Treatment With ABT-199 (Venetoclax) and Purine Analogues in Relapsed/Refractory Acute Myeloid Leukemia

Inclusion Criteria: * Relapsed or refractory AML * Relapsed after or refractory to at least one cycle of intensive chemotherapy (combination of ara-c/anthracyclin) or four cycles of HMA (hypomethylating agents) * Adult AML aged \>/= 18 years * WHO performance status: grade 0-2 at the time of enrollment * ABT-199 (venetoclax) and PA-naïve. Patient may be prior exposed but not refractory to venetoclax. In case of previous therapy with venetoclax inclusion is only possible after discussion with the PI. Exclusion Criteria: * Participation in any other interventional clinical trial during the study period * Active presence (or known history of) central nervous system disease * History or concomitant presence of any other malignancy, except for non-melanoma skin cancer, carcinoma in situ of the cervix, any other effectively treated malignancy that has been in remission for \>5 years or that is highly likely to be cured at the time of enrollment. * Active HIV, hepatitis B or hepatitis C infection * Use of any antitumoral agent within less than 5 times the half-life of the agent prior to the screening bone marrow examination. After the screening bone marrow examination, the use of cytoreductive treatment prior to the initiation of venetoclax is permitted in order to lower the WBC-count to \<25 000/µl (e.g. hydroxyurea). * Medical conditions requiring chronic therapy of moderate or strong CYP3A4 inducers without alternative * Patients with known hypersensitivity to the active substance or to any of the excipients * Pregnant or breastfeeding woman * Active uncontrolled systemic infection