This study is divided into 3 periods: the screening period, the study regimen period, and the follow-up period. If you choose to join the study, during the screening period you will:

• Have a physical exam
• Have blood draws
• Have a scan of your abdomen
• Have a bone marrow sample taken

If you are found to be eligible during the screening period, you will continue on to the study regimen period. During this period, you will get a random assignment (like a coin flip) to 1 of 2 study regimens:

• If you are assigned to study regimen A, you will get the study drug
• If you are assigned to study regimen B, you will get the best available therapy

Regardless of assignment, all study participants will:

• Visit our clinic for regular check-ups
• Have blood draws
• Answer questionnaires
• Keep a diary of your symptoms on an electronic device

Your study doctor will discuss the best available therapy options to treat you if you are assigned to regimen B. If your disease does not improve while you receive regimen B, you might be eligible to switch to regimen A and get the study drug. The study regimen period will last for as long as you continue to receive a positive benefit from either regimen. The follow-up period will begin when you or your study doctor decides to stop the study regimen. We will call you every 12 weeks during this period to see how you are doing and ask some questions.