Abstract A68 Background Childhood cases (<18yrs of age) represent approximately 2% of all patients who develop chronic myeloid leukemia (CML). The disease in children is similar in behavior to that of adults, however the outcome of treatment with stem cell transplant is better in young individuals. The aim of our study was to see the molecular response of CML with imatinib mesylate therapy. Materials and Methods During the period from January 2003 to December 2007 we selected 56 cases of pediatric chronic myeloid leukemia who could not afford bone marrow transplant treatment in the pediatric Haemato-Oncolgy Department of Netaji Subhash Chandra Bose Cancer Research Institute, a tertiary cancer center from eastern India. All cases were Philadelphia chromosome and bcr/abl molecular transcript positive. The distribution of patients in the age group 1-5, 6-12 & 12-18 were 4 (7.14%), 15 (26.79%) and 37 (66.07%) respectively. The dose of imatinib mesylate (Veenat in Natco Pharma) given was 100 mg in 1-5 yrs, 200 mg in 6-12 yrs and 400 mg in older children. The maximum duration given was 5 years. bcr/abl molecular testing was done by RT-PCR method. In all patients it was done before diagnosis at 6 months, 1 year and then yearly up to 5years. Result With median follow up of 25 months (range 4 months - 48 months), Twenty-five children (44.64%) showed complete molecular response. Sixteen patients (28.57%) showed complete hematological, partial cytogenetic and partial molecular response. Eleven patients (19.64%) showed partial haematological response only. Four patients (7.14%) died during treatment because of blast crisis. Conclusion Imatinib is a good curative drug in chronic myeloid leukemia in pediatric patients. Citation Information: Cancer Prev Res 2008;1(7 Suppl):A68.