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)

August 11, 2026 updated by: Merck Sharp & Dohme LLC

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

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).

Study Overview

Status

Active, not recruiting

Conditions

Intervention / Treatment

Study Type

Interventional

Enrollment (Estimated)

340

Phase

  • Phase 3

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • Argentina
    • Buenos Aires
      • Pilar, Buenos Aires, Argentina, B1629AHJ
        • Hospital Universitario Austral ( Site 0104)
    • Buenos Aires F.D.
      • ABB, Buenos Aires F.D., Argentina, C1199ABB
        • Hospital Italiano de Buenos Aires ( Site 0105)
    • Tucumán Province
      • San Miguel de Tucumán, Tucumán Province, Argentina, T4000IKO
        • C.I.C.E. 9 de Julio ( Site 1001)
  • Australia
    • New South Wales
      • Camperdown, New South Wales, Australia, 2050
        • Royal Prince Alfred Hospital ( Site 1100)
      • Liverpool, New South Wales, Australia, 2170
        • Liverpool Hospital-Haematology ( Site 0501)
      • St Leonards, New South Wales, Australia, 2065
        • Royal North Shore Hospital ( Site 0003)
      • Waratah, New South Wales, Australia, 2298
        • Calvary Mater Newcastle ( Site 0505)
    • South Australia
      • Adelaide, South Australia, Australia, 5000
        • Royal Adelaide Hospital-Haematology Clinical Trials Unit ( Site 0001)
    • Victoria
      • Clayton, Victoria, Australia, 3168
        • Monash Health-Haematology Research ( Site 0006)
      • Melbourne, Victoria, Australia, 3021
        • Western Health-Sunshine & Footscray Hospitals-Cancer Services-Cancer Research ( Site 0502)
    • Western Australia
      • Perth, Western Australia, Australia, 6000
        • Royal Perth Hospital-Haematology ( Site 0504)
  • Belgium
      • Antwerp, Belgium, 2030
        • ZAS Cadix ( Site 1200)
  • Canada
    • Alberta
      • Edmonton, Alberta, Canada, T6G 2B7
        • University Of Alberta Hospital ( Site 1504)
    • New Brunswick
      • Moncton, New Brunswick, Canada, E1C 6Z8
        • The Moncton Hospital-Oncology ( Site 1500)
  • China
    • Anhui
      • Bengbu, Anhui, China, 233004
        • The First Afflilated Hospital of Bengbu Medical College ( Site 3509)
      • Hefei, Anhui, China, 230071
        • Anhui Provincial Hospital ( Site 3513)
    • Beijing Municipality
      • Beijing, Beijing Municipality, China, 100191
        • Peking University Third Hospital-Hematology ( Site 3502)
      • Beijing, Beijing Municipality, China, 100730
        • Peking Union Medical College Hospital ( Site 3531)
    • Fujian
      • Quanzhou, Fujian, China, 362000
        • The Second Affiliated Hospital Of Fujian Medical University ( Site 3525)
      • Xiamen, Fujian, China, 361003
        • The First Affiliated hospital of Xiamen University ( Site 3515)
    • Guangdong
      • Guangzhou, Guangdong, China, 510120
        • Sun Yat-sen Memorial Hospital of Sun Yat-sen University ( Site 3524)
      • Guangzhou, Guangdong, China, 510515
        • Southern Medical University Nanfang Hospital-Department of Hematopathology ( Site 3511)
    • Hebei
      • Shijiazhuang, Hebei, China, 050031
        • The First Hospital of Hebei Medical University ( Site 3510)
    • Henan
      • Zhengzhou, Henan, China, 450008
        • Henan Cancer Hospital-hematology department ( Site 3504)
    • Hubei
      • Wuhan, Hubei, China, 430022
        • Wuhan Union Hospital ( Site 3500)
    • Jiangsu
      • Nanjing, Jiangsu, China, 210029
        • Jiangsu Province Hospital ( Site 3507)
      • Nantong, Jiangsu, China, 226001
        • Affiliated Hospital of Nantong University ( Site 3527)
    • Jiangxi
      • Nanchang, Jiangxi, China, 330209
        • The First affiliated hospital of Nanchang University (Xianghu campus) ( Site 3505)
    • Jilin
      • Changchun, Jilin, China, 130021
        • The First Hospital of Jilin University-Hematology ( Site 3526)
