To determine safety, tolerability and maximum tolerated dose of BMS-63233/XL413 in subjects with Refractory Hematologic Cancer

Inclusion Criteria:

• AML by current WHO diagnostic criteria, any FAB type (except APML), Refractory ALL, Accelerated/blast phase CML and Refractory MDS with total IPSS score of 2 or higher
• ECOG performance status <= 2
• Accessible for treatment, PK sample collection and required study follow-up
• Total Bilirubin ≤ 1.5 x ULN and ALT, AST ≤ 3 x ULN

Exclusion Criteria:

• Women who are pregnant or breastfeeding
• Subjects with Acute Promyelocytic leukemia disease or CNS leukemia disease)
• Hyperleukocytosis (defined as peripheral WBC >50,000/uL)
• Treatment with any other investigational agent for any indication within 30 days of protocol enrollment
• Subjects a history of gastrointestinal disease
• Subjects less than four weeks from allogenic or autologous stem cell transplant infusion