GOSSAMER ASTELLAS: This phase III trial is assessing the relapse-free survival of patients who are in complete first remission for Acute Myeliod Leukaemia (AML) and who are randomised to receive gilteritinib after they have completed two years of induction chemotherapyA Phase 3 Multicenter, Randomized, Double-Blind, Placebo-Controlled Trial of the FLT3 Inhibitor Gilteritinib (ASP2215) Administered as Maintenance Therapy Following Induction/Consolidation Therapy for Subjects With FLT3/ITD AML in First Complete Remission

Inclusion

• Subject is considered an adult according to local regulation at the time of obtaining consent form (ICF).
• Subject consents to allow access to subject's diagnostic bone marrow aspirate or peripheral blood sample and/or the DNA derived from that sample, if available, that may be used to validate a companion diagnostic test for gilteritinib.
• Subject has confirmed morphologically documented AML, excluding acute promyelocytic leukemia (APL), in CR1 (including CRp and CRi). For the purposes of enrollment, CR will be defined as < 5% blasts in the bone marrow with no morphologic characteristics of acute leukemia (e.g., Auer rods) in the bone marrow with no evidence of extramedullary disease such as central nervous system involvement or granulocytic sarcoma.
• Subject will not proceed with transplantation as either a decision not to proceed with transplantation has been made either on the recommendation of the treating physician or by the patient or a suitable donor could not be identified.
• Subject is < 2 months from the start of the last cycle of consolidation and should have completed the recommended number of consolidations per local practice.
• Subject has had no use of investigational agents, with the exception of FLT3 inhibiting agents during induction and/or consolidation therapy, within the prior 4 weeks.
• Subject has had presence of the FLT3/ITD activating mutation in the bone marrow or peripheral blood as determined by the local institution at diagnosis.
• Subject has an ECOG performance status 0 to 2.

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

  • Serum creatinine ≤ 1.5 x institutional upper limit of normal (ULN), or if serum creatinine outside normal range, then glomerular filtration rate (GFR) > 40 mL/min/1.73m^2 as calculated with the 4-parameter Modification of Diet in Renal Disease (MDRD) equation.
  • Serum total bilirubin ≤ 2.5 mg/dL (43 μmol/L), except for subjects with Gilbert's syndrome.
  • Serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT) < 3 x ULN.
  • Serum potassium and serum magnesium ≥ institutional lower limit of normal (LLN).
  • Absolute neutrophil count (ANC) ≥ 500/μl and platelets ≥ 20000/μl (unsupported by transfusions).
• Subject is suitable for oral administration of study drug.

• Female subject must either:

  • Be of nonchildbearing potential:
  • Postmenopausal (defined as at least 1 year without any menses) prior to screening, or
  • Documented surgically sterile or status posthysterectomy (at least 1 month prior to screening)
  • Or, if of childbearing potential,
  • Agree not to try to become pregnant during the study and for 6 months after the final study drug administration
  • And have a negative urine or serum pregnancy test at screening
  • 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 6 months after the final study drug administration.
• Female subject must agree not to breastfeed starting at screening and throughout the study period, and for 2 months and 1 week after the final study drug administration.
• Female subject must not donate ova starting at screening and throughout the study period, and for 6 months after the final study drug administration.
• Male subject and subject's 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 4 months and 1 week after the final study drug administration.
• Male subject must not donate sperm starting at screening and throughout the study period and for 4 months and 1 week after the final study drug administration.
• Subject agrees not to participate in another interventional study while on treatment.