Efficacy and tolerability of imatinib mesylate in pediatric chronic myeloid leukemia in a large cohort: Results from a tertiary care referral center in India

Abstract

10047 Background: Chronic myeloid leukemia (CML) is a rare disease in children and there is limited data of safety and efficacy of imatinib mesylate (IM) in this age group. Methods: We analyzed the outcomes of 48 consecutive children (September 1998 to December 2008) in chronic phase (CP) or accelerated phase (AP) CML not eligible for Allo-SCT and were treated with IM [Glivec (Novartis), through patient assistance programme GIPAP or Veenat (NATCO), generic brand for GIPAP ineligible patients] within 12 months of diagnosis. The dose of IM was 260 mg/m2(maximum 400 mg) per day. Results: The median age at the time of diagnosis was 12 years (range 3–18 years). Of 48 patients, (34 males and 14 females) 46 were in CP and 2 in AP. Forty-three patients (89.5 %) achieved complete cytogenetic response (CCR) at median time of 10 months (range 3–31 months). Five patients (10 %) had hematological response but did not have CCR, of which 2 progressed to AP and 1 had hematological relapse. One patient had secondary IM resistance and had progressive disease even on dose escalation. Two patients in AP at diagnosis achieved CCR at 5 and 7 months and continue to be in CCR. Thirty-one out of 35 patients on Glivec and 12 out of 13 patients on Veenat achieved CCR. At a median follow up 29 months, the event free survival and overall survival was 74.1% and 100 % respectively. IM was well tolerated with grade III and IV neutropenia and thrombocytopenia seen in 2 and 7 patients respectively. Significant non hematological toxicities were uncommon except for hypopigmentation which was seen in more than half the cohort. Conclusions: Results from this largest single center study indicate that outcome of children with CML receiving IM is similar to adults. This data will be especially useful for financially challenged patients in developing countries where Allo-SCT is still not an affordable option while generic brand of IM seems to be feasible alternative. No significant financial relationships to disclose.