The prospects and promise of chimeric antigen receptor immunotherapy in multiple myeloma

Despite encouraging therapeutic advances, multiple myeloma (MM) remains an incurable malignancy. The exciting results of chimaeric antigen receptor (CAR)-based immunotherapy in CD19(+) B-cell malignancies have spurred a great interest in extending the use of the CAR technology to other cancers, including MM. Availability of a specific, tumour-restricted antigen is crucial for the design of successful antibody-based CAR therapy. However, in MM, as in other malignancies, the relative dearth of such antigens-targets represents the main obstacle for the wider pre-clinical development and clinical application of the CAR technology. Here we provide an overview of the current progress and future promises of CAR technology in MM therapy. We highlight that, owing to its complexity, phenotypic and functional heterogeneity and the impact of the microenvironment, MM poses several challenges for CAR-based therapeutic approaches. Nevertheless, for the same reasons, MM can serve as a paradigm for better understanding, optimization and overall improvement of the CAR technology for the benefit of cancer and myeloma patients.