Allogeneic CD19 CAR T cells armed with an anti-rejection CD70 CAR overcome antigen escape and evade alloimmune responses.

Chimeric antigen receptor (CAR) T cells can achieve sustained clinical benefit in B cell malignancies and autoimmune diseases. Despite the many potential advantages over autologous products, allogeneic CAR T cells carry a higher risk of rejection, which may limit persistence and therapeutic efficacy. We report the design and evaluation of an optimized CD70 CAR that prevents rejection of allogeneic CAR T cells by targeting activated alloreactive lymphocytes. Co-expression of this CD70 CAR with a CD19 CAR resulted in sustained CAR T cell persistence in the presence of alloreactive lymphocytes and prolonged antitumor activity in a CD19 antigen escape model. In vivo, CD19/CD70 dual CAR T cells eliminated B cells and CD70+ T cells derived from patients with systemic lupus erythematosus in humanized mouse models, resulting in reduced immunoglobulin production. An allogeneic CD19/CD70 dual CAR T cell therapy may therefore broaden clinical applicability while enabling the use of less intensive lymphodepleting conditioning regimens prior to CAR T cell infusion.