The remarkable response to ponatinib therapy in a child with blastic phase of chronic myeloid leukemia

Background. Chronic myeloid leukemia (CML) rarely occurs in children and adolescents, which shows more aggressive features like high risk of more advanced disease at the time of diagnosis. Suboptimal response to tyrosine kinase inhibitors (TKIs), adverse events, or advanced disease may impede the treatment. Case. Herein we present a nine-year-old chronic phase CML case. He had no major molecular response (MMR) to imatinib, which was switched to dasatinib. MMR was ensured for 24 months, yet he developed a lymphoid blastic phase under dasatinib. He obtained a remarkable response to ponatinib when administered in parallel to multiagent induction chemotherapy. Conclusion. Ponatinib therapy is effective and promising as a bridge to hematopoietic stem cell transplantation in children. Although more studies are necessary to determine indications, dose, efficacy, and safety data.