An Open Label, Single-arm Clinical Study Evaluating the Safety and Efficacy of ICI201 Infusion in Relapsed/Refractory Multiple Myeloma

Inclusion Criteria: * 1\. According to the multiple myeloma diagnostic criteria of the International Myeloma Working Group (IMWG), there is the initial diagnosis of multiple myeloma. 2. Subjects must have previously received at least 3 anti-myeloma regimens. Subjects must have documented disease progression (according to IMWG criteria) during or within 12 months of completing their last anti-myeloma regimen prior to study entry; and prior regimens must have included proteasome inhibitor (PI) and immunomodulatory drug (IMiD). 3. Measurable disease as defined by the protocol 4. ECOG score is 0 or 1. 5. Expected survival time ≥12 weeks. 6. GPRC5D positive expression in bone marrow plasma cells Exclusion Criteria: * 1\. Patients suffering from graft-versus-host disease (GVHD) or requiring immunosuppressants drugs. 2. Patients who received autologous hematopoietic stem cell transplantation (ASCT) or prior allogeneic hematopoietic stem cell transplantation (ALLo-HSCT) within 12 weeks prior to mononuclear cell collection. 3. Screening subjects who were receiving systemic steroids during the previous 7 days or who were determined by the investigator to require long-term systemic steroid use during treatment (except for inhaled or topical use, except at doses \< 10mg/ day). 4. Patients with a history of hypertension that cannot be controlled by medication (blood pressure ≥140/90 mmHg). 5. Patients who have recieved GPRC5D-targeted therapy