A Study of ASP2215 Versus Salvage Chemotherapy in Patients With Relapsed or Refractory Acute Myeloid Leukemia (AML) With FMS-like Tyrosine Kinase (FLT3) Mutation

* Untreated first hematologic relapse is defined as:

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.

Participant is positive for FLT3 mutation in bone marrow or whole blood as determined by the central lab. A Participant with rapidly proliferative disease and unable to wait for the central lab results can be enrolled based on a local test performed after completion of the last interventional treatment. Participants can be enrolled from a local test result if they have any of the following FLT3 mutations: FLT3 internal tandem duplication (ITD), FLT3 tyrosine kinase domain (TKD)/D835 or FLT3- TKD/I836.

Participant has an Eastern Cooperative Oncology Group (ECOG) performance status ≤ 2.

Participant is eligible for pre-selected salvage chemotherapy.

Participant must meet the following criteria as indicated on the clinical laboratory tests:

* Serum aspartate aminotransferase and alanine aminotransferase ≤ 2.5 x upper limit of normal (ULN)

* Serum total bilirubin ≤ 1.5 x ULN

* Serum creatinine ≤ 1.5 x ULN or an estimated glomerular filtration rate of \> 50 mL/min as calculated by the Modification of Diet in Renal Disease equation.

Participant is suitable for oral administration of study drug.

Female Participant must either:

* Be of non-child bearing potential:

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)

* Or, if of childbearing potential,

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.

Female Participant must agree not to breastfeed at Screening and throughout the study period and for 60 days after the final study drug administration.

Female Participant must not donate ova starting at Screening and throughout the study period and for 180 days after the final study drug administration.

Male Participant and their female partners who are of childbearing potential must be using highly effective contraception per locally accepted standards in addition to a barrier method starting at Screening and continue throughout the study period and for 120 days after the final study drug administration.

Male Participant must not donate sperm starting at Screening and throughout the study period and 120 days after the final study drug administration.

Participant agrees not to participate in another interventional study while on treatment.

Participant was diagnosed as acute promyelocytic leukemia (APL).

Participant has BCR-ABL-positive leukemia (chronic myelogenous leukemia in blast crisis).

Participant has AML secondary to prior chemotherapy for other neoplasms (except for MDS).

Participant is in second or later hematologic relapse or has received salvage therapy for refractory disease

Participant has clinically active central nervous system leukemia.

What this study is about