Novel emerging therapies in atherosclerosis targeting lipid metabolism

INTRODUCTION

Recent years have brought significant developments in lipid and atherosclerosis research. Although statins are a cornerstone in hyperlipidemia management, new non-statin therapies have had an impact. The reduction of low-density lipoprotein cholesterol (LDL-C) further translates into the lowering of cardiovascular mortality. Additionally, lipid research has progressed beyond LDL-C reduction and this has brought triglyceride (TG) and other apoprotein-B containing lipids into focus.

AREAS COVERED

Inclisiran and pemafibrate, with expected approval soon, come under the spotlight. We discuss other therapeutics such as lomitapide, mipomersen, volanesorsen, and evinacumab and newly approved non-statin-based therapies such as ezetimibe, icosapent ethyl (IPE), and bempedoic acid.

EXPERT OPINION

New options now exist for the prevention of atherosclerosis in patients that are not optimized on statin therapy. Multiple guidelines endorse ezetimibe, PCSK9 inhibitors, bempedoic, and IPE as add-on therapy. Recently approved bempedoic acid/ezetimibe combination might gain popularity among clinicians. Inclisiran and pemafibrate show promise in the reduction of LDL-C and TG, respectively, and results are pending in cardiovascular outcome trials. Combination strategies could improve outcomes, but the challenge will be balancing cost and selecting the correct patient population for each treatment modality to maximize benefit with the fewest medications.

Effect of alirocumab on individuals with type 2 diabetes, high triglycerides, and low high-density lipoprotein cholesterol

BACKGROUND

Mixed dyslipidemia [elevated non-high-density lipoprotein cholesterol (non-HDL-C) and triglycerides (TGs), and decreased HDL-C] is common in type 2 diabetes mellitus (T2DM) and is associated with increased cardiovascular risk. Non-HDL-C and apolipoprotein B (ApoB) are the preferred therapeutic targets for mixed dyslipidemia. Alirocumab is a monoclonal antibody to proprotein convertase subtilisin/kexin type 9 (PCSK9) that effectively reduces low-density lipoprotein cholesterol (LDL-C), non-HDL-C, ApoB, and lipoprotein(a) (Lp[a]), and is well-tolerated in individuals with T2DM.

METHODS

The previously reported open-label ODYSSEY DM-DYSLIPIDEMIA trial data demonstrated the effects of alirocumab on individuals with non-HDL-C ≥ 100 mg/dL and TGs ≥ 150 and < 500 mg/dL receiving stable maximally tolerated statin (n = 413). This post hoc subgroup analysis of the primary trial investigated the effects of alirocumab [75 mg every 2 weeks (Q2W) with possible increase to 150 mg Q2W at Week 12] versus usual care [ezetimibe, fenofibrate, or no additional lipid-lowering therapy (LLT)] on non-HDL-C and other lipids in individuals with T2DM and baseline TGs ≥ 200 mg/dL and HDL-C < 40 mg/dL (men) or < 50 mg/dL (women).

RESULTS

Alirocumab significantly reduced non-HDL-C [LS mean difference (standard error (SE)), - 35.0% (3.9)], ApoB [LS mean difference (SE), - 34.7% (3.6)], LDL-C [LS mean difference (SE), - 47.3% (5.2)], LDL particle number [LS mean difference (SE), - 40.8% (4.1)], and Lp(a) [LS mean difference (SE), - 29.9% (5.4)] versus usual care from baseline to Week 24 (all P < 0.0001). Results were similar for alirocumab versus usual care. TG reductions were similar between alirocumab and usual care (no significant difference), but greater with fenofibrate versus alirocumab (P = 0.3371). Overall, alirocumab significantly increased HDL-C versus usual care [LS mean difference (SE), 7.9% (3.6); P < 0.05], although differences with alirocumab versus ezetimibe or fenofibrate were non-significant. Most individuals receiving alirocumab achieved ApoB < 80 mg/dL (67.9%) and non-HDL-C < 100 mg/dL (60.9%). Adverse event frequency was similar between alirocumab (67.2%) and usual care (70.7%). Additionally, no clinically relevant effect of alirocumab on change in glycemic parameters or use of antihyperglycemic agents was observed.

CONCLUSIONS

Alirocumab is an effective therapeutic option for individuals with T2DM, TGs ≥ 200 mg/dL, and HDL-C < 40 mg/dL (men) or < 50 mg/dL (women). Atherogenic lipid (ApoB and non-HDL) reductions were greater with alirocumab than ezetimibe, fenofibrate, or no LLT. Consistent with previous studies, alirocumab was generally well tolerated. Trial registration Clinicaltrials.gov, NCT02642159. Registered December 24, 2015, https://clinicaltrials.gov/ct2/show/NCT02642159.

