Cost effectiveness of lifelong therapy with PCSK9 inhibitors for lowering cardiovascular events in patients with stable coronary artery disease: Insights from the Ludwigshafen Risk and Cardiovascular Health cohort

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSION

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

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

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

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

Aims

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

Methods and results

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

Conclusion

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

Trimming the Fat: Is there a Health Economic Case for use of New Lipid Lowering Drugs in Chronic Kidney Disease? A Scoping Review

Background

Individuals with chronic kidney disease (CKD) are at a very high risk for atherosclerotic cardiovascular disease (ASCVD). New lipid-lowering agents offer hope of improved outcomes where traditional agents have been less efficacious, yet the cost of these agents needs consideration in this population before their widespread application.

Objective

We sought to evaluate the cost-effectiveness of novel lipid-lowering therapies for a CKD population.

Methods

We searched four electronic databases, one government registry and the reference lists of included literature to identify cost-effectiveness analyses of novel lipid-lowering agents in CKD. Costs were converted to a single currency to allow cross-country comparisons. Completeness of reporting was analysed using the Consolidated Health Economic Evaluation Reporting Standards checklist. Results were synthesized in narrative form with graphical representation of cost-effectiveness ratios.

Results

Of the 1041 identified studies, 4 met the inclusion criteria. None were specific to a CKD-only population. All examined the impact of proprotein convertase subtilisin/kexin type 9 inhibitors (PCSK9is) in the secondary prevention of ASCVD. Incremental cost-effectiveness ratios of new agents compared with standard care were between €7288 and €112 530 per quality-adjusted life year gained. Cost-effectiveness was sensitive to the degree of cardiovascular risk of the underlying populations.

Conclusion

This review found PCSK9is were moderately cost-effective in populations with high cardiovascular risk. People with CKD were included as an undifferentiated subpopulation in the primary studies, but application of these findings to CKD-specific populations should be interpreted with caution. There is insufficient evidence for a health economic case to support novel lipid-lowering therapies for advanced CKD.

PCSK9 inhibition-based therapeutic approaches: an immunotherapy perspective

Proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors (PCSK9-I) are novel therapeutic tools to decrease cardiovascular risk. These agents work by lowering the low-density lipoprotein cholesterol (LDL-C) in hypercholesterolemic patients who are statin resistant/intolerant. Current clinically approved and investigational PCSK9-I act generally by blocking PCSK9 activity in the plasma or suppressing its expression or secretion by hepatocytes. The most widely investigated method is the disruption of PCSK9/LDL receptor (LDLR) interaction by fully-humanized monoclonal antibodies (mAbs), evolocumab and alirocumab, which have been approved for the therapy of hypercholesterolemia and atherosclerotic cardiovascular disease (CVD). Besides, a small interfering RNA called inclisiran, which specifically suppresses PCSK9 expression in hepatocytes, is as effective as mAbs but with administration twice a year. Because of the high costs of such therapeutic approaches, several other PCSK9-I have been surveyed, including peptide-based anti-PCSK9 vaccines and small oral anti-PCSK9 molecules, which are under investigation in preclinical and phase I clinical studies. Interestingly, anti-PCSK9 vaccination has been found to serve as a more widely feasible and more cost-effective therapeutic tool over mAb PCSK9-I for managing hypercholesterolemia. The present review will discuss LDL-lowering and cardioprotective effects of PCSK9-I, mainly immunotherapy-based inhibitors including mAbs and vaccines, in preclinical and clinical studies.

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

INTRODUCTION

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

METHODS

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

RESULTS

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

CONCLUSION

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

PROSPERO REGISTRATION

ID CRD42020206043.

