Schematic diagram of CT103A CAR construct and treatment response and outcome in patients with CT103A infusion. (A) The second-generation CAR consisted of a scFv from a fully human antibody against human BCMA, the hinge and transmembrane domain from CD8a, the costimulatory domain from 4-1BB (CD137), and the activation domain from CD3ζ. (B) The best responses of all 18 patients with different infusion doses (1 × 10⁶ cells/kg to 6 × 10⁶ cells/kg) are shown. The responses were assessed according to the criteria described in the Methods. Underlined italic numbers indicate patients who relapsed after a prior murine BCMA CAR T-cell treatment. Bold numbers in red indicate patients with EMM. Arrows indicate ongoing remission. L, linker; MR, minor response; NA, not applicable; PR, partial response; SP, signal peptide; VGPR, very good partial response; VL, variable light chain; VH, variable heavy chain.