Decitabine and Midostaurin in Treating Older Patients With Newly Diagnosed Acute Myeloid Leukemia

Inclusion Criteria: * Newly-diagnosed acute myeloid leukemia (AML) per the World Health Organization \[WHO\] 2008 classification \[except t (15; 17)\], including: * De novo AML * Secondary AML * Secondary AML arising from previously-diagnosed myelodysplastic syndromes (MDS) treated with deoxyribonucleic acid (DNA) methyltransferase inhibitor (DNMTi) (ie, decitabine or azacitidine) * FLT3-ITD mutation confirmed in bone marrow aspirate * Eastern Cooperative Oncology Group (ECOG) performance status ≤ 2 * Aspartate aminotransferase (AST) and alanine aminotransferase (ALT) ≤ 2.5 x upper limit of normal (ULN) * Serum bilirubin ≤ 2.5 ULN * Serum creatinine ≤ 1.5 mg/dL and/or creatinine clearance ≥ 50 mL/min * Ejection fraction ≥ 50% by echocardiogram * Unwillingness or inability to receive conventional chemotherapy * Ability to understand and the willingness to sign a written informed consent document * Ability to adhere to the study visit schedule and other protocol requirements * Life expectancy \> 2 months Exclusion Criteria: * Receiving concomitant treatment with other anti-neoplastic agents (EXCEPTION: hydroxyurea). Prior treatment with DNMTi therapy (ie, decitabine or azacitidine) for MDS is allowed * Received anti-neoplastic treatment within 4 weeks prior to enrollment (EXCEPTION: hydroxyurea) * Received any surgical procedure, excluding central venous catheter placement or other minor procedures (eg, skin biopsy) within 14 days of study day 1 * Received any investigational agent within 4 weeks prior to enrollment * Previous or current history of a myeloproliferative disease * Known active central nervous system (CNS) malignancy * Any other known disease (except carcinoma in-situ), concurrent severe and/or uncontrolled medical condition which could compromise participation in the study (eg, uncontrolled diabetes; cardiovascular disease including congestive heart failure; myocardial infarction within 6 months with poorly controlled hypertension; chronic renal disease; active uncontrolled infection) * Active opportunistic infection or treatment for opportunistic infection within 4 weeks of first day of study drug dosing * Known confirmed diagnosis of human immunodeficiency virus (HIV) infection or active viral hepatitis * Known impairment of gastrointestinal (GI) function or GI disease that may significantly alter the absorption of midostaurin * History of allergic reactions attributed to compounds of similar chemical or biologic composition to midostaurin and/or decitabine * Impaired cardiac function including any of the following: * Screening electrocardiogram (ECG) with a corrected QT interval (QTc) \> 450 msec * Bradycardia defined as heart rate (HR) \< 50 beats per minute (bpm) * Right bundle branch block + left anterior hemiblock (bifascicular block) * Patients with myocardial infarction or unstable angina \< 3 months prior to starting study drug * Congestive heart failure (CHF) New York (NY) Heart Association class 3 or 4 * Inability to swallow or absorb drug * Other medical or psychiatric illness or organ dysfunction or laboratory abnormality which in the opinion of the investigator would compromise the patient's safety or interfere with data interpretation * Unwillingness or inability to comply with the protocol * Pregnant * nursing (lactating) * Women of child-bearing potential, defined as all women physiologically capable of becoming pregnant, UNLESS they are using highly effective methods of contraception during dosing and for 3 months after midostaurin medication; highly effective contraception methods as follows: * Total abstinence, when this is in line with the preferred and usual lifestyle of the subject \[periodic abstinence (eg, calendar, ovulation, symptothermal, post-ovulation methods) and withdrawal are not acceptable methods of contraception\] * Female sterilization (surgical bilateral oophorectomy with or without hysterectomy; or tubal ligation at least six weeks before taking study treatment). In case of oophorectomy alone, reproductive status must be confirmed by follow-up hormone level assessment * Male sterilization, at least 6 months prior to screening (for female subjects on the study, the vasectomized male partner should be the sole partner for that subject) * Combination of any two of the following (a+b or a+c, or b+c): * Use of oral, injected or implanted hormonal methods of contraception or other forms of hormonal contraception that have comparable efficacy (failure rate \< 1%), eg, hormone vaginal ring or transdermal hormone contraception. For oral contraception, women should have been stable on the same pill for a minimum of 3 months before taking study treatment * Placement of an intrauterine device (IUD) or intrauterine system (IUS) * Barrier methods of contraception: Condom or Occlusive cap (diaphragm or cervical/vault caps) with spermicidal foam/gel/film/cream/vaginal suppository