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A Study of Bomedemstat (IMG-7289/MK-3543) Compared to Best Available Therapy (BAT) in Participants With Essential Thrombocythemia and an Inadequate Response or Intolerance of Hydroxyurea (MK-3543-006)

A Phase 3, Randomized, Open-label, Active-Comparator-Controlled Clinical Study to Evaluate the Safety and Efficacy of Bomedemstat (MK-3543/IMG-7289) Versus Best Available Therapy (BAT) in Participants With Essential Thrombocythemia Who Have an Inadequate Response to or Are Intolerant of Hydroxyurea

Status
Recruiting
Phases
Phase 3
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT06079879
Enrollment
340
Registered
2023-10-12
Start date
2023-12-31
Completion date
2028-08-18
Last updated
2026-03-13

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Essential Thrombocythemia

Keywords

essential thrombocythemia, ET, bomedemstat, IMG-7289

Brief summary

This is a study evaluating the safety and efficacy of bomedemstat (MK-3543) compared with the best available therapy (BAT) in participants with essential thrombocythemia (ET) who have an inadequate response to or are intolerant of hydroxyurea. The primary study hypothesis is that bomedemstat is superior to the best available therapy with respect to durable clinicohematologic response (DCHR).

Interventions

Oral Capsule

Oral Capsule

DRUGBusulfan

Oral Tablet

DRUGInterferon alfa/pegylated interferon alfa 2a/pegylated interferon alfa 2b

Subcutaneous Solution

DRUGRuxolitinib

Oral Tablet

Sponsors

Merck Sharp & Dohme LLC
Lead SponsorINDUSTRY

Study design

Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
SINGLE (Outcomes Assessor)

Eligibility

Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No

Inclusion criteria

* Has a diagnosis of ET per WHO 2016 diagnostic criteria for myeloproliferative neoplasms (confirmed by a central pathologist) * Has a centrally assessed bone marrow fibrosis score of Grade 0 or Grade 1, as per a modified version of the European Consensus Criteria for Grading Myelofibrosis * Has a history of inadequate response to or intolerance of hydroxyurea based on modified European LeukemiaNet (ELN) criteria for hydroxyurea resistance or intolerance * Has an inadequate or loss of response to their most recent prior ET therapy, requiring a change of cytoreductive therapy * Has a platelet count \> 450 × 10\^9/L (450k /μL) assessed up to 72 hours before first dose of study intervention * Has an absolute neutrophil count (ANC) ≥0.75 × 10\^9/L assessed up to 72 hours before first dose of study intervention * Participants may have received up to 3 prior ET-directed cytoreductive agents including hydroxyurea

Exclusion criteria

* Known immediate or delayed hypersensitivity reaction or idiosyncrasy to drugs chemically related to bomedemstat or lysine demethylase or monoamine oxidase inhibitor (LSDi or MAOi) or the chosen best available therapy (including anagrelide, interferon alfa/pegylated interferon, ruxolitinib, or busulfan) that contraindicates participation * History of any illness/impairment of GI function that might interfere with drug absorption (eg, chronic diarrhea or history of gastric bypass surgical procedure), confound the study results or pose an additional risk to the individual by participation in the study * Evidence at the time of Screening of increased risk of bleeding * History of a malignancy, unless potentially curative treatment has been completed with no evidence of malignancy for 2 years. Note: The time requirement does not apply to participants who underwent successful definitive resection of basal cell carcinoma of the skin, squamous cell carcinoma of the skin, or carcinoma in situ, excluding carcinoma in situ of the bladder * Human immunodeficiency virus (HIV)-infected participants with a history of Kaposi's sarcoma and/or Multicentric Castleman's Disease

Design outcomes

Primary

MeasureTime frameDescription
Durable Clinicohematologic Response (DCHR) RateUp to approximately 52 weeksDCHR rate is the percentage of participants with DCHR, defined as a confirmed reduction of platelet count to ≤400 × 10\^9/L, absence of white blood cell (WBC) count elevation to \>10 × 10\^9/L locally assessed to be due to ET, and the absence of any thrombotic or major hemorrhagic events or disease progression to myelofibrosis (MF), myelodysplastic syndrome (MDS) or acute myeloid leukemia (AML) by Week 52.

