Essential ThrombocythemiaPhase 2NCT04254978
Study of Bomedemstat in Participants With Essential Thrombocythemia (IMG-7289-CTP-201/MK-3543-003)
A Phase 2 study testing Bomedemstat in people with Essential Thrombocythemia, run by Imago BioSciences, Inc., a subsidiary of Merck & Co., Inc., (Rahway, New Jersey USA) at 26 sites in 7 countries.
Trial summary
This is a Phase 2b open label study of an orally administered LSD1 inhibitor, Bomedemstat (MK-3543, formerly called IMG-7289), in patients with essential thrombocythemia. This study investigates the following: The safety and tolerability of Bomedemstat The pharmacodynamic effect of Bomedemstat Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Essential Thrombocythemia
- What is being tested?
- Bomedemstat
- Type of treatment
- Pill or oral medicine
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 73 participants
- Where
- 26 sitesin 7 countries
- Study dates
- 8 Sep 2020to 23 Mar 2023
- Phase
- Phase 2
- Are there results?
- Yes, posted in the registrySummary in the doctors' view
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Diagnosis of Essential Thrombocythemia per World Health Organization (WHO) diagnostic criteria for myeloproliferative neoplasms.
- Requires treatment in order to lower platelet count based on patient age over 60 or history of thrombosis.
- Have failed at least one standard therapy
- Must have discontinued ET therapy at least 1 week (4 weeks for interferon) prior to study drug initiation.
Who cannot join
- Has undergone major surgery ≤4 weeks prior to starting study drug or has not recovered from side effects of such surgery.
- Unresolved treatment related toxicities from prior therapies (unless resolved to ≤ Grade 1).
- Uncontrolled active infection.
- Current use of prohibited medications
- Known HIV infection or active Hepatitis B or Hepatitis C virus infection
- Other hematologic/biochemistry requirements, as per protocol
- Use of investigational agent within last 14 days
- Pregnant or lactating females
Trial locations and contacts
26 sites in 7 countries.
26 sites in 7 countries
United States7 sites
Local Institution
Ann Arbor, Michigan, 48109
Cleveland Clinic
Cleveland, Ohio, 44195
Local Institution
Durham, North Carolina, 27710
Local Institution
Jacksonville, Florida, 32209
Local Institution
New York, New York, 10021
Local Institution
Pittsburgh, Pennsylvania, 15232
Local Institution
Seattle, Washington, 98109
Australia6 sites
Royal Adelaide Hospital
Adelaide, South Australia, 5000
Local Institution
Camperdown, New South Wales
Local Institution
Clayton, Victoria, 3168
Local Institution
Herston, Brisbane
Local Institution
Southport, Queensland
Local Institution
St Leonards, New South Wales, 2065
Italy4 sites
Local Institution
Alessandria
Local Institution
Bologna
CRIMM; Centro Ricerca e Innovazione delle Malattia Mieloproliferative, Azienda ospedaliera Universitaria Careggi
Florence, 50139
Local Institution
Varese
United Kingdom4 sites
Local Institution
London, NW1
Guys and St Thomas Hospital
London, SE1 9RT
Local Institution
London, W12
Local Institution
Oxford
Germany2 sites
Department of Hematology and Stem Cell Transplantation, West German Cancer Center (WTZ)
Essen, 45147
Local Institution
Jena
About this study
Official title: A Phase 2 Multi-Center, Open Label Study to Assess the Safety, Efficacy and Pharmacodynamics of IMG-7289 in Patients With Essential Thrombocythemia
This is a Phase 2b open label study of an orally administered LSD1 inhibitor, Bomedemstat (MK-3543, formerly called IMG-7289), in patients with essential thrombocythemia.
This study investigates the following:
- The safety and tolerability of Bomedemstat
- The pharmacodynamic effect of Bomedemstat
Read the detailed description
This is a Phase 2 multi-center, open-label study evaluating the safety, efficacy and pharmacodynamics of Bomedemstat administered orally once daily in patients with essential thrombocythemia (ET). Patients will be dosed with Bomedemstat for 169 consecutive days in the Initial Treatment Period (ITP). Qualifying patients may continue to receive Bomedemstat in the Additional Treatment Period (ATP).
Safety will be evaluated by clinical assessments of safety parameters i.e., safety laboratory testing, adverse event reporting, physical examination and vital sign assessments. Pharmacodynamics will be evaluated by hematology assessment, patient reported symptom burden, change in spleen size by palpation and other measures.
To ensure safety, a Safety Advisory Board will perform periodic reviews of safety parameters and pharmacodynamic markers.
