Imatinib Has a Negative Impact On Growth In Children With Previously Untreated Chronic Myeloid Leukaemia (CML) In Early Chronic Phase (CP): Results Of The French National Study

The French pediatric CML working group conducted a retrospective study analysing the growth of patients under 18 years with CML treated with imatinib front-line.

Data from 78 patients receiving imatinib (260 mg/m²) for newly diagnosed CML in chronic phase between July 2001 and August 2012 were collected. Height was expressed as standard deviation score (SDS). Height SDS was calculated using French growth standard, as patient height minus mean height for age and sex, divided by standard deviation of height for age and sex. Pre-pubertal age was defined as being younger than 9 years for girls or 11 years for boys.

A gradual decrease in the median of the height SDS score is observed over time since the start of imatinib. Sixty three patients were assessable for paired analysis at onset of imatinib and 12 months later. The median height-SDS in this group of patients was significantly lower (p < 10^-4) 12 months after the start of imatinib. Variance analysis was performed in 36 children at onset of imatinib, 12 months and 24 months later. The median height-Z score in this group of patients was significantly lower 12 months and 24 months after the start of imatinib (p < 10^-4) compared to initial diagnosis. The 63 patients assessable for paired data analysis at onset of imatinib and 12 months later were classified by sex and pubertal status. The median height Z score in boys and girls was significantly (p < 10^-4) lower 12 months after the start of imatinib. When the patients were analysed according to the pubertal status at onset of imatinib, the median height SDS score was significantly (p < 10^-4) lower 12 months after the start of imatinib in the prepurbertal group as well as in the postpubertal group. A similar finding was observed in the subgroups of boys and girls starting imatinib at a prebubertal or postpubertal age. No significant difference was observed when the median M12 height SDS score in patients who started imatinib at a prepubertal stage or a pospubertal stage were compared. Moreover, no significant difference was observed when the median M12 height-Z score in boys and girls were compared.

This retrospective analysis revealed a statistically significant deceleration in growth during the first 2 years of imatinib treatment in children and adolescents with CML and an absence of influence of sex and pubertal status on the depth of growth deceleration.

No relevant conflicts of interest to declare.