    • Shaanxi
      • Xi'an, Shaanxi, China, 710068
        • Shaanxi provincial people's hospital ( Site 3516)
    • Shandong
      • Jinan, Shandong, China, 250013
        • Jinan Central Hospital ( Site 3523)
    • Shanghai Municipality
      • Shanghai, Shanghai Municipality, China, 200032
        • Zhongshan Hospital,Fudan University-Hematology ( Site 3530)
      • Shanghai, Shanghai Municipality, China, 200040
        • Huashan Hospital, Fudan University ( Site 3529)
    • Sichuan
      • Chengdu, Sichuan, China, 610041
        • West China Hospital, Sichuan University ( Site 3518)
    • Tianjin Municipality
      • Tianjin, Tianjin Municipality, China, 300020
        • Institute of hematology&blood disease hospital ( Site 3501)
    • Zhejiang
      • Hangzhou, Zhejiang, China, 310006
        • The first Affiliated Hospital, Zhejiang University School of Medicine ( Site 3508)
      • Yiwu, Zhejiang, China, 322000
        • Zhejiang University School of Medicine-The Fourth Affiliated Hospital ( Site 3517)
  • Colombia
    • Antioquia
      • Medellín, Antioquia, Colombia, 050030
        • Fundacion Colombiana de Cancerología Clinica Vida ( Site 1403)
    • Bogota D.C.
      • Bogotá, Bogota D.C., Colombia, 110121
        • Los Cobos Medical Center ( Site 1404)
    • Departamento de Córdoba
      • Montería, Departamento de Córdoba, Colombia, 230002
        • IMAT S.A.S ( Site 1401)
  • France
      • Paris, France, 75010
        • Hôpital Saint-Louis-Centre d'Investigations Cliniques ( Site 0405)
    • Brittany Region
      • Rennes, Brittany Region, France, 35000
        • Centre Hospitalier Universitaire de Rennes - Hôpital Pontchaillou ( Site 0417)
    • Indre-et-Loire
      • Tours, Indre-et-Loire, France, 37000
        • Centre Hospitalier Régional Universitaire de Tours - Hôpital-Hématologie et Thérapie Cellulaire ( Site 0413)
    • Limousin
      • Limoges, Limousin, France, 87042
        • Centre Hospitalier Universitaire de Limoges - Hôpital Dupuyt-Hématologie Clinique et Thérapie Cellu ( Site 1701)
    • Lorraine
      • Vandœuvre-lès-Nancy, Lorraine, France, 54511
        • Centre Hospitalier Régional Universitaire de Nancy - Hôpitaux de Brabois-HEMATOLOGY ( Site 0407)
    • Nord
      • Roubaix, Nord, France, 59100
        • Centre Hospitalier de Roubaix ( Site 1703)
    • Rhone
      • Pierre-Bénite, Rhone, France, 69310
        • centre hospitalier lyon sud ( Site 0406)
    • Île-de-France Region
      • Paris, Île-de-France Region, France, 75571
        • Hôpital Saint Antoine-Service d'Hématologie et de Thérapie Cellulaire ( Site 1702)
  • Germany
    • North Rhine-Westphalia
      • Aachen, North Rhine-Westphalia, Germany, 52074
        • Universitätsklinikum Aachen ( Site 1801)
    • Saxony
      • Dresden, Saxony, Germany, 01307
        • Universitaetsklinikum Carl Gustav Carus Dresden-Medical Dept I - Medical Oncology ( Site 0402)
    • Saxony-Anhalt
      • Halle, Saxony-Anhalt, Germany, 06120
        • Universitätsklinikum Halle ( Site 0401)
  • Hong Kong
      • Hksar, Hong Kong
        • Queen Mary Hospital ( Site 1901)
  • Hungary
      • Budapest, Hungary, 1088
        • Semmelweis Egyetem-Belgyógyászati és Hematológiai Klinika ( Site 0708)
      • Debrecen, Hungary, 4032
        • Debreceni Egyetem Klinikai Kozpont-Belgyógyászati Klinika (Haematologia) ( Site 0707)
    • Győr-Moson-Sopron
      • Győr, Győr-Moson-Sopron, Hungary
        • Petz Aladar Egyetemi Oktato Korhaz ( Site 2000)
    • Szabolcs-Szatmár-Bereg
      • Nyíregyháza, Szabolcs-Szatmár-Bereg, Hungary, 4400
        • Szabolcs-Szatmár-Bereg Megyei Kórházak és Egyetemi Oktatókór-Haematológia osztály ( Site 0706)
  • Israel
      • Beersheba, Israel, 8410101
        • Soroka Medical Center ( Site 2100)
      • Haifa, Israel, 3109601
        • Rambam Health Care Campus ( Site 2102)
      • Haifa, Israel, 3436212
        • Carmel Hospital ( Site 0906)
      • Jerusalem, Israel, 9112001
        • Hadassah Medical Center ( Site 0904)
