Response to imatinib mesylate in childhood chronic myeloid leukemia in chronic phase.

introductionChildhood chronic myeloid leukemia (CML) accounts for less than 3% of all childhood leukemias, hence, data on imatinib (IM) in adult CML patients has been largely extrapolated to children. We have analyzed our data to add to the existing literature.

aimsPrimary objective is to assess the progression-free survival (PFS). Secondary objective are cytogenetic response, overall survival (OS), and toxicities. SETTINGS AND

designThis is a retrospective analysis from the case records from a single institution. MATERIALS AND

methodsInstitutional ethics committee approval was obtained. All the children diagnosed CML in chronic phase (CML-CP) aged less than 18 years registered between 2000 and 2009 were enrolled. All the patients were started on IM at 260 mg/m(2). STATISTICAL ANALYSIS: Kaplan-Meier curves were used to calculate the PFS and OS.

resultsThere were 64 children with median age of 13 years (range, 1-18) with male predominance (male:female (M: F) - 1.85:1). Sixty-one patients (95.4%) achieved complete hematological response (CHR) at median of 8 weeks. Thirty-seven (57.8%) patients had evaluation of cytogenetic response and were subjects for outcome analysis. The median time to best cytogenetic response evaluation was 13 months (range, 4-52). Twenty-nine patients (78.3%) achieved complete cytogenetic response (CCyR). At a median follow-up of 36 months (range 5-75), 21 (56.8%) remained progression free and 35 (94.5%) are alive. Adverse events were tolerable.

conclusionsPFS at a median follow-up of 36 months is 56.8% and OS 94.5%.