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Study on Bomedemstat for Patients with Essential Thrombocythemia Not Responding to or Intolerant of Hydroxyurea, Comparing with a Drug Combination

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 trial is focused on studying a condition called Essential Thrombocythemia, which is a type of blood disorder where the body produces too many platelets. Platelets are small blood cells that help with clotting, and having too many can lead to problems like blood clots or bleeding. The study is looking at a new treatment called Bomedemstat (also known by its code name MK-3543) and comparing it to the best available therapy for patients who have not responded well to or cannot tolerate a common treatment called hydroxyurea.

The purpose of the study is to compare the effectiveness and safety of Bomedemstat against other treatments that are currently available. Participants in the study will receive either Bomedemstat or another treatment, which could include medications like Ruxolitinib, Peginterferon Alfa-2a, Anagrelide Hydrochloride Monohydrate, or Busulfan. Some participants may receive a placebo. The study will last for a period of up to 36 months, during which time participants will be monitored for their response to the treatment and any side effects they may experience.

Throughout the study, researchers will assess various outcomes, such as the rate of durable clinicohematologic response, which refers to how well the blood disorder is controlled over time. They will also look at changes in symptoms and overall health, as well as any adverse events or complications that may occur. The goal is to determine if Bomedemstat is a safe and effective option for managing Essential Thrombocythemia in patients who have limited treatment options.

The research process

The trial runs in 7 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, eligibility is confirmed based on specific criteria, including a diagnosis of essential thrombocythemia and a history of inadequate response to or intolerance of hydroxyurea.

  2. Step 2

    Initial assessment

    An initial assessment is conducted to evaluate the current health status. This includes checking platelet and neutrophil counts, which must meet specific thresholds.

  3. Step 3

    Randomization

    Participants are randomly assigned to receive either bomedemstat or the best available therapy. This process ensures that the study results are unbiased.

  4. Step 4

    Treatment phase

    Participants receiving bomedemstat take it orally in capsule form. The dosage and frequency are determined by the study protocol.

    Participants receiving the best available therapy may be given medications such as ruxolitinib, peginterferon alfa-2a, anagrelide hydrochloride monohydrate, or busulfan, depending on individual needs and previous treatments.

  5. Step 5

    Ongoing monitoring

    Regular monitoring is conducted to assess the effectiveness and safety of the treatment. This includes tracking changes in symptoms and any side effects experienced.

  6. Step 6

    Evaluation of outcomes

    The primary outcome measured is the durable clinicohematologic response rate. Secondary outcomes include changes in fatigue levels, symptom scores, and the occurrence of thrombotic or hemorrhagic events.

  7. Step 7

    Completion of study

    The study is expected to conclude by October 2028. Participants' health and response to treatment are evaluated to determine the overall effectiveness of bomedemstat compared to the best available therapy.

Who can join the trial?

9 criteria

  • The patient must have a diagnosis of essential thrombocythemia (ET), which is a condition where the body produces too many platelets, according to specific criteria set by the World Health Organization.
  • The patient must have a bone marrow fibrosis score of Grade 0 or Grade 1. This score is a way to measure the amount of scar tissue in the bone marrow.
  • The patient must have a history of not responding well to or not being able to tolerate hydroxyurea, a medication used to treat ET, based on specific guidelines.
  • The patient must have not responded well or lost response to their most recent ET treatment, which means they need to change their current treatment.
  • The patient must have a platelet count greater than 450,000 per microliter, which is a measure of the number of platelets in the blood, checked within 72 hours before starting the study treatment.
  • The patient must have an absolute neutrophil count (ANC) of at least 0.75 x 10^9/L, which is a measure of a type of white blood cell, checked within 72 hours before starting the study treatment.
  • The patient may have received up to 3 previous treatments, including hydroxyurea.
  • Both male and female patients can participate.
  • The study includes patients from vulnerable populations, which means those who might need extra protection or care.

Who cannot join the trial?

4 criteria

  • Patients who have a different condition than Essential Thrombocythemia with an inadequate response to or intolerance of hydroxyurea.
  • Patients who are not within the specified age range for the study.
  • Patients who are not part of the specified clinical trial groups.
  • Patients who are considered part of a vulnerable population that is not eligible for this study.
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Investigated drugs

Bomedemstat is a medication being studied for its safety and effectiveness in treating patients with essential thrombocythemia, a condition where the body produces too many platelets. This medication is being compared to other therapies to see if it can provide a better or more durable response for patients who have not responded well to or cannot tolerate another treatment called hydroxyurea.

What is already known about the treatment

Bomedemstat – Bomedemstat is administered orally in the form of tablets. It is currently being studied in clinical trials for its effectiveness and safety in treating patients with essential thrombocythemia who do not respond well to or cannot tolerate hydroxyurea. The main therapeutic indication for bomedemstat is essential thrombocythemia, a condition characterized by an overproduction of platelets. At the molecular level, bomedemstat works by inhibiting an enzyme called lysine-specific demethylase 1 (LSD1), which plays a role in regulating blood cell production. It is classified pharmacologically as an enzyme inhibitor.

Investigated diseases

Essential Thrombocythemia – This is a chronic blood disorder characterized by the overproduction of platelets by the bone marrow. It often progresses slowly and may not cause symptoms initially. Over time, individuals may experience headaches, dizziness, or vision changes due to increased blood viscosity. The condition can lead to complications such as blood clots or bleeding due to the abnormal platelet function. In some cases, the disease may evolve into more severe blood disorders. Regular monitoring is essential to manage the progression and potential complications.
Trial detailsLast updated 7 Oct 2026
Age18+ yearsPhasePhase IIITrial ID2023-504865-21-00Protocol codeMK-3543-006Estimated enrolment384 patientsSponsorMerck Sharp & Dohme LLC

sourced from the EU Clinical Trials Register and site verification

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