      • Petah Tikva, Israel, 4941492
        • Rabin Medical Center ( Site 0905)
      • Ramat Gan, Israel, 5265601
        • Sheba Medical Center ( Site 2101)
      • Tel Aviv, Israel, 6423906
        • Sourasky Medical Center ( Site 0902)
      • Ẕerifin, Israel, 7033001
        • Yitzhak Shamir Medical Center. ( Site 0901)
  • Italy
      • Alessandria, Italy, 15121
        • Azienda Ospedaliero-Universitaria SS. Antonio e Biagio e Cesare Arrigo ( Site 0034)
      • Ancona, Italy, 60126
        • Azienda Ospedaliero Universitaria delle Marche ( Site 0302)
      • Reggio Emilia, Italy, 42123
        • Arcispedale Santa Maria Nuova ( Site 0301)
      • Torino, Italy, 10128
        • Ospedale Mauriziano ( Site 0305)
      • Varese, Italy, 21100
        • Ospedale di Circolo e Fondazione Macchi Varese ( Site 2200)
    • Ferrara
      • Cona, Ferrara, Italy, 44124
        • Azienda Ospedaliero Universitaria di Ferrara ( Site 0304)
    • Forli-Cesena
      • Meldola, Forli-Cesena, Italy, 47014
        • IRCCS - Istituto Romagnolo per lo Studio dei Tumori (IRST) "Dino Amadori" ( Site 0308)
    • Lombardy
      • Milan, Lombardy, Italy, 20122
        • Fondazione IRCCS Cà Granda Ospedale Maggiore Policlinico ( Site 2201)
    • Tuscany
      • Florence, Tuscany, Italy, 50134
        • Azienda Ospedaliera Universitaria Careggi ( Site 0030)
      • Pisa, Tuscany, Italy, 56126
        • Azienda Ospedaliero Universitaria Pisana-UO Ematologia UNIV ( Site 0309)
    • Veneto
      • Castelfranco Veneto, Veneto, Italy, 31033
        • Istituto Oncologico Veneto IRCCS-Oncoematologia ( Site 0306)
  • Japan
      • Fukuoka, Japan, 812-8582
        • Kyushu University Hospital ( Site 3605)
      • Fukushima, Japan, 960-1295
        • Fukushima Medical University Hospital ( Site 3616)
      • Miyazaki, Japan, 889-1692
        • University of Miyazaki Hospital ( Site 3609)
      • Okayama, Japan, 700-8558
        • Okayama University Hospital ( Site 3604)
    • Aichi-ken
      • Toyoake, Aichi-ken, Japan, 470-1192
        • Fujita Health University Hospital ( Site 3613)
    • Chiba
      • Kashiwa, Chiba, Japan, 277-8577
        • National Cancer Center Hospital East ( Site 3610)
    • Ehime
      • Tōon, Ehime, Japan, 791-0295
        • Ehime University Hospital ( Site 3612)
    • Hokkaido
      • Sapporo, Hokkaido, Japan, 060-8648
        • Hokkaido University Hospital ( Site 3601)
    • Hyōgo
      • Kobe, Hyōgo, Japan, 650-0047
        • Kobe City Medical Center General Hospital ( Site 3603)
    • Ishikawa-ken
      • Kanazawa, Ishikawa-ken, Japan, 920-8641
        • Kanazawa University Hospital ( Site 3614)
    • Mie-ken
      • Tsu, Mie-ken, Japan, 514-8507
        • Mie University Hospital ( Site 3615)
    • Miyagi
      • Sendai, Miyagi, Japan, 983-8520
        • National Hospital Organization Sendai Medical Center ( Site 3617)
    • Osaka
      • Hirakata, Osaka, Japan, 573-1191
        • Kansai Medical University Hospital ( Site 3607)
      • Sakai, Osaka, Japan, 590-0197
        • Kindai University Hospital ( Site 3600)
    • Tokyo
      • Bunkyo-ku, Tokyo, Japan, 113-8431
        • Juntendo University Hospital ( Site 3611)
      • Bunkyo-ku, Tokyo, Japan, 113-8603
        • Nippon Medical School Hospital ( Site 3608)
    • Yamanashi
      • Chūō, Yamanashi, Japan, 409-3898
        • University of Yamanashi Hospital ( Site 3606)
  • Netherlands
      • Groningen, Netherlands, 9713 GZ
        • University Medical Center Groningen ( Site 2304)
      • Groningen, Netherlands, 9728 NT
        • Martini Ziekenhuis ( Site 2300)
    • North Holland
      • Hoofddorp, North Holland, Netherlands, 2134 TM
        • Spaarne Gasthuis - Hoofddorp-Oncology ( Site 2301)
    • South Holland
      • Dordrecht, South Holland, Netherlands, 3318 AT
        • Albert Schweitzer Ziekenhuis, locatie Dordwijk-Internal Medicine ( Site 2302)
  • New Zealand
      • Auckland, New Zealand, 0622
        • North Shore Hospital-Department of Haematology ( Site 0051)
