in 75% of patients, while in the remaining cases, the indication was statin intolerance. The mean reduction of LDL-C at 3 months was 56.2% and remained constant at 12 months (55.8% reduction from baseline). LDL-C target was achieved by 68.1% of patients at 3 months. "Totally" intolerant to statins patients (unable to tolerate any statin dose, n = 23) showed the lowest LDL-C reduction (47.7%). Side effects attributed to treatment were reported by 14 patients (10%). The total number of patients who stopped PCSK9i at 1 year was 14 (10%) but only 2 (1.4%) discontinued treatment because of side effects (myalgias).

CONCLUSIONS

Our real-world results of PCSK9i showed comparable efficacy and tolerability to those reported in clinical trials and highlighted the value of treatment with PCSK9i heFH patients not achieving LDL-C targets despite maximum LLT and high or very high risk statin intolerant patients.

The PCSK9 revolution: Current status, controversies, and future directions

Proprotein Convertase Subtilisin/Kexin Type 9 (PCSK9) has revolutionized our understanding of cholesterol homeostasis and added to our arsenal against atherosclerotic cardiovascular disease (ASCVD). In a span of approximately 15 years, PCSK9 has morphed from an esoteric and rare cause of familial hypercholesterolemia (FH) into the most efficient cholesterol-lowering target ever known, with the completion of two large scale cardiovascular outcome trials showing positive results. Current Food and Drug Administration (FDA) approved modalities to inhibit PCSK9 are in the form of monoclonal antibodies which display an unparalleled degree of low-density lipoprotein cholesterol (LDL-C) lowering and expand upon the notion that lower LDL-C is better for ASCVD risk reduction. However, the accelerated pace of discovery and therapeutic development has left large gaps in our knowledge regarding the physiology and function of PCSK9. The aim of this review is to provide context to the discovery, history, treatment and current status of PCSK9 and its therapeutic inhibitors and highlight areas of controversy and future directions.

[Are there different responses to different PCSK9 inhibitors?]

The case is presented of a 62-year-old patient who required lipid-lowering therapy with proprotein convertase subtilisin/kexin type9 (PCSK9). It was empirically decided to change one drug to another of the two currently available, obtaining a different response. Our objective is to present our experience and to consider a possible therapeutic option in patients in whom, exceptionally, this could happen.

Alirocumab for low-density lipoprotein cholesterol lowering

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