A Phase II Study to Evaluate the Efficacy and Safety of Teclistamab in Combination With Daratumumab (Tec-Dara) in Newly Diagnosed Multiple Myeloma With Concurrent Light Chain Amyloidosis (MM+AL).

Inclusion Criteria:

1. Age ≥18 years, any sex/gender
2. Diagnosis of multiple myeloma according to IMWG criteria
3. Histopathologic diagnosis of AL amyloidosis confirmed by:

   * Green birefringence under polarized light microscopy with Congo red staining; AND at least one of the following:

     1. Immunohistochemistry and/or immunofluorescence
     2. Mass spectrometry
     3. Electron microscopy/immunoelectron microscopy
4. Measurable disease at screening
5. Newly diagnosed, no prior anti-plasma cell therapy
6. Adequate laboratory values:

   * Hemoglobin ≥7.5 g/dL
   * Absolute neutrophil count ≥1.0×10⁹/L
   * Platelet count ≥70×10⁹/L (platelet transfusion acceptable; \>50×10⁹/L if ≥50% bone marrow nucleated cells are plasma cells)
   * ALT ≤2.5× upper limit of normal (ULN)
   * AST ≤2.5× ULN
   * Total bilirubin ≤2.0× ULN
   * Creatinine clearance ≥30 mL/min
   * Corrected serum calcium ≤14 mg/dL
7. Male and female participants of childbearing potential must use at least 2 effective contraceptive methods during the study
8. Voluntarily signed informed consent form (ICF)

Exclusion Criteria:

1. Prior anti-myeloma therapy or stem cell transplantation
2. Diagnosis of monoclonal gammopathy of undetermined significance (MGUS), smoldering multiple myeloma, primary AL amyloidosis without concurrent MM, Waldenström macroglobulinemia, plasma cell leukemia, POEMS syndrome, or other malignancies within 3 years prior to enrollment
3. Active infection or autoimmune disease
4. Uncontrolled diabetes, hypertension, or other comorbidities
5. Pregnant or lactating female
6. Currently participating in another interventional study
7. Any other condition that the investigator considers unsuitable for study participation