Safety and Efficacy of IM21 Car-t Cells in Patients With Recurrent or Refractory BCMA Positive Multiple Myeloma

Inclusion Criteria:

1. The patient had multiple myeloma (according to the updated IMWG diagnostic criteria)Active (symptomatic) myeloma
2. Refractory and recurrent multiple myeloma Refractory definition: 1) treated with at least second-line bortezomib or lenalidomide 2) determined by the clinician Definition of recurrence: refer to NCCN clinical guidelines for multiple myeloma (2016. V2), including recurrence after transplantation.
3. Age: 18 to 80 years old;
4. The expected survival time was more than 3 months;
5. ECoG score 0-2 (refer to Annex 2)
6. Hemoglobin (HB)≥80g/L; absolute neutrophil count (ANC)\>1×10\^9/L; platelet count(PLT)≥50×10\^9/L.

Those who voluntarily participated in the experiment and signed informed consent.

Exclusion Criteria:

1. High risk organ involvement patients: tumor invasion of central nervous system, gastrointestinal tract,lung,pericardium,one of the major vessels;
2. Those who have graft-versus-host reaction and need to use immunosuppressants, or who have autoimmune diseases;
3. Chemotherapy or radiotherapy was used within 3 days before blood collection;
4. Patients who used systemic steroids within 5 days before blood collection (except those who have recently or are currently using inhaled steroids);
5. The patients who used drugs to stimulate the production of bone marrow hematopoietic cells within 5 days before the blood collection period;
6. Those who have previously used any gene therapy products;
7. History of epilepsy or other central nervous system diseases;
8. New York Heart Association (NYHA) grade III or above (refer to Annex 3) (for patients with heart disease, this assessment is required);
9. Creatinine \> 1.5 times normal upper limit, ALT / AST\>3 times normal upper limit or bilirubin \>2 times normal upper limit;
10. Active hepatitis B or hepatitis C virus, HIV or other uncured active infections;
11. Pregnant or lactating women;
12. Those who suffer from other uncontrolled diseases are not suitable to join the study; Any situation that the researchers believe may increase the risk of subjects or interfere with the test results.