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Study of Imetelstat Compared to Drug Combination for Treating Intermediate-2 or High-Risk Myelofibrosis in Patients Not Responding to JAK-Inhibitor Treatment

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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 called Myelofibrosis, which is a type of blood cancer that affects the bone marrow. The study is comparing a new treatment called Imetelstat with the best available therapies currently used for patients with intermediate-2 or high-risk myelofibrosis who have not responded to a type of medication known as a JAK-inhibitor. Imetelstat is given as a solution for infusion, which means it is administered directly into the bloodstream through a vein.

The purpose of the study is to compare the overall survival of patients treated with Imetelstat versus those receiving the best available therapy. Participants in the study will be randomly assigned to receive either Imetelstat or one of the standard treatments, which may include medications like Danazol, Corticosteroids, Busulfan, Anagrelide, Cladribine, Hydroxycarbamide, Mercaptopurine, or other supportive care options. Some participants may receive a placebo, which is a substance with no active medication, to help compare the effects of the treatments.

The study will take place over a period of time, with regular check-ups and assessments to monitor the participants' health and response to the treatment. The main goal is to see if Imetelstat can help patients live longer compared to the current best available therapies. Participants will be closely monitored for any changes in their condition, including symptoms and spleen size, which is often affected in myelofibrosis. The study aims to provide valuable information that could lead to better treatment options for people with this challenging condition.

The research process

The trial runs in 4 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, the patient is randomly assigned to receive either imetelstat or the best available therapy (BAT) for their condition.

    The study focuses on patients with intermediate-2 or high-risk myelofibrosis who have not responded to previous treatment with a JAK-inhibitor.

  2. Step 2

    Treatment administration

    If assigned to the imetelstat group, the patient receives the medication as a solution for infusion. The specific dosage and frequency are determined by the study protocol.

    If assigned to the BAT group, the patient receives one of the available therapies, which may include medications such as anagrelide hydrochloride, cladribine, hydroxycarbamide, or mercaptopurine. The choice of therapy is based on the patient's medical condition and previous treatments.

  3. Step 3

    Monitoring and assessments

    Throughout the study, the patient's health and response to treatment are closely monitored. This includes regular assessments of symptoms, spleen size, and overall health.

    The primary goal is to evaluate overall survival, while secondary goals include symptom response and spleen response at specific time points, such as Week 24.

  4. Step 4

    End of study participation

    The study is expected to conclude by April 2026. At the end of the study, the patient's overall health and treatment outcomes are evaluated.

    The results contribute to understanding the effectiveness of imetelstat compared to other available therapies for treating myelofibrosis.

Who can join the trial?

7 criteria

  • Must have a confirmed diagnosis of **Myelofibrosis** (MF), which is a type of blood cancer, according to specific medical criteria.
  • Must be classified as having **intermediate-2 or high-risk** MF based on a scoring system that predicts the disease's progression.
  • Must have tried **JAK-inhibitor treatment** for at least 3 to 6 months without success, meaning the disease did not improve or got worse, and cannot have a stem cell transplant.
  • Must have a **measurable enlarged spleen**, which is an organ in the body, either by feeling it or by imaging tests like MRI or CT scans.
  • Must have **active symptoms** of MF, such as fatigue, night sweats, itchiness, abdominal discomfort, pain under the ribs on the left side, feeling full quickly, or bone pain, with a certain severity score.
  • Must have specific **blood test results**: a certain level of white blood cells called neutrophils and a certain number of platelets, which help with blood clotting, without needing support from medications or transfusions.
  • Must be an adult, as the study includes both male and female participants.

Who cannot join the trial?

4 criteria

  • Patients who have not experienced a return or worsening of their condition after treatment with a JAK-inhibitor cannot participate. A JAK-inhibitor is a type of medication used to treat certain blood disorders.
  • Patients who do not have intermediate-2 or high-risk **Myelofibrosis** are excluded. **Myelofibrosis** is a condition where scar tissue forms in the bone marrow, affecting blood cell production.
  • Patients who are not within the specified age range for the study cannot participate. The study is open to adults.
  • Patients who are not able to provide informed consent or who are considered part of a vulnerable population may be excluded. A vulnerable population includes individuals who may have difficulty understanding the study or making decisions about participation.
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Investigated drugs

  • Imetelstat (GRN163L)

    is a medication being studied for its potential to treat patients with a type of blood cancer called myelofibrosis. This medication is being tested to see if it can help patients who have not responded well to previous treatments with a type of drug known as a JAK-inhibitor. Imetelstat works by targeting and inhibiting a specific enzyme that is involved in the growth of cancer cells, potentially slowing down or stopping the progression of the disease.

  • Best Available Therapy (BAT)

    refers to the standard treatments that are currently used for patients with myelofibrosis. These treatments can vary depending on the patient's specific condition and may include a range of medications or therapies that are considered effective based on current medical knowledge. The goal of using BAT in this study is to compare its effectiveness against imetelstat in improving the survival of patients with myelofibrosis.

What is already known about the treatment

Imetelstat – Imetelstat is administered intravenously, meaning it is given directly into a vein. It is currently being studied in clinical trials for its effectiveness in treating myelofibrosis, particularly in patients who have not responded to or have relapsed after treatment with Janus Kinase (JAK) inhibitors. The main therapeutic indication for imetelstat is myelofibrosis, a type of bone marrow cancer. At the molecular level, imetelstat works by inhibiting telomerase, an enzyme that helps cancer cells maintain their ability to divide and grow. It is classified as a telomerase inhibitor in pharmacology.

Investigated diseases

Myelofibrosis – Myelofibrosis is a rare bone marrow disorder characterized by the replacement of bone marrow with fibrous tissue, leading to a decrease in the production of blood cells. This condition often results in anemia, fatigue, and an enlarged spleen. Over time, the disease can cause significant scarring in the bone marrow, which disrupts normal blood cell production. Patients may experience symptoms such as weakness, weight loss, and night sweats. The progression of myelofibrosis can vary, with some individuals experiencing a slow progression while others may have a more rapid decline in blood cell production.
Trial detailsLast updated 2 Oct 2026
Age18+ yearsPhasePhase IIITrial ID2023-509120-17-00Protocol codeGRN163LMYF3001Estimated enrolment354 patientsSponsorGeron Corp.

sourced from the EU Clinical Trials Register and site verification

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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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