FT819-102

June 4, 2026: Fate Therapeutics, Inc. (NASDAQ: FATE) presented EULAR 2026 data on off-the-shelf CAR T-cell programs FT819 (clinical) and FT839 (preclinical) in autoimmune disease.

FT819 (anti-CD19 CAR T) in systemic lupus erythematosus (SLE), Phase 1: As of May 14, 2026, 21 SLE patients were treated; 16 were in Regimen A receiving a single FT819 dose with reduced-intensity conditioning (cyclophosphamide or bendamustine alone). In Regimen A (N=16), there were no DLTs, no Grade ≥3 CRS (Grade 1–2 CRS 25%), and no ICANS, GvHD, hypogammaglobulinemia, or deaths; Grade ≥3 AEs occurred in 37.5% (Grade ≥3 infection 18.8%; Grade ≥3 cytopenia 18.8%). Disease activity measures (cSLEDAI-2K, UPCr, PGA, FACIT-Fatigue) improved rapidly and were sustained, with deeper responses reported with bendamustine vs cyclophosphamide. Among 10 patients on baseline glucocorticoids with ≥1 month follow-up, 7 reached ≤5 mg/day and 5 discontinued steroids. B-cell depletion was deep and durable with “reset” toward naïve phenotype; BCR sequencing (n=5) showed 74–96% reduction in top clones with no re-emergence through 12 months; vaccine titers (tetanus/measles/mumps IgG) were maintained in tested patients. The company plans a Phase 2 potentially registrational lupus nephritis trial, RECLAIM-LN (NCT07570862), and said it will provide an update “soon.”

FT839 (dual CAR targeting CD19 and CD38), preclinical: In assays using rheumatoid arthritis PBMCs, FT839 eliminated multiple activated/pathogenic immune subsets while sparing non-activated CD38-negative T cells; “Sword and Shield” engineering was described as suppressing alloreactivity in allogeneic settings without conditioning chemotherapy. IND-enabling activities are ongoing to support initial clinical investigation in 2026.