Inclusion Criteria:

- Confirmed primary AML diagnosis with presence of either FLT3 ITD and/or other FLT3
activating mutations

- Males and females age ≥ 18 years

- ECOG PS 0-2

- Adequate liver function, defined as bilirubin ≤ 1.5x ULN, ALT ≤ 3.0x ULN, and AST ≤
3.0x ULN.

- Adequate renal function, defined as serum creatinine ≤ 1.5x ULN

- Recovery from non-hematological toxicities of prior therapy (including HSCT) to no
more than grade 1 (except alopecia)

- In the absence of rapidly progressing leukemia, subjects should have received no
anti-leukemic therapy (except hydroxyurea) prior to the first dose of crenolanib for
2 weeks (for classical cytotoxic agents and FLT3 inhibitors; 4 weeks for radiation).

- Negative serum pregnancy test for WOCBP.

- Able and willing to provide written informed consent.

Exclusion Criteria:

- Absence of a FLT3 activating mutation

- Secondary AML or AML in the setting of antecedent hematological disorders

- < 5% blasts in blood or marrow at screening

- Concurrent chemotherapy, systemic immuno-suppressants, or targeted anti-cancer
agents, other than hydroxyurea.

- Patient with concurrent severe and/or uncontrolled medical conditions that in the
opinion of the investigator may impair the participation in the study or the
evaluation of safety and/or efficacy.

- HIV infection or active hepatitis B or C

- Known clinically active central nervous system (CNS) leukemia

- Patients who have had HSCT and are within 180 days of an allogeneic transplant or 90
days of an autologous transplant, and/or have received immunosuppressive drugs for
management or prophylaxis of GVHD within 30 days of enrollment, and/or have
clinically significant graft-versus-host disease requiring treatment, and/or have >
Grade 1 persistent non hematological toxicity related to the transplant

- Major surgical procedures within 14 days of Day 1 administration of crenolanib.

- Unwillingness or inability to comply with protocol.