An open-label phase 1 study to assess safety and efficacy of once-weekly STA-9090 (ganetespib) in subjects with AML, ALL and blast-phase CML.

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.