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Study of ISIS 678354 for Patients with Severe High Triglycerides

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What is this trial about?

A plain-language summary of the goals, design and what participants do

This clinical trial is focused on studying a condition known as severe hypertriglyceridemia, which is characterized by very high levels of triglycerides in the blood. Triglycerides are a type of fat found in the blood, and having too much can increase the risk of heart disease and other health issues. The study will test a treatment called olezarsen, also known by its code name ISIS 678354. Olezarsen is administered through a subcutaneous injection, which means it is injected under the skin. The study will compare the effects of olezarsen to a placebo, which is an inactive substance used to assess the treatment's effectiveness.

The purpose of the study is to evaluate how well olezarsen works in reducing the levels of fasting triglycerides from the start of the study. Participants will receive either olezarsen or a placebo and will be monitored over a period of time to see how their triglyceride levels change. The study will also look at other factors, such as changes in certain proteins and cholesterol levels, and the occurrence of any related health events.

Participants in the study will be required to follow a specific diet and lifestyle, and they will continue their current lipid-lowering therapy, which is a treatment to help manage fat levels in the blood. The study will last for about 53 weeks, during which time participants will have regular check-ups to monitor their health and the effects of the treatment. The goal is to determine if olezarsen can effectively lower triglyceride levels and improve overall health outcomes for those with severe hypertriglyceridemia.

The research process

The trial runs in 5 steps – from screening to follow-up. Each step says what happens and what the team monitors.

  1. Step 1

    Initial visit

    Upon joining the study, you will attend an initial visit. During this visit, your fasting triglyceride levels will be measured to ensure they are at least 500 mg/dL (5.65 mmol/L).

    You will be asked about your current medications and lifestyle to confirm that your lipid-lowering therapy is stable and follows standard care guidelines.

  2. Step 2

    Randomization

    After the initial assessments, you will be randomly assigned to receive either the study medication, olezarsen, or a placebo. A placebo is a substance that looks like the medication but does not contain the active ingredient.

    This process is double-blind, meaning neither you nor the study team will know which treatment you are receiving.

  3. Step 3

    Treatment administration

    You will receive the assigned treatment as a subcutaneous injection. This means the injection is given under the skin.

    The injections will be administered regularly, and the study team will provide specific instructions on the frequency and duration of the treatment.

  4. Step 4

    Follow-up visits

    Throughout the study, you will attend follow-up visits to monitor your health and the effects of the treatment.

    Your fasting triglyceride levels and other health markers will be measured at these visits, including at baseline, month 6, and month 12.

  5. Step 5

    End of treatment

    The study will continue for approximately 12 months, with the final assessments conducted at the end of this period.

    The study aims to evaluate the change in fasting triglyceride levels and other health markers compared to the placebo group.

Who can join the trial?

6 criteria

  • Participants must have severe hypertriglyceridemia, which means very high levels of triglycerides (a type of fat) in the blood.
  • Participants must have fasting triglycerides levels of 500 mg/dL (5.65 mmol/L) or higher at two specific times during the study process.
  • Participants must be on lipid-lowering therapy, which are medications that help reduce fat levels in the blood. These medications should follow local health guidelines and be stable for at least 4 weeks before the study starts.
  • Participants must be willing to follow specific diet and lifestyle recommendations during the study.
  • Both men and women can participate in the study.
  • The study includes individuals from vulnerable populations, which may include groups like children, elderly, or those with certain health conditions.

Who cannot join the trial?

1 criterion

  • Patients with severe hypertriglyceridemia cannot participate. This means having very high levels of triglycerides, which are a type of fat found in your blood.
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Investigated drugs

Olezarsen is a medication being studied for its ability to help people with a condition called severe hypertriglyceridemia. This condition means that there are very high levels of triglycerides, a type of fat, in the blood. High triglycerides can increase the risk of heart disease and other health problems. Olezarsen is given as an injection under the skin. The main goal of using this medication in the trial is to see if it can lower the levels of triglycerides in the blood when compared to not using the medication. This could help reduce the risk of complications related to high triglycerides.

What is already known about the treatment

Olezarsen – Olezarsen is administered through an injection under the skin, known as subcutaneous administration. It is currently being studied in clinical trials and is not yet widely available in medical practice. The main use of olezarsen is to help people with severe hypertriglyceridemia, a condition where there are very high levels of triglycerides, a type of fat, in the blood. Olezarsen works by targeting specific molecules in the body to reduce the production of triglycerides, helping to lower their levels in the blood. It is classified as a lipid-lowering agent, which means it helps to manage and reduce fats in the bloodstream.

Investigated diseases

Severe hypertriglyceridemia – Severe hypertriglyceridemia is a condition characterized by extremely high levels of triglycerides in the blood. Triglycerides are a type of fat that circulates in the bloodstream, and when their levels become excessively high, it can lead to various health issues. The condition progresses as triglyceride levels continue to rise, which can result in the development of fatty deposits in the skin and organs. Over time, severe hypertriglyceridemia can cause inflammation of the pancreas, known as pancreatitis. This inflammation can lead to abdominal pain and other digestive issues. The condition requires careful management to prevent complications.
Trial detailsLast updated 7 Oct 2026
Age18+ yearsPhasePhase IIITrial ID2022-501420-20-00Protocol codeISIS 678354-CS6Estimated enrolment448 patientsSponsorIonis Pharmaceuticals Inc.

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