Effects of an initial anti-CD19 CAR T-cell therapy on subsequent anti-CD22 CAR T-cell manufacturing and clinical outcomes in patients with r/r LBCL

Patients with large B-cell lymphoma (LBCL) progressing after anti-CD19 CAR T-cell (CAR19) therapy have poor outcomes. Subsequent CAR T-cell therapy shows promise, but the impact of residual CAR19 and early relapse remains unclear. We evaluated 37 CAR19-refractory LBCL patients who received anti-CD22 CAR T-cell (CAR22) in a phase 1b trial (NCT04088890). Residual CAR19 was unquantifiable in 17 of 33 evaluable patients post-CAR22 infusion. Single-cell RNA sequencing revealed minimal CAR19/CAR22 co-transduction. Peak CAR19 transgene levels did not affect CAR22 efficacy or toxicities. CAR22 products from patients undergoing leukapheresis > 6 months post-CAR19 had higher CD4+ naïve T and CD4+/CD8+ T- central memory (TCM) cells, with lower CD4+ T-effector memory cells. High and low percentages of CAR22 TCM and TEM, respectively, were correlated with CAR22 transduction efficiency and achieving complete response. Residual CAR19 and leukapheresis timing did not significantly affect outcomes, while CAR22 product composition was significantly correlated with treatment response.