FastBack Bio is a biotechnology company with a novel CAR-T platform. FastBack Bio will develop CAR-T therapeutics with a novel co-stimulatory domain, M83, from its in-licensed platform. The M83 technology is an alternative to the more commonly used co-stimulatory domains, CD28 and 4-1BB. In vitro experiments indicate that M83 provides CAR-T with cells enhanced expansion kinetics, a balance of effector and central memory phenotypes, and resistance to T cell exhaustion. In vivo solid tumor murine models demonstrate that M83-based CAR-T cells have enhanced tumor-killing capabilities and are superior to both CD28- and 4-1BB-based CAR-T cells.