BCMA/CD3 BsAb Therapy for POEMS Syndrome

Inclusion Criteria: 1. Age ≥ 18 years. 2. Diagnosed with POEMS syndrome according to the 2025 Chinese Expert Consensus. 3. Deemed suitable for BCMA/CD3 bispecific antibody therapy by the investigator. 4. ECOG performance status 0-2. 5. Adequate organ function. 6. Provided written informed consent. Exclusion Criteria: 1. Not meeting the diagnostic criteria for POEMS syndrome, including: * Chronic inflammatory demyelinating polyneuropathy (CIDP), * MGUS, multiple myeloma, amyloidosis, or other plasma cell disorders not meeting POEMS diagnostic criteria. 2. History of prior anti-plasma cell therapy, such as melphalan, cyclophosphamide, proteasome inhibitors, IMiDs, monoclonal antibodies, CAR-T, or bispecific antibodies (except: 1. Immunosuppressants used for autoimmune neuropathy; 2. Bisphosphonates used for bone disease; 3. Topical or low-dose steroids ≤20 mg/day for rheumatic disease). 3. Investigator judges the patient unsuitable for BCMA/CD3 bispecific therapy (e.g., severe cardiopulmonary dysfunction). 4. Known allergy or intolerance to BCMA/CD3 bispecific antibody or any component.