This is an investigator-initiated, single-center, early-phase clinical study comprising dose escalation and dose expansion phases, designed to evaluate the safety and efficacy of IMV102 in subjects with relapsed/refractory multiple myeloma (RRMM). Eligible subjects will receive an infusion of IMV102 injection. Blood and urine samples will be collected before and after infusion for pharmacokinetic, pharmacodynamic, immunogenicity, and safety assessments.

Tumor response will be evaluated according to the International Myeloma Working Group (IMWG) uniform response criteria (2016). Assessments will be performed at baseline, and then at Day 28 post-infusion, Month 2, Month 3, and subsequently every 3 months from Month 3 to Month 24, until the subject completes the 24-month follow-up period, experiences disease progression (PD)/relapse, initiates new anti-tumor therapy, dies, or withdraws from the study, whichever occurs first.

Inclusion Criteria:

1. Age: Aged 18 to 80 years (inclusive), of either sex.
2. Performance Status: Eastern Cooperative Oncology Group (ECOG) performance status of 0-2.
3. Diagnosed with relapsed/refractory multiple myeloma according to the IMWG criteria, who have received at least 3 prior lines of therapy (including a proteasome inhibitor and an immunomodulatory agent-based regimen).
4. Reproductive Status: Subjects of childbearing potential and their partners must agree to use medically accepted highly effective contraceptive methods (e.g., intrauterine device, condom) from the time of signing the informed consent form until 12 months after the last dose. They must not donate germ cells, including sperm or oocytes, during this period.
5. Informed Consent: Subjects must voluntarily sign and date a written informed consent form (ICF) indicating agreement to participate in this study.
6. Compliance: Subjects must be willing and able to comply with the scheduled treatment plan, laboratory tests, follow-up, and other study requirements.

Exclusion Criteria:

1. Pregnancy/Lactation: Women who are pregnant or breastfeeding.
2. Other Malignancies: Subjects with a prior or concurrent other malignancy.
3. Infectious Diseases: Positive for human immunodeficiency virus (HIV) antibody; active hepatitis B virus infection (HBV-DNA > 10³ IU/mL); acute or chronic active hepatitis C (HCV antibody positive); positive syphilis antibody; cytomegalovirus (CMV) infection (IgM positive or DNA positive).
4. Presence of clinically active uncontrolled infection based on assessment done by treating physicians.
5. Effusions: Presence of uncontrolled pleural effusion, pericardial effusion, or ascites prior to enrollment.
6. Allergies: History of other severe allergies such as anaphylactic shock; known severe allergic reaction to IMV102 or any of its components; known severe allergic reaction to tocilizumab.
7. Psychiatric Disorders: Subjects with severe mental disorders.
8. Transplant History: History of solid organ transplantation.
9. Compliance: Subjects whom the investigator assesses as unable or unwilling to comply with the requirements of the study protocol.
10. Other Conditions: Subjects with any other concurrent severe and/or uncontrolled medical conditions that, in the judgment of the investigator, make them unsuitable for participation in this study.