A Study of ASP2215 versus Salvage Chemotherapy in Patients with Relapsed or Refractory Acute Myeloid Leukemia (AML) with FMS-like tyrosine kinase (FLT3) Mutation

1. Participant did not achieve complete remission/complete remission with incomplete hematologic recovery/complete remission with incomplete platelet recovery (CR/CRi/CRp) under initial therapy. A Participant eligible for standard therapy must receive at least one cycle of an anthracycline containing induction block in standard dose for the selected induction regimen. A Participant not eligible for standard therapy must have received at least one complete block of induction therapy seen as the optimum choice of therapy to induce remission for this subject.

1. Participant must have achieved a CR/CRi/CRp (criteria as defined by [Cheson et al, 2003], see Section 5.3) with first line treatment and has hematologic relapse.

1. post-menopausal (defined as at least 1 year without any menses) prior to Screening, or

2. documented as surgically sterile (at least 1 month prior to Screening)

1. Agree not to try to become pregnant during the study and for 180 days after the final study administration

2. And have a negative urine pregnancy test at Screening

3. And, if heterosexually active, agree to consistently use highly effective contraception per locally accepted standards in addition to a barrier method starting at Screening and throughout the study period and for 180 days after the final study drug administration.