Fate Therapeutics Shows Deep B-Cell Depletion in 21 SLE Patients with FT819
FATE•Fate Therapeutics has treated 21 systemic lupus erythematosus patients with off-the-shelf CAR T-cell candidate FT819 using less-intensive conditioning, achieving deep and sustained B-cell depletion alongside glucocorticoid discontinuation or tapering in most evaluable patients. In preclinical rheumatoid arthritis studies, FT839 eliminated activated immune cells in patient samples without conditioning chemotherapy.
1. FT819 Phase 1 Trial Progress
Fate Therapeutics has enrolled 21 systemic lupus erythematosus patients in its Phase 1 FT819 trial, including 16 on Regimen A with a single FT819 dose plus less-intensive conditioning of cyclophosphamide or bendamustine. Patients, mean age 33.8 years and median seven prior therapies, received same-day outpatient infusions at community hospitals, broadening access beyond academic centers.
2. Safety and Efficacy Outcomes
FT819 demonstrated a favorable safety profile in Regimen A, with no dose-limiting toxicities, no Grade ≥3 cytokine release syndrome, neurotoxicity, graft-versus-host disease or deaths. Deep and sustained B-cell depletion correlated with reconstitution of less-differentiated B-cell subsets, and a majority of evaluable patients achieved complete glucocorticoid discontinuation or guideline-based tapering targets.
3. FT839 Preclinical Rheumatoid Arthritis Data
In preclinical studies, FT839, a next-generation dual-CAR iPSC-derived candidate, eliminated activated immune cells in rheumatoid arthritis patient samples without any conditioning chemotherapy. This allogeneic approach achieved comprehensive immune cell clearance, supporting its potential to address aberrant immune-driven autoimmune conditions with reduced treatment intensity.
