CD 19 CAR T-cells is a new and promising approach to treatment of B-cell malignancies. It is known that prior chemotherapy can alter T-cell numbers. In current trials, patients receive unselected CAR T-cell products with large variation in composition of T-cells subsets (CD4+ /CD8+ naïve, central memory, effector memory). The authors compared the in-vivo potency of CD19 CAR T-cell products prepared from pre- sorted/purified subsets of T-cells. They found that a combination of CAR T-cells derived from CD8+ central memory T-cells and CD4+ naïve / central memory T-cells showed synergistic effect, with superior proliferation of the CD8+ CAR T-cells with enhanced anti-tumor effect. They concluded that the composition of CAR-T-cell products influences function and therapeutic efficacy.
* This study helps to understand one of the variables which affect the efficacy and toxicity of CAR T-cells in individual patients and across studies. The advancement of cell selection methods should enable production of CAR T-cell products with specific cell composition and doses in future.