Inclusion Criteria:

- Diagnosis of primary myelofibrosis, essential thrombocythemia related myelofibrosis
or polycythemia vera related myelofibrosis requiring therapy including previously
treated and relapsed or refractory or newly diagnosed or with symptomatic
splenomegaly or if newly diagnosed, with intermediate or high risk or with
symptomatic splenomegaly

- Detectable JAK2 V617F mutation

- Signed Informed Consent: Patients must have signed consents for both the arsenic
trioxide with ascorbic acid protocol and for the Hematologic Malignancy Procurement
protocol to be eligible to participate.

- Must have been off any experimental PMF-directed therapy for 4 weeks prior to
entering study and have recovered from the toxic effects of that therapy Treatment
with hydroxyurea and erythropoetin are permitted until study initiation.

- Serum bilirubin levels <2 X Upper Limits of Normal

- Serum SGPT and ALT levels <2 X Upper Limits of Normal

- Serum creatinine levels <1.5 X Upper Limits of Normal

- Negative pregnancy Test

- At least 18 years old

Exclusion Criteria:

- Nursing and pregnant females

- NYHA Grade II or greater congestive heart failure

- Unstable angina

- QTc >450 in the presence of potassium >4 mEq/L and magnesium >1.5mEq/L

- ECOG > 2

- Major surgical procedure within 28 days of entering the study

- Biopsy or minor surgical procedure within 7 days prior to study enrollment

- Known hypersensitivity to any compound of arsenic trioxide

- Ongoing serious, Non-healing wound, ulcer or bone fracture