Dasatinib as Therapy for Myeloproliferative Disorders (MPDs)

Inclusion Criteria:

1. Patients >/= 18 years old who meet the following eligibility criteria
2. Patients must have one of the following hematopoietic malignancies: C-kit positive (10% or more BM or PB MNC positive by flow) acute myeloid leukemia (AML excluding acute promyelocytic leukemia) or myelodysplastic syndrome (MDS) of the following types: Refractory-relapse AML-MDS including those who fail to achieve CR after the first cycle of induction; Second or subsequent AML-MDS refractory-relapse; Newly diagnosed AML-MDS patients over 60 years of age with karyotype other than t(15:17), inv16, t(8:21), who do not want chemotherapy.
3. (Con't from # 2) Patients with MDS who do not want chemotherapy as initial treatment, or who are not eligible for the treatments of higher priority.
4. Agnogenic myeloid metaplasia - myelofibrosis (MMM)
5. Hypereosinophilic syndrome (HES)
6. Polycythemia vera (PV)
7. Mastocytosis
8. Serum bilirubin less than 2mg%, serum creatinine less than 2mg% unless abnormality is considered due to hematologic malignancy by investigator.
9. ECOG Performance Status < 3
10. Patients must sign an informed consent indicating they are aware of the investigational nature of this study, in keeping with the policies of the hospital.
11. Women of pregnancy potential must practice an effective method of birth control during the course of the study, in a manner such that risk of failure is minimized. Prior to study enrollment, women of childbearing potential (WOCBP) (defined as not post-menopausal for 12 months or no previous surgical sterilization) must be advised of the importance of avoiding pregnancy during trial participation and the potential risk factors for an unintentional pregnancy.
12. Continued from #11: In addition, men enrolled on this study should understand the risks to any sexual partner of childbearing potential and should practice an effective method of birth control.Women and men must continue birth control for the duration of the trial and at least 3 months after the last dose of study drug.
13. Inclusion of women and minorities: As per NIH policy, women and members of minorities will be included in this protocol as they are referred in the relevant populations. There are no exclusions of women or minorities based on the study objectives.
14. NYHA Class < 3
15. Ph negative MPD including chronic myelomonocytic leukemia (CMML).

Exclusion Criteria:

1. Pregnant or breast-feeding women are excluded.
2. All WOCBP MUST have a negative pregnancy test prior to first receiving investigational product. If the pregnancy test is positive, the patient must not receive investigational product and must not be enrolled in the study.