Efficacy and safety of alirocumab in Korean patients with hypercholesterolemia and high cardiovascular risk: subanalysis of the ODYSSEY-KT study

BACKGROUND/AIMS

Efficacy and safety data of alirocumab, a fully human monoclonal antibody to proprotein convertase subtilisin/kexin type 9 (PCSK9), is not yet well established in the Korean population. We assessed them in ODYSSEY-KT through the pre-specified Korean subanalysis.

METHODS

In the ODYSSEY-KT study, South Korean and Taiwanese patients with hypercholesterolemia and high cardiovascular risks were randomized (1:1) to alirocumab or placebo. Alirocumab was self-administered subcutaneously at 75 mg every 2 weeks with a maximally tolerated statin dose with or without other lipid-modifying therapies. Alirocumab dose was increased to 150 mg every 2 weeks at week 12 if low density lipoprotein cholesterol (LDL-C) ≥ 70 mg/dL at week 8. Primary endpoint was percent change in LDL-C from baseline to week 24. Results from Korean cohort (n = 83: 40 for alirocumab and 43 for placebo, respectively) analyses are reported here.

RESULTS

In alirocumab group, the least square of mean change percent in LDL-C levels was -65.7% (placebo: 11.1%; p < 0.0001) and 92.0% of them achieved LDL-C < 70 mg/dL (placebo: 12.7%; p < 0.0001) at week 24. Alirocumab also showed significantly greater improvements in high density lipoprotein cholesterol (HDL-C), non-HDL-C, total cholesterol, lipoprotein(a), and apolipoprotein B than placebo (p < 0.05). Two consecutive calculated LDL-C values < 25 mg/dL were observed in 37.5% of alirocumab-treated patients. Overall, 45.0% alirocumab-treated and 51.2% placebo-treated patients experienced treatment-emergent adverse events (TEAEs) without discontinuation of treatment due to TEAEs.

CONCLUSION

Alirocumab has demonstrated to be effective in improvement of LDL-C and related lipid profiles in Korean cohort. Alirocumab was generally well tolerated with no significant safety signals.

An update on pharmacotherapies in diabetic dyslipidemia

Hyperlipidemia plays a crucial role in the underlying pathogenesis of multiple cardiovascular diseases (CVD), including coronary artery disease, peripheral arterial disease, carotid stenosis, and heart failure. The risk of developing such diseases in the diabetic population is relatively high. Diabetes mellitus (DM) is an independent risk factor for premature atherosclerosis. The hallmark of DM dyslipidemia is a demonstrably high level of atherogenic triglyceride rich lipids including very low-density lipoprotein, chylomicrons, and small dense low-density lipoprotein (LDL). Moderate to high intensity statins, targeting LDL cholesterol reduction, remain the cornerstone in the management of this unique disorder. Many 'non-statin' drugs have recently been studied in the DM patients who were either on a 'maximally tolerated statin' or 'statin intolerant'. Ezetimibe and proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors are particularly important and were incorporated in the recent guidelines by the European Society of Cardiology, American College of Cardiology, American Heart Association, and American Diabetes Association. Icosapent Ethyl has garnered huge interest this year following publication of the REDUCE-IT trial. There are several newer hypolipidemic drugs, including Bempedoic acid, Inclisiran and RVX-208, that are in different phases of clinical trials. In this article, we review the underlying pathophysiology of DM dyslipidemia, existing guidelines related to its management, and the potential of newer hypolipidemic and anti-inflammatory drugs being incorporated in the management of DM.

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.

Design and rationale of the ODYSSEY DM-DYSLIPIDEMIA trial: lipid-lowering efficacy and safety of alirocumab in individuals with type 2 diabetes and mixed dyslipidaemia at high cardiovascular risk

Background

Type 2 diabetes mellitus (T2DM) is often associated with mixed dyslipidaemia, where non-high-density lipoprotein cholesterol (non-HDL-C) levels may more closely align with cardiovascular risk than low-density lipoprotein cholesterol (LDL-C). We describe the design and rationale of the ODYSSEY DM-DYSLIPIDEMIA study that assesses the efficacy and safety of alirocumab, a proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitor, versus lipid-lowering usual care in individuals with T2DM and mixed dyslipidaemia at high cardiovascular risk with non-HDL-C inadequately controlled despite maximally tolerated statin therapy. For the first time, atherogenic cholesterol-lowering with a PCSK9 inhibitor will be assessed with non-HDL-C as the primary endpoint with usual care as the comparator.