Acanthaster planci Inhibits PCSK9 and Lowers Cholesterol Levels in Rats

Atherosclerosis is the main cause of cardiovascular diseases which in turn, lead to the highest number of mortalities globally. This pathophysiological condition is developed due to a constant elevated level of plasma cholesterols. Statin is currently the widely used treatment in reducing the level of cholesterols, however, it may cause adverse side effects. Therefore, there is an urgent need to search for new alternative treatment. PCSK9 is an enzyme responsible in directing LDL-receptor (LDL-R)/LDL-cholesterols (LDL-C) complex to lysosomal degradation, preventing the receptor from recycling back to the surface of liver cells. Therefore, PCSK9 offers a potential target to search for small molecule inhibitors which inhibit the function of this enzyme. In this study, a marine invertebrate Acanthaster planci, was used to investigate its potential in inhibiting PCSK9 and lowering the levels of cholesterols. Cytotoxicity activity of A. planci on human liver HepG2 cells was carried out using the MTS assay. It was found that methanolic extract and fractions did not exhibit cytotoxicity effect on HepG2 cell line with IC50 values of more than 30 µg/mL. A compound deoxythymidine also did not exert any cytotoxicity activity with IC50 value of more than 4 µg/mL. Transient transfection and luciferase assay were conducted to determine the effects of A. planci on the transcriptional activity of PCSK9 promoter. Methanolic extract and Fraction 2 (EF2) produced the lowest reduction in PCSK9 promoter activity to 70 and 20% of control at 12.5 and 6.25 μg/mL, respectively. In addition, deoxythymidine also decreased PCSK9 promoter activity to the lowest level of 60% control at 3.13 μM. An in vivo study using Sprague Dawley rats demonstrated that 50 and 100 mg/kg of A. planci methanolic extract reduced the total cholesterols and LDL-C levels to almost similar levels of untreated controls. The level of serum glutamate oxalate transaminase (SGOT) and serum glutamate pyruvate transaminase (SGPT) showed that the administration of the extract did not produce any toxicity effect and cause any damage to rat liver. The results strongly indicate that A. planci produced a significant inhibitory activity on PCSK9 gene expression in HepG2 cells which may be responsible for inducing the uptake of cholesterols by liver, thus, reducing the circulating levels of total cholesterols and LDL-C. Interestingly, A. planci also did show any adverse hepato-cytotoxicity and toxic effects on liver. Thus, this study strongly suggests that A. planci has a vast potential to be further developed as a new class of therapeutic agent in lowering the blood cholesterols and reducing the progression of atherosclerosis.

Practical guidance for combination lipid-modifying therapy in high- and very-high-risk patients: A statement from a European Atherosclerosis Society Task Force

BACKGROUND AND AIMS

This European Atherosclerosis Society (EAS) Task Force provides practical guidance for combination therapy for elevated low-density lipoprotein cholesterol (LDL-C) and/or triglycerides (TG) in high-risk and very-high-risk patients.

METHODS

Evidence-based review.

RESULTS

Statin-ezetimibe combination treatment is the first choice for managing elevated LDL-C and should be given upfront in very-high-risk patients with high LDL-C unlikely to reach goal with a statin, and in primary prevention familial hypercholesterolaemia patients. A proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitor may be added if LDL-C levels remain high. In high and very-high-risk patients with mild to moderately elevated TG levels (>2.3 and < 5.6 mmol/L [>200 and < 500 mg/dL) on a statin, treatment with either a fibrate or high-dose omega-3 fatty acids (icosapent ethyl) may be considered, weighing the benefit versus risks. Combination with fenofibrate may be considered for both macro- and microvascular benefits in patients with type 2 diabetes mellitus.

CONCLUSIONS

This guidance aims to improve real-world use of guideline-recommended combination lipid modifying treatment.

PCSK9 Inhibition: Insights From Clinical Trials and Future Prospects

In 2003, clinical observations led to the discovery of the involvement of proprotein convertase subtilisin/kexin type 9 (PCSK9) in lipid metabolism. Functional studies demonstrated that PCSK9 binds to the low-density lipoprotein (LDL) receptor directing it to its lysosomal degradation. Therefore, carriers of gain-of-function mutations in PCSK9 exhibit decreased expression of LDL receptors on the hepatocyte surface and have higher LDL cholesterol (LDL-C) levels. On the contrary, loss-of-function mutations in PCSK9 are associated with low LDL-C concentrations and significantly reduced lifetime risk of cardiovascular disease. These insights motivated the search for strategies to pharmacologically inhibit PCSK9. In an exemplary rapid development, fully human monoclonal antibodies against PCSK9 were developed and found to effectively reduce LDL-C. Administered subcutaneously every 2–4 weeks, the PCSK9 antibodies evolocumab and alirocumab reduce LDL-C by up to 60% in a broad range of populations either as monotherapy or in addition to statins. Two large cardiovascular outcome trials involving a total of ∼46,000 cardiovascular high-risk patients on guideline-recommended lipid-lowering therapy showed that treatment with evolocumab and alirocumab led to a relative reduction of cardiovascular risk by 15% after 2.2 and 2.8 years of treatment, respectively. These findings expanded the armamentarium of pharmacological approaches to address residual cardiovascular risk associated with LDL-C. Furthermore, the unprecedented low LDL-C concentrations achieved (e.g., 30 mg/dL in the FOURIER study) suggest that the relationship between LDL-C and cardiovascular risk is without a lower threshold, and without associated adverse events during the timeframe of the studies. The side effect profile of PCSK9 antibodies is favorable with few patients exhibiting injection-site reactions. Currently, the access to PCSK9 antibodies is limited by high treatment costs. The development of novel approaches to inhibit PCSK9 such as the use of small interfering RNA to inhibit PCSK9 synthesis seems promising and may soon become available.

