Abstract: Multiple myeloma (MM) is an incurable haematological malignancy of the blood system. For patients suitable for transplantation, autologous stem cell transplantation (ASCT) can significantly enhance the rate of remission and prolong progression⁃free survival. Over the past decade, with a deeper understanding of the disease biology and advances in therapeutic approaches, many MM patients have been able to control disease and improve their quality of life, but they ultimately face the relapse. For patients with relapsed/refractory MM, chimeric antigen receptor T (CAR⁃T) cell therapy has demonstrated notable efficacy and superior safety, significantly delaying disease progression. This review focuses on the current status and progress of CAR⁃T cell therapy in the treatment of MM, as well as the reasons for its failure, to provide new ideas for the further development of CAR⁃T cell therapy in MM. 

Key words: Multiple myeloma, Relapsed, Refractory, Immunotherapy, CAR-T