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