The treatment of multiple myeloma has changed dramatically in recent years, with huge strides forward made in the field. Chimeric antigen receptor T-cell therapy targeting the B cell maturation antigen (BCMA) is now widely approved in relapsed refractory patients and is moving into earlier treatment lines. In this review, we discuss the evidence underpinning current regulatory approvals and consider mechanisms through which CAR-T cell efficacy could be improved. These include tackling BCMA-loss, harnessing the immunosuppressive tumour microenvironment, manufacturing concerns including the potential role of other cellular sources, safety issues such as cytokine release syndrome and neurotoxicity, and optimal patient selection.