Study to Determine Safety, Pharmacokinetics and Efficacy of GMI-1271 in Combination With Chemotherapy in AML

Inclusion criteria: 1. AML (including secondary AML) diagnosed as per WHO criteria 2. For relapsed/refractory subjects only: * Subjects age ≥ 18 years with relapsed or refractory AML after ≤ 2 prior induction regimens, at least one containing anthracyclines * Medically eligible to receive MEC * Absolute blast count (ABC) ≤ 40,000/mm 3. For treatment-naïve subjects only: * Subjects ≥ 60 years of age with newly diagnosed AML * Medically eligible to receive "7+3" cytarabine/idarubicin * ABC count ≤ 40,000/mm 4. ECOG performance status 0-2 5. Hemodynamically stable and adequate organ function Exclusion criteria: 1. Acute promyelocytic leukemia 2. Acute leukemia of ambiguous lineage (biphenotypic leukemia) 3. Active signs or symptoms of CNS involvement by malignancy 4. No prior G-CSF, GM-CSF or plerixafor within 14 days of study drug dosing 5. Known history or evidence of active hepatitis A, B, or C or HIV 6. Uncontrolled acute life threatening bacterial, viral or fungal infection 7. Active graft versus host disease (GVHD) ≥ Grade 2 or extensive chronic GVHD requiring immunosuppressive therapy 8. Hematopoietic stem cell transplantation ≤ 4 months of dosing 9. Clinically significant cardiovascular disease