OBJECTIVETo evaluate the efficacy and safety of imatinib in the treatment of adult patients with chronic granulocytic leukemia (CGL) in accelerated phase.

METHODSThirty patients with CGL in accelerated phase were orally administered with imatinib 400 or 600 mg daily for 7 approximately 9 months.

RESULTSHematological responses occurred in 28 of 30 patients (93.3%) in the treatment: 14 (46.7%) had a complete hematological response, 10 (33.3%) had a marrow response, and 4 (13.3%) returned to chronic phase. Bone pain and splenomegaly disappeared soon after the administration of imatinib. Eight patients relapsed 30 approximately 172 days after hematological responses. Six of them received imatinib with daily dose increment to 800 mg. Four of these 6 patients had no response and 2 returned to chronic phase again. The risk factors for relapse were blasts > or = 15% in bone marrow or in peripheral blood, extramedullary leukemia involvement, hemoglobin < 100 g/L before the administration of imatinib, and lack of a complete hematological response after the treatment. Cytogenetic remission occurred in 6 of 27 patients (21.4%) after 3 months treatment: 4 (14.3%) were complete cytogenetic response and 2 (7.1%) major cytogenetic response. Mild non-hematologic adverse effects occurred in most of the patients, but were manageable and tolerable, or disappeared automatically. Severe neutropenia or thrombocytopenia appeared in more than half of the patients.

CONCLUSIONSImatinib has substantial activity and is well-tolerated in the treatment of accelerated phase of CGL.