Perspectives on a new prescription omega-3 fatty acid, icosapent ethyl, for hypertriglyceridemia

Defining the Role of Icosapent Ethyl in Clinical Practice

The health benefit of fish oil, i.e. omega-3 fatty acids (ω-3 FA) has a long history of debate. While there are a number of medications to reduce serum triglyceride levels, none have shown unanimous cardiovascular (CV) benefits. The most recent Reduction of Cardiovascular Events with Icosapent Ethyl-Intervention Trial (REDUCE-IT) assessing the CV outcome of one highly purified prescription ω-3 FA has certainly rejuvenated the debate. While this trial has been regarded as one of the most important landmark trials in preventive cardiology, the tolerability issue in a very high dose (4 g/day, as administered in the trial) is still a matter of concern. This article summarizes the current status and future perspective of icosapent ethyl in clinical practice in light of REDUCE-IT.

History and future of omega-3 fatty acids in cardiovascular disease

BACKGROUND/OBJECTIVES

Epidemiological, diet-based, and some interventional outcomes studies suggest that polyunsaturated omega-3 fatty acids (OM3FAs), specifically eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), confer cardiovascular protection in some patient populations. This review examines the historical context of OM3FAs in cardiovascular disease and future perspectives on the place of OM3FA products in reducing cardiovascular risk.

METHODS

Relevant articles were identified via PubMed/Medline and Google Scholar searches through 2015 and through reference lists of selected publications. Articles determined by the authors to be relevant to the topic of this review were included.

RESULTS

Review of the identified articles indicated that inconsistent results among interventional outcomes studies have been attributed to use of low doses of OM3FAs, patient cohorts with non-elevated triglyceride (TG) levels, differential use of concomitant statin therapy, and study designs with insufficient statistical power. Several prescription OM3FA products are now approved as an adjunct to diet to reduce TG levels in adults with severe (≥500 mg/dL) hypertriglyceridemia. Most formulations contain both EPA and DHA; one formulation contains purified EPA. In randomized controlled trials, these products significantly reduced TG levels in patients with very high TG levels (≥500 mg/dL [≥13.0 mmol/L]) and in statin-treated patients with high TG levels (200-499 mg/dL [5.2-12.9 mmol/L]). The DHA-containing products raised LDL-C levels in these studies, whereas the EPA-only product had no effect on LDL-C, suggesting that all OM3FA prescription products are not therapeutically equivalent. Besides lowering TG levels, OM3FAs (particularly EPA) exert anti-inflammatory effects and may slow multiple atherogenic processes. Two well designed interventional outcomes studies (REDUCE-IT and STRENGTH) are evaluating prescription-strength, high-dose OM3FAs (4 g/day) in statin-treated patients with persistently high TG levels.

CONCLUSIONS

The results of the ongoing prescription-strength, high-dose OM3FA interventional trials will help define the potential role of OM3FAs in addressing residual cardiovascular risk despite statin therapy.

Icosapent ethyl: a review of its use in severe hypertriglyceridemia

Icosapent ethyl (Vascepa®) is a high-purity ethyl ester of eicosapentaenoic acid (EPA) that is de-esterified to EPA following oral administration. Both EPA and docosahexaenoic acid (DHA) are long-chain omega-3 fatty acids that have been associated with triglyceride (TG)-lowering. However, DHA has been associated with increased low-density lipoprotein cholesterol (LDL-C) levels. Icosapent ethyl contains ≥96 % of the EPA ethyl ester, does not contain DHA, and is approved in the USA for use as an adjunct to diet to lower TG levels in adult patients with severe (≥500 mg/dL [≥5.65 mmol/L]) hypertriglyceridemia. In a pivotal phase III trial, oral icosapent ethyl 4 g/day significantly decreased the placebo-corrected median TG levels by 33.1 %. It did not increase LDL-C, had favorable effects on other lipid parameters, and had a tolerability profile similar to that of placebo. Therefore, icosapent ethyl is an effective and well-tolerated agent for the treatment of severe hypertriglyceridemia in adults.