Azacitidine and Decitabine

Another term for myelodysplastic syndrome is bone marrow failure. The bone marrow is where components of blood such as red cells, platelets and white cells are made. In bone marrow failure, the ability for bone marrow to make these cells is decreased. In myelodysplastic syndrome, this decreased bone marrow function is believed to result from abnormalities that prevent the normal maturation process by which bone marrow cells develop into red blood cells, white blood cells and platelets. In myelodysplastic syndrome, these abnormal bone marrow cells occupy space in the bone marrow and prevent the function of remaining normal bone marrow cells. One approach to treating the abnormal growth of immature cells is to give chemotherapy which damages DNA within these cells and causes their death. Unfortunately, such therapy has side-effects, since even normal cells can be affected by the treatment. Both 5-azacitidine (5AZA) and decitabine (DEC) are FDA-approved to treat MDS. In this study, 5AZA and DEC will be administered using an alternating low doses schedule in an attempt to overcome the known mechanisms of resistance to the administration of 5AZA or DEC as single agents caused by automatic adaptive shifts in DNA metabolism.