Insights from ANCHOR: omega-3 fatty acids in type 2 diabetes patients with residual hypertriglyceridaemia

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Macrovascular Residual Risk Studies

9 January 2013

Treatment with icosapent ethyl (IPE, a high-purity formulation of the omega-3 fatty acid eicosapentaenoic acid [EPA] ethyl ester, 4 g/day) was effective in managing residual elevated triglyceride-rich lipoproteins in type 2 diabetes patients at LDL-C goal on statin therapy.

Effects of icosapent ethyl on lipid and inflammatory parameters in patients with diabetes mellitus-2, residual elevated triglycerides (200--500 mg/dL), and on statin therapy at LDL-C goal: the ANCHOR study.
Brinton EA, Ballantyne CM, Bays HE, Kastelein JJ, Braeckman RA, Soni PN.
Cardiovasc Diabetol 2013;12:100. [Epub ahead of print].

STUDY SUMMARY

Objective:

To evaluate the effects of IPE on lipid, lipoprotein and inflammatory biomarkers in patients with diabetes in the ANCHOR (AMR101 [Ethyl Icosapentate] on Triglyceride Levels in Patients on Statins With High Triglyceride Levels)

Study design:

Post hoc subgroup analysis of patients with diabetes in ANCHOR, a 12-week, randomized, placebo-controlled phase III study of IPE (4 g/day or 2 g/day) in patients with residual hypertriglyceridaemia (≥200 and

Study population:

514 patients with diabetes; all except one had type 2 diabetes. The intention to treat (ITT) population comprised 501 patients, 165 allocated to IPE 4 g/day, 171 allocated to IPE 2 g/day and 165 allocated to placebo. Overall, median HbA1c was 6.8% at baseline; median HbA1c was 6.2% in patients with better controlled diabetes (n=253) and 7.6% in patients with less well-controlled diabetes (n=261)

Primary variable:

• Median placebo-adjusted percent change from baseline to week 12 in fasting triglycerides (TG) levels
• Secondary variables included LDL-C, non-high-density lipoprotein cholesterol (non-HDL-C), very low-density lipoprotein cholesterol (VLDL-C), apolipoprotein B100 (apoB), and lipoprotein-associated phospholipase A2.
• Exploratory variables included total cholesterol, HDL-C, VLDL-TG, high-sensitivity C-reactive protein (hs-CRP), oxidized LDL, and remnant-like particle cholesterol.

Methods:

In the ANCHOR trial, patients initially entered a 4-6 week lead-in period to stabilize diet and lifestyle and washout non-statin lipid-modifying therapy, followed by a 2-3 week lipid-qualifying period in which patients were required to satisfy the criteria of TG≥200 mg/dL and

The analysis of TG levels was pre-specified; all other analyses were post hoc. All analyses were based on the ITT population, defined as all randomized patients who took at least one dose of study drug, and had valid baseline and at least one post-baseline efficacy measurement. The effects of treatment were evaluated overall and for patients with better or less well-controlled diabetes.

Main results:

Compared with placebo, IPE 4 g/day significantly reduced TG, for all patients and those with better or less well-controlled diabetes (Table 1). In addition, this IPE dose also significantly reduced non-HDL-C, VLDL-C, lipoprotein-associated phospholipase A2, apoB, total cholesterol, HDL-C, VLDL-TG, oxidized LDL and remnant-like particle cholesterol in all three diabetes groups. There was no evidence to suggest deterioration in glycaemic control with either IPE dose regimen.

Table 1. Triglycerides (mg/dL) at baseline, 12 weeks and median placebo-adjusted percent change from baseline to week 12

Patient group	Baseline	12 weeks	Median percent change from baseline
All patients
IPE 4 g/day	262	217	-23.2%**
IPE 2 g/day	254	244	-9.8%*
Placebo	259	276

Better diabetes control, HbA1c <6.8%
IPE 4 g/day	262	228	-21.0%**
IPE 2 g/day	264	238	-15.1%*
Placebo	258	276

Worse diabetes control, HbA1c ³6.8%
IPE 4 g/day	268	203	-24.8%**
IPE 2 g/day	250	248	-4.8%
Placebo	260	274

* p<0.01, **p<0.0001

Authors’ conclusion:

IPE 4 g/day significantly improved lipid parameters, including TG-rich remnant lipoproteins, without worsening glycaemic control in patients with diabetes and mixed dyslipidaemia.

