Imatinib has adverse effect on growth in children with chronic myeloid leukemia

Long-term adverse effects of Imatinib in children with chronic myeloid leukemia (CML) are uncertain. The aim was to study the effect of imatinib on growth in children with CML.

Children ≤13 years of age at diagnosis were enrolled retrospectively, from 2004 to 2011, from a single center in India. Patients who received imatinib for >1 year were included for growth assessment. Height standard deviation scores (SDS) were derived from WHO-AnthroPlus, a global growth monitoring tool.

Thirty-four children received imatinib. Twenty children fulfilled the criteria for assessment of growth. Median age was 10 years (range: 2-13). Of 20 children, 13 were prepubertal at commencement of imatinib. The mean duration of imatinib in 20 children was 61.3 ± 16.2 months (range: 31-83). No patient was treated with a second-generation tyrosine kinase inhibitor or a stem cell transplant. Highly significant reduction in height SDS's was observed (P = 0.002 at 5th year). Children who started imatinib therapy after the onset of puberty were immune to this adverse effect (P = 0.448 and 0.003 at 5th year of treatment for pubertal and prepubertal children, respectively). The 5-year survival probability of 33 children who received imatinib in chronic phase was 80% with a median survival time of 60 months (mean: 70.2; 95% CI: 60-80.5).

Growth retardation is a significant adverse effect of imatinib in children with CML. The failure to gain appropriate height was most discernible when imatinib was initiated in the prepubertal period. Etiology and remedial measures need to be investigated.