Higher dose imatinib for children with de novo chronic phase chronic myelogenous leukemia: a report from the Children's Oncology Group

Abstract

Purpose: To determine the efficacy of imatinib in children with newly diagnosed chronic phase (CP) chronic myelogenous leukemia (CML).

Methods: This was an open label, multi-center phase II clinical trial. Courses were defined as consecutive 28-day intervals. Oral imatinib was administered daily at 340 mg/m² without interruption in the absence of toxicity.

Results: Fifty-one children received 978 28-day courses of imatinib. The most common toxicities encountered were hematologic. Forty-one patients (80%) achieved a complete hematologic response by the end of course 2. Nineteen children (38%) obtained a complete cytogenetic response (CCyR) at the end of course 3. Overall, 72% achieved CCyR at a median time of 5.6 months. The rate of complete molecular response (>3 log reduction) was 27%. Progression-free and overall survival at 3 years were 72% ± 6.4% and 92% ± 3.9%, respectively.

Conclusions: Daily oral imatinib at a dose of 340 mg/m² is well tolerated in children. In addition, imatinib therapy is effective in inducing a high percent of hematologic, cytogenetic and molecular responses, comparable to adults with CML. (This study was registered at ClinicalTrials.gov under identifier NCT00030394.).

Conflict of interest statement

Nothing to declare.

Copyright © 2011 Wiley-Liss, Inc.

Figures

Fig. 1

Primary endpoint for this study was a major cytogenetic response at end-of-course-3. The end-of-course-3 cytogenetic response (CyR) could not be determined for 19 patients. Of 32 evaluable patients for CyR at end-of-course-3, 12 achieved complete CyR, 10 achieved partial CyR, 8 achieved minor/minimal responses, and 2 had no response. The development of CyR following end-of-course 3 is schematized in this figure.

Fig. 2

Overall survival and progression-free survival (N = 51).