The purpose of this study is to characterize the regimen limiting toxicities (RLT) and recommended Phase 2 dose (RP2D) of indoximod in patients with newly diagnosed AML receiving remission induction chemotherapy with cytarabine and idarubicin.

Inclusion Criteria:

• A histologically or pathologically confirmed diagnosis of AML based on WHO classification with or without extramedullary disease except for central nervous system disease.
• ECOG performance status ≤ 2
• Left ventricular ejection fraction (LVEF) ≥ 50%
• Female patients of childbearing potential must have a negative pregnancy test < 1 week prior to enrollment.
• Ability to understand and willingness to sign a written informed consent document.

Exclusion Criteria:

• Patients receiving any other investigational agents or immunotherapy
• Patients who have received prior chemotherapy for AML with the exception of hydroxyurea or leukapheresis for leukocytosis; prior hypomethylating or immunomodulatory agents for MDS are allowed
• Previous allo-HSCT of any kind
• Active, uncontrolled infection including known hepatitis B or C
• Active autoimmune disease and chronic inflammatory conditions requiring concurrent use of any systemic immunosuppressants or steroids.
• History of any other active cancer diagnosis
• Pregnant women
• Known HIV-infected patients