Anti-CD19 CAR-T Cell Therapy in Participants With Moderate to Severe Active Systemic Lupus Erythematosus

This is an open, Phase I, investigator-initiated study (IIT) to evaluate the safety, tolerability, pharmacokinetics, pharmacodynamics, and efficacy of RD06-04 in patients with moderate or severe active SLE. This study will explore the safety of escalating doses of RD06-04 by presetting two dose levels (DL), with 3 to 6 patients enrolled in each dose level. After safety conclusions are reached in each group, the investigator can select the corresponding dose group to expand cases based on treatment response, but the total number of cases will not exceed 12. This study will enroll patients in a 3+3 design with two DLS: 1×105 CAR+T cells /kg for DL1 and 5×105 CAR+T cells /kg for DL2. Dose increment Refer to the 3+3 dose increment principle. Three subjects are expected to be enrolled in each dose group. 1. Dose increment should start from the minimum dose, and it is not possible to conduct an incremental study of 2 or more dose groups at the same time. 2. If 1 case of DLT occurs in each dose group, the dose level will be extended to 6 subjects. If 6 subjects at this dose level ≥2 subjects develop DLT, the dose level exceeds the MTD. The previous lower dose level will be extended to 6 subjects, and if 6 subjects have already been enrolled in the previous lower dose level, and only ≤1 of these 6 subjects develop DLT, this lower dose level will be considered MTD. 3. If DLT occurred in ≥2 subjects in the highest dose group, the researcher could select a dose between the high dose group and the medium dose group according to the specific situation and perform MTD evaluation. 4. If the dose increase to the highest dose group still does not reach DLT, researchers can explore the safety and efficacy of higher doses according to specific circumstances. Case expansion: After the completion of DLT evaluation in all dose groups, the investigators could select the corresponding dose group of extended cases according to the treatment response, but the total number of cases shou