|Inclusion Criteria:||1) Relapsed/refractory patients with primary AML with FLT3-ITD and/or other FLT3 activating mutations, whose leukemia has recurred after prior chemotherapy but never received a FLT3 inhibitor (Cohort A) or whose leukemia has progressed after prior therapy and have history of prior exposure to one or more FLT3 TKIs (Cohort B).|
2) Patients must have tested positive for FLT3-ITD and/or other FLT3 activating mutations.
3) Males and females age >/=18 years.
4) ECOG PS 0-2.
5) Adequate liver function, defined as bilirubin </=1.5x ULN, ALT </=3.0x ULN, and AST </=3.0x ULN.
6) Adequate renal function, defined as serum creatinine </=1.5x ULN.
7) Recovery from non-hematological toxicities of prior therapy (including HSCT) to no more than grade 1 (except alopecia).
8) In the absence of rapidly progressing leukemia, subjects should have received no anti-leukemic therapy (except hydroxyurea) for 2 weeks (for classical cytotoxic agents and FLT3 inhibitors) prior to first dose of crenolanib.
9) Negative pregnancy test for women of childbearing potential (WOCBP). WOCBP must practice contraception. Acceptable methods of contraception are double barrier methods (condoms with spermicidal jelly or foam and diaphragm with spermicidal jelly or foam), oral, depo provera, or injectable contraceptives, intrauterine devices, and abstention. Male patients with female partners who are of childbearing potential: Recommendation is for male and partner to use effective contraceptive methods, as described above, during the study. Women considered not of childbearing potential include any of the following: no menses for at least 5 years or menses within 5 years but amenorrheic for at least 2 months and luteinizing hormone (LH) and follicular stimulating hormone (FSH) values within normal range (according to definition of postmenopausal for laboratory used) or bilateral oophorectomy or radiation castration and amenorrheic for at least 3 months or with bilateral tubal ligation.
10) Able and willing to provide written informed consent.