5-azacytidine is designed to turn off the growth of cancer cells. This may be increased by ara-C, which is designed to kills leukemia cells by helping to stop the cells from dividing.~If you are found to be eligible to take part in this study, you will be assigned to a treatment group. You will be randomly assigned (as in the toss of a coin) to one of the 4 treatment groups. The first 3 to 6 patients will be assigned to Group 1. If no serious side effects are experienced, the next 3 to 6 patients will be assigned to Group 2. If no serious side effects are experienced, the next 3 to 6 patients will be assigned to Group 3. If no serious side effects are experienced, the next 3 to 6 patients will be assigned to Group 4.~If you are in Group 1, you will receive low-dose 5-azacytidine as an infusion by vein over 20 to 30 minutes every day for 7 days. You will also receive low-dose ara-C as a continuous infusion by vein for 7 days.~If you are in Group 2, you will receive high-dose 5-azacytidine as an infusion by vein over 20 to 30 minutes every day for 7 days. You will also receive low-dose ara-C as a continuous infusion by vein for 7 days.~If you are in Group 3, you will receive low-dose 5-azacytidine as an infusion by vein over 20 to 30 minutes every day for 7 days. You will also receive high-dose ara-C as a continuous infusion by vein for 3 days (if you are 65 years of age or older) or for 4 days (if you are younger than 65 years of age).~If you are in Group 4, you will receive high-dose 5-azacytidine as an infusion by vein over 20 to 30 minutes every day for 7 days. You will also receive high-dose ara-C as a continuous infusion by vein for 3 days (if you are 65 years of age or older) or for 4 days (if you are younger than 65 years of age).~Each group's treatment will be repeated every 4 to 8 weeks (this is considered 1 cycle of treatment), depending on your blood counts and how well your bone marrow is recovering. You will receive at least 2 cycles of treatment. You will continue to receive treatment, unless your disease gets worse or if you experience intolerable side effects. If your disease gets worse or you experience intolerable side effects, you may be taken off this study.~This is an investigational study. 5-azacytidine has been approved by the FDA for the treatment of MDS. Ara-C has been approved by the FDA for the treatment of AML. Up to 80 patients will take part in this study. All will be enrolled at M. D. Anderson.
The goal of this clinical research study is to find the highest tolerable dose of Azacytidine (5-azacytidine) combined with cytosine arabinoside (ara-C) for the treatment of patients with relapsed and/or refractory Acute Myeloid Leukemia (AML) or high-risk Myelodysplastic Syndrome (MDS). The safety and effectiveness of this treatment combination will also be studied.