Ionis Pharmaceuticals has announced positive topline results from its Phase 3 Essence study evaluating olezarsen for the treatment of moderate hypertriglyceridemia (HTG) in patients diagnosed with or at risk for atherosclerotic cardiovascular disease (ASCVD).
The global, multicenter, randomized, double-blind, placebo-controlled trial enrolled 1,478 participants and demonstrated that olezarsen, an investigational RNA-targeted medicine, achieved statistically significant reductions in triglyceride levels compared to placebo.
Significant Triglyceride Reductions Achieved
The study met its primary endpoint with olezarsen showing placebo-adjusted reductions in triglyceride (TG) levels of 61% and 58% at 6 months with the 80 mg and 50 mg monthly doses, respectively. Notably, these substantial reductions were achieved despite nearly all participants already being on standard lipid-lowering medicines at baseline.
The majority of participants reached triglyceride levels below 150 mg/dL, indicating a reduction to normal levels. This is particularly significant as elevated triglycerides are associated with increased risk of acute pancreatitis and cardiovascular disease.
Dr. Richard Geary, Executive Vice President of Development at Ionis Pharmaceuticals, commented, "These results represent an important step in potentially bringing forward a new treatment for people with severely elevated triglycerides, expanding the potential benefit of olezarsen beyond individuals with FCS to a broader population living with SHTG."
Study Design and Patient Population
The Essence study (Essence-TIMI 73b), conducted in partnership with The TIMI Study Group, enrolled adults aged 18 and older with moderate hypertriglyceridemia, defined as fasting triglyceride levels ≥150 mg/dL to <500 mg/dL. A small percentage of participants (9%) had fasting triglycerides ≥500 mg/dL at baseline.
Participants were randomized to receive either 50 mg (n=276) or 80 mg (n=832) of olezarsen or placebo (n=369) every 4 weeks via subcutaneous injection for 12 months. All participants had received stable and optimized standard of care lipid-lowering therapies for at least four weeks prior to screening.
The primary endpoint was the percent change from baseline in fasting TG levels at six months compared to placebo. Key secondary endpoints included percent changes in triglyceride levels at 12 months, proportion of patients achieving fasting TG<150 mg/dL, and percent changes in other lipid parameters, including apoC-III, remnant cholesterol, non-HDL-C and apoB.
Safety and Tolerability Profile
Olezarsen demonstrated a favorable safety and tolerability profile in the Essence study. The most common treatment-emergent adverse event was injection site reactions, the majority of which were mild in severity. This safety profile is consistent with previous studies of the drug.
Mechanism of Action
Olezarsen is designed to lower the body's production of apolipoprotein C-III (apoC-III), a protein produced in the liver that regulates triglyceride metabolism in the blood. By targeting apoC-III, olezarsen aims to reduce triglyceride levels and potentially decrease the risk of serious health complications associated with hypertriglyceridemia.
Regulatory Status and Future Directions
Olezarsen was recently approved in the U.S. under the trade name Tryngolza™ as an adjunct to diet to reduce triglycerides in adults with familial chylomicronemia syndrome (FCS), a rare genetic disorder characterized by extremely high triglyceride levels.
The positive results from the Essence study support the broader potential of olezarsen in addressing the needs of individuals with severe hypertriglyceridemia (SHTG). The drug is currently being evaluated in two additional Phase 3 clinical trials – CORE and CORE2 – specifically for the treatment of SHTG.
Data from these pivotal studies are expected in Q3 2025 and will serve as the basis for a potential supplemental new drug application (sNDA) filing for SHTG by year-end. If approved for this indication, olezarsen could provide a new treatment option for millions of people at risk for acute pancreatitis and cardiovascular disease due to severely elevated triglycerides.
Hypertriglyceridemia: A Significant Health Concern
Hypertriglyceridemia is a condition characterized by elevated levels of triglycerides in the blood. While optimal levels for adults are typically below 150 mg/dL, levels higher than 150 mg/dL indicate hypertriglyceridemia, and levels exceeding 500 mg/dL are classified as severe hypertriglyceridemia (SHTG).
SHTG puts millions of people at risk of potentially life-threatening acute pancreatitis and atherosclerotic cardiovascular disease despite current standard of care treatments. Individuals with triglyceride levels above 880 mg/dL, including those with familial chylomicronemia syndrome (FCS), face an even greater risk of acute pancreatitis.
The positive results from the Essence study suggest that olezarsen could potentially address a significant unmet medical need for patients with moderate to severe hypertriglyceridemia who remain at risk despite existing therapies.
