A Phase 1/2 Study of the HSP90 Inhibitor, STA-9090, Administered Once-Weekly in Subjects With Acute Myeloid Leukemia, Acute Lymphoblastic Leukemia and Blast-phase Chronic Myelogenous Leukemia

Inclusion Criteria:

- Subjects with a pathologic confirmation of the diagnosis of AML, ALL, or blast-phase
CML

- ECOG Performance Status 0-2

- Adequate organ function as defined in the protocol.

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

Exclusion Criteria:

- Hyperleukocytosis

- Acute Promyelocytic Leukemia (FAB-M3) subtype

- Uncontrolled Disseminated Intravascular Coagulation (DIC)

- Active central nervous system leukemia

- Concomitant radiation therapy, chemotherapy, or immunotherapy

- Women who are pregnant or lactating

- Neuropathy ≥ grade 2 (NCI CTCAE) at time of enrollment

- Chemotherapy (with the exception of hydroxyurea) or radiotherapy within two weeks or
within six times the agent's half life

- Require ongoing therapy with either G- or GM-CSF, or long-acting versions of these
molecules

- Use of any investigational agents within two weeks or within six times the agent's
half life --Treatment with chronic immunosuppressants

- Other medical/psychiatric condition that may increase the risk associated with study
participation as defined by the protocol.