- Conditions
- Essential Thrombocythemia
- Being tested
- Bomedemstat
- Medical subject headings
- Thrombocythemia, Essential
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
BomedemstatDrug
Also called IMG-7289, MK-3543
Oral administration
| Study group | Role | What they receive |
|---|---|---|
| Bomedemstat | Experimental | Bomedemstat administered daily for 169 consecutive days Receives: Drug: Bomedemstat |
What is being measured
The primary outcome is the main question the study is designed to answer.
Number of Participants Who Experienced an Adverse Event (AE)
An AE is any undesirable physical, psychological or behavioral effect experienced by a participant during the study, in conjunction with the use of the drug or biologic, whether or not product related. This includes any untoward signs or symptoms experienced by the participant from the time of first dose with study treatment until completion of the study. The number of participants who experienced an AE is reported.
Measured: Up to approximately 30 months
Number of Participants Who Discontinued Study Treatment Due to an AE
An AE is any undesirable physical, psychological or behavioral effect experienced by a patient during participation in the study, in conjunction with the use of the drug or biologic, whether or not product-related. This includes any untoward signs or symptoms experienced by the patient from the time of first dose with study treatment until completion of the study. The number of participants who discontinued study treatment due to an AE is reported.
Measured: Up to approximately 28 months
Percentage of Participants With Platelet Count ≤400 k/μL at Day 169
Blood samples were collected at pre-specified timepoints to determine platelet counts. The percentage of participants who achieved reduction in platelet count to ≤400k/μL in the absence of new thrombolytic events is reported.
Measured: Up to day 169
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted5 Feb 2020
- Study start8 Sep 2020
- Primary completion23 Mar 2023
- Study completion23 Mar 2023
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Posted resultsParticipant flow, outcome measures and adverse events reported by the sponsor.
- Publications (1)Papers the sponsor has linked to this study.
- Other trials for Essential ThrombocythemiaStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 2
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Single group
- Model description
- Multi-center, open-label
- Masking
- None (open label)
- Enrolment
- 73 participants (actual)
Sponsor and investigators
- Lead sponsor
- Imago BioSciences, Inc., a subsidiary of Merck & Co., Inc., (Rahway, New Jersey USA)
- Sponsor type
- Industry (pharma, biotech, devices)
- Responsible party
- Sponsor
- Investigators
- Medical Director, Study director, Merck Sharp & Dohme LLC
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT04254978
- Sponsor's protocol ID
- IMG-7289-CTP-201
- Other IDs
- MK-3543-003, 2019-003659-13, 2019
- Status last verified
- Apr 2026
- First submitted
- 15 Jan 2020
- Last updated
- 4 May 2026
- Results posted
- Yes, on ClinicalTrials.gov
- Data monitoring committee
- Yes
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- No
Publications
Gill H, Palandri F, Ross DM, Gothert JR, Cochrane T, Larsen SR, Halpern AB, Shortt J, Rossetti JM, Liang J, Marchetti M, Wilson AJ, Innes AJ, Hanna M, Vianelli N, Stevenson WS, Vannucchi AM, Kleppe M, Flynn J, Natsoulis G, Harrison CN, Rienhoff HY Jr. Phase 2 study of the lysine-specific demethylase 1 inhibitor bomedemstat for essential thrombocythemia. Blood Adv. 2026 May 26;10(10):3494-3504. doi: 10.1182/bloodadvances.2025017575.
PubMed 41758981
Study at a glance
From the registry record, last updated by the sponsor on 4 May 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- A Phase 2 Multi-Center, Open Label Study to Assess the Safety, Efficacy and Pharmacodynamics of IMG-7289 in Patients With Essential Thrombocythemia
- ClinicalTrials.gov ID
- NCT04254978
- Acronym / sponsor ID
- IMG-7289-CTP-201
- Conditions
- Essential Thrombocythemia
- Phase
- Phase 2
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 73 participants (actual)
- Lead sponsor
- Imago BioSciences, Inc., a subsidiary of Merck & Co., Inc., (Rahway, New Jersey USA)Industry (pharma, biotech, devices)
- Study start
- 8 Sep 2020 (actual)
- Primary completion
- 23 Mar 2023 (actual)
- Study completion
- 23 Mar 2023 (actual)
- First posted
- 5 Feb 2020 (actual)
- Results
- Posted 2 Apr 2024
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
This is a Phase 2b open label study of an orally administered LSD1 inhibitor, Bomedemstat (MK-3543, formerly called IMG-7289), in patients with essential thrombocythemia.
