A Trial to Find and Investigate a Safe Dose of BI 836858 in Combination With Decitabine for Patients With Acute Myeloid Leukemia (AML)

Inclusion criteria:

1\)

Phase I Dose Escalation:

* Male or female patients \>/= 18 years of age with relapsed or refractory AML
* Male or female patients \>/= 65 years of age with previously untreated AML ineligible for receiving standard intensive therapy

Phase I Extension and Phase II:

\-- Male or female patients \>/= 65 years of age with previously untreated AML ineligible for receiving standard intensive therapy

2\) Histologically or cytologically confirmed AML according to the WHO classification 3) Patients must be eligible for treatment with decitabine 4) Eastern co-operative oncology group (ECOG) performance score \</=2 at screening Further inclusion criteria apply.

Exclusion criteria:

1. Acute promyelocytic leukemia (APL, French-American-British (FAB) subtype M3), according to WHO classification.
2. Patients who are candidates for allogeneic stem cell transplantation.
3. Active chronic graft versus host disease requiring immunosuppressive treatment.
4. Phase I extension and Phase II only:

   Prior treatment with a hypomethylating agent, such as prior treatment for Myelodysplastic Syndrome (MDS).
5. Prior treatment with Cluster of differentiation 33 (CD33) antibody. Further exclusion criteria apply.