RecruitingPhase 2Drug trialRisk-ADAPTed Conditioning Regimen for Allogeneic Hematopoietic Stem Cell TransplantationThis is a prospective, single-arm, phase II study. Patients will be treated with an allogeneic stem cell transplantation (AHSCT) using fludarabine, melphalan and total body irradiation (TBI) conditioning with different melphalan and TBI doses based on patient- and disease-related risk.