      • Auckland, New Zealand, 2025
        • Aotearoa Clinical Trials ( Site 0050)
  • Poland
    • Silesian Voivodeship
      • Katowice, Silesian Voivodeship, Poland, 40-519
        • Pratia Onkologia Katowice ( Site 0702)
    • Świętokrzyskie Voivodeship
      • Kielce, Świętokrzyskie Voivodeship, Poland, 25-734
        • Swietokrzyskie Centrum Onkologii, Samodzielny Publiczny Zakl-Klinika Hematologii i Transplantacji S ( Site 2504)
  • Portugal
      • Braga, Portugal, 4710-243
        • Unidade Local de Saude de Braga - Hospital de Braga ( Site 0415)
      • Lisbon, Portugal, 1449-005
        • Unidade Local de Saude Lisboa Ocidental - Hospital de São Francisco Xavier ( Site 2600)
      • Porto, Portugal, 4200-072
        • Instituto Português de Oncologia do Porto Francisco Gentil, EPE ( Site 0414)
  • South Korea
      • Seoul, South Korea, 02841
        • Korea University Anam Hospital ( Site 0604)
      • Seoul, South Korea, 05505
        • Asan Medical Center ( Site 0603)
      • Seoul, South Korea, 06591
        • The Catholic Univ. of Korea Seoul St. Mary's Hospital ( Site 0606)
    • Kyonggi-do
      • Seongnam, Kyonggi-do, South Korea, 13620
        • Seoul National University Bundang Hospital-Hematology ( Site 0605)
  • Spain
      • Albacete, Spain, 02006
        • Hospital General Universitario de Albacete ( Site 0408)
      • Barcelona, Spain, 08035
        • Hospital Universitari Vall d'Hebron-Departamento de Oncologia- VHIO ( Site 0404)
      • Madrid, Spain, 28041
        • Hospital Universitario 12 de Octubre ( Site 2806)
      • Málaga, Spain, 29010
        • Hospital Universitario Virgen de la Victoria ( Site 0418)
      • Salamanca, Spain, 37007
        • Hospital Universitario de Salamanca - Complejo Asistencial U-Servicio de Hematologia ( Site 0419)
      • Valencia, Spain, 46017
        • Hospital Universitario Doctor Peset ( Site 0411)
    • Barcelona
      • Badalona, Barcelona, Spain, 08916
        • Hospital Germans Trias i Pujol-Instituto Catalán de Oncología de Badalona ( Site 0409)
      • L'Hospitalet Del Llobregat, Barcelona, Spain, 08908
        • Institut Català d'Oncologia - L'Hospitalet-Haematology Department ( Site 2801)
    • Catalonia
      • Barcelona, Catalonia, Spain, 08003
        • Hospital del Mar ( Site 2807)
      • Barcelona, Catalonia, Spain, 08036
        • HOSPITAL CLÍNIC DE BARCELONA ( Site 2800)
    • La Coruna
      • Santiago de Compostela, La Coruna, Spain, 19706
        • CHUS - Hospital Clinico Universitario ( Site 0421)
    • Madrid, Comunidad de
      • Madrid, Madrid, Comunidad de, Spain, 28034
        • Hospital Universitario Ramón y Cajal-Hematology ( Site 2803)
    • Malaga
      • Marbella, Malaga, Spain, 29603
        • Hospital Costa del Sol-Hematology Service ( Site 0412)
  • Sweden
    • Stockholm County
      • Huddinge, Stockholm County, Sweden, 141 86
        • Karolinska Universitetssjukhuset Huddinge ( Site 2900)
    • Örebro County
      • Örebro, Örebro County, Sweden, 701 85
        • Universitetssjukhuset Örebro ( Site 0403)
  • Taiwan
      • Kaohsiung City, Taiwan, 83301
        • Chang Gung Memorial Hospital at Kaohsiung-Division of Hematology and Oncology ( Site 3104)
      • Tainan, Taiwan, 704
        • National Cheng Kung University Hospital-Clinical Trial Center ( Site 3105)
      • Taipei, Taiwan, 10048
        • National Taiwan University Hospital ( Site 3101)
      • Taoyuan, Taiwan, 33305
        • Chang Gung Medical Foundation-Linkou Branch ( Site 3103)
    • Chiayi
      • Chiayi City, Chiayi, Taiwan, 613
        • Chang Gung Memorial Hospital- Chiayi ( Site 3102)
  • Turkey (Türkiye)
      • Ankara, Turkey (Türkiye), 06230
        • Hacettepe Universite Hastaneleri-Department of Hematology ( Site 3204)
      • Ankara, Turkey (Türkiye), 06620
        • Ankara UTF Cebeci Arastırma ve Uygulama Hastanesi ( Site 3210)
      • Ankara, Turkey (Türkiye), 06800
