Fate Therapeutics Presents New Clinical Data at ACR Convergence 2025 Demonstrating Immune Remodeling and Durable Responses in Patients with Systemic Lupus Erythematosus Treated with FT819 Off-the-Shelf CAR T-Cell Therapy

Core Insights - Fate Therapeutics has reported promising initial clinical data for FT819, an off-the-shelf CAR T-cell therapy for moderate-to-severe systemic lupus erythematosus (SLE), demonstrating significant clinical activity and a favorable safety profile [2][3] - The company aims to accelerate patient enrollment in its Phase 1 trial and is in discussions with the FDA regarding a registrational study design, with plans to initiate a pivotal study in 2026 [2][8] Clinical Data Summary - As of September 25, 2025, 10 patients have been treated with FT819, with 5 patients showing significant reductions in SLE Disease Activity Index (SLEDAI-2K) scores and improvements in renal response [1][3] - Patients treated with a less-intensive conditioning regimen exhibited notable reductions in SLEDAI-2K scores, with one patient achieving complete renal response and remaining in drug-free remission at 15 months [1][4] - In the conditioning-free regimen, patients on maintenance therapy also showed meaningful reductions in disease activity scores, with one patient achieving low lupus disease activity state by 3 months [5] Safety Profile - The safety profile of FT819 is favorable, with no dose-limiting toxicities observed and a low incidence of low-grade cytokine release syndrome [6][8] - All patients were discharged on the same day post-infusion, supporting the potential for outpatient administration [6][8] Mechanistic Insights - FT819 treatment led to rapid CD19+ B cell depletion and immune remodeling towards a naïve B-cell repertoire, correlating with reductions in disease activity [8] - The unique ability of FT819 to remodel the B-cell compartment without intensive conditioning chemotherapy highlights its transformative potential in treating autoimmune diseases [8] Program Expansion and Future Outlook - Fate Therapeutics is expanding its clinical program to include additional cohorts for other autoimmune diseases and is preparing for a pivotal study in 2026 [8][9] - The company currently has approximately 600 cryopreserved drug product bags of FT819 available for patient treatment [9]