Dual-targeting CAR-T cells with optimal co-stimulation and metabolic fitness enhance antitumor activity and prevent escape in solid tumors

Chimeric antigen receptor (CAR)-T cells showed great activity in hematologic malignancies. However, heterogeneous antigen expression in tumor cells and suboptimal CAR-T-cell persistence remain critical aspects to achieve clinical responses in patients with solid tumors. Here we show that CAR-T cells targeting simultaneously two tumor-associated antigens and providing trans-acting CD28 and 4-1BB co-stimulation, while sharing the same CD3ζ-chain cause rapid antitumor effects in in vivo stress conditions, protection from tumor re-challenge and prevention of tumor escape due to low antigen density. Molecular and signaling studies indicate that T cells engineered with the proposed CAR design demonstrate sustained phosphorylation of T-cell-receptor-associated signaling molecules and a molecular signature supporting CAR-T-cell proliferation and long-term survival. Furthermore, metabolic profiling of CAR-T cells displayed induction of glycolysis that sustains rapid effector T-cell function, but also preservation of oxidative functions, which are critical for T-cell long-term persistence. Dotti and colleagues present a CAR design featuring trans-acting CD28 and 4-1BB co-stimulation and shared CD3ζ-chain, which improved CAR-T cell metabolic and antitumor functions and avoided tumor escape through simultaneous targeting of two antigens.