A Phase 1 trial at Charité - Universitätsmedizin Berlin has shown that CAR T-cell therapy, originally developed to fight blood cancers, can drive severe, treatment-resistant rheumatoid arthritis into remission. The COMPARE trial treated six patients aged 31 to 69 whose disease had failed up to eight prior therapies.
Doctors extracted each patient's T cells, genetically engineered them to target the CD19 marker found on disease-driving B cells, and reinfused them to "reset" the immune system. All six patients saw a marked reduction in disease activity, and three achieved medication-free remission; only mild-to-moderate cytokine release syndrome was observed, with no severe side effects reported. One patient's disease returned after an initial remission.
Researchers noted that when the B-cell population later recovered, it was made up mostly of naive, non-disease-causing cells, while the harmful autoimmune cells remained undetectable in nearly all patients. The team now plans a Phase 2 trial comparing CAR T-cell therapy against existing B-cell-targeting drugs in ten additional patients. The results were published in Nature Medicine.