BCMA/GPRC5D Dual-Target CAR-T Cell Immunotherapy for Relapsed/Refractory Multiple Myeloma

Inclusion Criteria:

• Voluntarily agrees to participate in the study (signed informed consent form by the participant or a legally authorized representative), and is willing and able to comply with scheduled visits, study treatment, laboratory tests, and other study procedures.
• Clinically diagnosed relapsed/refractory multiple myeloma, meeting both of the following:

Clonal plasma cells positive for BCMA and/or GPRC5D by flow cytometry or immunohistochemistry.

Prior treatment with at least 3 drug classes (proteasome inhibitors [PIs], immunomodulatory drugs [IMiDs], and an anti-CD38 monoclonal antibody), with best response less than partial response (PR) or disease progression after achieving PR or better.

• Male or female participants aged 18 to 75 years, inclusive.
• Eastern Cooperative Oncology Group (ECOG) performance status of 0-2.
• Estimated life expectancy of more than 3 months from the date of signing the informed consent form.
• Adequate renal, hepatic, cardiac, and pulmonary function, defined as follows:

Creatinine clearance (estimated by the Cockcroft-Gault formula) ≥60 mL/min or serum creatinine ≤1.5 × the upper limit of normal (ULN); Serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST)≤2.5×upper limit of normal (ULN), total bilirubin≤1.5×ULN; Cardiac ejection fraction≥50%, no pericardial effusion on echocardiography, and no significant abnormalities on electrocardiogram (ECG); No clinically significant pleural effusion, and oxygen saturation >92% on room air at baseline.

• Participants of reproductive potential must agree to use highly effective contraception before enrollment and for at least 12 months after CAR-T cell infusion. A negative serum pregnancy test is required for women of childbearing potential at screening. Participants must immediately notify the investigator if pregnancy occurs or is suspected.

Exclusion Criteria:

• The patient has severe cardiac dysfunction, or left ventricular ejection fraction (LVEF) <50%, or a history within the 12 months prior to enrollment of myocardial infarction, coronary angioplasty or coronary stent implantation, unstable angina, clinically significant arrhythmia, or other severe cardiovascular diseases.
• A history of severe pulmonary disease with impaired lung function.
• Concurrent progressive malignancy other than multiple myeloma.
• Severe active infection that cannot be effectively controlled.
• Severe autoimmune disease or congenital immunodeficiency.
• Active hepatitis, defined as hepatitis B virus DNA (HBV-DNA) or hepatitis C virus RNA (HCV-RNA) levels above the lower limit of detection, or human immunodeficiency virus (HIV) infection, known acquired immunodeficiency syndrome (AIDS), or syphilis infection.
• A history of severe allergic reactions to biological products, including antibiotics.
• The patient has severe autoimmune disease, congenital immunodeficiency or active autoimmune disease requiring ongoing systemic immunosuppressive treatment, or is currently within the washout period after having received medications that may affect CAR-T cell immunotherapy, or is anticipated to require medications during the study period that may affect CAR-T cell immunotherapy treatment.
• The investigator judges that the patient is unlikely to complete all visits and procedures required by the study protocol (including medium- and long-term follow-up visits), such as insufficient willingness of the patient and their family members to participate in the study, refusal to participate, inability of the patient to fully cooperate with the study arrangements, or inadequate compliance on the part of the patient and their family members.
• Any other severe physical or psychiatric disorder or clinically significant laboratory abnormality that may increase the risk associated with study participation, interfere with the interpretation of study results, or, in the investigator's judgment, make the participant unsuitable for participation in the study.
• Female participants of childbearing potential who are pregnant or breastfeeding.