Fate Therapeutics Announces Updated Clinical Data for FT819 Off-the-shelf CAR T-cell Product Candidate Demonstrating Durability of Drug-free Remission for Severe Lupus Nephritis at EULAR 2025 Congress

Core Insights - Fate Therapeutics announced promising clinical data for FT819, an off-the-shelf CAR T-cell therapy for moderate-to-severe systemic lupus erythematosus (SLE), showing all five patients treated achieved significant disease improvement [2][3] - The first patient reached a 12-month follow-up and continues in drug-free remission, indicating the potential for durable treatment effects [2][4] - The company is expanding its clinical trials to include multiple B cell-mediated autoimmune diseases, with plans for independent dose-expansion cohorts in various conditions [8] Clinical Data Summary - A multi-center, Phase 1 clinical trial is evaluating FT819's safety and efficacy in patients with moderate-to-severe SLE, including lupus nephritis and extrarenal lupus [3] - As of May 15, 2025, five patients have been treated, with all showing significant improvements in disease activity scores [3][4] - Three patients with active lupus nephritis achieved primary efficacy renal response, with reductions in SLEDAI-2K scores of 10 points or more [4][5] Treatment Regimens - FT819 was administered under two regimens: a fludarabine-free conditioning regimen and a conditioning-free regimen [3][6] - In the fludarabine-free regimen, three patients with active lupus nephritis showed significant reductions in SLEDAI-2K scores, with one patient achieving a score reduction from 20 to 4 at 12 months [4] - One patient with extrarenal lupus on maintenance therapy achieved low lupus disease activity state (LLDAS) at 3 months, maintained at 6 months, with a reduction in SLEDAI-2K from 8 to 2 [6] B-cell Remodeling - Patients treated with FT819 exhibited rapid B-cell depletion and a shift towards a non-switched, naïve B-cell repertoire within the first 60 days [7] - This remodeling was observed in both treatment regimens, indicating a potential mechanism of action for FT819 [7] Safety Profile - The treatment demonstrated a favorable safety profile, with low incidence of cytokine release syndrome and no events of neurotoxicity or graft-versus-host disease [8][10] - All patients were discharged after a short hospitalization, supporting the potential for outpatient administration [10] Regulatory and Development Plans - Fate Therapeutics has reached an agreement with the FDA to investigate multiple autoimmune diseases under its Phase 1 trial for FT819 [8] - The company plans to discuss registrational strategies with the FDA for FT819 in SLE under its RMAT designation [8]