Assessment of the Efficacy and Safety of Injectable TQB2934 (Subcutaneous Injection) in Systemic Light Chain Amyloidosis Patients

Inclusion Criteria: * The subjects voluntarily joined this study, signed the informed consent form, and exhibited good compliance; * Aged 18 to 80 years old, with an Eastern Cooperative Oncology Group (ECOG) score of 0 to 2, and an expected survival of more than 12 weeks; * Systemic light chain amyloidosis with diagnostic records (i.e., primary light chain amyloidosis); * Presence of measurable lesions; * At least one organ involved; * Have previously received at least one line of systemic treatment, and recurred and progressed after the remission of the last line treatment; * N-terminal pro-B-type natriuretic peptide (NT-proBNP) ≤ 8500 ng/L; * The corresponding organ function conforms to the protocol requirements; * Women of childbearing age should agree to use contraception during the study period and for 6 months after its completion; they must have a negative serum pregnancy test within 7 days before enrollment in the study and must be non-lactating subjects; men should agree to use contraception during the study period and for 6 months after its completion. Exclusion Criteria: * Diagnosed with other types of amyloidosis, active plasma cell leukemia, active multiple myeloma, etc. * Have received allogeneic hematopoietic stem cell transplantation within 1 year prior to the first dose, or have received autologous hematopoietic stem cell transplantation within 12 weeks prior to the first dose; * Previously received treatment with drugs targeting the same target; * Within 4 weeks prior to the first dose, the patient has received a cumulative dose of dexamethasone \>160 mg or an equivalent dose of other glucocorticoids, or within 3 weeks prior to the first dose, the patient has received targeted therapy, cytotoxic drugs, or any antibody therapy, or within 2 weeks prior to the first dose, the patient has received proteasome inhibitor therapy or radiotherapy, or within 1 week prior to the first dose, the patient has received immunomodulator therapy; * Those who have received treatment with traditional Chinese patent medicines and simple preparations with clear anti-tumor indications specified in the National Medical Products Administration (NMPA) approved drug instructions within 2 weeks before the first administration; * Those who have received attenuated live vaccine within 4 weeks before the first dose or plan to receive attenuated live vaccine during the study period; * Individuals with a history of severe allergies of unknown cause, or known allergies to monoclonal antibody drugs or exogenous human immunoglobulins, or known allergies to the excipients in injectable TQB2934 or pharmaceutical preparations; * Having had or currently suffering from other malignant tumors within 3 years before the first medication; * Unresolved toxic reactions above Common Terminology Criteria (CTC) AE Grade 1 caused by any previous treatment; * Those who have undergone major surgical treatment, significant traumatic injury, or are expected to undergo major surgery during the study treatment period within 4 weeks before the first dose of medication; * Arterial/venous thromboembolic events occurred within 6 months before the first dose; * Individuals with a history of abuse of psychotropic drugs who are unable to quit or who have mental disorders; or intractable seizures that require treatment; * Those with unsatisfactory blood pressure control; * Patients with poorly controlled diabetes; * Patients who have active or uncontrolled severe bacterial, viral, or systemic fungal infections (≥CTC AE Grade 2 infections) within 4 weeks before the first dose of medication; * Patients with hepatitis or decompensated liver cirrhosis (Child-Pugh Class B or C); * Individuals with active tuberculosis, history of idiopathic pulmonary fibrosis, organizing pneumonia, drug-induced pneumonia, radiation pneumonia requiring treatment, or clinically symptomatic active pneumonia; * Those who have experienced asthma within 2 years before the first medication or currently suffer from asthma or chronic obstructive pulmonary disease; * Individuals with significant cardiovascular diseases; * Individuals with a history of immune deficiency, or active autoimmune diseases requiring systemic immunosuppressive therapy, etc. * Exclude subjects with organ failure unrelated to systemic light-chain (AL) amyloidosis; * Subjects deemed unsuitable for enrollment by the researchers.