Inclusion Criteria:

- Diagnosis of 1 of the following hematologic malignancies:

- Acute myeloid leukemia

- Acute lymphoblastic leukemia

- Myelodysplastic syndromes

- Chronic myelogenous leukemia in blastic phase

- Chronic lymphocytic leukemia

- Relapsed or refractory disease

- No immediately available, potentially curable options (e.g., stem cell
transplantation) available

- Bilirubin normal (unless elevated due to Gilbert's syndrome)

- HIV positivity allowed provided CD4 counts are normal with no AIDS-defining disease

- Not pregnant or nursing

- Negative pregnancy test

- Fertile patients must use effective contraception

- No uncontrolled intercurrent illness including, but not limited to, any of the
following:

- Ongoing or active infection

- Symptomatic congestive heart failure

- Unstable angina pectoris

- Cardiac arrhythmia

- Psychiatric illness or social situations that would limit study compliance

- Recovered from prior therapy

- ECOG performance status =< 2

- SGOT and SGPT =< 2.5 times upper limit of normal (ULN)

- Creatinine normal OR creatinine clearance >= 60 mL/min

- Primary resistance (i.e., failed to achieve a complete remission [CR] to a standard
induction regimen) or relapsed after achievement of a CR.

- Must have documented failure to last cytotoxic regimen prior to study entry.

- Ability to understand and the willingness to sign a written informed consent
document.

Exclusion Criteria:

- No known CNS disease

- No history of allergic reactions attributed to compounds of similar chemical or
biologic composition to SJG-136

- More than 7 days since radiotherapy

- No concurrent combination antiretroviral therapy for HIV-positive patients

- No other anti-leukemia agents except hydroxyurea =< 5 grams/day =< 14 days prior to
and during first course of treatment to control blood counts