Study of Decitabine Alone or in Combination With Valproic Acid and All-trans Retinoic Acid in Acute Myeloid Leukemia

Inclusion Criteria: 1. Written informed consent obtained according to international guidelines and local law; 2. Male or female patients aged \> 60 years without upper age limit; 3. Patients with primary or secondary AML according to WHO (≥ 20% blasts in the peripheral blood (pB) or bone marrow (BM)) who are not expected to benefit from standard remission-induction chemotherapy; 4. Patients with \< 30 000 leukocytes/μl; 5. Performance status ECOG 0, 1, 2; 6. Creatinine \< 2.0 mg/dl (unless leukemia-related); 7. Ability to understand the nature of the study and the study related procedures and to comply with them. Exclusion Criteria: 1. AML of FAB subtype M3; 2. Previous remission-induction chemotherapy for MDS or AML, previous allografting; 3. Previous treatment with DAC, 5-azacytidine, VPA or another HDAC inhibitor, or ATRA; 4. "Low-dose" chemotherapy (e.g. hydroxyurea, cytosine arabinoside (Ara-C), melphalan, clofarabine etc.) within 4 weeks prior to DAC treatment, except for cytoreduction of leukocytosis ≥ 30 000/μl with hydroxyurea or Ara-C as proscribed by the study protocol (section 7.3 and 7.4); the patient must have recovered from all clinically relevant reversible non-hematologic toxicities; 5. Treatment with tyrosine kinase inhibitors, immunomodulating agents (IMIDS) or other investigational AML treatment within the last 4 weeks or in a time period of drug half-life x 5 (whatever is shorter) before the first administration of DAC; 6. Treatment with cytokines within previous 4 weeks; 7. Concomitant therapy which is considered relevant for the evaluation of efficacy or safety of the trial drug (i.e. other chemo- or immunotherapy); 8. Other malignancy requiring treatment (previous chemotherapy for other malignancies is not an exclusion criteria); 9. Cardiac insufficiency NYHA IV; 10. Insufficient hepatic function (bilirubin, AST or ALT \> = 2.5 x Upper Limit of Normal (ULN)) (unless leukemia-related); 11. Fatal hepatic function disorder during treatment with valproic acid in siblings; 12. Hepatic porphyria; 13. Manifest serious pancreatic function disorder; 14. Plasmatic coagulation disorder not related to AML; 15. Known active hepatitis B or C; 16. Known HIV infection; 17. Other uncontrolled active infections; 18. Known allergy against soy beans or peanuts; 19. Psychiatric disorder that interferes with treatment; 20. Patient without legal capacity who is unable to understand the nature, significance and consequences of the study; 21. Known hypersensitivity to, or intolerance of, one of the trial drugs, another retinoid or the excipients of the trial drugs; 22. Concomitant use of any other investigational drug or participation in a clinical trial within the last thirty days before the start of this study; simultaneous participation in registry and diagnostic trials is allowed; 23. Female patients who are pregnant or breast feeding; 24. Fertile patients refusing to use safe contraceptive methods during the study (for details see clinical trial protocol section 5.3); 25. Known or persistent abuse of medication, drugs or alcohol.