Sorafenib Maintenance Therapy for Patients With AML After Allogeneic Stem Cell Transplant

Inclusion Criteria:

* Subjects with AML with the FLT3-ITD mutation who have undergone allogeneic HSCT
* Peripheral blood chimerism studies showing \>/= 70% of all cells are of donor origin
* Adequate hematologic and hepatic function
* ECOG performance status 0-2
* Able to swallow whole pills

Exclusion Criteria:

* Evidence of relapsed/recurrent/residual disease as assessed by bone marrow aspirate and biopsy performed between days 30-60 after HSCT
* Active acute graft vs host disease requiring an equivalent dose of \> 0.5 mg/kg/day of prednisone or equivalent or those patients which necessitated the addition of another agent for the treatment of GVHD beyond corticosteroids
* Ongoing uncontrolled infection
* Cardiac disease: congestive heart failure \> class II NYHA, unstable angina or new onset angina (began within the last 3 months) or myocardial infarction within the past 6 months
* Cardiac ventricular arrhythmias requiring anti-arrhythmic therapy
* Uncontrolled hypertension
* Known HIV infection or chronic hepatitis B or C
* Thrombotic or embolic events such as cerebrovascular accident including transient ischemic attacks within the past 6 months
* Pulmonary hemorrhage/bleeding event \> CTCAE v 4.0 Grade 2 within 4 weeks of starting study drug
* Any other hemorrhage/bleeding event \> CTCAE v. 4.0 Grade 3 within 4 weeks of starting study drug
* Serious non-healing wound, non-healing ulcer, or bone fracture
* Evidence or history of bleeding diathesis or coagulopathy
* Major surgery or significant traumatic injury within 4 weeks of starting study drug
* Use of St. John's Wort or rifampin (rifampicin)
* Known or suspected allergy to sorafenib
* Pregnant or breast-feeding
* Receiving any other investigational agents