Study of a Reduced-toxicity "Submyeloablative" Conditioning Regimen Prior to Allogeneic Stem Cell Transplantation in Patients With Hematological Malignancies

Inclusion Criteria: * Patients affiliated to a social security reimbursement system * Adults (men or women) aged between 18 and 65 years * Negative test for pregnancy * ECOG 0-1 or Karnofsky Index ≥ 70% * Availability of an HLA-identical sibling donor, or an HLA-matched unrelated donor (10/10 HLA compatibility in A, B, C, DRB1, DQB1 (a single allelic mismatch at the level of Cw can be accepted) * Life expectancy \> 6 months * Signed informed consent * Diagnosis of an hematological malignancy that is considered to be eligible for an allogeneic stem cell transplantation Exclusion Criteria: * Pregnant woman or not willing to take effective contraception * Classical contra-indications to the allogeneic stem cell transplantation procedure * Any contra-indication to the use of the drugs contained within the conditioning regimen according to the summary of product characteristics * Patients aged \< 50 years and deemed to be eligible for a "standard" or conventional myeloablative conditioning regimen * An HLA-matched sibling donor who has a contra-indication for stem cell mobilization and collection * History of uncontrolled psychiatric condition * Patients who have participated to another trial testing an experimental drug within one month prior to inclusion in this protocol.