        • Ankara Bilkent Şehir Hastanesi ( Site 3201)
      • Antalya, Turkey (Türkiye), 07100
        • Antalya Egitim ve Arastırma Hastanesi ( Site 3207)
      • Edirne, Turkey (Türkiye), 22030
        • Trakya University Medical Faculty Hospital-Hematology ( Site 3200)
      • Istanbul, Turkey (Türkiye), 34214
        • Medipol Mega Universite Hastanesi-oncology ( Site 3203)
      • Kocaeli, Turkey (Türkiye), 41380
        • Kocaeli Üniversitesi-Hematology ( Site 3205)
      • Mersin, Turkey (Türkiye), 33440
        • VM Medical Park Mersin Hastanesi ( Site 3208)
      • Samsun, Turkey (Türkiye), 55270
        • Ondokuz Mayıs Universitesi-hematology ( Site 3206)
    • İzmir
      • Bornova, İzmir, Turkey (Türkiye), 35100
        • Ege Universitesi Hastanesi ( Site 3202)
  • United Kingdom
      • Manchester, United Kingdom, m20 4bx
        • The Christie NHS Foundation Trust ( Site 3307)
    • Cambridgeshire
      • Cambridge, Cambridgeshire, United Kingdom, CB2 2QQ
        • Addenbrooke's Hospital ( Site 3303)
    • Gloucestershire
      • Gloucester, Gloucestershire, United Kingdom, Gl1 3NN
        • Gloucestershire Royal Hospital ( Site 3302)
    • Great Britain
      • Lincoln, Great Britain, United Kingdom, LN2 5QY
        • Lincoln County Hospital ( Site 3310)
    • Lincolnshire
      • Boston, Lincolnshire, United Kingdom, PE21 9QS
        • Boston Pilgrim Hospital ( Site 3301)
    • London, City of
      • London, London, City of, United Kingdom, NW1 2PG
        • University College London Hospital ( Site 3300)
      • London, London, City of, United Kingdom, SE1 9RT
        • Guy's & St Thomas' NHS Foundation Trust ( Site 3305)
      • London, London, City of, United Kingdom, SE5 9RS
        • King's College Hospital ( Site 3308)
    • Newport
      • Gwent, Newport, United Kingdom, NP20 2UB
        • Royal Gwent Hospital ( Site 3304)
    • Windsor And Maidenhead
      • Windsor, Windsor And Maidenhead, United Kingdom, SL4 3HD
        • GenesisCare - Windsor ( Site 3309)
  • United States
    • Arizona
      • Glendale, Arizona, United States, 85304
        • Palo Verde Hematology/ Oncology Center, Ltd. ( Site 3496)
    • California
      • Glendale, California, United States, 91206
        • Los Angeles Cancer Network ( Site 3491)
      • Stanford, California, United States, 94305-5826
        • Stanford Cancer Institute ( Site 0107)
      • Torrance, California, United States, 90502
        • The Lundquist Institute ( Site 3423)
    • Colorado
      • Aurora, Colorado, United States, 80045
        • University of Colorado Anschutz Medical Campus ( Site 3425)
    • Massachusetts
      • Boston, Massachusetts, United States, 02111
        • Tufts Medical Center ( Site 3408)
    • Michigan
      • Ann Arbor, Michigan, United States, 48109
        • University of Michigan ( Site 0008)
      • Detroit, Michigan, United States, 48202
        • Henry Ford Hospital ( Site 3413)
    • Nevada
      • Las Vegas, Nevada, United States, 89102
        • Optum Care Cancer Center ( Site 3497)
    • New York
      • Buffalo, New York, United States, 14263
        • Roswell Park Cancer Institute ( Site 3421)
    • North Carolina
      • Durham, North Carolina, United States, 27710
        • Duke University Health System (DUHS) ( Site 0016)
      • Winston-Salem, North Carolina, United States, 27157
        • Wake Forest Baptist Health-Internal Medicine, Section on Hematology & Oncology ( Site 3400)
    • Oregon
      • Eugene, Oregon, United States, 97401
        • Oncology Associates of Oregon, P.C.(Willamette Valley Cancer Institute) (WVCI) ( Site 8000)
    • South Carolina
      • Charleston, South Carolina, United States, 29425
        • Medical University of South Carolina-Hollings Cancer Center ( Site 3426)
    • Virginia
      • Charlottesville, Virginia, United States, 22908
        • University of Virginia ( Site 3422)
      • Richmond, Virginia, United States, 23219
        • VCU Health Adult Outpatient Pavillion ( Site 3416)

