Can a gentler chemo prep make stem cell transplants safer for blood cancer patients?

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

Inclusion Criteria: 1. Patients with a haematological chemosensitive malignancy indicated for an allogeneic transplantation, but presenting an increased toxicity risk for classical (high-dose busulfan or standard-dose total body irradiation) conditioning therapies (remission criteria ref. to Appendix L): * CML in first or subsequent chronic phase * NHL in 2nd CR/PR, chemosensitive PR after autologous transplantation ; CLL in 2nd or subsequent CR/PR * Relapsed Morbus Hodgkin (MH) after autologous transplantation * Multiple Myeloma (MM) stage II and III according to Durie and Salmon * AML in 2nd CR/PR or high-risk AML in 1st CR/PR High-risk defined for example by the following: * Cytogenetics: -5/5q, -7/7q, del(5q), abnormalities of 3q, complex karyotype (\> 3 abnormalities), or * PR after 1 cycle of induction therapy * ALL in 2nd CR/PR or high-risk ALL in 1st CR/PR High-risk defined as follows: * Leukocytes \> 3000/µl (B-Linage) or \> 100000/µl (T-Linage); * Pro-B-ALL, pre-T-ALL * Cytogenetics: t(9;22)/BCR-ABL; t(4;11)/ALL1-AF * MDS (patients without prior chemotherapy may be included) 2. Availability of an HLA-identical sibling donor (MRD) or HLA-identical unrelated donor (MUD) or one mismatch (out of the 6 standard markers) sibling donor (1 misMRD): • HLA-identity defined by the following markers: A, B, DRB1. DQB1 must be recorded. 3. Age \> 18 years 4. Karnofsky Index \> 80 % 5. Adequate contraception in female patients of child-bearing potential 6. Co-operative behavior of individual patients 7. Written informed consent Exclusion Criteria: 1. Completely chemotherapy-resistant disease 2. Severe cardiac insufficiency, severe cardio-vascular or other severe concomitant diseases 3. Symptomatic malignant involvement of the CNS 4. Active infectious disease 5. HIV-positive or active hepatitis infection 6. Impaired liver function (Bilirubin \> 1.5 x upper normal limit; Transaminases \> 3.0 x upper normal limit) 7. Impaired renal function (Creatinine-clearance \< 60 ml/min; Serum Creatinine \> 1.5 x upper normal limit). 8. Pleural effusion or ascites \> 1.0 L 9. Pregnancy or lactation 10. Known hypersensitivity to fludarabine and/or treosulfan 11. Parallel participation in another experimental drug trial