A Study of CAR-T Cells Targeting Both BCMA and GPRC5D in Treatment of Relapsed or Refractory Multiple Myeloma

Inclusion Criteria:

• Signed and dated, written informed consent prior to any study specific procedures;
• Estimated life expectancy of minimum of 12 weeks;
• ECOG 0-2;
• Diagnosed as multiple myeloma according to the IMWG criteria;
• Evidence of cell membrane GPRC5D and/or BCMA expression, as determined by a validatedimmunohistochemistry (IHC) or flow cytometry of tumor tissue; Subjects should havemeasurable disease. At least meet one of the following criteria:

1. If IgG type MM, serum M protein ≥10g/L; if IgA, IgD, IgE or IgM type MM, serum Mprotein ≥5g/L;
2. urine M protein level ≥0.2g(200mg/24h);
3. light chain type MM, serum free light chain (sFLC) ≥ 100mg / L and K/ λ FLC ratiois abnormal;
4. there are extramedullary lesions;

• Subjects have had at least 3 prior lines of therapy including chemotherapy based onproteasome inhibitors (PIs) and immunomodulatory agents (IMiDs);
• Adequate organ functions

Exclusion Criteria:

• Active smoldering multiple myeloma;
• Active plasma cell leukemia;
• With organ amyloidosis;
• Central nervous system (CNS) involvement;
• Pregnant or breastfeeding;
• Hepatitis B virus (HBV) surface antigen (HBsAg) or hepatitis B core antibody-positiveand detectable HBV DNA in peripheral blood; Hepatitis C virus (HCV) antibody andhepatitis C virus RNA in peripheral blood; Human immunodeficiency virus (HIV) antibody
• Uncontrolled Hypertension hypertension defined as a blood pressure (BP) ≥150/95 mmHg;Symptomatic heart failure per New York Heart Association Classification Class II, IIIor IV), Mean resting corrected QT interval corrected by Fridericia's formula (QTcF) > 470 msec (female), 450 msec (male) obtained from ECG; Baseline left ventricularejection fraction (LVEF) below institution's lower limit of normal (LLN) or <50%;
• Have a history of another primary malignancy within 5 years prior to starting studytreatment. Exceptions here are as follows: the disease under study; adequately treatedbasal or squamous cell carcinoma of the skin; cancer of the cervix in situ.