Olezarsen for Hypertriglyceridemia in Patients at High Cardiovascular Risk

Etiology and emerging treatments for familial chylomicronemia syndrome

INTRODUCTION

Familial chylomicronemia syndrome (FCS) is a rare autosomal recessive condition. Effective treatment is important as patients are at risk for severe and potentially fatal acute pancreatitis. We review recent developments in pharmacologic treatment for FCS, namely biological inhibitors of apolipoprotein (apo) C-III and angiopoietin-like protein 3 (ANGPTL3).

AREAS COVERED

FCS follows a biallelic inheritance pattern in which an individual inherits two pathogenic loss-of-function alleles of one of the five causal genes - LPL (in 60-80% of patients), GPIHBP1, APOA5, APOC2, and LMF1 - leading to the absence of lipolytic activity. Patients present from childhood with severely elevated triglyceride (TG) levels >10 mmol/L. Most patients with severe hypertriglyceridemia do not have FCS. A strict low-fat diet is the current first-line treatment, and existing lipid-lowering therapies are minimally effective in FCS. Apo C-III inhibitors are emerging TG-lowering therapies shown to be efficacious and safe in clinical trials. ANGPTL3 inhibitors, another class of emerging TG-lowering therapies, have been found to require at least partial lipoprotein lipase activity to lower plasma TG in clinical trials. ANGPTL3 inhibitors reduce plasma TG in patients with multifactorial chylomicronemia but not in patients with FCS who completely lack lipoprotein lipase activity.

EXPERT OPINION

Apo C-III inhibitors currently in development are promising treatments for FCS.

Hypertriglyceridemia: Molecular and Genetic Landscapes

Lipid disorders represent one of the most worrisome cardiovascular risk factors. The focus on the impact of lipids on cardiac and vascular health usually concerns low-density lipoprotein cholesterol, while the role of triglycerides (TGs) is given poor attention. The literature provides data on the impact of higher plasma concentrations in TGs on the cardiovascular system and, therefore, on the outcomes and comorbidities of patients. The risk for coronary heart diseases varies from 57 to 76% in patients with hypertriglyceridemia. Specifically, the higher the plasma concentrations in TGs, the higher the incidence and prevalence of death, myocardial infarction, and stroke. Nevertheless, the metabolism of TGs and the exact physiopathologic mechanisms which try to explain the relationship between TGs and cardiovascular outcomes are not completely understood. The aims of this narrative review were as follows: to provide a comprehensive evaluation of the metabolism of triglycerides and a possible suggestion for understanding the targets for counteracting hypertriglyceridemia; to describe the inner physiopathological background for the relationship between vascular and cardiac damages derived from higher plasma concentrations in TGs; and to outline the need for promoting further insights in therapies for reducing TGs plasma levels.

Highlights of Cardiovascular Disease Prevention Studies Presented at the 2024 American College of Cardiology Conference

PURPOSE OF REVIEW

To summarize selected late-breaking science on cardiovascular (CV) disease prevention presented at the 2024 Scientific Session of the American College of Cardiology (ACC) conference.

RECENT FINDINGS

The LIBerate-HR trial showed the efficacy and safety of lerodalcibep, a subcutaneous injection that prevents binding of Pro-Protein Convertase Subtilisin/Kexin (PCSK) 9 to low-density lipoprotein (LDL)-receptors resulting in LDL-cholesterol (LDL-C) lowering in patients at very high risk or high risk of atherosclerotic CV disease (ASCVD). The AEGIS-II randomized patients with type 1 myocardial infarction (MI) with multivessel coronary artery disease and additional CV risk factors and found no benefit in major adverse CV events (MACE) with CSL112, an apolipoprotein A1 infusion shown to increase cholesterol efflux capacity. The Bridge-TIMI 73a trial showed a significant reduction in triglyceride (TG) levels with olezarsen, an antisense mRNA, in patients with moderate hyperTG with elevated CV risk. The BE ACTIVE trial showed significant improvement in step counts in patients given behavioral and financial incentives. The DRIVE study showed a significant increase in the prescription of either sodium-glucose co-transporter-2 inhibitors or glucagon-like peptide-1 receptor agonists in patients with type 2 diabetes mellitus (T2DM) at elevated CV or renal risk with a remote team-based, non-licensed navigator and clinical pharmacist approach. The TACTiC trial showed increased and sustained use of statin therapy by patient-driven use of a web-based portal that calculated the ASCVD risk score and gave prompts. The VICTORIAN-INITIATE trial showed efficacy and safety in early use of inclisiran in patients with ASCVD who did not reach target LDL-C < 70 mg/dL despite maximally tolerated statin therapy. The ARISE-HF trial showed no difference in change of peak oxygen consumption with the use of an oral aldose reductase inhibitor, AT-001, in patients with well-controlled T2DM and diabetic cardiomyopathy with high-risk features compared to placebo. The PREVENT trial showed a significant reduction in target vessel failure at 2 years in patients with non-flow limiting vulnerable plaques with percutaneous coronary intervention and optimal medical therapy (OMT) compared to OMT alone. The late-breaking clinical science presented at the 2024 Scientific Session of the ACC paves the way for an evidence-based alternative to statin therapy and provides data on several common clinical scenarios encountered in daily practice.

