Inclusion Criteria:

- Patients with acute myeloid leukaemia (AML) according to WHO classification (> 20%
myeloblasts in peripheral blood or bone marrow at initial diagnosis) with < 5%
myeloblast in the bone marrow, indicated for allogeneic transplantation

- Availability of an HLA-identical sibling donor (MRD) or HLA-identical unrelated donor
(MUD) HLA-identity defined by the following markers: A, B, DRB1, DQB1.

- Target graft size (unmanipulated)

- bone marrow: 2 - 10 x 106 CD34+ cells/kg BW recipient or > 2 x 108 nucleated cells/kg
BW recipient or

- peripheral blood: 4 - 10 x 106 CD34+ cells/kg BW recipient

- Age > 18 and < 60 years

- Karnofsky Index > 80 %

- Adequate contraception in female patients of child-bearing potential

- Written informed consent

Exclusion Criteria:

- Therapy related secondary AML

- AML with t(8;21)(q22;q22) in CR1

- Acute promyelocytic leukaemia with t(15;17)(q22;q12) in CR1

- Secondary malignancies

- Previous allogeneic transplantation

- Severe concomitant illnesses / medical conditions (e.g. impaired respiratory and/or
cardiac function)

- Known and manifested malignant involvement of the CNS

- Active infectious disease

- HIV- positivity or active hepatitis infection

- Impaired liver function (Bilirubin > upper normal limit; Transaminases > 3.0 x upper
normal limit)

- Impaired renal function (Creatinine-clearance < 60 ml/min; Serum Creatinine > 1.5 x
upper normal limit).

- Pleural effusion or ascites > 1.0 L

- Pregnancy or lactation

- Known hypersensitivity to treosulfan and/or fludarabine

- Participation in another experimental drug trial within 4 weeks before day -6

- Non-co-operative behaviour or non-compliance

- Psychiatric diseases or conditions that might impair the ability to give informed
consent