BCMA/CD3 BiTE for RRAL or NDAL Amyloidosis With Insufficient Depth of Hematologic Response After Induction Therapy

Inclusion Criteria:

• Male or female patients aged 18 years or older

• Biopsy-proven diagnosis of AL amyloidosis, according to the following standardcriteria:

• Histochemical diagnosis of amyloidosis, as based on tissue specimens with Congo redstaining with exhibition of an apple-green birefringence

• If clinical and laboratory parameters are insufficient to establish AL amyloidosis,or in cases of doubt, amyloid typing may be necessary

• Provide informed consent form

• Measurable disease, as defined by serum differential free light-chain concentration (dFLC; defined as the difference between amyloid forming [involved] and nonamyloidforming [uninvolved] free light-chain [FLC]) ≥50 mg/L)

• Received at least one prior line of therapy

• Must have been exposed to CD38 mAb

• Relapsed/refractory AL amyloidosis or newly diagnosed AL amyloidosis withinsufficient depth of hematologic response after induction therapy

• Relapsed is defined as documented progressive disease >60 days after the last doseof prior therapy

• Refractory is defined as the documented absence of a hematologic response orhematologic progression on or within 60 days after the last dose of prior therapy

• Insufficient depth of hematologic response is defined as less than hematological PRby 2 cycles or less than hematologic VGPR by 4 cycles

• Eastern Cooperative Oncology Group performance status ≤3

• Clinical laboratory values:

• Absolute neutrophil count ≥1000/µL

• Platelet count ≥75,000/µL

• Hemoglobin ≥75g/L

• Total bilirubin ≤1.5× the upper limit of normal (ULN), except for patients withGilbert's syndrome (as defined by >80% unconjugated bilirubin and total bilirubin ≤6mg/dL)

• Alkaline phosphatase ≤5× ULN

• Alanine aminotransferase or aspartate aminotransferase ≤3× ULN

• Calculated creatinine clearance ≥30 mL/min

• The woman is not breastfeeding, is not pregnant, and agrees not to be pregnantduring the study period and for the following 12 months.

• Male patients agreed that their spouse would not become pregnant during the studyperiod and for 12 months thereafter.

Exclusion Criteria:

• Non-AL amyloidosis, including hereditary amyloidosis

• Diagnosed with multiple myeloma, according to the International Myeloma WorkingGroup criteria

• Have been exposed to BCMA-targeted treatment

• Known intolerance, hypersensitivity, or contraindication to BCMA BiTE cellularproducts

• Patients with peripheral neuropathy greater than grade 2 or peripheral neuropathygreater than grade 2 with pain at baseline, regardless of whether they werecurrently receiving medical therapy, after excluding AL amyloidosis-relatedperipheral neuropathy

• Medically documented cardiac syncope, myocardial infarction within the previous 6months, unstable angina pectoris, clinically significant repetitive ventriculararrhythmias despite antiarrhythmic treatment, or severe orthostatic hypotension orclinically important autonomic disease

• Ongoing or active infection, known HIV-positive status, or active hepatitis B or Cinfection

• Women who are pregnant or breastfeeding

• Subjects had major surgery within 2 weeks before randomization (for example, generalanesthesia), or have not fully recovered from the surgery, or surgery is arrangedduring the study period

• Received live attenuated vaccine within 4 weeks prior to study treatment

• According to the researcher's judgment, any condition including but not limited toserious mental illness, medical illness, or other symptoms/conditions that mayaffect study treatment, compliance, or the capability of providing informed consent.

Necessary medication or supportive therapy is contraindicated with study treatment.

Any diseases or complications that may interfere with the study. Patients are not willing to or cannot comply with study scheme.