Bomedemstat vs Hydroxyurea for Essential Thrombocythemia (MK-3543-007)

Merck Sharp & Dohme (MSD)

Status and phase: Enrolling; Phase 3

Conditions: Essential Thrombocythemia

Treatments: Drug: Bomedemstat; Drug: Hydroxyurea; Drug: Hydroxyurea placebo; Drug: Bomedemstat placebo

Study type: Interventional

Funder types: Industry

Identifiers

NCT06456346

2023-505232-36-00 (Registry Identifier)

jRCT2031240181 (Registry Identifier)

U1111-1290-8287 (Other Identifier)

MK-3543-007 (Other Identifier)

3543-007

Details and patient eligibility

About

The purpose of this study is to evaluate the efficacy and safety of bomedemstat compared with hydroxyurea in cytoreductive therapy naïve essential thrombocythemia (ET) participants for whom cytoreductive therapy is indicated. Its primary objective is to compare bomedemstat to hydroxyurea with respect to durable clinicohematologic response (DCHR). The primary hypothesis is that bomedemstat is superior to hydroxyurea with respect to DCHR.

Enrollment: 300 estimated patients

Sex: All

Ages: 18+ years old

Volunteers: No Healthy Volunteers

Inclusion criteria

• Diagnosis of Essential Thrombocythemia (ET) based on World Health Organization Criteria for myeloproliferative neoplasms, and an indication for cytoreductive therapy regardless of age or risk status
• 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 received no prior cytoreductive treatment for their ET
• Human Immunodeficiency Virus (HIV)-infected participants have well controlled HIV on antiretroviral therapy
• Participants who are Hepatitis B surface antigen (HBsAg) positive are eligible if they have received Hepatitis B Virus (HBV) antiviral therapy for at least 4 weeks and have undetectable HBV viral load
• Participants with history of Hepatitis C Virus (HCV) infection are eligible if HCV viral load is undetectable

Exclusion criteria

• History of any illness/impairment of gastrointestinal function that might interfere with drug absorption
• History of a malignancy, unless potentially curative treatment has been completed with no evidence of malignancy for 2 years
• HIV-infected participants with a history of Kaposi's sarcoma and/or Multicentric Castleman's Disease
• Has an active infection requiring systemic therapy
• Has had a major surgery <4 weeks prior to first dose of study intervention or has not recovered from side effects of major surgery >4 weeks prior to first dose

Trial design

Primary purpose: Treatment

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: Double Blind

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300 participants in 2 patient groups

Bomedemstat

Experimental group

Description:

Participants will receive active bomedemstat and hydroxyurea placebo daily for up to approximately 52 weeks. 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. Participants who complete treatment at Week 52 will be eligible to continue treatment in the extended treatment phase. Unblinding will occur and placebo discontinued once all participants have completed at least 52 weeks of therapy or otherwise discontinued.

Treatment:

Drug: Hydroxyurea placebo

Drug: Bomedemstat

Hydroxyurea

Active Comparator group

Description:

Participants will receive active hydroxyurea and bomedemstat placebo daily for up to 52 weeks. 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. Participants who complete treatment at Week 52 will be eligible to continue treatment in the extended treatment phase. Unblinding will occur and placebo discontinued once all participants have completed at least 52 weeks of therapy or otherwise discontinued.

Treatment:

Drug: Bomedemstat placebo

Drug: Hydroxyurea