Decitabine in Patients With Chronic Myelomonocytic Leukemia (CMML)

Inclusion Criteria: * Age 18 or older * CMML diagnosis according to WHO criteria * Stable excess in blood monocytes,\>1x10G/l and \>10% of WBC * Bone marrow blasts \<20% * Dysplasia of at least one lineage or clonality marker or blood monocytosis during more than 3 months w/o other explanation * With: * if WBC \< or= 12 000/mm3: IPSS high or intermediate 2 * if WBC \> 12 000/mm3: at least two of the following criteria: blast cells \> 5% in the bone marrow, clonal cytogenetic abnormality other than t(5;12)(q33;p13), anemia (Hb \< 100 g/l), thrombocytopenia (platelet count \< 100G/l), splenomegaly \> 5 cm below costal margin, extramedullary localization * Either untreated or previously treated with * Hydrea or Etoposide given orally * non intensive chemotherapy * intensive chemotherapy given more than 3 months before inclusion * With performance status 0-2 on the ECOG scale * With estimated life expectancy of at least 12 weeks * With adequate organ function including the following: * Hepatic: total bilirubin \< 1.5 times upper limit of normal (ULN), alanine transaminase (ALT) and aspartate transaminase (AST) \< 3 times ULN * Renal: serum creatinine \< 1.5 times ULN, creatinine clearance \> 30 ml/min * With informed consent * Negative pregnancy and adequate contraception if relevant Exclusion Criteria: * Myeloproliferative/myelodysplastic syndrome other than CMML * Acute blastic transformation of CMML with bone marrow blasts\>20% * Patients eligible for allogenic bone marrow transplantation with identified donor * CMML with t(5;12) or PDGFbetaR rearrangement that could receive Imatinib * Previous treatment with a hypomethylating agent * Age \< 18 years old * Pregnancy or breastfeeding * Performance status\> 2 on the ECOG Scale * Estimated life expectancy \< 12 weeks * Serious concomitant systemic disorder, including active bacterial, fungal or viral infection, that in the opinion of the investigator would compromise the safety of the patient and/or his/her ability to complete the study