Safety and Efficacy of Quizartinib in Children and Young Adults With Acute Myeloid Leukemia (AML), a Cancer of the Blood

Inclusion Criteria: Participants must meet all of the following criteria to be eligible for enrollment into the study: * Has diagnosis of AML according to the World Health Organization (WHO) 2008 classification with ≥5% blasts in bone marrow, with or without extramedullary disease * In first relapse or refractory to first-line high-dose chemotherapy with no more than 1 attempt (1 to 2 cycles of induction chemotherapy) at remission induction - prior HSCT is permitted * Has presence of the FLT3-ITD activating mutation in bone marrow or peripheral blood as defined in the protocol * Is between 1 month and 21 years of age at the time the Informed Consent/Assent form is signed * Has protocol-defined adequate performance status score * Has fully recovered from the acute clinically significant toxicity effects of all prior chemotherapy, immunotherapy, or radiotherapy, per protocol guidelines * Has protocol-defined adequate renal, hepatic and cardiac functions * If of reproductive potential, is permanently sterile or agrees to use highly effective birth control upon enrollment, during the period of therapy, and for 6 months following the last dose of quizartinib, etoposide, fludarabine, methotrexate, or cytarabine, whichever is later * If female of child-bearing potential, tests negative for pregnancy and agrees not to breast feed * Male participants must be surgically sterile or willing to use highly effective birth control during the treatment period, and for 6 months following th…