Conclusions
hsCD19 CAR-T treatment shows efficacy in highly treated B-ALL patients who have relapsed after receiving CD19 mCAR-T therapies.
Purpose
CD19 chimeric antigen receptor (CAR)-T therapy has shown impactful
Results
hsCAR possessed around 6-fold higher affinity to CD19 versus murine CAR (mCAR). Incubation with selective domain-specific mAbs (SmAb) selectively expanded CAR-transduced T cells, and led to a higher proportion of central memory T cells in the final products. SmAb-stimulated CD19 hsCAR-T cells exhibited superior antitumor cytotoxic functions in vitro and in vivo. Autologous (n = 2) and allogeneic donor (n = 3, with hematopoietic stem cell transplantation) hsCAR-T cells were infused into 5 patients who had relapsed after receiving mCAR-T treatments. Two patients received mCAR-T treatments twice previously but the second treatments were ineffective. In contrast, subsequent hsCAR-T treatments proved effective in all 5 patients and achieved complete molecular remission in four, including one with extramedullary disease with central nervous system involvement. Conclusions: hsCD19 CAR-T treatment shows efficacy in highly treated B-ALL patients who have relapsed after receiving CD19 mCAR-T therapies.