DB-67 in Myelodysplastic Syndrome (MDS)

The Study Drug:

AR-67 is designed to block the function of an important protein (topoisomerase I) in cancer
cells that helps repair damage to DNA (the genetic material of cells). When this protein is
blocked, cancer cells may die.

Study Drug Administration:

If you are found to be eligible to take part in this study, on Days 1-5 of each 28-day study
"cycle", you will receive AR-67 through a needle into the vein or a central venous catheter
(CVC) into your vein over about 1 hour. A CVC is a sterile flexible tube that will be
placed into a large vein while you are under local anesthesia. Your doctor will explain
this procedure to you in more detail, and you will be required to sign a separate consent
form for this procedure.

On Days 6-28 of each cycle, you will receive no study drug.

If your doctor thinks it is needed, your study cycles may be shortened so that you will
receive the study drug more often.

Study Visits:

Before the start of each cycle, you will have a physical exam and your medical history will
be recorded.

Once or twice every week of Cycle 1 and then every 2-4 weeks after that, blood (about 2
tablespoons each time) will be drawn for routine tests.

At the end of Cycle 1, and then once every 1-3 cycles, you will have a bone marrow aspirate
and/or biopsy to check the status of the disease.

If you take the study drug for more than 12 months, you will have bone marrow aspirates and
biopsies every 6-12 months. They may be performed more often if the study doctor thinks it
is needed.

Length of Study:

You may continue taking the study drug for as long as you are benefitting. You will be taken
off study if the disease gets worse or you experience intolerable side effects.

This is an investigational study. AR-67 is not FDA approved or commercially available. At
this time, AR-67 is only being used in research.

Up to 25 participants will take part in this study. All will be enrolled at M. D. Anderson.