Imatinib in the Treatment of Chronic Myeloid Leukemia in Children and Adolescents is Effective and well-tolerated. Report of the Polish Pediatric Study Group for Treatment of Leukemias and Lymphomas

Chronic Myeloid Leukemia (CML) constitutes only 2-3% of all leukemias in pediatric patients. Philapelphia chromosome and BCR-ABL fusion are genetic hallmarks of CML, and their presence is crucial for targeted molecular therapy with Tyrosine Kinase Inhibitors (TKI), which replaced Hematopoietic Stem Cell Transplantation (HSCT) as a standard first-line therapy. The disease in pediatric population is rare, and despite molecular and clinical similarities different approach is warranted due to long lifetime expectancy and distinct developmental characteristics of affected children. We have analyzed the results of treatment with imatinib in 57 pediatric patients from 14 Polish Pediatric Hematology Oncology Centres. In the study group 40 patients (pts) continue imatinib (median follow-up 23.4 months) while in 17 the treatment was terminated (median follow-up 15.1 months) due to therapy failure. In the latter group, 13 pts underwent HSCT while 4 switched to second-generation TKIs. 5-year Overall Survival (OS) in the study group was 96% and 5-year Event-Free Survival (EFS) 81%.