CAR'TCR-T cells co-expressing CD33-CAR and dNPM1-TCR as superior dual-targeting approach for AML treatment

Acute myeloid leukemia (AML), a fast-progressing hematological malignancy affecting myeloid cells, is typically treated with chemotherapy or hematopoietic stem cell transplantation. However, approximately half of the patients face relapses and 5-year survival rates are poor. With the goal to facilitate dual-specificity, boosting anti-tumor activity, and minimizing the risk for antigen escape, this study focused on combining chimeric antigen receptor (CAR) and T cell receptor (TCR) technologies. CAR'TCR-T cells, co-expressing a CD33-CAR and a transgenic dNPM1-TCR, revealed increased and prolonged anti-tumor activity , particularly in case of low target antigen expression. The distinct transcriptomic profile suggested enhanced formation of immunological synapses, activation, and signaling. Complete elimination of AML xenografts was only achieved with a cell product containing CAR'TCR-T, CAR-T, and TCR-T cells, representing the outcome of co-transduction with two lentiviral vectors encoding either CAR or TCR. A mixture of CAR-T and TCR-T cells, without CAR'TCR-T cells, did not prevent progressive tumor outgrowth and was comparable to treatment with CAR-T and TCR-T cells individually. Overall, our data underscore the efficacy of co-expressing CAR and transgenic TCR in one T cell, and might open a novel therapeutic avenue not only for AML but also other malignancies.