Effect of sBCMA on anti-BCMA CAR T cytotoxicity. (A) Design of CAR T^tecli. Anti-BCMA scFv domain of CAR T^ide was replaced with the anti-BCMA heavy and light chain variable domains of teclistamab to generate CAR T^tecli. Figure created with BioRender.com. (B) Histogram of PE-conjugated BCMA peptide binding on CAR T^ide, CAR T^tecli, and CAR T^cilta in the presence of recombinant sBCMA. (C) OPM2 or OPM2_BCMA^high cell viability 48 hours after coculture with anti-BCMA CAR T. Raw values for the triplicate experiments of cell viability measurement and calculated P values are indicated in supplemental Table 10. ∗∗∗P ≤ .001; ∗∗∗∗P ≤ .0001.