YTS109 in Pediatric Relapsed/Refractory Autoimmune Diseases

This exploratory, single-arm, open-label study will evaluate the safety and preliminary efficacy of YTS109 cell therapy in pediatric patients with relapsed/refractory autoimmune diseases, including systemic lupus erythematosus, diffuse systemic sclerosis, idiopathic inflammatory myopathies, and Sjögren's syndrome, as well as other eligible autoimmune diseases defined by the protocol eligibility criteria. Approximately 12 patients aged 5 to \<18 years will be enrolled at Children's Hospital of Fudan University and will receive a single intravenous infusion of YTS109 cells. Dose escalation will follow a standard 3+3 design starting at 1.5 × 10\^6 cells/kg. The primary objective is to assess the safety and preliminary efficacy of YTS109 cell therapy in this population. Secondary objectives include characterizing the pharmacokinetic and pharmacodynamic profiles of YTS109 cells. Primary endpoints include the type, severity, and frequency of adverse events, along with efficacy assessments.