A Phase 2/3 interventional study of Bomedemstat and Ruxolitinib in Polycythemia Vera, sponsored by Merck Sharp & Dohme LLC. Recruiting at 5 sites in 3 countries. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-11-05.
Sponsored by Merck Sharp & Dohme LLC (part of Merck & Co., Inc) · Phase 2/3, Interventional, and Treatment
Researchers are looking for new ways to treat polycythemia vera (PV). People with PV may receive treatment to lower the number of red blood cells in the blood, but the usual treatments may not work for everyone. Researchers want to learn if a trial medicine called bomedemstat, also called MK-3543, can treat PV. In this study, researchers will compare bomedemstat to 2 usual treatments for PV.
The goal of this study is to learn if more participants who take bomedemstat reach healthy blood cell counts and avoid major health problems from PV, compared to those who receive a usual treatment.
278 studies on the registry are indexed under Polycythemia Vera; 53 are open to participants now.
This study's planned enrollment of 380 is above the median of 52 across 204 interventional studies indexed under Polycythemia Vera.
Browse Polycythemia Vera studies →Merck Sharp & Dohme LLC is the lead sponsor of 2,166 studies on the registry; 132 are open to participants now.
Of its 501 completed or terminated interventional studies of FDA-regulated products, 370 (74%) have results posted.
Counted across the registry records on this site, refreshed daily.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
The main inclusion criteria include but are not limited to the following:
Exclusion Criteria:
The main exclusion criteria include but are not limited to the following:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
The human immunodeficiency virus, which weakens the immune system.
Many studies now accept people whose HIV is controlled on treatment, judged by the viral load and the CD4 count. Check the limits this study sets.
Hepatitis B is a virus that infects the liver. These are separate tests: HBsAg positive usually means a current infection (a recent vaccination can briefly cause it too); total anti-HBc (HBcAb) positive means an infection now or in the past; HBV DNA measures how much virus is in the blood.
Some studies accept a past infection if HBV DNA is undetectable, sometimes with antiviral medicine during the study. Check what this study allows.
Hepatitis C is a virus that infects the liver. An HCV antibody test can stay positive after an infection has cleared (and is occasionally positive without one); an HCV RNA test shows whether the virus is there now.
After treatment, hepatitis C counts as cured when HCV RNA is still undetectable 12 weeks or more after the treatment ended. Studies often accept people cured this way.
Malignancy means cancer. Criteria about another or earlier malignancy ask whether you have had a different cancer, usually within a set number of years.
Some are commonly allowed, such as treated skin cancers other than melanoma and early cancers removed completely — check the exceptions this study lists.
HIV
The human immunodeficiency virus, which weakens the immune system.
Many studies now accept people whose HIV is controlled on treatment, judged by the viral load and the CD4 count. Check the limits this study sets.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Hepatitis B tests
Hepatitis B is a virus that infects the liver. These are separate tests: HBsAg positive usually means a current infection (a recent vaccination can briefly cause it too); total anti-HBc (HBcAb) positive means an infection now or in the past; HBV DNA measures how much virus is in the blood.
Some studies accept a past infection if HBV DNA is undetectable, sometimes with antiviral medicine during the study. Check what this study allows.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Hepatitis C tests
Hepatitis C is a virus that infects the liver. An HCV antibody test can stay positive after an infection has cleared (and is occasionally positive without one); an HCV RNA test shows whether the virus is there now.
After treatment, hepatitis C counts as cured when HCV RNA is still undetectable 12 weeks or more after the treatment ended. Studies often accept people cured this way.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Cancer (malignancy)
Malignancy means cancer. Criteria about another or earlier malignancy ask whether you have had a different cancer, usually within a set number of years.
Some are commonly allowed, such as treated skin cancers other than melanoma and early cancers removed completely — check the exceptions this study lists.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Participants will receive bomedemstat daily for up to approximately 52 weeks. Per protocol, dosage may be adjusted within specified time parameters for each participant to achieve and maintain protocol-specified platelet and hematocrit target ranges. Eligible participants who do not discontinue study treatment at Week 52, may continue to receive study treatment.
Drug: Bomedemstat
Participants will receive either ropeinterferon alfa-2b or ruxolitinib as determined by investigator. All participants will be treated per respective approved product labels for up to approximately 52 weeks.
Drug: Ruxolitinib · Drug: Ropeginterferon alfa-2b
Oral Capsule
Also known as: MK-3543, IMG-7289, Bomedemstat tosylate
Oral Tablet
Subcutaneous Solution
Clinicohematologic Response (CHR) Rate
CHR Rate is defined as all of the following: (i) a confirmed hematologic remission sustained for at least 12 consecutive weeks by Week 40 through Week 52, (ii) and absence of any of the following as assessed by the adjudication committee Week 52: thrombotic event; major hemorrhagic events; disease progression to myelofibrosis (MF) or myelodysplastic syndrome (MDS)/acute myeloid leukemia (AML). CHR will begin on the date of the first confirmed assessment achieving CHR criteria and will end on the earliest date of the following: 1) day of the first confirmed assessment not achieving CHR criteria, 2) date of first major hemorrhagic event or thrombotic event as assessed by the adjudication committee, or 3) disease progression as assessed by the adjudication committee. The CHR rate will be presented.
Time frame: Up to approximately Week 52
Clinicohematologic Response Sustained for a 24-Week Time Period (CHR24)
CHR24 is defined as all of the following: (i) a confirmed hematologic remission sustained for at least 24 consecutive weeks by Week 52, (ii) and absence of any of the following as assessed by the adjudication committee Week 52: thrombotic event; major hemorrhagic events; disease progression to MF or MDS/AML. CHR24 will begin on the date of the first confirmed assessment achieving CHR24 criteria and will end on the earliest date of the following: 1) day of the first confirmed assessment not achieving CHR24 criteria, 2) date of first major hemorrhagic event or thrombotic event as assessed by the adjudication committee, or 3) disease progression as assessed by the adjudication committee. The CHR24 will be presented.
