A Clinical Study to Evaluate LVIVO-TaVec400 for the Treatment of Relapsed/Refractory Multiple Myeloma（LB2505-0001）

Inclusion Criteria: 1. Subjects voluntarily participate in clinical studies; Fully informed of this study and signed informed consent; Informed consent form must be obtained prior to initiation of any study-related tests or procedures that are not part of the standard treatment for the subject's disease; Good compliance and cooperation with follow-up. 2. Age ≥ 18 years. 3. Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1. 4. Has measurable lesions 5. Relapsed and/or refractory multiple myeloma 6. Life expectancy≥ 3 months 7. Clinical laboratory values meet screening visit criteria 8. Adequate organ function. Exclusion Criteria: 1. Prior antitumor therapy with insufficient washout period ; 2. Patients who are positive for hepatitis B surface antigen (HBsAg), hepatitis B virus deoxyribonucleic acid (HBV DNA), hepatitis C antibody (HCV-Ab), hepatitis C virus ribonucleic acid (HCV RNA), and human immunodeficiency virus antibody (HIV-Ab). 3. Those who have experienced life-threatening allergic reactions, hypersensitivity reactions or intolerances to the excipients and related additives of the investigational drug; or those with a previous history of severe allergic reactions (such as hypersensitivity reactions, or those for whom the investigator assesses the need to use glucocorticoids to prevent severe immune-related reactions such as allergic reactions). 4. Any condition deemed by the investigator as rendering the subject unsuitable for participation in this study. 5. Also enrolled in other clinical studies.