Obatoclax for Systemic Mastocytosis

Inclusion Criteria:

1. Patients with Systemic Mastocytosis (SM); including mast cell leukemia.
2. Age equal to or greater than 18 years
3. Minimum of two weeks since any major surgery or completion of radiation
4. Eastern Cooperative Oncology Group (ECOG) performance status equal to or less than 2
5. Adequate liver function as shown by serum bilirubin equal to or less than 1.5 \* upper limit of normal (ULN), and serum alanine aminotransferase (ALT) equal to or less than 3 \* ULN.
6. Signed informed consent

Exclusion Criteria:

1. Patients with low blood cell counts (Grade 3 or 4), unless it is known that the low blood cell count is due to systemic mastocytosis.
2. Treatment with any conventional (specifically, interferon or cladribine) or investigational medicine for SM within the preceding 4 weeks
3. Chronic treatment with systemic steroids (unless limited to 10 mg prednisone equivalent per day or less) or another immunosuppressive agent
4. Other malignancies within the past 3 years except for adequately treated carcinoma of the cervix or basal or squamous cell carcinomas of the skin. Patient may have SM-associated clonal hematologic disease that does not require therapy, as judged by the treating physician and approved by the principal investigator).
5. Other concurrent severe and/or uncontrolled medical disease which could compromise participation in the study as judged by the Principal Investigator (i.e., severely impaired lung function, uncontrolled diabetes, uncontrolled hypertension, severe infection, severe malnutrition, unstable angina, or congestive heart failure - New York Heart Association Class III or IV, ventricular arrhythmias, active ischemic heart disease, myocardial infarction within six months, chronic liver or renal disease, active upper GI tract ulceration)
6. A known history of human immunodeficiency virus (HIV) seropositivity
7. Women who are pregnant or breast feeding,or women/men able to conceive and unwilling to practice an effective method of birth control. Women of childbearing potential must have a negative urine or serum pregnancy test within 48 hours prior to administration of obatoclax. Women of childbearing potential is defined as women who have not undergone a hysterectomy or bilateral oophorectomy, has not been naturally postmenopausal for at least 24 consecutive months.
8. Patients with a known hypersensitivity to obatoclax mesylate or to its excipients (PEG 300 and Tween 20)
9. Patients unwilling to or unable to comply with the protocol