Expanded Access Study of Gilteritinib (ASP2215) in Patients With FMS-like Tyrosine Kinase 3 (FLT3) Mutated Relapsed or Refractory Acute Myeloid Leukemia (AML) or FLT3-Mutated AML in Complete Remission (CR) With Minimal Residual Disease (MRD)

Inclusion Criteria: * Subject is considered an adult according to local regulation at the time of signing informed consent. * Subject has a diagnosis of primary AML or AML secondary to myelodysplastic syndrome (MDS) or therapy-related AML according to World Health Organization (WHO) classification. * Subject has presence of the FLT3-mutated relapsed or refractory AML or FLT3-mutated AML in CRc (CR, CRi, CRp) with MRD in bone marrow or peripheral blood. \[Specific to investigational sites in Japan: FLT3-mutated AML in CRc (CR, CRi, CRp) with MRD subjects will not be included.\] * Subject has refractory or relapsed AML (with or without hematopoietic stem cell transplant \[HSCT\]) or AML in CRc (CR, CRi, CRp) with MRD by flow cytometry or genetic testing for the FLT3 mutation after induction/consolidation regimen or HSCT. \[Specific to investigational sites in Japan: FLT3-mutated AML in CRc (CR, CRi, CRp) with MRD subjects will not be included.\] * Subject must wait for at least 5 half-lives after stopping therapy with any investigational agent and before starting ASP2215. * Subject must meet the following criteria as indicated on clinical laboratory tests: * Serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT) ≤ 3x institutional upper limit of normal (ULN) * Serum total bilirubin ≤ 2.5 mg/dL, except for subjects with Gilbert's syndrome * Serum potassium and serum magnesium ≥ institutional lower limit of normal (LLN). * Subject is able to tolerate or…