- Pharmacokinetic (PK) blood tests: One of the main reasons for this study is to find the highest dose of the study drug combination that can be used safely without experiencing severe side effects to use for future studies. Once this dose is found (the maximum tolerated dose, or MTD), additional blood samples will be drawn from a small set of participants (about 5 participants total) to learn more about the activity of the study drugs in the body over a period of time, including the ways the study drugs are absorbed, distributed, and then released from the body. If participating in this group (the participant will be informed from the Investigator) these pharmacokinetic (PK) samples will be drawn repeatedly over a period of 24 hours on certain days: Blood samples will be drawn at 0, 15, 30, 60, 90 minutes, and 2, 4, 6, 8 and 24 hours after the study drug dosing on Days 1-2, 4-5, and 9 of Cycle 1.