TST801

TST801 is a first-in-class bifunctional antibody fusion protein of anti-BAFF antibody and TACI receptor. BAFF and APRIL, two ligands for TACI receptor, are involved in regulating B cell activation and differentiation. Both are validated targets for several autoimmune diseases including SLE, LN and IgAN. Therefore, TST801 has the potential of delivering better efficacy for the treatment of those diseases and potentially other B-cell related autoimmune diseases. We have selected the lead molecule and initiated IND-enabling studies. The in vivo study of such molecule in the human BAFF overexpressing transgenic mice demonstrated promising activity in reducing memory B cells, and dsDNA, IgA, IgM and IgG as well as reducing proteinuria and kidney damage scores.