Time frame: Up to approximately Week 52
Number of Participants Who Experience an Adverse Event (AE)
An AE is any untoward medical occurrence in a participant, temporally associated with the use of study treatment, whether or not considered related to the study treatment. The number of participants who experience AE will be reported.
Time frame: Up to approximately Week 52
Number of Participants Who Discontinue Study Treatment Due to an AE
An AE is any untoward medical occurrence in a participant, temporally associated with the use of study treatment, whether or not considered related to the study treatment. The number of participants who discontinue study treatment due to an AE will be reported.
Time frame: Up to approximately Week 52
Duration of Clinicohematologic Response Sustained for a 24-Week Time Period (DOCHR24)
For participants who show CHR24, DOCHR24 is defined as the time from the first confirmed hematologic remission to first documented evidence of: 1) confirmed platelet increase, confirmed WBC increase, or a required phlebotomy (defined as a confirmed HCT reduction) after latest confirmed hematologic remission date, 2) thrombotic event as assessed by the adjudication committee, 3) major hemorrhagic event as assessed by the adjudication committee, or 4) disease progression to MF or MDS/AML as assessed by the adjudication committee.
Time frame: Up to approximately Week 52
Duration of Clinicohematologic Response (DOCHR)
For participants who show CHR, DOCHR is defined as the time from the first confirmed hematologic remission to first documented evidence of: 1) confirmed platelet increase, confirmed WBC increase, or a required phlebotomy (defined as a confirmed HCT reduction) after latest confirmed hematologic remission date, 2) thrombotic event as assessed by the adjudication committee, 3) major hemorrhagic event as assessed by the adjudication committee, or 4) disease progression to MF or MDS/AML as assessed by the adjudication committee.
Time frame: Up to approximately Week 52
Duration of Hematologic Remission (DOHR)
For participants who show confirmed hematologic remission, DOHR is defined as the time from the first hematologic remission until loss of hematologic remission.
Time frame: Up to approximately Week 52
Number of Participants Who Experience Phlebotomies
Per protocol, a required phlebotomy is defined as confirmed hematocrit (HCT) ≥45% with a ≥3% increase from baseline HCT or confirmed HCT ≥48%. The number of participants who experienced phlebotomies will be presented.
Time frame: Up to approximately Week 52
Disease Progression Rate
Disease progression is defined as the transformation to post polycythemia vera myelofibrosis, myelodysplastic syndrome, or acute myeloid leukemia as assessed by the adjudication committee. The disease progression rate will be presented.
Time frame: Up to approximately Week 52
Number of Participants Who Experience Thrombotic Events
Thrombotic events are defined as new or recurrent acute myocardial infarction, unstable angina, stroke, transient ischemic attack (TIA), deep venous thrombosis (DVT), pulmonary embolism (PE), thrombotic digital ischemia, other thrombotic events such as peripheral limb ischemia or Budd-Chiari syndrome assessed to be due to underlying polycythemia vera (PV), and other vascular occlusive events such as symptoms of cardiac, abdominal, or peripheral limb ischemia supported by objective evidence of vessel disease and/or ischemia. The number of participants who experience thrombotic events will be presented.
Time frame: Up to approximately Week 52
Number of Participants Who Experience Major Hemorrhagic Events
Major hemorrhagic events include but are not limited to fatal bleeding, symptomatic bleeding in a critical area or organ (including intracranial, intraspinal, intraocular, retroperitoneal, intra-articular, pericardial, or intramuscular with compartment syndrome), or bleeding causing a decrease in hemoglobin of 2 g/dL or more or leading to transfusion of 2 or more units of whole blood or red cells, and clinically relevant non-major bleeding events leading to hospitalization or increased level of care or clinically important bleeding prompting a face-to-face medical evaluation.
Time frame: Up to approximately Week 52
Change From Baseline in Myelofibrosis Symptom Assessment Form version 4.0 (MFSAF v4) Total Symptom Score
The MFSAF v4.0 is a 7-item participant-reported symptom assessment that 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. The MFSAF v4.0 7-day recall format is used. Individual symptoms are assessed on an 11-point numeric rating scale with a total symptom score range of 0 (absent) to 70 (worst imaginable). The change from baseline in MFSAF total score for all symptoms will be presented
Time frame: Up to approximately Week 52
Change From Baseline in Patient-Reported Outcomes Measurement Information System (PROMIS) Fatigue Short Form (SF) 7a Total Fatigue Score
The PROMIS Fatigue SF 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). A total score is obtained by summing the responses to the seven items \[range 7 (never) to 35 (always)\] and converting to a standardized T-score. The change from baseline in PROMIS Fatigue SF-7a Total Fatigue Score will be presented.
Time frame: Up to approximately Week 52
Plan to share: Yes — https://trialstransparency.msdclinicaltrials.com/pdf/ProcedureAccessClinicalTrialData.pdf
Data sharing details ↗ · externaldatasharing-msd.com
No publications or documents are linked to this record.
Started Oct 2026 (actual). Primary completion is estimated for Jun 2032, 67 months after the start.
Start moved 3 times since we started tracking on Sep 25, 2026: Sep 2026 → Oct 2026, last on Nov 5, 2026.
Earlier changes are on the record history on ClinicalTrials.gov ↗
How these figures are worked out, and which studies are left out of them.
From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
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Studies of the drug tested here: Bomedemstat