Elsevier

International Journal of Cardiology

Volume 267, 15 September 2018, Pages 183-187
International Journal of Cardiology

The cost-effectiveness of PCSK9 inhibitors - The Australian healthcare perspective

https://doi.org/10.1016/j.ijcard.2018.04.122Get rights and content

Highlights

  • PCSK9 inhibitors are an efficacious alternative for those with statin intolerance.

  • This is the first cost-effectiveness analysis of PCSK9 inhibitors in Australia.

  • The analysis was from the Australian healthcare perspective.

  • The model comprised a secondary prevention population based on the FOURIER study.

  • At current prices, PCSK9 inhibitors would not be considered cost-effective.

Abstract

Background

For patients in whom statins are not tolerated or effective as monotherapy, proprotein convertase subtilisin/kexin type 9 inhibitors (PCSK9i) represent a new class of lipid lowering therapies that may reduce low-density lipoprotein cholesterol (LDL-C) levels by up to 50% and lower cardiovascular events. While an important treatment option, the cost-effectiveness of PCSK9i in Australia remains unknown. This study aimed to determine the cost-effectiveness of PCSK9i compared to placebo in the prevention of atherosclerotic cardiovascular disease (CVD).

Methods and results

A Markov cohort state-transition model was developed in Microsoft Excel. A hypothetical sample of 1000 individuals based on subjects in the Further Cardiovascular Outcomes Research with PCSK9 Inhibition in Subjects with Elevated Risk (FOURIER) trial populated the model. With each five-year cycle, model subjects could have non-fatal CVD events (myocardial infarction and/or stroke), or die from CVD or other causes. Follow-up was simulated for 25 years. CVD risk reduction, cost and utility data were gathered from published sources. At current acquisition prices (AU$8174 per person per year), the incremental cost effectiveness ratio (ICER) was AU$308,558 per quality-adjusted life year (QALY) saved. Acquisition prices would need to be reduced to approximately AU$1500 per person per annum for PCSK9i to reach the arbitrary cost-effectiveness threshold of AU$50,000 per QALY saved.

Conclusion(s)

PCSK9i are an effective alternative for those with existing CVD or at high risk of CVD in whom statin therapy alone is ineffective, but are not cost-effective to the Australian healthcare system based on current prices.

Introduction

3-Hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase inhibitors (statins) are highly efficacious at reducing low density lipoprotein cholesterol (LDL-C) levels and lowering CVD risk [1] and currently comprise first line therapy in the treatment of hyperlipidaemia and prevention of CVD [2]. Previous research has demonstrated that a decrease of 1 mmol/L of LDL-C results in an approximate 20% decrease in risk of CVD major vascular events [1,3].

However, statins are unsuitable for approximately 5 to 10% of individuals, predominantly due to intolerance or ineffectiveness as monotherapy [4]. For such people, the new class of lipid lowering agents, proprotein convertase subtilisin/kexin type 9 inhibitors (PCSK9i), represents an alternative treatment option. Randomised controlled trials of PCSK9i thus far have demonstrated reductions in LDL-C levels by >50% compared to placebo [5]. More recently, the Further Cardiovascular Outcomes Research with PCSK9 Inhibition in Subjects with Elevated Risk (FOURIER) trial reported that on a background of statin therapy, the PCSK9i evolocumab reduced the risk of CVD outcomes [6]. Hence PCSK9i represent an important treatment option for patients with statin intolerance and/or ineffectiveness, but their cost-effectiveness is currently unknown.

This study sought to determine the long-term effectiveness and cost-effectiveness of PCSK9i from the Australian healthcare perspective.

Section snippets

Model structure

A Markov state-transition model was developed in Microsoft Excel to assess the cost-effectiveness of PCSK9i versus placebo in the prevention of CVD. The model structure is conceptualized in Fig. 1.

With each 5-year cycle, model subjects could develop non-fatal CVD events (myocardial infarction [MI] and/or stroke), fatal CVD or die from other causes. All events were assumed to occur half-way through the cycle. Individuals continued to cycle through the model for 25 years or until death.

The model

Results

Table 2 summarizes the simulated results of the effectiveness of PCSK9i compared to placebo, determined by the number of CVD events prevented. Seventy CVD events were prevented in 1000 individuals over a 25-year time horizon, equating to a number needed to treat of 14 over this period. In total, 210 years of life (discounted) and 236 QALYs (discounted) were saved in the cohort, at a net cost (discounted) of AU$72,946,713 (discounted). These equated to ICERs of AU$347,164 per year of life saved

Discussion

To the best of the authors' knowledge, this is the first cost-effectiveness analyses of PCSK9i for the prevention of CVD in the general Australian population. The analysis demonstrates PCSK9i would not be cost-effective at current acquisition costs of AU$8174 per person per annum.

Cost-effectiveness analyses of PCSK9i in the US have showed conflicting results. Gandra et al. [17] found that evolocumab, at a cost of US$14,100 per person per annum, met cost-effectiveness thresholds in patients with

Conclusions

Those with existing CVD disease or at high risk of CVD in whom statin therapy is ineffective would benefit from treatment with other lipid lowering therapies such as PCSK9i. However, at current acquisition costs (reimbursed for patients with homozygous familial hypercholesterolemia) in Australia, PCSK9i would not be considered cost-effective within the Australian healthcare system. Cost-effectiveness is much improved in high risk patients, such as those with PAD. As long-term data on the

Sources of funding

No funding was required for this publication.

Disclosures

AT and DL have received honoraria from Amgen, including pertaining to work on evolocumab.

Conflict of interest

AT and DL have received honoraria from Amgen, including pertaining to work on evolocumab. RK and EZ report no relationships that could be construed as a conflict of interest.

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    These authors take responsibility for all aspects of the reliability and freedom from bias of the data presented and their discussed interpretation.

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