[Current status of cancer immunotherapy for relapsed/refractory acute lymphoblastic leukemia in children and adolescents in Japan].

Several novel therapeutics that employ immunological mechanisms have been introduced in recent years for the treatment of hematological malignancies. To date, very few drugs have been introduced for acute lymphoblastic leukemia (ALL). Nonetheless, three novel agents have been approved recently in the US, Europe, Australia, and Japan: blinatumomab, which kills CD19-positive leukemia cells via cytotoxic activity of the patient's autologous T cells; inotuzumab ozogamicin, which delivers the anti-cancer antibiotic calicheamicin via CD22 internalization after antibody binding; and tisagenlecleucel, which uses patient's T cells via anti-CD19 chimeric antigen receptors. Aggressive multi-agent chemotherapy followed by allogeneic hematopoietic cell transplantation has been the only curative strategy for relapsed or refractory ALL. However, treatment strategies for such patients are about to change dramatically. In this article, I review the clinical development of the new therapeutics and discuss their roles in modern therapy for ALL in children and adolescents. An approach for treatment selection has not yet been established. Therefore, it is important to understand the advantages and disadvantages of each treatment for choosing a treatment strategy for each individual.