Inclusion Criteria:

- Diagnosis of 1 of the following:

- Acute myeloid leukemia

- Acute lymphoblastic leukemia

- Myelodysplastic syndromes

- Refractory anemia with excess blasts [RAEB]

- RAEB in transformation

- Chronic myelomonocytic leukemia in transformation with ≥ 10% peripheral
blood/bone marrow blasts

- Chronic myelogenous leukemia in blastic phase

- Disease status must meet 1 of the following criteria:

- Primary resistant disease (i.e., failed to achieve a complete response [CR] to a
prior standard induction regimen)

- Relapsed disease after achieving a CR

- Documented failure to most recent cytotoxic regimen

- No other potentially curative options

- No known CNS disease

- Performance status - ECOG 0-2

- SGOT or SGPT < 3 times upper limit of normal*

- Bilirubin ≤ 2 mg/dL*

- Creatinine ≤ 2 mg/dL (unless due to organ leukemic involvement)

- No symptomatic congestive heart failure

- No unstable angina pectoris

- No cardiac arrhythmia

- Not pregnant or nursing

- Negative pregnancy test

- Fertile patients must use effective contraception

- No prior allergic reaction attributed to compounds of similar chemical or biological
composition to CCI-779

- No ongoing or active infection

- No psychiatric illness or social situation that would preclude study compliance

- No AIDS-defining disease

- HIV positive allowed if CD4 counts normal

- No other concurrent uncontrolled illness

- No concurrent prophylactic hematopoietic colony-stimulating factors

- More than 2 weeks since prior cytotoxic chemotherapy (except hydroxyurea) and
recovered

- More than 2 weeks since prior radiotherapy and recovered

- No concurrent combination antiretroviral therapy for HIV-positive patients

- No other concurrent investigational agents

- No other concurrent anticancer agents or therapies