Methods

DM-DYSLIPIDEMIA is a Phase 3b/4, randomised, open-label, parallel group, multinational study that planned to enrol 420 individuals. Main inclusion criteria were T2DM and mixed dyslipidaemia (non-HDL-C ≥100 mg/dl [≥2.59 mmol/l], and triglycerides ≥150 and <500 mg/dl [≥1.70 and <5.65 mmol/l]) with documented atherosclerotic cardiovascular disease or ≥1 additional cardiovascular risk factor. Participants were randomised (2:1) to alirocumab 75 mg every 2 weeks (Q2W) or lipid-lowering usual care on top of maximally tolerated statin (or no statin if intolerant). If randomised to usual care, investigators were able to add their pre-specified choice of one of the following to the patient’s current statin regimen: ezetimibe, fenofibrate, omega-3 fatty acids or nicotinic acid, in accordance with local standard-of-care. Alirocumab-treated individuals with non-HDL-C ≥100 mg/dl at week 8 will undergo a blinded dose increase to 150 mg Q2W at week 12. The primary efficacy endpoint is non-HDL-C change from baseline to week 24 with alirocumab versus usual care; other lipid levels (including LDL-C), glycaemia-related measures, safety and tolerability will also be assessed. Alirocumab will be compared to fenofibrate in a secondary analysis.

Results

Recruitment completed with 413 individuals randomised in 14 countries worldwide. Results of this trial are expected in the second quarter of 2017.

Conclusions

ODYSSEY DM-DYSLIPIDEMIA will provide information on the efficacy and safety of alirocumab versus lipid-lowering usual care in individuals with T2DM and mixed dyslipidaemia at high cardiovascular risk using non-HDL-C as the primary efficacy endpoint.

Trial registration NCT02642159 (registered December 24, 2015)

Electronic supplementary material

The online version of this article (doi:10.1186/s12933-017-0552-4) contains supplementary material, which is available to authorized users.

Efficacy and safety of alirocumab in insulin-treated patients with type 1 or type 2 diabetes and high cardiovascular risk: Rationale and design of the ODYSSEY DM-INSULIN trial

AIMS

The coadministration of alirocumab, a PCSK9 inhibitor for treatment of hypercholesterolaemia, and insulin in diabetes mellitus (DM) requires further study. Described here is the rationale behind a phase-IIIb study designed to characterize the efficacy and safety of alirocumab in insulin-treated patients with type 1 (T1) or type 2 (T2) DM with hypercholesterolaemia and high cardiovascular (CV) risk.

METHODS

ODYSSEY DM-INSULIN (NCT02585778) is a randomized, double-blind, placebo-controlled, multicentre study that planned to enrol around 400 T2 and up to 100 T1 insulin-treated DM patients. Participants had low-density lipoprotein cholesterol (LDL-C) levels at screening≥70mg/dL (1.81mmol/L) with stable maximum tolerated statin therapy or were statin-intolerant, and taking (or not) other lipid-lowering therapy; they also had established CV disease or at least one additional CV risk factor. Eligible patients were randomized 2:1 to 24weeks of alirocumab 75mg every 2weeks (Q2W) or a placebo. Alirocumab-treated patients with LDL-C≥70mg/dL at week 8 underwent a blinded dose increase to 150mg Q2W at week 12. Primary endpoints were the difference between treatment arms in percentage change of calculated LDL-C from baseline to week 24, and alirocumab safety.

RESULTS

This is an ongoing clinical trial, with 76 T1 and 441 T2 DM patients enrolled; results are expected in mid-2017.

CONCLUSION

The ODYSSEY DM-INSULIN study will provide information on the efficacy and safety of alirocumab in insulin-treated individuals with T1 or T2 DM who are at high CV risk and have hypercholesterolaemia not adequately controlled by the maximum tolerated statin therapy.

Low High-Density Lipoprotein and Risk of Myocardial Infarction

Low HDL is an independent risk factor for myocardial infarction. This paper reviews our current understanding of HDL, HDL structure and function, HDL subclasses, the relationship of low HDL with myocardial infarction, HDL targeted therapy, and clinical trials and studies. Furthermore potential new agents, such as alirocumab (praluent) and evolocumab (repatha) are discussed.