• Determine the efficacy of azacitidine in patients with myelofibrosis (MF). [ Time Frame: December 2008 ] [ Designated as safety issue: No ]
  

• Evaluate the toxicities of azacitidine in patients with MF. [ Time Frame: December 2008 ] [ Designated as safety issue: Yes ]
  

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.

Before you can start treatment on this study, you will have what are called "screening tests." These tests will help the doctor decide if you are eligible to take part in the study. You will have a bone marrow biopsy and aspirate to check on the status of the disease. To collect a bone marrow biopsy, an area of the hip or chest bone is numbed with anesthetic and a small amount of bone marrow and bone is withdrawn through a large needle. To collect a bone marrow aspirate, an area of the hip or chest bone is numbed with anesthetic and a small amount of bone marrow is withdrawn through a large needle. Blood (about 4 teaspoons) will be drawn for routine tests. Women who are able to have children must have a negative blood-pregnancy test.

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. Pharmion Corporation will provide you with azacitidine free of charge while you are being treated on this study. The optional procedures will be free of charge to participants. You or your insurance will be responsible for the costs of all other tests and procedures. A total of up to 34 patients will take part in this study. All will be enrolled at M. D. Anderson.

Optional Procedures: If you agree, between 4-10 teaspoons of blood will be drawn within 24 hours before starting therapy, once a week (+/- 2 days) during the first cycle of therapy, and then on Days 1 and 7 of each later cycle. The total amount of blood drawn for these optional tests will depend on the number of cycles you receive.

If you agree, you will also have an additional bone marrow biopsy collected once every 2 cycles.

You do not have to agree to take part in the optional procedures in order to receive treatment on this study.