GR1803

GR1803 is a bispecific monoclonal antibody (bsAb) that targets both CD20 on B cells and CD3 on T cells. Developed by Genrix (Shanghai) Biopharmaceutical, it is designed as a T-cell engager to treat B-cell-mediated autoimmune diseases and malignancies. In the context of systemic lupus erythematosus (SLE), GR1803 facilitates the formation of an immunological synapse between cytotoxic T cells and CD20+ B cells, leading to the targeted depletion of the B-cell population. This depletion is intended to eliminate the source of pathogenic autoantibodies and reset the immune system in patients with refractory SLE. The drug is currently undergoing Phase Ib/IIa clinical evaluation for safety and efficacy in SLE patients.