Barriers to CAR T-cell therapy in rheumatology.

Chimeric antigen receptor (CAR) T cells have recently shown remarkable promise in treating rheumatic diseases, including systemic lupus erythematosus (SLE), idiopathic inflammatory myopathies, and systemic sclerosis. Currently, there are 37 clinical trials registered for CAR T-cell therapy in rheumatic diseases and many more are being planned. Much of this enthusiasm is justifiable, but widespread adoption of CAR T-cell therapy in rheumatology faces several barriers. The trajectory of autoimmune diseases differs from malignancies and a surprisingly narrow population could be eligible for CAR T-cell therapy. Current CAR T-cell approaches rely on B-cell depletion, which has a mixed record of success for many diseases. The high cost of CAR T-cell therapy and potential safety concerns, such as cytokine release syndrome and long-term infection risks, also pose substantial challenges. Moving forward, more targeted CAR T-cell approaches, such as antigen-specific chimeric autoantibody receptors or chimeric autoantigen T-cell receptors, could offer greater efficacy and safety in treating rheumatic diseases.