KQ-2003

Phase I study (dose escalation study): Primary objectives: (1) To evaluate the safety and tolerability of KQ-2003 CAR-T cells in R/R MM patients, and determine the maximum tolerated dose (MTD), dose-limiting toxicity (DLT) and phase II recommended dose (RP2D); (2) To investigate the pharmacokinetic (PK)/pharmacodynamic (PD) characteristics and immunogenicity of KQ-2003 CAR-T cells in R/R MM patients. Secondary objectives: To evaluate the preliminary efficacy of KQ-2003 CAR-T cells in R/R MM patients. Phase IIa study (cohort expansion study): Primary objectives: To evaluate the safety, tolerability and preliminary efficacy of KQ-2003 CAR-T cells RP2D in R/R MM patients; Secondary objectives: To investigate the PK/PD characteristics and immunogenicity of KQ-2003 CAR-T cells in R/R MM patients.