Evaluating nilotinib and dasatinib in pediatric patients with chronic myeloid leukemia

This study evaluated the effectiveness and safety of second-generation tyrosine kinase (TK) inhibitors after imatinib (Gleevec) therapy in children and adolescents with chronic myeloid leukemia (CML). The authors concluded that second-generation TK inhibitors may be a viable first-line treatment option for these patients.

Second-generation TK inhibitors have become a part of standard first-line treatment for chronic phase CML. These include drugs like nilotinib (Tasigna) or dasatinib (Sprycel). This type of treatment is a targeted therapy. This treatment blocks cancer cell survival. This leads to cancer cell death.

Previous studies have shown that nilotinib and dasatinib are effective in adult patients with CML. The effectiveness and safety of these drugs following imatinib therapy in children and adolescents with CML remains under investigation.

This study included the records of 152 Japanese children and adolescents with chronic phase CML. All patients received imatinib as first-line (primary) therapy.

20.39% of patients switched to nilotinib (10.53%) or dasatinib (9.87%) as second-line treatment after an average of 25 months of imatinib therapy. This was due to either poor treatment response or side effects with imatinib. Switches due to side effects occurred significantly earlier than switches due to poor treatment response (7 months vs. 33 months). Patients were followed-up for an average of 64 months. 

Response to treatment improved in 63% of patients who switched from imatinib to nilotinib or dasatinib. 45.2% of patients had a complete response (no signs of CML). 48.3% of patients had a partial response (some signs or symptoms of CML remain). 25.8% of patients later switched again to another TK inhibitor.

Most reported side effects were mild to moderate. Significantly more patients treated with nilotinib experienced jaundice (yellow appearance of the skin and eyes because of too much of the pigment bilirubin in the blood) compared to patients treated with dasatinib (33% vs. 0%). More patients treated with dasatinib experienced muscle or joint pain compared to patients treated with nilotinib (80% vs. 33.3%).

The authors concluded that second-generation TK inhibitors may be a viable first-line treatment option for children and adolescents with chronic phase CML.

This study was retrospective, meaning it looked back in time to analyze data. This study only included Japanese patients, so the results may not be applicable to all patients.

This study analyzed data for only 31 out of 152 patients who switched from imatinib to another TK inhibitor. This patient population is quite small. Larger studies are needed to confirm these results.