SITC 2021 | Efficacy of bispecific CD19/CD22 CAR T-cells in B-cell malignancies
Crystal Mackall, MD, Stanford University, Stanford, CA, explains the rationale and the results from a Phase I trial investigating the safety and efficacy of a bispecific chimeric antigen receptor (CAR) T-cell targeting CD19 and CD22 in combination with chemotherapy in adult patients with recurrent or refractory B-cell malignancies (NCT03233854). Previous studies have revealed that up to two thirds of patients treated with CAR T-cell therapy relapse because of antigen modulation, either by complete loss or by downregulation of the CD19 target antigen. Monospecific CD22-directed CAR T-cells developed to overcome that challenge have shown remarkable activity in antigen loss variants of leukemia and in patients with lymphoma who have progressed after CD19-targeting CAR T-cell therapy. However, the bispecific CAR T-cells targeting both CD19 and CD22 tested in the Phase I trial were not more effective than monospecific CAR T-cells and showed good potency on CD19 but not on CD22. It is thus important to design novel strategies to deliver bispecific CAR T-cells. This interview took place during the 36th Society for Immunotherapy of Cancer (SITC) Annual Meeting in Washington, D.C.
