Complete Regression of Hepatoblastoma after Interleukin-15– and Interleukin-21–Coexpressing CAR T-Cell Therapy

A patient with hepatoblastoma achieved complete regression following treatment with CAR T cells engineered to coexpress interleukin-15 and interleukin-21, as reported in a brief communication in the New England Journal of Medicine. The dual-cytokine CAR-T construct represents a novel approach to enhancing T-cell persistence and antitumor activity in a pediatric solid tumor that has limited options when refractory to standard chemotherapy. While the result is striking, the report spans only four pages, consistent with a single-case or very-small-series format, and larger studies are needed to confirm efficacy and safety.