BCMA Nano Antibody CAR-T Cells for Patients With Refractory and Relapsed Multiple Myeloma

This clinical study is an exploratory study, mainly to study the safety and efficacy of BCMA nano-antibody CAR-T in the treatment of MM. In this study, a 3 + 3 dose gradient climbing design was used. Three dosage groups, 5 x 106 / kg, 7.5 x 106 / kg and 1.5 x 107 / kg, were divided into three groups. Patients were enrolled in the sequence from low to high doses. When each dose group was completed, the next dose group could be enrolled if there was no more than 3-level toxicity or unpredictable severe toxicity. If the dose group had more than 3-level toxicity or unpredictable severe toxicity, two patients were enrolled to observe if there was any toxicity. Sexual occurrence, if two patients in each group developed grade 3 or more toxicity or unpredictable severe toxicity, the dose group was the dose-limiting group, and the dose group in front of the group was the maximum tolerated dose, at which the initial efficacy was observed. Nine patients were enrolled in the hill climbing test, and six patients were enrolled in the follow-up preliminary efficacy study, with an estimated 15 enrolled.