RATIONALE: Drugs used in chemotherapy use different ways to stop cancer cells from dividing so they stop growing or die.

PURPOSE: Phase II trial to study the effectiveness of troxacitabine in treating patients who have blast phase chronic myelogenous leukemia.

OBJECTIVES: I. Determine the response rate, in terms of achieving complete hematologic remission, partial hematologic remission, hematologic improvement, partial response, or back to chronic phase status, in patients with blastic phase chronic myelogenous leukemia treated with troxacitabine. II. Determine the proportion of patients whose disease returns to chronic phase and remains at that level for at least 3 months when treated with this drug. III. Determine the toxicity profile of this drug in these patients. IV. Determine the duration of survival of patients treated with this drug.

OUTLINE: This is a multicenter study. Patients receive troxacitabine IV over 30 minutes on days 1-5. Treatment repeats every 4 weeks in the absence of disease progression or unacceptable toxicity. Patients are followed every 4 weeks until relapse.

PROJECTED ACCRUAL: A maximum of 50 patients will be accrued for this study within 14 months.

DISEASE CHARACTERISTICS: Diagnosis of Philadelphia chromosome-positive blastic phase chronic myelogenous leukemia (CML) with blasts of non-lymphoid origin Blastic phase defined as: At least 30% blasts in the blood or bone marrow OR Presence of extramedullary infiltration outside the liver or spleen No leukemic CNS involvement

PATIENT CHARACTERISTICS: Age: 16 and over Performance status: ECOG 0-2 Life expectancy: Not specified Hematopoietic: Not specified Hepatic: Bilirubin no greater than 2.0 mg/dL AST or ALT less than 3 times upper limit of normal Renal: Creatinine no greater than 1.5 mg/dL OR Creatinine less than 1.8 mg/dL if creatinine clearance at least 45 mL/min Other: No known hypersensitivity to troxacitabine or its analogues No active uncontrolled serious infection No other severe medical condition that would preclude study No neurologic or psychiatric disorders that would preclude informed consent No uncontrolled underlying medical condition or underlying condition that could be aggrevated by treatment Not pregnant or nursing Negative pregnancy test Fertile patients must use effective contraception

PRIOR CONCURRENT THERAPY: Biologic therapy: Not specified Chemotherapy: At least 24 hours since prior hydroxyurea Prior STI571 for blastic phase chronic myelogenous leukemia allowed No other prior chemotherapy for blastic phase disease Endocrine therapy: Not specified Radiotherapy: Not specified Surgery: Not specified Other: At least 14 days since prior investigational agents and recovered No other concurrent investigational agents