Safety and Efficacy of Anti-BCMA/FcRL5 CAR-T Cell Therapy in Treating Relapsed and Refractory Multiple Myeloma (R/R MM)

Inclusion Criteria: Age is 18\~70 years old; Expected survival period of\>12 weeks; Multiple myeloma was diagnosed by physical examination, pathological examination, laboratory examination and imaging; Patients with refractory multiple myeloma; Patients with multiple myeloma recurrence; ALT and AST \<3 times normal; bilirubin \<2.0mg / dl; Quality of survival score (KPS)\> 50%; The patient has no serious heart, liver, kidney and other diseases; Recurrence or no disease remission after hematopoietic stem cell transplantation or cellular immunotherapy; Is not suitable for stem cell transplantation conditions or to abandon transplantation due to conditional restrictions; Blood can be obtained intravenously, without other contraindications to leukapheresis; Understand and voluntarily sign a written informed consent form. Exclusion Criteria: Women who are pregnant or breastfeeding, or who have a pregnancy plan within six months; Infectious diseases (such as HIV, active tuberculosis, etc.); Active hepatitis B or hepatitis C infection; Feasibility assessment screening demonstrated \<10% transfection of targeted lymphocytes or underamplification under CD3 / CD28 costimulation (\<5-fold); Abnormal vital signs, and unable to cooperate with the examination; Have mental or mental illness who cannot cooperate with the treatment and efficacy evaluation; Highly allergic constitution or have a history of severe allergies, especially allergic to IL-2; Subjects with a systemic infection or a severe local infection requiring anti-infective treatment; Subjects with severe autoimmune disease; The doctor believes there were other reasons for inclusion