COMMENT

Atherogenic dyslipidaemia, i.e. the combination of elevated TG (a marker of TG-rich apoB-containing lipoproteins [TRL]) and low plasma concentrations of HDL-C, is commonly exhibited by patients with type 2 diabetes. While statin therapy is effective in managing LDL-C plasma levels, a considerable proportion of patients often have residual hypertriglyceridaemia. For example, data from the Dyslipidaemia International Study (DYSIS) study in Europe and Canada showed that nearly one-half (44%) of patients with diabetes have persistently elevated TG (³1.7 mmol/L or 150 mg/dL) despite statin therapy.(1) This is clearly clinically relevant, given re-consideration of the role of TRL and their remnants in atherosclerosis and CVD.(2,3) Indeed, a recent Mendelian randomisation study showed that lifelong exposure to elevated remnant cholesterol, carried in TRL, is causal for ischaemic heart disease. Each 1 mmol/L (39 mg/dL) increase in levels of non-fasting remnant cholesterol (a measure of TRL cholesterol) due to genetic variants affecting remnant cholesterol metabolism was associated with a 2.8-fold increase in causal risk for ischaemic heart disease, independent of HDL-C.(3)

Therapeutic options for the management of residual hypertriglyceridaemia in statin-treated patients includes fibrates and omega-3 fatty acids.(4) The formulation of omega-3 fatty acids tested in the ANCHOR trial is a high purity formulation of EPA, which is currently approved in the USA as an adjunct to diet to lower severe hypertriglyceridaemia (³500 mg/dL). In the primary publication of the ANCHOR study,(5) IPE 4 g/day was shown to significantly improve residual hypertriglyceridaemia in high-risk patients at LDL-C goal with statin treatment, and was well tolerated. Despite the limitations inherent in a post hoc analysis, the current report extends the evidence-base for this EPA formulation as a therapeutic option for managing residual hypertriglyceridaemia that persists in high-risk patients with or without type 2 diabetes. Whether this strategy confers clinical benefits is contentious, with conflicting conclusions from recent trials, and meta-analyses.(6-10) The ongoing REDUCE-IT (Reduction of Cardiovascular Events with EPA-Intervention) primary prevention trial (11) in about 8000 high-risk patients with residual hypertriglyceridaemia will provide important insights into the appropriateness of this therapeutic strategy for reducing residual cardiovascular risk.

References

1. Gitt AK, Drexel H, Feely J et al, (on behalf of the DYSIS Investigators). Persistent lipid abnormalities in statin-treated patients and predictors of LDL-cholesterol goal achievement in clinical practice in Europe and Canada. Eur J Prevent Cardiol 2012;19: 221-30.
2. Chapman MJ, Ginsberg HN, Amarenco P et al. Triglyceride-rich lipoproteins and high-density lipoprotein cholesterol in patients at high risk of cardiovascular disease: evidence and guidance for management. Eur Heart J 2011; 32:1345–61.
3. Varbo A, Benn M, Tybjærg-Hansen A, Jørgensen AB, Frikke-Schmidt R, Nordestgaard BG. Remnant cholesterol as a causal risk factor for ischemic heart disease. J Am Coll Cardiol 2013;61:427-36.
4. Reiner Z, Catapano AL, De Backer G et al. ESC/EAS Guidelines for the management of dyslipidaemias: the Task Force for the management of dyslipidaemias of the European Society of Cardiology (ESC) and the European Atherosclerosis Society (EAS). Eur Heart J 2011;32:1769-818.
5. Ballantyne CM, Bays HE, Kastelein JJ et al. Efficacy and safety of eicosapentaenoic acid ethyl ester (AMR101) therapy in statin-treated patients with persistent high triglycerides (from the ANCHOR study). Am J Cardiol 2012;110:984-92.
6. Yokoyama M, Origasa H, Matsuzaki M et al; Japan EPA lipid intervention study (JELIS) Investigators. Effects of eicosapentaenoic acid on major coronary events in hypercholesterolaemic patients (JELIS): a randomized open-label, blinded endpoint analysis. Lancet 2007;369:1090-8,
7. Saito Y, Yokoyama M, Origasa H et al; JELIS Investigators, Japan. Effects of EPA on coronary artery disease in hypercholesterolemic patients with multiple risk factors: sub-analysis of primary prevention cases from the Japan EPA Lipid Intervention Study (JELIS). Atherosclerosis 2008;200:135-40.
8. Kromhout D, Giltay EJ, Geleijnse JM; Alpha Omega Trial Group. n-3 fatty acids and cardiovascular events after myocardial infarction. N Engl J Med 2010;363:2015-26.
9. ORIGIN Trial Investigators, Bosch J, Gerstein HC, Dagenais GR et al. n-3 fatty acids and cardiovascular outcomes in patients with dysglycemia. N Engl J Med 2012;367:309-18.
10. Rizos EC, Ntzani EE, Bika E, Kostapanos MS, Elisaf MS. Association between omega-3 fatty acid supplementation and risk of major cardiovascular disease events: a systematic review and meta-analysis. JAMA 2012;308:1024-33.
11. REDUCE-IT trial. Available at http://www.amarincorp.com/products.html. Accessed 23 July 2013.

Key words

triglycerides; residual hypertriglyceridemia; residual cardiovascular risk; omega-3 fatty acids; icosapent ethyl; eicosapentoic acid; diabetes