A small Phase 1 trial at Charité—Universitätsmedizin Berlin reported that CD19 CAR T-cell therapy (mivocabtagene autoleucel; miv-cel) drove substantial reductions in disease activity in six patients with treatment-refractory, ACPA-positive rheumatoid arthritis. During follow-up of up to about one year, three patients entered sustained remission without ongoing RA medication. The study enrolled patients who had failed up to eight prior targeted or biologic therapies and required standard lymphodepletion before a single infusion. Investigators reported the remissions as particularly notable given the lack of adequate symptom control with established options. While early and limited in size, the results position CAR T beyond oncology into severe autoimmune disease with a mechanistic focus on B-cell biology. The trial’s signal also sets expectations for subsequent cohorts on safety, durability, and steroid-free outcomes.