Bispecific Antibody Armed Metabolically Enhanced Headless CAR T Cells.

Adoptive T cell therapies for solid tumors is challenging. We generated metabolically enhanced co-activated-T cells by transducing intracellular co-stimulatory (41BB, ICOS or ICOS-27) and CD3ζ T cell receptor signaling domains followed by arming with bispecific antibodies (BiAbs) to produce armed "Headless CAR T cells" (hCART). Various hCART armed with BiAb directed at CD3ϵ and various tumor associated antigens were tested for: 1) specific cytotoxicity against solid tumors targets; 2) repeated and dual sequential cytotoxicity; 3) survival and cytotoxicity under hypoxic condition; and 4) cytokine secretion. The 41BBζ transduced hCART (hCART) armed with HER2 BiAb (HER2 hCART) or armed with EGFR BiAb (EGFR hCART) killed multiple tumor lines significantly better than control T cells and secreted Th cytokines/chemokines upon tumor engagement at effector to target ratio (E:T) of 2:1 or 1:1. HER2 hCART serially killed tumor targets up to 14 days. Sequential targeting of EGFR or HER2 positive tumors with HER2 hCART followed by EGFR hCART showed significantly increased cytotoxicity compared single antigen targeting and continue to kill under hypoxic conditions. In summary, metabolically enhanced headless CAR T cells are effective serial killers of tumor targets, secrete cytokines and chemokines, and continue to kill under hypoxic condition.