This is a prospective, single-arm, open-label dose-escalation clinical study to evaluate LVIVO-TaVec200 in the treatment of relapsed/refractory multiple myeloma.

This is a prospective, single-arm, open-label dose-escalation and dose-expansion study, designed to evaluate the safety, tolerability, anti-tumor efficacy profile, and pharmacokinetic characteristics of the LVIVO-TaVec200 in subjects with relapsed/refractory multiple myeloma who have failed at least 3 lines of prior standard therapies. The subject who meet the defined eligibility criteria will be enrolled with a core study period of approximately 2 years, including the screening, bridging therapy(if needed), treatment, and follow-up.

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. Prior treatment targeting GPRC5D;
3. 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).
4. Known life-threatening allergic reaction, hypersensitivity reaction, or intolerance to study drug excipients and related excipients, including but not limited to DMSO; or those with a history of severe allergic reactions in the past (such as hypersensitivity reactions, or those with severe immune-related reactions such as the need for glucocorticoids to prevent anaphylaxis as assessed by the investigator).
5. Any condition deemed by the investigator as rendering the subject unsuitable for participation in this study.