To evaluate the safety and preliminary efficacy of CD19 CAR T cell therapy in patients with severe, treatment-refractory rheumatoid arthritis.
Approach:
Study Design: A single-arm, open-label phase I clinical trial was conducted with six participants receiving mivocabtagene autoleucel after lymphodepleting chemotherapy.
Participants: The study included three women and three men aged 31–69 with longstanding seropositive rheumatoid arthritis, previously treated with multiple therapies.
Treatment Administration: Participants received a single infusion of 100 million CAR T cells, targeting CD19-positive B cells.
Key Findings:
All six participants showed a reduction in disease activity scores, with a median reduction of 49% at week 24 and 34% at the latest follow-up.
Three participants maintained remission without medication during follow-up of 36 to 52 weeks.
Four participants achieved clinical remission; one relapsed after 31 weeks.
Autoantibody levels decreased significantly, with a median decline of 94% in anti-mutated citrullinated vimentin antibodies.
Limitations:
The study was small and open-label, limiting the ability to establish efficacy.
Longer follow-up is needed to assess the impact on protective immunity.
Conclusion:
The study will advance to a randomized phase II trial comparing CD19 CAR T therapy with rituximab to evaluate response duration and depth.
