Clinical Trials | 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

The University of Virginia Comprehensive Cancer Center seeks participants ages 18 and over with essential thrombocythemia (ET). ET is a type of blood disorder. In ET, the bone marrow makes too many platelets. Platelets are a type of blood cell. They help blood to clot. The purpose of this study is to test the safety and efficacy of the experimental drug: bomedemstat. Bomedemstat has not been approved by the Food and Drug Administration. It is also known as MK-3543 and IMG 7289. A standard treatment for ET is hydroxyurea. When hydroxyurea does not work well or causes too many side effects, people with ET often get other treatments, including anagrelide, busulfan, interferon, or ruxolitinib. In this trial, these are called the best available treatments. This trial will compare bomedemstat to the best available treatments. In this study, you will be randomly placed into one of two groups: Group 1, receiving bomedemstat daily in the form of a capsule, and Group 2, receiving the standard treatment. You, your trial doctor, and trial staff will know which group you are in. The most important risks or discomforts that you may expect from bomedemstat include change in the taste of foods or liquids, difficulty having a bowel movement, joint pain, low number of blood cells (platelets) that help to clot blood which may increase your risk of bleeding or bruising, feeling tired or low energy, diarrhea. Your ET may or may not get better as a result of your participation in this study. However, this study may also help doctors learn things that can help other people in the future. During the study you will undergo tests and procedures including: • Eye exam • 12-lead ECG • Blood for safety assessments and urine or serum for pregnancy • Bone marrow aspirate and biopsy • Fasting (refraining from eating food) For your initial treatment, you can get the trial drug up to 1 year and you will visit the trial site about: o Once every 2 weeks for the first 12 weeks o Then every 4 weeks If you complete the 1-year Initial Treatment Phase, you may have the option to continue trial treatment for up to 2 more years. This is called the Extended Treatment Phase. The trial doctor will discuss this with you. For questions, contact: [email protected]