Effects of nilotinib on height and safety in children with chronic myeloid leukemia.

This study assessed the safety and impact on the growth of nilotinib (Tasigna) in children with chronic myeloid leukemia (CML). The data indicated reduced growth rates with nilotinib treatment in children with CML.

Chronic myeloid leukemia (CML) is rare in children. However, it affects younger patients more aggressively than adults. Nilotinib, imatinib (Gleevec), and dasatinib (Sprycel) are tyrosine kinase inhibitors (TKIs) approved for the treatment of CML in both adults and children. Although TKIs target specific proteins on cancer cells, longer exposure times to TKIs which are common in younger patients may lead to unwanted effects including reduced growth rates and affected puberty.

Previous studies of older generations TKIs such as imatinib and dasatinib showed that there is a reduction in growth rate in children with CML receiving these treatments. However, fewer information exists on the effects of nilotinib on growth and other side effects in younger patients with CML.

This study included 58 patients younger than 18 years of age with CML. 33 had chronic phase CML (CP-CML) resistant to or intolerant of imatinib or dasatinib (group 1). 25 patients were newly diagnosed patients with CP-CML. All patients received nilotinib treatment with 230 mg/m² twice daily for at least 48 cycles of 28 days. All patients had regular height measurements and any side effects were evaluated.

A significant reduction in growth was seen over time compared to the beginning of the study in both groups. Patients in group 1 were shorter than group 2 at the beginning of the study and remained like this throughout the study. No impact on weight and bone density was seen with nilotinib treatment. 

The most common side effects were increased blood bilirubin (product of red blood cells breakdown; 53.4%), headaches (46.6%), fever (37.9%), and increased liver enzymes (indicated liver damage; 36.2%).

This study showed that reduced growth rates occurred with nilotinib in children with CML.

This study had a relatively small number of patients. This study was funded by Novartis, the manufacturer of nilotinib.