Recombinant Anti-BAFF x Anti-B7RP1 Bispecific Antibody (Tandem scFv-Fc) is designed to be expressed as a homodimer, which has 2+2 antigen-binding valency. This format consists of one Fc region and two tandem scFv fragments, in which the anti-BAFF/B7RP1 tandem scFv is fused to the Fc domain. The engineered fragment format is used to extend the half-life. This BsAb can bind and inactivate two ligands simultaneously. It can inhibit B cell survival and T cell costimulation. It is designed for the research of Systemic lupus erythematosus (SLE) therapy.