Inclusion Criteria:

          -  Diagnosis of AML (≥ 20% blasts in the bone marrow based on WHO 2016 classification).
             Patients with APL (acute promyelocytic leukemia) with PML-RARA are not eligible

          -  Documented presence of an ITD and/or TKD activating mutation in the FLT3 gene, as
             determined by analysis in a Novartis designated laboratory An exception will be
             patients who are enrolled into the part 1 in Japan, who may be treated with
             midostaurin irrespective of AML FLT3 genotype.

          -  Patients must meet the following laboratory value criteria that indicate adequate
             organ function at the screening visit:

               -  Estimated creatinine clearance ≥ 30 ml/min

               -  Total bilirubin ≤ 1.5 x ULN, except in the setting of isolated Gilbert syndrome

               -  Aspartate transaminase (AST) ≤ 3.0 x ULN

               -  Alanine transaminase (ALT) ≤ 3.0 x ULN

          -  Suitability for intensive chemotherapy in the judgment of the investigator

        Exclusion Criteria:

          -  Neurologic symptoms suggestive of CNS leukemia unless CNS leukemia has been excluded
             by a lumbar puncture. Patients with CSF fluid positive for AML blasts are not eligible

          -  Developed therapy-related AML after prior radiotherapy (RT) or chemotherapy for
             another cancer or disorder

          -  Known hypersensitivity to midostaurin, cytarabine or daunorubicin or to any of the
             excipients of midostaurin/placebo, cytarabine or daunorubicin

          -  Abnormal chest X-ray unless the abnormality represents a non-active, or non-clinically
             significant finding, such as scarring (subjects with controlled non active lung
             infection are eligible)

          -  Known impairment of gastrointestinal (GI) function or GI disease that might alter
             significantly the absorption of midostaurin

          -  Cardiac or cardiac repolarization abnormality

          -  Pregnant or nursing (lactating) women

          -  Women of child-bearing potential, unless they are using highly effective methods of
             contraception during dosing and for 4 months after stopping medication Other
             protocol-defined Inclusion/Exclusion criteria may apply.