Progress in clinical studies of chimeric antigen receptor engineered T cells for treatment of childhood cancer

Abstract:

Nowadays, the 5-year survival rate of childhood cancer patients can be more than 80%, but some patients with relapse and refractory cancers have shown no good response to traditional strategies. Chimeric antigen receptor engineered T (CAR-T) cell therapy is promising for these patients. CAR-T cells recognize the tumor-associated antigens in a non-major histocompatibility complex-restricted manner, so their anti-tumor ability is enhanced. There are four generations of CAR-T cells now. The complete remission rate of pediatric patients with relapse and refractory acute lymphoblastic leukemia can be as high as 90% when treated with CD19-targeting CAR-T cells. Furthermore, CAR-T cell therapy can also be used to bridge to transplantation and donor CAR-T cell infusion can be a strategy to prevent relapse after hematopoietic stem cell transplantation. As to solid tumors, only patients with neuroblastoma present good response to the GD2-targeting CAR-T cell therapy. The toxic or side effects of CAR-T cell therapy include cytokine release syndrome, off-tumor effect, tumor lysis syndrome, and insertion mutation. Although the CD19-targeting CAR-T cell therapy for childhood cancer can result in a high remission rate, the relapse rate is high, including CD19⁺ and CD19^- relapse. The mechanisms for relapse merit further investigation.