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Study of Imetelstat in Patients with Low or Intermediate Risk Myelodysplastic Syndromes (MDS) Refractory to Erythropoiesis-Stimulating Agents

Fast replyRegistered drugNo placebo
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What is this trial about?

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

This clinical study is focused on myelodysplastic syndromes (MDS), a group of disorders caused by poorly formed or dysfunctional blood cells. The study is particularly for individuals who have low or intermediate-1 risk according to something called the IPSS scale, and who are dependent on blood transfusions. Moreover, these individuals have not responded well to a treatment known as ESA, which is supposed to stimulate red blood cell production. The therapy being tested here is called imetelstat (also known by the code GRN163L), administered as a solution directly into a vein. There is also a placebo being used for comparison in some parts of the study.

The main goal of this study is to evaluate if imetelstat is effective and safe for individuals with the specified type of MDS. This happens in two parts: the first part examines the treatment's overall impact, while the second part compares its effects directly against a placebo. Additionally, there is an extension phase to assess long-term safety, survival rates, and disease progression, including potential progression to a more severe condition called acute myeloid leukemia (AML).

The study doesn't just look at immediate effects; it also aims to observe longer-term outcomes like how long patients go without needing blood transfusions, any changes in their health status over time, and how they respond to the treatment regarding side effects. The study plan involves close monitoring of vital signs and lab results to ensure patient safety. Data collected will help understand the potential benefits of imetelstat for people with this form of MDS, whose current treatment options are limited.

The research process

The trial runs in 6 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 diagnosis of myelodysplastic syndromes (MDS) is confirmed through a bone marrow test. This test must be conducted within 12 weeks before the first day of the study.

    Eligibility is determined based on specific criteria, including age, diagnosis, and previous treatment history.

  2. Step 2

    Initial treatment phase

    The study involves the administration of imetelstat, a solution given through an intravenous infusion. This means the medication is delivered directly into the bloodstream through a vein.

    The primary goal during this phase is to evaluate the effectiveness and safety of imetelstat in patients who are dependent on blood transfusions.

  3. Step 3

    Randomization and comparison

    Participants are randomly assigned to receive either imetelstat or a placebo. A placebo is a substance with no active medication, used to compare the effects of the actual drug.

    The effectiveness of imetelstat is compared to the placebo by observing the reduction in the need for blood transfusions over a specified period.

  4. Step 4

    Extension phase

    In this phase, the long-term safety and overall survival of participants receiving imetelstat are evaluated.

    The progression of the disease, including any advancement to acute myeloid leukemia (AML), is monitored.

  5. Step 5

    Monitoring and assessments

    Throughout the study, regular assessments are conducted to monitor the safety and effectiveness of the treatment. This includes checking vital signs, laboratory tests, and heart function through ECGs.

    Participants' quality of life and any side effects experienced are also evaluated.

  6. Step 6

    Completion of the study

    The study is expected to conclude by October 2026. At the end of the study, the collected data will be analyzed to determine the overall outcomes and effectiveness of imetelstat in treating MDS.

Who can join the trial?

8 criteria

  • Must be a man or woman who is at least 18 years old, or the legal age of consent in the area where the study is happening.
  • Must have a diagnosis of myelodysplastic syndromes (MDS), confirmed by a bone marrow test within 12 weeks before starting the study. This diagnosis must be approved by the study sponsor.
  • Must have a low or intermediate-1 risk of MDS according to the International Prognostic Scoring System (IPSS).
  • Must be dependent on red blood cell (RBC) transfusions, needing at least 4 units of RBC transfusions over an 8-week period during the 16 weeks before starting the study. The hemoglobin level before transfusion should be 9.0 g/dL or less to count towards the 4 units total.
  • Must have MDS that has not responded to or has returned after ESA treatment (a type of treatment to stimulate red blood cell production). This is defined by one of the following:
    • Received at least 8 weeks of treatment with specific doses of medications like epoetin alfa, epoetin beta, or darbepoetin alfa, without a significant increase in hemoglobin or a decrease in RBC transfusion needs.
    • Continued need for transfusions or a drop in hemoglobin after improvement from at least 8 weeks of treatment, without another explanation.
    • Has a high level of endogenous serum EPO (a hormone that stimulates red blood cell production) greater than 500 mU/mL.
    • Must have an ECOG performance status of 0, 1, or 2, which means the person is fully active or has some limitations but can still take care of themselves.

Who cannot join the trial?

9 criteria

  • Patients who have a different type of blood disorder other than myelodysplastic syndromes (MDS) cannot participate. MDS is a condition where the bone marrow does not produce enough healthy blood cells.
  • Patients who are not dependent on blood transfusions are excluded. This means if you do not regularly need blood transfusions, you cannot join.
  • Patients who have not tried or have not stopped responding to ESA treatment are excluded. ESA treatment is a type of medication that helps the body make more red blood cells.
  • Patients with a high risk of developing acute myeloid leukemia (AML) are excluded. AML is a type of cancer that affects the blood and bone marrow.
  • 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 follow the study procedures or attend regular visits are excluded.
  • Patients who are pregnant or breastfeeding cannot participate.
  • Patients with other serious health conditions that might interfere with the study are excluded.
  • Patients who are currently participating in another clinical trial are excluded.
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Investigated drugs

Imetelstat (GRN163L) is a medication being studied for its potential to help patients with a specific type of blood disorder called myelodysplastic syndrome (MDS). This condition often requires patients to receive regular blood transfusions. Imetelstat is being tested to see if it can reduce the need for these transfusions in patients whose condition has not improved with other treatments known as erythropoiesis-stimulating agents (ESAs). The study aims to evaluate how effective and safe imetelstat is for these patients, and to see if it can help improve their overall health and survival over time.

What is already known about the treatment

Imetelstat – Imetelstat is administered intravenously and is currently being studied in clinical trials for its effectiveness in treating myelodysplastic syndromes (MDS), particularly in patients who are dependent on blood transfusions and have not responded to erythropoiesis-stimulating agents. The medication is in the investigational stage, with ongoing research evaluating its safety and efficacy. It is primarily indicated for low or intermediate-1 risk MDS that is relapsed or refractory to standard treatments. Imetelstat works by inhibiting the enzyme telomerase, which is involved in the maintenance of telomeres, thereby potentially limiting the proliferation of malignant cells. It is classified as a telomerase inhibitor in pharmacology.

Investigated diseases

Myelodysplastic Syndromes (MDS) – Myelodysplastic syndromes are a group of disorders caused by poorly formed or dysfunctional blood cells. These conditions occur when something goes wrong in the bone marrow, where blood cells are produced. People with MDS often have low levels of one or more types of blood cells, leading to symptoms like fatigue, infections, or easy bruising. Over time, MDS can progress to more severe forms of blood disorders, including acute myeloid leukemia. The progression of MDS varies among individuals, with some experiencing slow changes and others facing rapid deterioration. The disease is more common in older adults and can be associated with previous chemotherapy or radiation therapy.
Trial detailsLast updated 2 Oct 2026
Age18+ yearsPhasePhase IVTrial ID2024-511348-25-00Protocol code63935937MDS3001Estimated enrolment224 patientsSponsorGeron Corp.

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