Fate Therapeutics Inc. (NASDAQ: FATE) presented clinical trial data on its experimental cell therapies FT819 and FT839 for autoimmune diseases at the European Congress of Rheumatology in London.

The company reported that 21 systemic lupus erythematosus patients have been treated with FT819, an off-the-shelf CAR T-cell therapy. Among 16 patients who received the treatment with reduced-intensity conditioning chemotherapy, no dose-limiting toxicities, severe cytokine release syndrome, or treatment-related deaths were reported.

The trial showed that patients experienced reductions in disease activity scores and proteinuria within months of treatment. Of 10 patients on background glucocorticoids with at least one month of follow-up, seven achieved doses of 5 mg per day or less, with five discontinuing steroids entirely.

FT819 demonstrated deep B-cell depletion with elimination of dominant B-cell clones in a dose-dependent manner, while vaccination titers for tetanus, measles, and mumps remained unchanged. The treatment could be administered in outpatient settings with same-day discharge, including at community hospitals.

The company also presented preclinical data on FT839, a dual-CAR T-cell therapy targeting both CD19 and CD38. In laboratory studies using blood samples from rheumatoid arthritis patients, FT839 eliminated activated immune cells without requiring conditioning chemotherapy. The treatment selectively targeted pathogenic cells while preserving non-activated T cells.

Fate Therapeutics plans to advance to a Phase 2 trial in lupus nephritis called RECLAIM-LN and is completing regulatory preparations to begin clinical testing of FT839 in 2026. The information was disclosed in a company press release.