B Cell Depletion

Fate Therapeutics reported positive Phase 1 data for FT819, an off-the-shelf CAR T-cell therapy, in ten treatment-refractory SLE patients. A single dose resulted in rapid B-cell depletion and immune remodeling. The study showed durable clinical responses, including complete renal responses and steroid-free remission. FT819 demonstrated a favorable safety profile with low-grade CRS and no ICANS or GvHD. The data support potential outpatient administration and a pivotal study in 2026. These results suggest FT819’s transformative potential for SLE treatment.

Cullinan Therapeutics will present preclinical data on CLN-978, a CD19xCD3 bispecific T cell engager, at ACR Convergence 2025. Studies show CLN-978 rapidly depleted B cells in samples from RA, Sjögren’s, and SLE patients, and in nonhuman primates after subcutaneous dosing. In a SLE mouse model, it reduced B cells, anti-dsDNA IgG, and kidney IgG deposition. Cullinan is advancing CLN-978 in OUTRACE clinical programs for RA, SjD, and SLE.