RATIONALE: Drugs used in chemotherapy use different ways to stop cancer cells from dividing so they stop growing or die. Imatinib mesylate may stop the growth of cancer cells by blocking the enzymes necessary for cancer cell growth.

PURPOSE: This phase II trial is studying giving imatinib mesylate together with cytarabine to see how well it works in treating patients with chronic phase chronic myelogenous leukemia.

OBJECTIVES:

• Determine the rate and duration of complete or major and minor cytogenetic responses after 6 and 12 months of treatment in patients with chronic phase chronic myelogenous leukemia treated with imatinib mesylate and cytarabine.
• Determine the rate and duration of complete hematologic responses after 6 and 12 months of treatment in patients treated with this regimen.
• Determine the rate of molecular response in patients with a complete cytogenetic response after 6 and 12 months of treatment with this regimen.
• Determine the pharmacokinetics of this regimen in these patients.
• Determine the safety of this regimen in these patients.

OUTLINE: This is a nonrandomized, open-label, multicenter study.

Patients receive oral imatinib mesylate on days 1-28 and cytarabine subcutaneously on days 15-28. Courses repeat every 28 days for 12 months in the absence of disease progression or unacceptable toxicity.

Patients are followed for 30-60 days.

PROJECTED ACCRUAL: A total of 15 patients will be accrued for this study.

DISEASE CHARACTERISTICS:

• Cytogenetically confirmed chronic phase chronic myelogenous leukemia (CML)

  • Less than 15% blasts in peripheral blood or bone marrow
  • Less than 30% blasts and promyelocytes in peripheral blood or bone marrow
  • Less than 20% basophils in blood or bone marrow
  • Platelet count at least 100,000/mm^3

• Philadelphia chromosome positive

• No more than 6 months since initial diagnosis

• No presence of leukemia beyond the bone marrow, blood, liver, or spleen (i.e., chloroma)

• Refused allogeneic stem cell transplantation as first-line therapy

PATIENT CHARACTERISTICS:

Age:

• 18 and over

Performance status:

• Eastern Cooperative Oncology Group (ECOG) 0-2

Life expectancy:

• Not specified

Hematopoietic:

• See Disease Characteristics

Hepatic:

• Bilirubin no greater than 1.5 times upper limit of normal (ULN)
• AST or ALT no greater than 2 times ULN

Renal:

• Creatinine no greater than 1.5 times ULN

Cardiovascular:

• No New York Heart Association class III or IV heart disease

Other:

• Not pregnant or nursing
• Negative pregnancy test
• Fertile patients must use effective barrier contraception during and for at least 3 months after study participation
• No other serious uncontrolled medical condition
• No history of noncompliance to medical regimens or potential unreliability

PRIOR CONCURRENT THERAPY:

Biologic therapy:

• See Disease Characteristics
• No prior biologic therapy for CML

Chemotherapy:

• No prior chemotherapy for CML except hydroxyurea
• Concurrent hydroxyurea to control blood counts during first 3 months of treatment allowed
• No other concurrent chemotherapy

Endocrine therapy:

• No prior endocrine therapy for CML

Radiotherapy:

• No prior radiotherapy for CML

Surgery:

• Not specified

Other:

• More than 28 days since prior investigational anticancer agents
• Prior anagrelide hydrochloride for CML allowed
• Concurrent anagrelide hydrochloride to control blood counts during first 3 months of treatment allowed
• No concurrent grapefruit juice or grapefruit

Study was terminated, therefore the 12 month response data was not analyzed.