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Study on Extended Access to Momelotinib for Patients with Myelofibrosis

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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 bone marrow disorder. The study includes patients with primary myelofibrosis as well as those who have developed myelofibrosis after having other conditions like polycythemia vera or essential thrombocythemia. The treatment being tested in this study is a medication called momelotinib dihydrochloride monohydrate, which is taken in the form of a tablet.

The purpose of this study is to provide extended access to momelotinib and to assess its long-term safety for patients who are already receiving this treatment and have not experienced a worsening of their disease. Participants in the study will continue to take the medication as they have been, and their health will be monitored over time to ensure the treatment remains safe and effective.

Throughout the study, researchers will keep track of any side effects that occur, as well as how serious they are and whether they are related to the medication. They will also look at how long patients live without their disease getting worse and whether they remain free from developing leukemia. This information will help determine the long-term safety and benefits of using momelotinib for treating myelofibrosis.

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

    Participation begins after enrollment in one of the specified studies: GS-US-352-0101, GS-US-352-1214, GS-US-352-1154, or SRA-MMB-301.

    Eligibility requires the ability to understand and sign the informed consent form.

  2. Step 2

    Medication administration

    The medication used in this study is momelotinib dihydrochloride monohydrate, administered in the form of a tablet.

    The route of administration is oral use.

  3. Step 3

    Treatment duration

    The study provides extended access to the medication for subjects who have not experienced disease progression.

    The estimated end date for the trial is December 31, 2026.

  4. Step 4

    Safety monitoring

    The primary focus is on safety, monitoring the incidence, severity, and seriousness of any adverse effects.

    Adverse effects are assessed according to the Common Terminology Criteria for Adverse Events (CTCAE) Version 4.03.

  5. Step 5

    Efficacy assessment

    Secondary assessments include measuring overall survival and leukemia-free survival.

Who can join the trial?

4 criteria

  • Must be currently enrolled in one of the following studies: GS-US-352-0101, GS-US-352-1214, GS-US-352-1154, or SRA-MMB-301.
  • Must be able to understand and willing to sign the informed consent form. This means you agree to participate in the study after understanding what it involves.
  • Both men and women can participate.
  • Participants can be from vulnerable populations, which means groups that might need special protection or care.

Who cannot join the trial?

3 criteria

  • Patients who have experienced a progression of disease. This means that their condition has gotten worse.
  • Patients who are not currently receiving treatment with MMB (momelotinib), which is a specific medication used in the study.
  • Patients who are not part of the specific studies mentioned (GS-US-352-0101, GS-US-352-1214, GS-US-352-1154, SRA-MMB-301) related to Primary Myelofibrosis or Post-polycythemia Vera or Post-essential Thrombocythemia Myelofibrosis. These are specific types of blood disorders.
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Investigated drugs

Momelotinib is a medication being studied for its potential to help people with a type of bone marrow disorder called myelofibrosis. This condition can occur on its own or after other blood disorders like polycythemia vera or essential thrombocythemia. The trial aims to provide extended access to this medication for patients who are already receiving it and to monitor its long-term safety.

What is already known about the treatment

Momelotinib – Momelotinib is administered orally in tablet form and is currently being studied in clinical trials for its long-term safety and effectiveness. It is primarily used for treating conditions like Primary Myelofibrosis and Myelofibrosis that develop after Polycythemia Vera or Essential Thrombocythemia. The medication works by inhibiting specific enzymes known as Janus kinases (JAK1 and JAK2), which play a role in the signaling pathways that control blood cell production and immune function. Momelotinib is classified as a JAK inhibitor, a type of medication that targets these enzymes to help manage symptoms and slow disease progression.

Investigated diseases

  • Primary Myelofibrosis

    A rare bone marrow disorder where the marrow is replaced by fibrous tissue, leading to severe anemia, weakness, and fatigue. Over time, the spleen and liver may enlarge due to the body's attempt to produce blood cells outside the bone marrow. Patients often experience symptoms like night sweats, fever, and weight loss. The disease progresses slowly, but the fibrous tissue can eventually lead to bone marrow failure. Blood cell production becomes increasingly impaired, causing complications related to low blood counts.

  • Post-polycythemia Vera Myelofibrosis

    This condition arises as a progression from polycythemia vera, a disorder where the body produces too many red blood cells. Over time, the bone marrow becomes fibrotic, leading to symptoms similar to primary myelofibrosis, such as anemia and an enlarged spleen. Patients may experience fatigue, night sweats, and weight loss. The disease progression involves increasing difficulty in producing blood cells, leading to various complications. The fibrotic transformation can cause significant changes in blood cell counts and function.

  • Post-essential Thrombocythemia Myelofibrosis

    This disease develops from essential thrombocythemia, a condition characterized by excessive platelet production. As the disease progresses, the bone marrow becomes fibrotic, resulting in symptoms like anemia, fatigue, and an enlarged spleen. Patients may also experience night sweats and weight loss. The progression involves a gradual decline in the bone marrow's ability to produce blood cells effectively. This leads to complications associated with low blood counts and impaired blood cell function.

Trial detailsLast updated 2 Oct 2026
Age18+ yearsPhasePhase IITrial ID2023-508018-41-00Protocol codeSRA-MMB-4365/219627Estimated enrolment335 patientsSponsorGlaxosmithkline Research & Development Limited

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