Prospective Study of Teclistamab in the Treatment of Systemic AL Amyloidosis

Who May Qualify: 1. Diagnosis of systemic AL amyloidosis; 2. Patients must have received standard-of-care daratumumab, bortezomib, they do not have at least one organ response, and have not get complete hematological response; 3. expected to live at least 12 weeks; 4. HGB ≥70g/L; 5. Blood oxygen saturation \> 90%; 6. Total bilirubin (TBil) ≤3×upper limit of normal (ULN); aspartate aminotransferase (AST) and alanine aminotransferase (ALT) ≤3.0×ULN; 7. willing to sign a consent form explained to, understood by and signed by the patient. Who Should NOT Join This Trial: 1. Fulfill with the criteria of active multiple myeloma or active lymphoplasmacytic lymphoma. 2. Presence of other tumors which is/are in advanced malignant stage and has/have systemic metastasis; 3. Severe or persistent infection that cannot be effectively controlled; 4. Presence of severe autoimmune conditions (where your immune system attacks your own body)s or weakened immune system disease; 5. Patients with active hepatitis B or hepatitis C (\[HBVDNA+\] or \[HCVRNA+\]); 6. Patients with HIV infection or syphilis infection; 7. Any situations that the researchers believe will increase the risks for the subject or affect the results of the study. Always talk to your doctor about whether this trial is right for you.