Older patients with acute myeloid leukemia (AML) have a small (< 10%) chance of long-term survival. Despite the treatment of elderly AML patients with intensive chemotherapy, the survival has not been improved during the last decades.

The purpose of this study is to determine whether frontline therapy with a 10-day decitabine schedule provides a better survival than standard intensive combination chemotherapy in elderly AML patients (>= 60 years).

• The overall survival (OS) of older AML patients has not been improved during the last decades with intensive chemotherapy based on cytarabine combined with an anthracycline ("3+7").
• Next generation sequencing technology reveals that mutations in genes involved in epigenetics are frequently mutated in AML (e.g. DNMT3a), suggesting an important role of epigenetics in the pathophysiology of AML. Decitabine (given in a 5-day schedule) has been shown to be superior to low-dose Ara-C.
• A retrospective analysis revealed that epigenetic therapy (either azacitidine or decitabine) is associated with similar survival rates as intensive chemotherapy in older patients (n=671) with newly diagnosed AML.
• The recently published encouraging phase 2 data with the 10-day decitabine schedule suggests that decitabine results in similar CR rates compared with intensive chemotherapy. Allogeneic transplantation (alloHCT) also offers the opportunity for cure among older AML patients, therefore treatment strategies should aim to allograft older AML patients.
• Decitabine treatment can lead to very interesting cure rates when used as "bridging" to allografting.

Based on the data summarized above, we hypothesize that decitabine at a daily dose of 20 mg/m² starting with the 10-day schedule followed by an alloHCT or by continuation of 5-days decitabine cycles is superior to conventional intensive chemotherapy in older AML patients.

Inclusion criteria:

1. Age ≥ 60 years

2. WHO Performance status ≤ 2

3. Eligible for standard intensive chemotherapy

4. Newly diagnosed AML cytopathologically confirmed to the WHO classification (up to 2 months prior to randomization)

5. De novo or secondary AML is allowed

6. White blood cell (WBC) count is ≤ 30x10E9/L (measured within 72 hours prior to randomization).

7. Laboratory assessments (measured prior to randomization):

   1. serum glutamate oxaloacetate transaminase (SGOT / ASAT) and serum glutamate pyruvate transaminase (SGPT / ALAT) < 2.5 x the upper limit of normal range unless considered AML-related
   2. Total serum bilirubin < 2.5 x the upper limit of normal range unless considered AML-related or due to Gilbert's syndrome
   3. Serum creatinine < 2.5 x the upper limit of normal range unless considered AML-related

8. Patients of reproductive potential should use adequate birth control measures, as defined by investigator, during the study treatment period and for at least 3 months after the last study treatment.

9. Before patient registration/randomization, written informed consent must be given according to the International Conference of Harmonization good clinical practice (ICH GCP) and national/local regulations

Exclusion criteria:

1. Presence of acute promyelocytic leukemia (APL, i.e. AML-M3 with t(15;17)(q22;q12); promyelocytic leukemia - retinoic acid receptor-alpha (PML-RARA) fusion gene and cytogenetic variants)

2. Presence of blast crisis of chronic myeloid leukemia

3. Presence of active central nervous system (CNS) leukemia

4. Patients did not receive any prior treatment for AML (relapsed AML is not allowed), such as any antileukemic therapy including investigational agents and hypomethylating agents (decitabine, 5-azacytidine). Treatment with hydroxyurea (HU) is allowed to control the leukocytosis if given preferably for less than 5 days and is stopped at least two days prior to the start of any of the protocol regimens

5. Patients received any prior treatment for myelodysplastic syndrome (MDS) or myeloproliferative neoplasms (MPN) with:

   1. hypomethylating agents (decitabine, 5-azacytidine), OR

   2. with intensive chemotherapy or transplantation within the last three years

   3. NOTE: The following treatments for previous MDS or MPN are allowed (up to one month before inclusion):

      • Growth factors, thrombomimetics, immunosuppression (cyclosporin A, steroids, antithymocyte globulin etc.), chelation, interferons, anagrelide
      • Lenalidomide, low-dose chemotherapy (low-dose melphalan, HU, low-dose cytarabine etc.), tyrosine-kinase inhibitors, histone deacetylase inhibitors (e.g. valproic acid, panobinostat etc.), mammalian target of rapamycin (mTOR) inhibitors, other experimental treatment that is not based on inhibition of deoxyribonucleic acid (DNA) methyltransferase

6. Presence of concomitant severe cardiovascular disease which would make intensive chemotherapy impossible, i.e. uncontrolled arrhythmias requiring chronic treatment, congestive heart failure or symptomatic ischemic heart disease, reduced left ventricular function assessed by multigated acquisition (MUGA) scan or echocardiogram

7. Presence of any malignancy (except basal and squamous cell carcinoma of the skin) for which the patient received systemic anticancer treatment within 6 months prior to randomization NOTE: Diagnosis of any previous or concomitant malignancy is thus not an exclusion criterion.

8. Presence of active uncontrolled infection

9. Presence of any psychological, familial, sociological or geographical condition in the opinion of the investigator potentially hampering compliance with the study protocol and follow-up schedule; those conditions should be discussed with the patient before registration in the trial