1102 - Chronic Myeloid Leukemia in Children- Experience with Imatinib Mesylate at a Regional Cancer Institute, Bangalore, India

Abstract

ABSTRACT Background Childhood Philadelphia chromosome-positive (Ph+) CML constitutes about 3- 5% of the total leukemias. Allogeneic stem cell transplantation (SCT) offers best survival but in view of unaffordability and non availability of suitable donor, Imatinib Mesylate becomes the next best treatment option. The present study was thus undertaken to evaluate the clinical profile, response, survival and adverse effects of the drug. Methods This is a retrospective study of Ph + CML in the age group of 4-18 yrs, at Medical & Paediatric Oncology department of our institute.50 patients of CML, enrolled under the Glivec International Patient Assistance Program (GIPAP) between Jan 2004 to Dec 2011 and started on Imatinib at 340 mg /m2/day were analyzed. Complete hemogram, liver function tests, bone marrow aspiration studies and BCR-ABL by RT-PCR were done at intervals as per institution protocol. Results Mean age of patients enrolled in the study was 12.8 yrs. Mass and pain abdomen were the predominant presentations in 21(42%) and 18(36%) respectively. One patient each was in accelerated phase and blast crisis. Complete Hematological Response (CHR) was achieved in 100% with 43 (86%) within 3 months. Complete cytogenetic response was achieved in 20(40%) with median duration of 14 months (8-18).13(26%) patients showed Major molecular response with a median of 16 months (6-29) & complete molecular response in 4 (8%) with a median of 21 months(16-22). One out of 4 patients with progressive disease is in blast crisis waiting for transplantation, 3 are on escalated dose of Imatinib and either Cytarabine or Interferons to maintain CHR. All 4 were negative for Imatinib Mutations. Most common adverse events were grade 1/2 skin toxicities and weight gain in about 40% of patients. About 8 (16%) patients had grade2/3 myelosupression which was manageable. Event free survival and overall survival were 94.4% and 64% at a median follow up of three years.Sokal score was evaluated with respect to the survival outcome but was not found to be statistically significant. Conclusions In view of good response and tolerance, our results reaffirm previously reported favorable results from various other centers. Imatinib can be considered as an alternative to SCT in Pediatric CML population to improve the survival and merits further evaluation. Disclosure All authors have declared no conflicts of interest.