A first-in-human Phase 1 trial at Charité—Universitätsmedizin Berlin reported that CD19 CAR T-cell therapy pushed severe, treatment-refractory seropositive rheumatoid arthritis into remission in a small cohort. Investigators treated six patients with mivocabtagene autoleucel (miv-cel) after standard lymphodepletion and after stopping background disease-modifying therapy. During 36–52 weeks of follow-up, the trial team reported marked reductions in disease activity in all participants, with three patients in sustained remission without any RA medication by the end of the observation period. Researchers said the cohort had received up to eight prior targeted or biologic therapies over the previous decade. While early and limited by sample size, the finding adds to a growing set of proof-of-concept experiences showing CAR T can be adapted beyond oncology into autoimmune B-cell-driven disease settings.