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

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

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Single

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Bomedemstat
Participants will begin treatment at a dose of 50 mg of bomedemstat daily. Dosage will be adjusted either up or down within specified time parameters for each participant to the dose that provides sufficient exposure to safely inhibit thrombopoiesis to decrease platelet counts to the target range. All participants will be treated daily for up to 52 weeks and are eligible for an extended treatment phase up to an additional 156 weeks.
Drug: Bomedemstat
Oral Capsule
Other Names:
  • IMG-7289
  • MK-3543
  • Bomedemstat tosylate
Active Comparator: Best Available Therapy
Each participant will receive either anagrelide, busulfan, interferon alfa/pegylated interferon alfa 2a/pegylated interferon alfa 2b, or ruxolitinib as determined by investigator. All participants will be treated per respective approved product labels for up to 52 weeks. Participants receiving BAT for 52 weeks who stop responding to BAT are eligible to switch to bomedemstat and receive this for up to 156 weeks at the investigator's discretion.
Drug: Anagrelide
Oral Capsule
Drug: Ruxolitinib
Oral Tablet
Drug: Busulfan
Oral Tablet
Drug: Interferon alfa/pegylated interferon alfa 2a/pegylated interferon alfa 2b
Subcutaneous Solution

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Durable Clinicohematologic Response (DCHR) Rate
Time Frame: Up to approximately 52 weeks
DCHR rate is the percentage of participants with DCHR, defined as a confirmed reduction of platelet count to ≤400 × 10^9/L and absence of white blood cell (WBC) count elevation to >10 × 10^9/L locally assessed to be due to ET, starting by Week 24 and maintained for at least 24 weeks, 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.
Up to approximately 52 weeks

