CD19 CAR T Cell Therapy Shows Promise for Refractory Rheumatoid Arthritis

Clinical Outcomes and Trial Findings

According to findings presented by Fredrik Albach at the 2026 Congress of EULAR (The European Alliance of Associations for Rheumatology), mivocabtagene autoleucel was administered to six patients with anti-citrullinated protein antibody (ACPA)-positive, treatment-refractory active rheumatoid arthritis. The therapy was generally well tolerated, with cytokine release syndrome restricted to mild-to-moderate events. Researchers observed no immune effector cell-associated neurotoxicity syndrome or unexpected toxicities.

Data from the trial showed that the CAR-T cells expanded rapidly, peaking within three weeks before declining gradually. B cells were effectively depleted in both blood and tissues. Furthermore, participants experienced a marked decrease in autoantibodies, showing a median reduction greater than 90%. Sustained seroconversion to normal ACPA levels was achieved in four patients, while five patients achieved normal RF-IgM levels. All six participants registered a decrease in disease activity, marked by a median 49% DAS28-CRP reduction and ACR20/50/70 responses in five, four, and two patients respectively. Half of the participants achieved sustained remission without ongoing immunosuppressive therapy during a follow-up period of 24 to 36 weeks.

Broader Application in Autoimmune Diseases

The promise of cellular therapy extends beyond rheumatoid arthritis into other refractory autoimmune conditions. A separate group presented findings on the first multicenter experience of dual-target CD19/BCMA CAR-T therapy in 11 patients suffering from refractory systemic sclerosis. Yajing Zhang of Beijing GoBroad Boren Hospital in China reported that the treatment induced rapid B-cell aplasia alongside significant improvements in skin thickness scores, with 73% of patients reaching low disease activity.

In patients with refractory systemic sclerosis, administering a dual-target CD19/BCMA CAR-T cell approach leads to profound and sustained clinical remission. By addressing both skin fibrosis and lung progression effectively, this immune ‘reset’ approach provides genuine curative potential, setting the stage for Phase 2 trials to reshape how this severe condition is managed in the future.

Yajing Zhang

In addition to skin manifestations, the dual-target trial tracked lung progression, observing stabilization or improvement in lung volume and oxygen transfer. High-resolution computed tomography scans confirmed the regression of interstitial changes in 80% of patients who had baseline interstitial lung disease. One patient with overlap syndrome required retreatment and achieved remission following a second infusion.

Microbiome Impacts and Safety Considerations

Because CD19 CAR-T therapy profoundly alters adaptive immunity, researchers continue to investigate secondary physiological effects. Yuichi Maeda and colleagues investigated gut microbiome composition and fecal IgA levels in patients with severe systemic lupus erythematosus, systemic sclerosis, or idiopathic inflammatory myopathy who received zorpocabtagene autoleucel. Microbial alpha-diversity remained low six months post-treatment in patients compared to healthy controls, though overgrowths of Streptococcus species decreased following the intervention.

Regarding safety in the rheumatoid arthritis cohort, B-cell repopulation did not trigger the reappearance of ACPA-positive memory B cells, rising autoantibodies, or increased disease activity. With the exception of a single patient who experienced a moderate flare upon drug withdrawal and required a return to glucocorticoids, all participants remained off immunosuppressive medications at the time of the data cut-off.