LCAR-B38M Cells in Treating Relapsed/Refractory (R/R) Multiple Myeloma

Inclusion Criteria: * Patients must have a confirmed prior diagnosis of active multiple myeloma as defined by the updated IMWG criteria. * Patients with refractory multiple myeloma. Clear BCMA expression must be detected on malignant plasma cells from either bone marrow or a plasmacytoma by flow cytometry or immunohistochemistry. * Refractory disease：1) At least 3 prior regimens, which must at least have contained bortezomi. or 2) other circumstances identified by clinical doctors. * Relapse criteria in NCCN clinical practice guidelines in Oncology: Multiple Myeloma (2016.V2) Exclusion Criteria: * Women of child-bearing potential or who are pregnant or breastfeeding. * Have any active and uncontrolled infection: hepatitis B, hepatitis C, HIV, or other fatal viral and bacterial infection. * Systemic corticosteroid steroid therapy of greater than 5 mg/day of prednisone or equivalent dose of another corticosteroid are not allowed within 2 weeks prior to either the required leukapheresis or the initiation of the conditioning chemotherapy regimen. * Patients with any uncontrolled intercurrent illness or serious uncontrolled medical disorder. * Patients with CNS metastases or symptomatic CNS involvement (including cranial neuropathies or mass lesions and spinal cord compression). * History of allogeneic stem cell transplantation. Have active acute or chronic graft-versus-host-disease (GVHD), or require immunosuppressant medications for GVHD, within 6 months of enrollment. * Patients with active autoimmune skin diseases such as psoriasis or other active autoimmune diseases such as rheumatoid arthritis.