DISEASE CHARACTERISTICS:

• Diagnosis of one of the following:

  • Acute lymphoblastic leukemia

    • Philadelphia chromosome (Bcr-abl) positive
    • Refractory to initial therapy OR recurrent following 1 induction therapy regimen with or without consolidation therapy and/or bone marrow transplantation

  • Blastic phase chronic myelogenous leukemia

    • Philadelphia chromosome (Bcr-abl) positive
    • Previously untreated OR recurrent or refractory following 1 induction therapy regimen with or without consolidation therapy including imatinib mesylate
• Must not be eligible for bone marrow transplant

PATIENT CHARACTERISTICS:

Age:

• 18 and over

Performance status:

• ECOG 0-2

Life expectancy:

• At least 8 weeks

Hematopoietic:

• Not specified

Hepatic:

• Bilirubin no greater than 2.0 times upper limit of normal (ULN)
• AST/ALT no greater than 2 times ULN

Renal:

• Creatinine no greater than 2.0 times ULN
• Creatinine clearance greater than 70 mL/min

Cardiovascular:

• No uncontrolled angina
• No New York Heart Association class III or IV heart disease
• No second degree heart block without pacemaker

Other:

• Not pregnant or nursing
• Negative pregnancy test
• Fertile patients must use effective contraception during and for 6 months after study
• HIV negative
• No uncontrolled infection or other serious concurrent illness
• No peripheral neuropathy
• No potassium less than 3.0 or greater than 5.5 mEq/L that can not be corrected OR
• No magnesium less than 1.2 or greater than 2.5 mEq/L that can not be corrected
• Electrolyte imbalances must be corrected prior to study entry

PRIOR CONCURRENT THERAPY:

Biologic therapy:

• See Disease Characteristics

Chemotherapy:

• See Disease Characteristics
• At least 28 days since prior chemotherapy
• At least 24 hours since prior hydroxyurea
• No prior arsenic trioxide
• No other concurrent cytotoxic chemotherapy except intrathecal chemotherapy for CNS leukemia

Endocrine therapy:

• Not specified

Radiotherapy:

• At least 28 days since prior radiotherapy
• No concurrent radiotherapy including for palliation

Surgery:

• Not specified

Other:

• At least 14 days since prior imatinib mesylate
• No other concurrent investigational agents
• No concurrent amphotericin B