A Promising Treatment That Could Reset the Immune System in Rheumatoid Arthritis

Rheumatoid arthritis is a chronic inflammatory disease in which the immune system mistakenly attacks the joints. Current treatments primarily aim to control the disease by suppressing the immune system. However, long term disease remission after stopping medication is not achievable for every patient.

In a Phase 1 study presented at the EULAR 2026 Congress, six patients with active rheumatoid arthritis that was resistant to standard treatments were evaluated. The patients received CD19 targeted CAR T cell therapy. In this approach, the patient's own immune cells are collected, modified in a laboratory, and then returned to the body to target specific immune cells involved in the disease.

The study reported that the treatment was generally well tolerated. Cytokine release syndrome, a known side effect of CAR T therapy, was observed only in mild to moderate forms. No serious neurological side effects or unexpected safety concerns were reported.

Following treatment, patients showed a marked reduction in certain autoantibodies associated with the immune system. The study reported an average reduction of more than 90 percent in autoantibody levels. In addition, disease activity decreased in all patients. Half of the participants achieved remission without the need to continue immunosuppressive therapy.

Researchers also found that although B cells gradually returned over time, certain harmful immune cells associated with the disease did not reappear, and no increase in disease activity was observed. These findings suggest that CAR T therapy may help reset the immune system in some patients.

Experts emphasize that while the results are encouraging, the study is still at a very early stage and included only six patients. Larger clinical studies are needed before CAR T cell therapy can be considered a standard treatment option for rheumatoid arthritis.