BCMA/CD3 Bispecific Antibody Treatment for Newly Diagnosed Amyloidosis

1. The patient is informed of and voluntarily signs the informed consent form (ICF). 2. Age ≥18 years, regardless of sex. 3. Confirmed diagnosis of primary light-chain (AL) amyloidosis, in accordance with the Guidelines for the Diagnosis and Treatment of Systemic Light-chain Amyloidosis (2021 Revision). 4. Measurable disease at screening, defined as: * Difference between involved and uninvolved free light chains (dFLC) ≥50 mg/L, or * Serum involved free light chain ≥50 mg/L with an abnormal κ:λ ratio. 5. ECOG performance status ≤2. 6. Adequate organ function within 3 days prior to the first dose of the investigational drug, meeting all of the following criteria: i. Absolute neutrophil count (ANC) ≥1.0 × 10⁹/L, with no granulocyte colony-stimulating factor (G-CSF) or granulocyte-macrophage colony-stimulating factor (GM-CSF) administration within 7 days, and no pegylated G-CSF administration within 14 days prior to testing; ii. Hemoglobin (Hb) ≥75 g/L, with no whole blood or red blood cell transfusion within 7 days prior to testing; iii. Platelet count ≥70 × 10⁹/L, with no whole blood transfusion, platelet transfusion, or thrombopoietin receptor agonist treatment within 7 days prior to testing; iv. Hepatic function: alanine aminotransferase (ALT) ≤3 × upper limit of normal (ULN), aspartate aminotransferase (AST) ≤3 × ULN, total bilirubin ≤2 × ULN (subjects with Gilbert's syndrome are eligible if direct bilirubin ≤2 × ULN); v. Coagulation: international normalized rat…