DISEASE CHARACTERISTICS:

• Diagnosis of 1 of the following relapsed or refractory hematologic malignancies for which all potentially curative therapy options have been exhausted:

  • Acute myeloid leukemia* (AML) (non-M3)
  • Acute lymphoblastic leukemia*

  • Myelodysplastic syndromes*, including the following:

    • Refractory anemia with excess blasts (RAEB)
    • RAEB in transformation
  • Chronic myelomonocytic leukemia in transformation* (CMML-t) with ≥ 10% peripheral blood/bone marrow blasts
  • Chronic myelogenous leukemia in blast crisis* (CML-BC)

  • Chronic lymphocytic leukemia

    • Rai stage III-IV

    • Failed prior fludarabine-based therapy and ≥ 1 other therapy

      • Fludarabine failure defined as failure to achieve partial response or complete response (CR) to at least 1 fludarabine-containing regimen; disease progression while on fludarabine; or disease progression within 6 months of response to fludarabine NOTE: *Relapsed disease defined as first (with an initial CR duration of < 12 months) or subsequent relapse after standard chemotherapy, autologous SCT, or imatinib mesylate-based therapy (for CML-BC); refractory disease defined as the failure to induce complete remission after 2 courses of standard induction therapy (for AML, ALL, MDS, or CMML-t) OR 1 course of induction therapy containing high-dose cytarabine (for AML) or high-dose imatinib mesylate therapy (for CML-BC)
• Not a candidate for autologous or allogeneic stem cell transplantation (SCT)
• Patients with previously untreated AML, MDS, or CMML-t who are considered inappropriate candidates for, or refused, standard induction chemotherapy due to older age or concurrent medical conditions are eligible
• No known CNS disease

PATIENT CHARACTERISTICS:

Age

• 18 and over

Performance status

• ECOG 0-2

Life expectancy

• Not specified

Hematopoietic

• See Disease Characteristics

Hepatic

• Bilirubin < 1.5 times upper limit of normal (ULN)
• AST and ALT < 5 times ULN

Renal

• Creatinine < 1.5 times ULN

Cardiovascular

• No symptomatic congestive heart failure
• No unstable angina pectoris
• No cardiac arrhythmia

Other

• Not pregnant or nursing
• Fertile patients must use effective contraception
• No ongoing or active infection
• No psychiatric illness or social situation that would preclude study compliance
• No history of allergic reactions attributed to compounds of similar chemical or biologic composition to XK469R
• No other uncontrolled illness
• HIV-positive patients allowed provided CD4 counts are normal with no AIDS-defining disease

PRIOR CONCURRENT THERAPY:

Biologic therapy

• See Disease Characteristics
• No prior allogeneic SCT
• No concurrent prophylactic hematopoietic colony-stimulating factors

Chemotherapy

• See Disease Characteristics
• More than 7 days since prior cytotoxic chemotherapy (except hydroxyurea)

Endocrine therapy

• Not specified

Radiotherapy

• More than 7 days since prior radiotherapy

Surgery

• Not specified

Other

• No concurrent combination antiretroviral therapy for HIV-positive patients
• No other concurrent investigational agents
• No other concurrent anti-leukemia agents
• No other concurrent anticancer therapy