Bomedemstat (IMG-7289/MK-3543) in Participants With Myelofibrosis (IMG-7289-CTP-102/MK-3543-002)

A Multi-Center, Open Label Study to Assess the Safety, Steady-State Pharmacokinetics and Pharmacodynamics of IMG-7289 in Patients With Myelofibrosis

This is a Phase 1/2 open-label study to evaluate the safety, tolerability, steady-state pharmacokinetic (PK) and pharmacodynamics (PD) of a lysine-specific demethylase 1 (LSD1) inhibitor, bomedemstat (IMG-7289/MK-3543), administered orally once daily in participants with myelofibrosis.

The primary hypothesis is that bomedemstat is a safe and tolerable orally available agent when administered to participants with myelofibrosis including primary myelofibrosis (PMF), post-polycythaemia vera-myelofibrosis (PPVMF), and post-essential thrombocythaemia-myelofibrosis (PET-MF) (collectively referred to as 'MF'); inhibition of LSD1 by bomedemstat will reduce spleen size in those with splenomegaly, improve haematopoiesis and reduce constitutional symptoms associated with these disorders.

This study initiated as a Phase 1/2a study assessing the safety of the starting dose, an 85-day duration of treatment, and the PK and PD effects of bomedemstat, with transition to a Phase 2b study incorporating changes supported by the Phase 1/2a data.

Inclusion Criteria:

• >18 years of age
• Diagnosis of either PMF per World Health Organization (WHO) diagnostic criteria for myeloproliferative neoplasms, or PPV-MF or PET-MF per the International Working Group for Myelofibrosis Research and Treatment
• High or intermediate-2 risk disease

Exclusion Criteria:

• Receiving other treatments for the condition (with exceptions and time limits)
• Major surgery in last 4 weeks, any surgery in the last 2 weeks
• History of, or scheduled, hematopoietic stem cell transplant within 24 weeks of Screening
• History of splenectomy
• Current use of prohibited medications
• A concurrent second active and nonstable malignancy
• Known human immunodeficiency virus infection or active Hepatitis B or Hepatitis C virus infection
• Other hematologic/biochemistry requirements, as per protocol
• Use of an investigational agent within last 14 days
• Pregnant or lactating females