- Inclusion criteria: at registration· Chronic myeloid leukaemia Ph+ confirmed by cytogenetic analysis or BCR-ABL translocation by molecular biology· Chronic phase:-<15% blast cells in blood and 5% in bone marrow-<30% blast cells+promyelocyte cells in blood and bone marrow-<20% basophils in blood->100.000 platelets· Without extra medullar attempt excepted hepatosplenomagalia· First line of treatment· Biology and biochemistry with normal levels· Male or female>18 years old· Signed written consent· ECOG<3At inclusion· Chronic myeloid leukaemia with cytogenetic response without molecular response after one year of treatment by imatinib and BCR-ABL transcript detected by RT-PCR