FLAT-Auto is a phase II trial. fludarabine and ARA-C will be combined with the alkylating agent treosulfan (FLAT), to investigate the feasibility and the efficacy of a new regimen, supported with autologous peripheral blood SCT (PBSCT), as final postremission consolidation in AML/MDS elderly patients.

Inclusion Criteria:

• Pts with de novo or secondary AML or with Int 2 or High risk MDS according to IPSS.
• Pts unable or unfit to receive SCT from an HLA (human leukocyte antigen)-identical related (SIB) or unrelated (MUD), or HLA-haploidentical related (HAPLO) donor.
• Hematologic CR (Appendix D) after 1 or 2 cycles of induction standard chemotherapy.
• Successful collection of autologous PBSC: ≥ 5.0x10e6 /kg patient bodyweight (BW)
• Age ≥ 65 years.
• Performance status 0-2 ECOG (Eastern Cooperative Oncology Group), 60-100% Karnofsky (Appendix E).
• Written informed consent.

Exclusion Criteria:

• Diagnosis of AML M3.
• Second concomitant malignancies.
• Severe concomitant illnesses/medical conditions (e.g. impaired respiratory and/or cardiac function).
• Known and manifested malignant involvement of the central nervous system (CNS)
• Active infectious disease
• HIV- positivity or active hepatitis infection
• Impaired liver function (bilirubin > 1.5 x 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).
• Known hypersensitivity to treosulfan and/or cytarabine and/or fludarabine
• Participation in another experimental drug trial within 4 weeks before day -6
• Non-cooperative behaviour or non-compliance
• Psychiatric diseases or conditions that might impair the ability to give informed consent