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Study of ISIS 678354 for Patients with Severe Hypertriglyceridemia

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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. The treatment being tested in this study is called Olezarsen, also known by its code name ISIS 678354. Olezarsen is a type of medication known as an antisense oligonucleotide, which is a small piece of DNA or RNA designed to bind to specific molecules in the body to alter their function. This medication is administered through an injection under the skin, using a device called YpsoMate, which is a single-use, automated injection system.

The purpose of this study is to evaluate the safety and tolerability of Olezarsen in patients with Severe Hypertriglyceridemia. Participants in the study will receive regular injections of the medication over a period of time. The study will monitor participants for any changes in their health, including laboratory values and any side effects they may experience. The study will also track the use of any additional medications that participants may need during the trial.

Participants will be involved in the study for a period of up to 66 weeks. During this time, they will receive injections and attend regular check-ups to monitor their health and the effects of the treatment. The study aims to provide valuable information on how well Olezarsen is tolerated by patients and its impact on 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

    Joining the study

    Upon joining the study, you will be informed about the purpose and procedures involved. This study is an open-label extension, meaning you will know the medication you are receiving.

    You will be required to have completed a previous study with an acceptable safety profile, as judged by the investigator.

  2. Step 2

    Medication administration

    You will receive the medication called olezarsen, also known as ISIS 678354. This medication is administered through an injection under the skin, known as a subcutaneous injection.

    The dosage and frequency of the medication will be determined by the study protocol and your healthcare provider.

  3. Step 3

    Ongoing treatment

    You will continue to receive the medication as part of your treatment for severe hypertriglyceridemia (SHTG). This condition involves high levels of triglycerides in the blood.

    Your treatment will be part of a stable regimen of lipid-lowering therapy, which should follow the standard of care according to local guidelines.

  4. Step 4

    Monitoring and assessments

    Throughout the study, your health will be closely monitored. This includes regular assessments of your clinical laboratory values, such as platelet count and kidney function.

    You will be observed for any adverse events, which are any unwanted effects you might experience during the study.

  5. Step 5

    Completion of the study

    The study is expected to last up to 66 weeks, with the primary endpoint being the change in clinical laboratory values from baseline to week 53.

    Upon completion, you will have a final assessment to evaluate the overall safety and tolerability of the medication.

Who can join the trial?

4 criteria

  • Must have completed either the ISIS 678354-CS5 or ISIS 678354-CS6 study successfully, with a good safety record as judged by the study doctor.
  • Must be on a stable treatment plan for lowering lipids (fats in the blood) that follows the standard medical guidelines in your area.
  • Open to both male and female participants.
  • Includes people from vulnerable groups, which means those who might need extra care or protection.

Who cannot join the trial?

10 criteria

  • Patients with other serious health conditions that could interfere with the study.
  • Patients who are pregnant or breastfeeding.
  • Patients who have participated in another clinical trial recently.
  • Patients with a history of allergic reactions to similar medications.
  • Patients who are unable to follow the study procedures or instructions.
  • Patients with certain liver or kidney problems.
  • Patients who have a history of drug or alcohol abuse.
  • Patients with uncontrolled diabetes or high blood pressure.
  • Patients who are taking medications that could interfere with the study drug.
  • Patients with a history of heart disease or stroke.
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Investigated drugs

Olezarsen is a medication being studied for its effects on people with a condition called severe hypertriglyceridemia, which means they have very high levels of triglycerides in their blood. Triglycerides are a type of fat, and having too much of them can increase the risk of heart disease and other health problems. Olezarsen is given as an injection under the skin, and the main goal of the study is to see how safe and tolerable it is for patients to use. This means researchers want to know if it causes any side effects and how patients feel while taking it.

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 to assess its safety and tolerability for patients with severe hypertriglyceridemia, a condition characterized by very high levels of triglycerides in the blood. The medication works by targeting specific molecules in the body to reduce triglyceride levels, helping to manage this condition. Olezarsen is classified as a therapeutic agent aimed at treating lipid disorders.

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 progression of this condition involves the accumulation of triglycerides, which can cause the blood to become thicker and more prone to clotting. Over time, this can lead to complications such as inflammation of the pancreas, known as pancreatitis. The condition may also contribute to the development of cardiovascular diseases due to the increased risk of plaque formation in the arteries. Managing triglyceride levels is crucial to prevent these complications and maintain overall health.
Trial detailsLast updated 2 Oct 2026
Age18+ yearsPhasePhase IIITrial ID2022-501999-26-00Protocol codeISIS 678354-CS15Estimated enrolment855 patientsSponsorIonis Pharmaceuticals Inc.

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On this site, “treatment” means an investigational medicine being studied in a clinical trial. Its safety and efficacy for the use being studied have not yet been confirmed, some participants may receive a placebo or a comparator medicine, and taking part does not guarantee any health benefit. The decision to take part is made by the doctor at the research site. This site is for information only and does not replace medical advice.

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