A Phase 1B/2 Study To Evaluate The Safety And Efficacy Of PF-04449913, An Oral Hedgehog Inhibitor, In Combination With Intensive Chemotherapy, Low Dose Ara-C Or Decitabine In Patients With Acute Myeloid Leukemia Or High Risk Myelodysplastic Syndrome

Inclusion Criteria:

- Patients with AML or RAEB 2 High Risk MDS who are newly diagnosed according to the
WHO 2008 Classification and previously untreated.

- Patients with AML (arising from an antecedent hematologic disease [AHD]) or MDS who
may have had one prior regimen with commercially available agents for the treatment
of their prior hematologic disease. The patients may not have had a prior therapy
for their AML.

- AML patients include de novo AML, AML evolving from MDS or other AHD and AML after
previous cytotoxic therapy or radiation (secondary AML)

- For a diagnosis of AML, a bone marrow blast count of 20% or more is required.

- For a diagnosis of high-risk Myelodysplastic Syndrome RAEB 2 the patient must have
10-19% bone marrow blasts

- Adequate Organ Function

- ECOG Performance Status 0, 1, or 2

Exclusion Criteria:

- AML M3 Acute Promyelocytic Leukemia (APL) or patients with a t(9:22) cytogenetic
translocation.

- Patients in whom, at the time of study entry, a stem cell transplant is planned
within the next 6 months.

- Patients with known active uncontrolled central nervous system (CNS) leukemia.