This is a phase I, interventional, single arm, open label, treatment study to evaluate the safety and tolerability of BCMA-CS1 cCAR in patients with relapsed and/or refractory multiple myeloma.

BCMA-CS1 cCAR (Compound CAR BCMA-CS1) is a chimeric antigen receptor immunotherapy treatment designed to treat multiple myeloma using two different antigen targets, BCMA (CD269) and CS1 (SLAMF7).

The use of two different targets widely expressed on plasma cells, BCMA and CS1, intends to increase coverage and eradicate cancerous cells before resistance develops in surviving cancer cells that have undergone selective pressures or antigen escape. BCMA-CS1 cCAR bears two distinct functional CAR molecules expressed on a T-cell, directed against the surface proteins BCMA and CS1.

Inclusion Criteria:

1. Diagnosis based on the World Health Organization (WHO) 2008
2. Patients have exhausted standard therapeutic options
3. Systematic usage of immunosuppressive drug or corticosteroid must have been stopped for more than 4 weeks
4. Female must be not pregnant during the study

Exclusion Criteria:

1. Prior solid organ transplantation
2. Potentially curative therapy including chemotherapy or hematopoietic cell transplant
3. Prior treatment with BCMAxCD3 or CS1xCD3 bispecific agents