Novel Treatment Strategies for Secondary Prevention of Cardiovascular Disease: A Systematic Review of Cost-Effectiveness

BACKGROUND

New pharmacological therapies for the treatment of cardiovascular disease (CVD) have emerged in recent years. The high rates of CVD and the need for long-term treatment to decrease risk factors makes cost-effectiveness crucial for their successful long-term implementation.

OBJECTIVE

This study assessed cost-effectiveness studies of novel pharmacological treatments (ezetimibe, proprotein convertase subtilisin/kexin type 9 [PCSK9] inhibitors, omega-3 polyunsaturated fatty acids [n-3 PUFAs], and the cardiovascular polypill) compared with standard care for the secondary prevention of CVD.

METHODS

We searched seven databases and the reference list of selected literature reviews for eligible cost-effective analyses (CEA) published between January 2009 and January 2020 that evaluated the above novel treatments versus standard care. Two independent reviewers performed the screening and evaluation in accordance with the Consolidated Health Economic Evaluation Reporting Standards statement. Cost results were adapted to 2018 US dollars (US$) to facilitate comparisons between studies. Consideration of cost-effectiveness was based on the original study criteria.

RESULTS

Thirty-two studies were included in this review, most of them adopting a healthcare perspective. Studies evaluating ezetimibe, PCSK9 inhibitors and n-3 PUFAs assessed their addition to standard care compared with standard care alone, while studies analysing the polypill evaluated the replacement of multiple monotherapies for a fixed-dose combination. Ten studies reported on ezetimibe, fifteen evaluated PCSK9 inhibitors, five focused on n-3 PUFAs and seven on the polypill. From a healthcare perspective, ezetimibe was cost effective in 62.5% of the studies (incremental cost-effectiveness ratios [ICERs] ranged from US$27,195 to US$204,140), n-3 PUFAs in 60% (ICERs from US$57,128 to US$139,082) and the cardiovascular polypill in 100% (ICERs from dominant to US$30,731) compared with standard care. Conversely, only 10% of the studies considered PCSK9 inhibitors cost effective compared with standard care from a healthcare perspective (ICERs ranged from US$231,119 to US$1,223,831). Additionally, ezetimibe was cost effective in 50% of the studies, PCSK9 inhibitors in 33% and the polypill in 50% of the studies adopting a societal perspective. The key model-related parameters predicting cost-effectiveness included drug cost, time horizon, and the baseline risk of cardiovascular events.

CONCLUSIONS

Based on current pricing and willingness-to-pay thresholds, most CEA studies considered ezetimibe, n-3 PUFAs and the polypill to be cost effective compared with standard care but not PCSK9 inhibitors for secondary prevention of CVD.

Progress and prospects of biological approaches targeting PCSK9 for cholesterol-lowering, from molecular mechanism to clinical efficacy

INTRODUCTION

Cardiovascular disorders are one of the leading causes of mortality and morbidity worldwide. Recent advances showed a promising role of proprotein convertase subtilisin/kexin type 9 (PCSK9) as a critical player in regulating plasma LDL levels and lipid metabolism.

AREAS COVERED

This review addresses the molecular functions of PCSK9 with a vision on the clinical progress of utilizing monoclonal antibodies and other biological approaches to block PCSK9 activity. The successful clinical trials with monoclonal antibodies are reviewed. Recent advances in (pre)clinical trials of other biological approaches, such as small interfering RNAs, are also discussed.

EXPERT OPINION

Discovery of PCSK9 and clinical use of its inhibitors to manage lipid metabolism is a step forward in hypolipidaemic therapy. A better understanding of the molecular activity of PCSK9 can help to identify new approaches in the inhibition of PCSK9 expression/activity. Whether if PCSK9 plays a role in other cardiometabolic conditions may provide grounds for further development of therapies.