Ph II Study of Azacitidine in Myelofibrosis

Azacitidine is a drug that is designed to block certain genes in cancer cells whose job is to stop the function of the tumor-fighting genes. By blocking the "bad" genes, the tumor-fighting genes may be able to work better. If you are found to be eligible to take part in this study, you will be able to begin treatment with azacitidine. You will receive azacitidine as an injection under the skin once a day for 7 days in a row. This will be repeated every 4 weeks (4 weeks equals 1 cycle). The first cycle of azacitidine will be given at M. D. Anderson, in an outpatient setting. Later cycles of treatment courses may be given at M. D. Anderson or by a cancer doctor in your community. You may receive up to 12 cycles of treatment if you are responding well to treatment. You will be taken off study if your disease gets worse or intolerable side effects occur. Once you go off study, you will receive follow-up as is standard of care for your disease. This is an investigational study. Azacitidine is FDA approved for the treatment of myelodysplastic syndrome. Its use in this study is experimental. A total of up to 34 patients will take part in this study. All will be enrolled at M. D. Anderson.