Olezarsen, Acute Pancreatitis, and Familial Chylomicronemia Syndrome

BACKGROUND

Familial chylomicronemia syndrome is a genetic disorder associated with severe hypertriglyceridemia and severe acute pancreatitis. Olezarsen reduces the plasma triglyceride level by reducing hepatic synthesis of apolipoprotein C-III.

METHODS

In a phase 3, double-blind, placebo-controlled trial, we randomly assigned patients with genetically identified familial chylomicronemia syndrome to receive olezarsen at a dose of 80 mg or 50 mg or placebo subcutaneously every 4 weeks for 49 weeks. There were two primary end points: the difference between the 80-mg olezarsen group and the placebo group in the percent change in the fasting triglyceride level from baseline to 6 months, and (to be assessed if the first was significant) the difference between the 50-mg olezarsen group and the placebo group. Secondary end points included the mean percent change from baseline in the apolipoprotein C-III level and an independently adjudicated episode of acute pancreatitis.

RESULTS

A total of 66 patients underwent randomization; 22 were assigned to the 80-mg olezarsen group, 21 to the 50-mg olezarsen group, and 23 to the placebo group. At baseline, the mean (±SD) triglyceride level among the patients was 2630±1315 mg per deciliter, and 71% had a history of acute pancreatitis within the previous 10 years. Triglyceride levels at 6 months were significantly reduced with the 80-mg dose of olezarsen as compared with placebo (-43.5 percentage points; 95% confidence interval [CI], -69.1 to -17.9; P<0.001) but not with the 50-mg dose (-22.4 percentage points; 95% CI, -47.2 to 2.5; P = 0.08). The difference in the mean percent change in the apolipoprotein C-III level from baseline to 6 months in the 80-mg group as compared with the placebo group was -73.7 percentage points (95% CI, -94.6 to -52.8) and between the 50-mg group as compared with the placebo group was -65.5 percentage points (95% CI, -82.6 to -48.3). By 53 weeks, 11 episodes of acute pancreatitis had occurred in the placebo group, and 1 episode had occurred in each olezarsen group (rate ratio [pooled olezarsen groups vs. placebo], 0.12; 95% CI, 0.02 to 0.66). Adverse events of moderate severity that were considered by a trial investigator at the site to be related to the trial drug or placebo occurred in 4 patients in the 80-mg olezarsen group.

CONCLUSIONS

In patients with familial chylomicronemia syndrome, olezarsen may represent a new therapy to reduce plasma triglyceride levels. (Funded by Ionis Pharmaceuticals; Balance ClinicalTrials.gov number, NCT04568434.).

New targets and mechanisms of action for lipid-lowering and anti-inflammatory therapies in atherosclerosis: where does the field stand?

INTRODUCTION

Atherosclerotic cardiovascular disease remains a leading cause of morbidity and mortality worldwide, despite widespread use of statins. There is a need to develop additional therapeutic strategies that will complement statins to achieve more effective reductions in cardiovascular risk.

AREAS COVERED

This review provides a comprehensive summary of current areas of therapeutic development targeting both lipid and inflammatory factors implicated in the pathogenesis of atherosclerosis. In addition to develop of novel approaches that will produce more effective lowering of low-density lipoprotein cholesterol, clinical trials are currently evaluating the potential to target other atherogenic lipid parameters such as triglyceride-rich lipoproteins and Lp(a), in addition to promoting the biological properties of high-density lipoproteins. Targeting inflammation within the vascular wall has emerged as a new frontier in cardiovascular prevention, with early evidence that use of anti-inflammatory agents have the potential to reduce cardiovascular risk.

EXPERT OPINION

Clinical practice has an increasing array of therapeutic tools to achieve more effective lowering of low-density lipoprotein cholesterol for high-risk patients. In addition, clinical trials have the potential to deliver a range of additional agents to the clinic, that target alternative lipid and inflammatory mediators. This will permit the potential to personalize cardiovascular prevention.