DISEASE CHARACTERISTICS:

• Diagnosis of chronic phase chronic myelogenous leukemia

  • Cytogenetically confirmed Philadelphia chromosome-positive disease or other variant of t(9;22)

    • No secondary chromosomal abnormalities
  • No more than 10% blasts in bone marrow
  • Newly diagnosed OR
  • Received prior imatinib mesylate as a single agent for no more than the past 9 months without achieving a complete cytogenetic response
• No evidence of extramedullary involvement except nodes, liver, or spleen

PATIENT CHARACTERISTICS:

Age

• Any age

Performance status

• ECOG 0-3

Life expectancy

• Not specified

Hematopoietic

• Platelet count greater than 100,000/mm^3
• Absolute neutrophil count greater than 1,500/mm^3

Hepatic

• Bilirubin no greater than 2 times upper limit of normal (ULN)
• SGOT no greater than 2 times ULN
• INR no greater than 1.5 times ULN*
• PTT no greater than 1.5 times ULN* NOTE: * Except patients on anticoagulants

Renal

• Creatinine no greater than 2 times ULN

Other

• Considered potentially reliable
• No history of noncompliance to medical regimens
• No other active malignancy requiring chemotherapy or radiotherapy
• Not pregnant or nursing
• Negative pregnancy test
• Fertile patients must use effective barrier-method contraception during and for at least 3 months after study

PRIOR CONCURRENT THERAPY:

Biologic therapy

• No prior interferon therapy
• No prior stem cell or bone marrow transplantation

Chemotherapy

• No prior chemotherapy (except hydroxyurea and/or anagrelide to control counts)

Endocrine therapy

• Not specified

Radiotherapy

• Not specified

Surgery

• At least 4 weeks since prior major surgery and recovered

Other

• No concurrent grapefruit juice or grapefruit products
• No concurrent warfarin
• Concurrent low-molecular weight heparin allowed