Selinexor (KPT-330) Plus FLAG-Ida for the Treatment of Relapsing/Refractory AML

Inclusion Criteria: * Written informed consent in accordance with national, local, and institutional guidelines. The patient must provide informed consent prior to the first screening procedure. * Age ≥ 18, and ≤ 65 years old. * Eastern Cooperative Oncology Group (ECOG) performance status of ≤ 2. * Diagnosis of AML (defined using WHO criteria) of any type except for acute promyelocytic leukemia (APL; AML M3). * Relapsing or refractory AML, defined as either: Recurrence of disease after first CR (duration of CR ≤ 24 months), or Failure to achieve CR or CRi after 1 or 2 identical induction cycles containing an anthracycline plus cytarabine based schedule. * No contraindications to receive intensive chemotherapy. * Female patients of child-bearing potential must have a negative serum pregnancy test at screening and agree to use two reliable methods of contraception for three months after their last dose of medication. Male patients must use a reliable method of contraception (if sexually active with a female of child-bearing potential). * Willingness and ability to comply with scheduled visits, treatment plans, laboratory tests and other study procedures. Exclusion Criteria: * Patients with APL/AML M3. * Patients who are pregnant or lactating. * Radiation, chemotherapy, or immunotherapy or any other anticancer therapy ≤ 2 weeks prior to Cycle 1 Day 1 or radio-immunotherapy 4 weeks prior to Cycle 1 Day 1. Hydroxyurea is permitted until 1 day prior to Cycle 1 Day 1. * Previous treatment with a SINE compound. * Major surgery within 2 weeks of first dose of study drug. * Any life-threatening illness, medical condition or organ system dysfunction which, in the Investigator's opinion, could compromise the patient's safety. * Unstable cardiovascular function: * Symptomatic ischemia, or uncontrolled clinically significant conduction abnormalities (i.e., ventricular tachycardia on anti-arrhythmia are excluded; 1st degree AV block or asymptomatic LAFB/RBBB will not be excluded), or congestive heart failure (CHF) of NYHA Class ≥ 3, or myocardial infarction (MI) within 3 months. * Uncontrolled (i.e., clinically unstable) infection requiring parenteral antibiotics, antivirals, or antifungals within one week prior to first dose; however, prophylactic use of these agents is acceptable even if parenteral. * Active hepatitis B or hepatitis C infection. * Known human immunodeficiency virus (HIV) infection (HIV testing is not required as part of this study). * Patients unable to swallow tablets, patients with malabsorption syndrome, or any other gastrointestinal (GI) disease or GI dysfunction that could interfere with absorption of study treatment. * Any of the following laboratory abnormalities unless due to leukemia: * Hepatic dysfunction: bilirubin \> 2.0 times the upper limit of normal (ULN) (except patients with Gilbert's syndrome: total bilirubin of \> 3 x ULN) and alanine aminotransferase (ALT) and aspartic aminotransferase (AST) \> 2.5 times ULN or in case of liver metastases: In patients with known liver involvement of their cancer, AST and ALT \> 5 x ULN. * Severe renal dysfunction: estimated creatinine clearance of \< 30 mL/min, measured in 24 hour urine or calculated using the formula of Cockroft and Gault: (140-Age) x Mass (kg)/\[72 x creatinine (mg/dL)\]; multiply by 0.85 if female