Inclusion Criteria

DISEASE CHARACTERISTICS:

- Histological confirmation of primary myelofibrosis or post essential thrombocythemic
or polycythemic vera myelofibrosis

- Reticulin fibrosis ≥ grade 1

- Evaluable and symptomatic disease worthy of treatment, characterized by ≥ 1 of the
following:

- Anemia, defined as hemoglobin < 11 g/dL or erythrocyte transfusion dependence

- Palpable and symptomatic splenomegaly (palpable and symptomatic hepatomegaly is
acceptable if previously splenectomized)

- Severe, disease-related constitutional symptoms, including ≥ 1 of the following:

- Severe night sweats

- Fevers

- Weight loss

- Bone pain

- Absence of t(9;22) by fluorescent in situ hybridization (FISH) or standard
cytogenetics OR prior demonstration of a lack of this translocation

PATIENT CHARACTERISTICS:

- Eastern Co-operative Oncology Group (ECOG) performance status 0-3

- Absolute neutrophil count (ANC) ≥ 1,000/mm³

- Platelet count ≥ 50,000/mm³

- Creatinine ≤ 2.0 mg/dL

- Direct or total bilirubin ≤ 2.0 mg/dL

- Aspartate aminotransferase (AST) and alanine aminotransferase (ALT) ≤ 3 times upper
limit of normal (ULN) (≤ 5 times ULN if elevation is attributed to hepatic
extramedullary hematopoiesis)

- Not pregnant or nursing

- Negative pregnancy test

- Fertile patients must use effective contraception

- Not incarcerated in a municipality, county, state, or federal prison

- No serious medical condition or psychiatric illness that would preclude signing the
informed consent

- No condition that, in the opinion of the treating physician, places the patient at
unacceptable risk for study participation or confounds the ability to interpret study
data

- Able to adhere to the study visit schedule and other study requirements

PRIOR CONCURRENT THERAPY:

- No other concurrent chemotherapy (e.g., hydroxyurea, thalidomide, interferon alpha,
anagrelide, or other myelosuppressive agent) or experimental therapy