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Clinicohematologic Response (CHR) Rate
Time Frame: Up to approximately 52 weeks
CHR rate is the percentage of participants with CHR, defined as a confirmed reduction of platelet count to ≤400 × 10^9/L and absence of WBC count elevation to >10 × 10^9/L locally assessed to be due to ET, maintained for at least 12 weeks, and the absence of any thrombotic or major hemorrhagic events or disease progression to MF, MDS or AML by Week 52.
Up to approximately 52 weeks
Hematologic Response (HR) Rate
Time Frame: Up to approximately 52 weeks
HR rate is the percentage of participants with HR, HR is defined as the time from the first confirmed hematologic response to first documented evidence of confirmed platelet increase or confirmed WBC increase after latest confirmed hematologic response date.
Up to approximately 52 weeks
Change From Baseline in Patient-reported Outcomes Measurement Information System (PROMIS) Fatigue SF-7a Total Fatigue Score
Time Frame: Baseline and pre-specified timepoints through Week 52
The PROMIS Fatigue 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. The total score is used in the analysis and is obtained by summing keyed scores of all items. Scores can range from 7 to 35, with higher scores indicating greater fatigue.
Baseline and pre-specified timepoints through Week 52
Change From Baseline in Total Symptom Score as Measured on the MFSAF v4.0
Time Frame: Baseline and pre-specified timepoints through Week 52
The 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.
Baseline and pre-specified timepoints through Week 52
Duration of Durable Clinicohematologic Response (DODCHR)
Time Frame: Up to approximately 52 weeks
For participants who demonstrate DCHR, DODCHR is defined as the time from the first documented evidence of confirmed reduction of platelet and WBC counts 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.
Up to approximately 52 weeks
Duration of Clinicohematologic Response (DOCHR)
Time Frame: Up to approximately 52 weeks
For participants who demonstrate CHR, DOCHR is defined as the time from the first documented evidence of confirmed reduction of platelet and WBC counts until confirmed increase of platelet and WBC count to above acceptable threshold, thrombotic or major hemorrhagic events, or disease progression to MF, MDS or AML.
Up to approximately 52 weeks
Duration of Hematologic Response (DOHR)
Time Frame: Up to approximately 52 weeks
For participants who demonstrate HR, DOHR is defined as the time from the first confirmed hematologic response to first documented evidence of confirmed platelet increase or confirmed WBC increase after latest confirmed hematologic response date.
Up to approximately 52 weeks
Percentage of Participants with Thrombotic Events
Time Frame: Up to approximately 52 weeks
Thrombotic 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.
Up to approximately 52 weeks
Percentage of Participants with Major Hemorrhagic Events
Time Frame: Up to approximately 52 weeks
Major 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.
Up to approximately 52 weeks
Percentage of Participants with Disease Progression to Post-ET MF or MDS/AML
Time Frame: Up to approximately 52 weeks
Disease progression rate is the percentage of participants with disease progression, defined as the transformation to post-ET MF, MDS, or AML as assessed by the adjudication committee.
Up to approximately 52 weeks
Number of Participants with An Adverse Event (AE)
Time Frame: Up to approximately 52 weeks
An 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.
Up to approximately 52 weeks
Number of Participants Discontinuing From Study Therapy Due to an AE
Time Frame: Up to approximately 52 weeks
An 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.
Up to approximately 52 weeks

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Merck Sharp & Dohme LLC

Investigators

  • Study Director: Medical Director, Merck Sharp & Dohme LLC

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

Helpful Links

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

December 31, 2023

Primary Completion (Estimated)

July 30, 2027

Study Completion (Estimated)

August 18, 2028

Study Registration Dates

First Submitted

October 6, 2023

First Submitted That Met QC Criteria

October 6, 2023

First Posted (Actual)

October 12, 2023

Study Record Updates

Last Update Posted (Actual)

August 13, 2026

Last Update Submitted That Met QC Criteria

August 11, 2026

Last Verified

August 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 3543-006
  • IMG-7289-CTP-301 (Other Identifier: Imagobio)
  • MK-3543-006 (Other Identifier: MSD)
  • jRCT2031230658 (Registry Identifier: Japan Registry of Clinical Trials (jRCT))
  • U1111-1290-2942 (Registry Identifier: UTN)
  • 2023-504865-21-00 (Registry Identifier: EU CT)

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

YES

IPD Plan Description

https://trialstransparency.msdclinicaltrials.com/pdf/ProcedureAccessClinicalTrialData.pdf

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

Yes

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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