This study investigates the following:
- The safety and tolerability of Bomedemstat
- The pharmacodynamic effect of Bomedemstat
Detailed description
This is a Phase 2 multi-center, open-label study evaluating the safety, efficacy and pharmacodynamics of Bomedemstat administered orally once daily in patients with essential thrombocythemia (ET). Patients will be dosed with Bomedemstat for 169 consecutive days in the Initial Treatment Period (ITP). Qualifying patients may continue to receive Bomedemstat in the Additional Treatment Period (ATP).
Safety will be evaluated by clinical assessments of safety parameters i.e., safety laboratory testing, adverse event reporting, physical examination and vital sign assessments. Pharmacodynamics will be evaluated by hematology assessment, patient reported symptom burden, change in spleen size by palpation and other measures.
To ensure safety, a Safety Advisory Board will perform periodic reviews of safety parameters and pharmacodynamic markers.
Study design
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
- Model description
- Multi-center, open-label
| Arm | Type | Receives |
|---|---|---|
| Bomedemstat | Experimental | Drug: BomedemstatBomedemstat administered daily for 169 consecutive days |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (4 listed)
- Diagnosis of Essential Thrombocythemia per World Health Organization (WHO) diagnostic criteria for myeloproliferative neoplasms.
- Requires treatment in order to lower platelet count based on patient age over 60 or history of thrombosis.
- Have failed at least one standard therapy
- Must have discontinued ET therapy at least 1 week (4 weeks for interferon) prior to study drug initiation.
Key exclusion criteria (8 listed)
- Has undergone major surgery ≤4 weeks prior to starting study drug or has not recovered from side effects of such surgery.
- Unresolved treatment related toxicities from prior therapies (unless resolved to ≤ Grade 1).
- Uncontrolled active infection.
- Current use of prohibited medications
- Known HIV infection or active Hepatitis B or Hepatitis C virus infection
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| BomedemstatAlso: IMG-7289, MK-3543Oral administration | Drug | Bomedemstat |
Primary outcome
Number of Participants Who Experienced an Adverse Event (AE)
Time frame: Up to approximately 30 months
An AE is any undesirable physical, psychological or behavioral effect experienced by a participant during the study, in conjunction with the use of the drug or biologic, whether or not product related. This includes any untoward signs or symptoms experienced by the participant from the time of first dose with study treatment until completion of the study. The number of participants who experienced an AE is reported.
Number of Participants Who Discontinued Study Treatment Due to an AE
Time frame: Up to approximately 28 months
An AE is any undesirable physical, psychological or behavioral effect experienced by a patient during participation in the study, in conjunction with the use of the drug or biologic, whether or not product-related. This includes any untoward signs or symptoms experienced by the patient from the time of first dose with study treatment until completion of the study. The number of participants who discontinued study treatment due to an AE is reported.
Percentage of Participants With Platelet Count ≤400 k/μL at Day 169
Time frame: Up to day 169
Blood samples were collected at pre-specified timepoints to determine platelet counts. The percentage of participants who achieved reduction in platelet count to ≤400k/μL in the absence of new thrombolytic events is reported.
Results and safety
Loading the posted results from ClinicalTrials.gov…
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 4 May 2026.
- Posted resultsParticipant flow, baseline, all outcome measures and adverse events.
- Results publication: PubMed 41758981Gill H, Palandri F, Ross DM, Gothert JR, Cochrane T, Larsen SR, Halpern AB, Shortt J, Rossetti JM, Liang J, Marchetti M, Wilson AJ, Innes AJ, Hanna M, Vianelli N, Stevenson WS, Vannucchi AM, Kleppe M, Flynn J, Natsoulis G, Harrison CN, Rienhoff HY Jr. Phase 2 study of the lysine-specific demethylase 1 inhibitor bomedemstat for essential thrombocythemia. Blood Adv. 2026 May 26;10(10):3494-3504. doi: 10.1182/bloodadvances.2025017575.
- Merck Clinical Trials InformationLink provided by the sponsor.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Medical Director study director
Merck Sharp & Dohme LLC
26 sites in 7 countries: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 2 study testing Bomedemstat in people with Essential Thrombocythemia, run by Imago BioSciences, Inc., a subsidiary of Merck & Co., Inc., (Rahway, New Jersey USA) at 26 sites in 7 countries.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 4 inclusion and 8 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 4 May 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 26 sites in United States, Australia, Italy, United Kingdom, Germany and 2 more countries. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Phase 2 studies give the treatment to a larger group to see whether it has the intended effect and to keep checking safety.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
Yes. Results are posted in the registry (first posted 2 Apr 2024). A summary is in the For doctors view, and the full results are on ClinicalTrials.gov.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Number of Participants Who Experienced an Adverse Event (AE) (time frame: Up to approximately 30 months). The study lists 3 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT04254978, which also lists 1 linked publication.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 4 May 2026.