Study of Dual Targeted CD19/BCMA FASTCART GC012F in Relapsed/ Refractory Multiple Myeloma

Inclusion Criteria: Eligible patients should meet all the following criteria: 1. Age of 18-70 years at the time of signing informed consent (contains critical values)； 2. Documented diagnosis at initial of active multiple myeloma according to IMWG criteria, and meet one or more of the following criteria at screening: 1. Serum M protein ≥ 1 g/dL 2. Urine M protein ≥ 200 mg/24h 3. Serum free light chain sFLC ≥ 10 mg/dL with abnormal serum κ/λ ratio 3. Have had at least 3 different prior lines of therapy or primary refractory and PD within 12 months of their last line of therapy (patient should undergo at least 1 complete cycle of treatment in each line of therapy) defined by Consensus recommendations for the uniform reporting of clinical trials: report of the International Myeloma Workshop Consensus Panel 1; or patients have had at least 2 different prior lines of therapy and refractory to both IMiD and PI; 4. Estimated life expectancy ≥3 months; 5. ECOG: 0 or 1; 6. Hemoglobin ≥ 7.0 g/dL (without prior RBC transfusion within 7 days before screening; recombinant human erythropoietin use is permitted); 7. Absolute neutrophil count ≥ 1×109/L (without recombinant human granulocyte colony-stimulating factor within 7 days before screening and without pegylated G-CSF within 14 days of the laboratory test); 8. Platelet count ≥50×109/L(without prior platelet transfusion within 7 days before the laboratory test) 9. Absolute lymphocyte count ≥ 0.1×109/L; 10. Adequate functional reserve of organs: 1. ALT/AST ≤ 2.5× UNL (upper normal limit); 2. Serum creatinine \> 45 mL/min, calculated by Cockcroft-Gault; 3. Serum total bilirubin ≤ 2× UNL, except in subjects with congenital bilirubinemia (for participants with Gilbert syndrome, direct bilirubin ≤ 1.5× UNL is required); 4. Calibrated serum calcium ≤ 12.5 mg/dL (≤ 3.1 mmol/L) or free ionized calcium ≤ 6.5 mg/dL (≤ 1.6 mmol/L); 11. Sufficient venous access for leukapheresis collection, and no other contraindications to leukapheresis; 12. Woman of childbearing age must have serum HCG negative during screen and baseline. Males agreed to avoid sperm donation at least 1 year after GC012F infusion. Males and sexual partner with fertility are willing to use effective and reliable method of contraception for at least 1 year after infusion; 13. Ability and willingness to adhere to the study visit schedule and all protocol requirements; 14. Subjects themselves or their legal representatives must voluntarily sign written informed consent form(s). Exclusion Criteria: • Patients should be excluded if they meet any one of the following criteria: Exclusion criteria: Patients should be excluded if they meet any one of the following criteria: 1. Presence of plasma cell leukemia (absolute number of peripheral plasma cells \>2.0×109/L), Waldenstrom's macroglobulinemia, POEMS syndrome (polyneuropathy, organomegaly, endocrinopathy, monoclonal protein disease, skin changes) or primary amyloidosis (AL) at screening; 2. Patients have other aggressive malignancies (except patients with disease free survival for more than 5 years from non-melanoma skin cancer and cervical carcinoma in situ, bladder cancer, or breast cancer); 3. Any situations not benefit for subjects to accept or tolerated to planned therapy or understand informed consent; or any situation in which investigators believe that participation in this study is not in the subject's best interests (e.g., harm to health), or any situation that may prevent, limit or confuse the assessment; 4. Patients with prior history of seizures or stroke within 6 months before signing ICF; 5. Patients following cardic condition: 1. New York Heart Association (NYHA) III or IV heart failure; 2. Myocardial infarction or coronary artery bypass graft (CABG) ≤ 6 months prior to signing ICF; 3. History of clinically significant ventricular arrhythmia or unexplained syncope, not believed to be vasovagal in nature or due to dehydration; 4. History of severe non-ischemic cardiomyopathy; 5. Impaired cardiac function (left ventricular ejection fraction \[LVEF\] \< 45%) as assessed by echocardiography or multiple gated acquisition scanning, or other heart diseases with clinically significant symptoms in 6 months prior to enrollment; 6. Patients have known active, or history of central nervous system involvement or exhibit clinical signs of meningeal involvement in multiple myeloma; 7. Patients positive for any of the following tests: 1. HIV antibody; 2. HCV antibody, those who are positive need to be tested for HCV-RNA, and those below the lower limit of the detection value can be enrolled; 3. HBsAg or HBcAb; if HBcAb positive then HBV DNA copies will be further detected by PCR with machine of COBAS AmpliPrep/COBAS Taqman (or other methods with equal sensitivity) and result negative patients can be enrolled. 4. TPPA antibody; 8. Suspect or evidence of serious active viral, bacterial or uncontrolled systemic fungal infections needs system anti-infection; active autoimmune disease or a history of autoimmune disease within 3 years prior to signing ICF; 9. Exist of pulmonary fibrosis; 10. Allergy subjects or history of severe hypersensitivity; 11. Oxygen inhalation requirement to maintain adequate oxygen saturation; 12. Patients have major surgery performed within 2 weeks prior to signing ICF, or planned during the study or within 2 weeks after GC012F infusion (except subjects who are planned for local anesthesia surgery); 13. Chemotherapy forbidden for cyclophosphamide and fludarabine; 14. Any tubes inserted or drain pipes except central venous catheter; 15. Pregnant or breast-feeding women who are and unwilling to stop breastfeeding, or men who are planned to have babies within 1 year of receiving treatment; 16. Patients who have received any prior therapy targeting BCMA; 17. Any conditions judge by investigator for patients not appropriate to participate in the study.