In patients with multiple myeloma with recurrent or refractory BCMA, CAR-T cell infusion was performed after screening, blood collection and pretreatment. Starting dose for 5 x 10^5 / kg, 1 x 10^6 doses sequentially. If dose-limiting toxicity is not observed in 3 patients in a dose group, the next dose group test can be performed; If more than 2/3 of patients (2 cases, included) in a dose group had DLT, dose-escalation was not performed. If 1 case of DLT (1/3) appears in the first 3 patients of a dose group, 3 patients need to be added to the dose group (at this time, there are 6 patients in the group). If DLT occurs in 1 of the 3 patients (with or without) or 2 of the 6 patients (with or without), no further dose escalation is allowed. Researchers and bidders to form drug safety monitoring committee (SRC), every dose group of subjects to complete the DLT observation period, after summarizing the security of this dose group, determine the test of the next dose, subjects such as draw up the highest dose group safety tolerance, SRC to decide whether to continue to increase the dose group of research, finally according to have obtained all the safety and efficacy of dose group information to determine the recommended dose (RP2D).Dose-limiting toxicity (DLT)
In patients with multiple myeloma with recurrent or refractory BCMA, CAR-T cell infusion was performed after screening, blood collection and pretreatment. Starting dose for 5 x 10^5 / kg, 1 x 10^6 doses sequentially. If dose-limiting toxicity is not observed in 3 patients in a dose group, the next dose group test can be performed; If more than 2/3 of patients (2 cases, included) in a dose group had DLT, dose-escalation was not performed. If 1 case of DLT (1/3) appears in the first 3 patients of a dose group, 3 patients need to be added to the dose group (at this time, there are 6 patients in the group).