Secondary

MeasureTime frameDescription
Change From Baseline in Myelofibrosis Symptom Assessment Form (MFSAF) v4.0 Individual Fatigue Symptom Item ScoreBaseline and pre-specified timepoints through Week 156The MFSAF v4.0 is a 7-item participant-reported myelofibrosis symptom assessment which asks respondents to report symptom severity at its worst for each of the 7 items on a 0 (Absent) to 10 (Worst Imaginable) numeric rating scale. For this outcome measure, the change from baseline through Week 156 in scores for the individual item of fatigue severity will be presented.
Change From Baseline in Patient-reported Outcomes Measurement Information System (PROMIS) Fatigue SF-7a Total Fatigue ScoreBaseline and pre-specified timepoints through Week 156The PROMIS F SF-7a is a 7-item participant-reported assessment that measures both the experience of fatigue and the interference of fatigue on daily activities over the past week. Response options are on a 5-point Likert scale, ranging from 1 = never to 5 = always. Change from baseline in PROMIS Fatigue SF-7a through Week 156 will be presented.
Change From Baseline in Total Symptom Score as Measured on the MFSAF v4.0Baseline and pre-specified timepoints through Week 156The MFSAF v4.0 is a 7-item participant-reported myelofibrosis symptom assessment which asks respondents to report symptom severity at its worst for each of the 7 items on a 0 (Absent) to 10 (Worst Imaginable) numeric rating scale. MFSAF total score for all symptoms at baseline through Week 156 will be presented.
Duration of Clinicohematologic Response (DOCHR)Up to approximately 52 weeksFor participants who demonstrate DCHR, duration of clinicohematologic response is defined as the time from the first documented evidence of confirmed reduction of platelet and WBC count until confirmed increase of platelet and WBC counts to above acceptable threshold, thrombotic or major hemorrhagic events or disease progression to MF, MDS or AML.
Duration of Hematologic Remission (DOHR)Up to approximately 52 weeksFor participants who demonstrate hematologic remission, DOHR is defined as the time from the first documented evidence of platelet and WBC counts reduction until platelet or WBC counts increase to above acceptable threshold.
Percentage of Participants with Thrombotic EventsUp to 156 weeksThrombotic events include but are not limited to new or recurrent acute myocardial infarction, unstable angina, stroke, transient ischemic attack, deep venous thrombosis, pulmonary embolism, thrombotic digital ischemia, or other thrombotic events.
Percentage of Participants with Major Hemorrhagic EventsUp to 156 weeksMajor hemorrhagic events include but are not limited to fatal bleeding, and/or symptomatic bleeding in a critical area or organ such as intracranial, intraspinal, intraocular, retroperitoneal, intra-articular or pericardial, or intramuscular with compartment syndrome, and/or bleeding causing a decrease in hemoglobin level of 2 g/dL or more, or leading to transfusion of 2 or more units of whole blood or red cells.
Disease Progression RateUp to approximately 52 weeksDisease progression rate is the percentage of participants with disease progression, defined as the transformation to post-essential thrombocythemia myelofibrosis, myelodysplastic syndrome, or acute myeloid leukemia as assessed by the adjudication committee. The disease progression rate of participants in each arm will be presented.
Number of Participants with An Adverse Event (AE)Up to 180 weeksAn AE is any untoward medical occurrence in a clinical study participant, temporally associated with the use of study intervention, whether or not considered related to the study intervention.
Number of Participants Discontinuing From Study Therapy Due to an AEUp to 152 weeksAn AE is any untoward medical occurrence in a clinical study participant, temporally associated with the use of study intervention, whether or not considered related to the study intervention. The number of participants who discontinue study treatment due to an adverse event will be presented.

Countries

Argentina, Australia, Belgium, Canada, China, Colombia, France, Germany, Hong Kong, Hungary, Israel, Italy, Japan, Netherlands, New Zealand, Poland, Portugal, South Korea, Spain, Sweden, Taiwan, Turkey (Türkiye), United Kingdom, United States

Contacts

CONTACTToll Free Number
Trialsites@msd.com1-888-577-8839
STUDY_DIRECTORMedical Director

Merck Sharp & Dohme LLC

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Mar 14, 2026