DISEASE CHARACTERISTICS:

• One of the following diagnoses:

  • Chronic myelogenous leukemia in lymphoid blast crisis

  • Acute lymphoblastic leukemia (ALL) that is in first relapse or failed induction

    • No more than 1 prior course of induction chemotherapy
    • Philadelphia chromosome-positive (Ph+) by cytogenetic analysis OR bcr/abl translocation by fluorescent in situ hybridization
• At least 30% blasts in bone marrow
• Ineligible for or refused allogeneic stem cell transplantation
• Not previously treated with imatinib mesylate OR currently receiving imatinib mesylate with stable disease on 2 bone marrow biopsies at least 2 weeks apart

PATIENT CHARACTERISTICS:

Age:

• 18 and over

Performance status:

• ECOG 0-2

Life expectancy:

• Not specified

Hematopoietic:

• See Disease Characteristics

Hepatic:

• Bilirubin less than 3 times upper limit of normal (ULN)
• ALT and AST less than 3 times ULN

Renal:

• Creatinine less than 2 times ULN

Cardiovascular:

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

Other:

• Not pregnant or nursing
• Negative pregnancy test
• Fertile patients must use effective barrier contraception during and for at least 2 weeks after study for female patients and at least 3 months after study for male patients

PRIOR CONCURRENT THERAPY:

Biologic therapy:

• See Disease Characteristics
• No prior allogeneic bone marrow or peripheral blood stem cell transplantation
• At least 48 hours since prior interferon alfa

Chemotherapy:

• See Disease Characteristics
• At least 24 hours since prior hydroxyurea
• At least 6 weeks since prior busulfan
• Concurrent hydroxyurea or anagrelide for severe leukocytosis or thrombocytosis allowed

Endocrine therapy:

• Not specified

Radiotherapy:

• Not specified

Surgery:

• Not specified

Other:

• No prior therapy for blast crisis except hydroxyurea
• No prior salvage or reinduction therapy for Ph+ ALL
• At least 4 weeks since other prior investigational agents