Allogeneic Stem Cell Transplantation (SCT) With Treosulfan, VP-16 and Cyclophosphamid for Patients With Acute Lymphoblastic Leukemia (ALL)

Inclusion Criteria: * Acute lymphoblastic leukemia in first or subsequent complete remission * Indication for allogeneic stem cell transplantation according to the actual protocol of the German Acute Lymphoblastic Leukemia Study Group * Patient's age: 18-65 years * HLA-identical or compatible related or unrelated donor (HLA-A, HLA-B, HLA-C, HLA-DRB1 and HLA-DQB1) (one antigen-mismatch allowed) * Not eligible for total-body irradiation due to one of the following reasons: * prior radiation of the spine \> 30 Gy * prior radiation of the mediastinum \> 30 Gy * severe pulmonary infection during induction chemotherapy * DLCO \> 50% * Patient's wishing to avoid total-body irradiation as conditioning regimen * Patient's written informed consent * Women and men capable of reproduction must agree to use highly effective methods of contraception until six months after treatment termination. For men: vasectomy, sexual abstinence, or partner is using hormonal IUD, implants, injectables, oral hormonal contraceptives or is surgically sterilized. For women: hormonal IUD, implants, injectables, sexual abstinence, surgical sterilization, vasectomised partner Exclusion Criteria: * No complete remission at time of registration * Severe irreversible renal, hepatic, pulmonary or cardiac disease, such as * total bilirubin, SGPT or SGOT \> 3 times upper the normal level * Left ventricular ejection fraction \< 30% * Creatinine clearance \< 30 ml/min * DLCO \< 35% and/ or receiving supplementary continuous oxygen * Positive serology HIV * Pregnant or lactating women * Severe florid infection * Experienced hypersensitivity against cyclophosphamid, etoposide, or treosulfan * Cystitis * Obstructive renal function * Participation in any other clinical drug trial * Serious psychiatric or psychological disorders * Progressive invasive fungal infection at time of registration