NCT07439029

YTS109 in Pediatric Relapsed/Refractory Autoimmune Diseases

An Exploratory Clinical Study of the Safety and Efficacy of YTS109 Cell Injection in Children With Relapsed/Refractory Autoimmune Diseases

• Status: Not Yet Recruiting
• Phase: Phase 1
• Study type: Interventional
• Enrollment: 12 (estimated)
• Sponsor: Children's Hospital of Fudan University · Academic / Other
• Sex: All
• Age: 5 Years – 18 Years
• Healthy volunteers: Not accepted

Summary

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.

Detailed description

Background: Autoimmune diseases (AIDs) comprise a heterogeneous group of disorders in which dysregulated immune responses target self-antigens, resulting in chronic inflammation and tissue damage. Although therapeutic options for AIDs have advanced in recent years, a subset of pediatric patients with relapsed or refractory disease continues to experience inadequate disease control, cumulative organ damage, and substantial treatment-related toxicity. B cells play a central role in the pathogenesis of many AIDs through autoantibody production, antigen presentation, and cytokine secretion. CD19-directed cellular immunotherapies, including CAR-T/related platforms, have emerged as promising approaches for severe autoimmune disease by enabling deep and potentially durable B-cell depletion, and therefore warrant further clinical evaluation in pediatric populations. YTS109 is a universal allogeneic CD19-targeting STAR-T cell therapy designed to efficiently eliminate CD19+ B cells and attenuate pathogenic autoimmune responses. Design: This is a single-center, single-arm, prospective exploratory clinical trial designed to evaluate the safety profile, preliminary therapeutic efficacy, and pharmacokinetic/pharmacodynamic (PK/PD) characteristics of YTS109 cell therapy in children with relapsed/refractory autoimmune diseases. Eligible indications include systemic lupus erythematosus, diffuse systemic sclerosis, idiopathic inflammatory myopathies, Sjögren's syndrome, ANCA-associated vasculitis, and antiphospholipid syndrome, as defined by the protocol eligibility criteria. Approximately 12 patients aged 5 to \<18 years will receive a single intravenous infusion of YTS109 cells, with dose escalation conducted using a standard 3+3 design starting at 1.5 × 10\^6 cells/kg. The primary endpoint includes the type, severity, and frequency of adverse events (AEs), together with protocol-defined efficacy assessments. Secondary endpoints include PK/PD measures of YTS109 cell kinetics and immune reconstitution biomarkers. The study was approved by the Ethics Committee of Children's Hospital of Fudan University (Approval No. 2025-207). Written informed consent will be obtained from all participants and/or their legal guardians prior to study procedures.

Conditions

• Systemic Lupus Erythematosus (SLE)
• Diffuse Systemic Sclerosis
• Idiopathic Inflammatory Myopathies (IIMs)
• ANCA Associated Vasculitis (AAV)
• Antiphospholipid Syndrome (APS)
• Sjogren's Syndrome (SS)

Interventions

Type	Name	Description
BIOLOGICAL	YTS109 cell	Single intravenous infusion of YTS109 cells; dose escalation per 3+3 design starting at 0.75×10\^6 cells/kg.
OTHER	YTS109 cell	Single intravenous infusion of YTS109 cells; dose escalation per 3+3 design starting at 0.75×10\^6 cells/kg.

Timeline

• Start date: 2026-03-01
• Primary completion: 2027-03-01
• Completion: 2030-07-01
• First posted: 2026-02-27
• Last updated: 2026-02-27

Locations

1 site across 1 country: China