Researchers at Charité – Universitätsmedizin Berlin have tested CAR T-cell therapy — originally developed to fight cancer — in six people with treatment-resistant rheumatoid arthritis, producing what may be a breakthrough for autoimmune disease treatment.
All six patients showed markedly reduced disease activity. Three achieved sustained remission without any rheumatoid arthritis medication for up to 12 months. The results, published in Nature Medicine, represent the world's first clinical trial of CD19 CAR T-cell therapy specifically for severe rheumatoid arthritis.
The therapy works by engineering a patient's own T cells to recognize and destroy CD19-positive B cells — the same marker found on many blood cancers. In autoimmune disease, these B cells carry disease-driving memory that persists in lymph nodes, bone marrow, and joint tissue, repeatedly reigniting inflammation even after conventional treatments fail.
Remarkably, the CAR T cells reached B cells hidden deep within the body's tissues — not just those circulating in blood. When the B-cell system later recovered, it returned predominantly with naïve B cells rather than the disease-directed ones. Crucially, antibodies from earlier vaccinations were still detectable, suggesting protective immunity was largely preserved.
Side effects were mild: all participants experienced only temporary, manageable cytokine release syndrome. No severe neurological complications or serious adverse events occurred. The second phase will enroll ten more patients and compare CAR T-cell therapy against an approved rheumatoid arthritis drug.
