Efficacy and safety of 5-Azacytidin in the treatment of the haematological relapse in patients suffering from acute myeloid leukaemia or myelodysplastic syndrome with falling CD34-chimerism after hematopoietic stem cell transplantation.

Inclusion Criteria:

Screening phase:

• Age > 18 years
• Patients with CD34+ AML or MDS post-allogeneic HSCT
• Written patient consent after consultation

Treatment phase

• AML/MDS: donor chimerism < 80% in the CD34+ subpopulation following allogeneic HSCT in patients with CD34+ AML or MDS, but with no haematological relapse (blasts < 5% in bone marrow)
• Leukocytes > 3 Gpt/l and platelets > 75 Gpt/l (transfusion-independent)

Exclusion Criteria:

• Known intolerance to 5-azacitidine or mannitol
• Uncontrollable infectious disease
• Patients with active hepatitis B or C or HIV infection
• Severe hepatic function impairment (ASAT and ALAT may not be above three times the normal value) or hepatic cirrhosis, or malignant hepatic tumour
• Renal function impairment (creatinine > twice the normal value, creatinine clearance < 50 ml/min)
• Pregnancy or lactation
• Women of childbearing age, except for those who meet the following criteria:
• postmenopausal (12 months natural amenorrhoea)
• postoperative (6 weeks after bilateral ovarectomy with or without hysterectomy)
• regular and correct use of a contraceptive method with an error rate < 1% per year (e.g. implants, depot injections, combined oral contraceptives, intrauterine device - IUD, whereby hormonal coils with a Pearl Index of < 1% are safer than copper coils)
• sexual abstinence
• Partner vasectomy
• Men who do not use one of the following for contraception:
• sexual abstinence
• post vasectomy
• condoms
• Participation of the patient in a drug trial outside the indication of allogeneic transplantation up to four weeks before study initiation
• Addictive or other illnesses that prevent the person concerned from comprehending the nature and impact, as well as potentical consequences of the clinical trial
• Evidence that the patient may intentionally not comply with the protocol, e.g. lack of cooperation With the exception of a known allergic reaction or intolerance to 5-azacitidine, these criteria do not apply to the screening phase.