Time from CAR-T to mosunetuzumab administration and changes in CAR transgene levels. Blue bars and blue circles indicate CR/PR. Red bars and red circles indicate SD/PD. Circles indicate a patient with large B-cell lymphoma. Square boxes indicate a patient with follicular lymphoma. (A) Time from CAR-T to the start of mosunetuzumab. R indicates patients who responded to CAR-T and subsequently relapsed at least 6 months after CAR-T. The remainder of patients are CAR-T refractory, that is, they did not respond to CAR-T. (B) Comparison of responding and nonresponding patients’ time from CAR-T to mosunetuzumab. ∗∗P = .006. (C) CAR transgene copy number per μg genomic DNA for responding and nonresponding patients before and after mosunetuzumab. (D) Difference in CAR transgene copy number after 1 cycle of mosunetuzumab between responding and nonresponding patients. ∗P = .04. C1, baseline prior to start of mosunetuzumab; C2, after one cycle of mosunetuzumab; CAR, chimeric antigen receptor-modified; CAR-T, chimeric antigen receptor–modified T-cell therapy; CR, complete response; DLBCL, diffuse large B-cell lymphoma; FL, follicular lymphoma; PMBCL, primary mediastinal large B-cell lymphoma; PD, progressive disease; PR, partial response; SD, stable disease; trFL, large cell transformation of follicular lymphoma.