If you choose to join this study, you will go through a screening period to find out if you are eligible. During this screening period, you will:

• Have a physical exam
• Have a heart scan (ECG)
• Have blood draws and give urine samples
• Have bone marrow samples taken
• Have images taken (X-ray or CT scan)

After screening, this study is divided into 2 different parts, Part 1 and Part 2:

• During Part 1, increasing doses of the study drug will be given to participants who have certain hematological malignancies
• During Part 2, a fixed dose of the study drug will be given to participants who have certain hematological malignancies based on the results of Part 1

The study drug period for Part 1 and Part 2 will consist of drug cycles, which will be 28 days. Subjects will take the study drug on Days 1 to 21 of each cycle (i.e., you will take the drug every day for 3 weeks, followed by 1 week of not taking the drug).

• During the first study drug cycle, you will have 4 visits
• Cycle 2 will have 4 visits
• Cycles 3 and onward will have 1 visit

More than 6 cycles of study drug will be allowed if you do not meet any stopping rules at the end of the first 6 cycles of study drug, and if you and your study doctor believe that you are benefiting from the study drug. Once you stop taking the study drug, we will schedule you for a series of follow-up visits to see how you are doing.