TNF receptor/IgG1 fusion protein(Anhui Anke Biotechnology)

Systemic lupus erythematosus (SLE) is a chronic autoimmune disease, in which aberrant immune cells and proinflammatory mediators act as key players in the pathogenesis of the disease. Telitacicept (RC-18) is a novel, recombinant fusion protein, consisting of transmembrane activator and calcium modulator and cyclophilin ligand interactor (TACI) and the Fc portion of human immunoglobulin G (IgG) (TACI-Fc). It was designed to inhibit the activity of two target cytokines, the B-cell lymphocyte stimulator (BLyS, also known as the B-cell activation factor [BAFF]) and a proliferation-inducing ligand (APRIL), both of which are involved in B cell-mediated autoimmune diseases. In Chinese patients with moderate to severe SLE, subcutaneous telitacicept (80, 160 and 240 mg) in combination with standard therapy was associated with clinical benefit and appeared to be well tolerated. On March 9, 2021, the Chinese National Medical Products Administration (NMPA) granted telitacicept conditional marketing approval for the treatment of adult patients with active, autoantibody-positive SLE. Additionally, on April 15, 2020, the U.S. Food and Drug Administration (FDA) granted fast track designation to telitacicept for the treatment of SLE. Here, we provide a comprehensive review of the preclinical and clinical activity of telitacicept in SLE.

Therapeutic proteins expressed using transgenic animals have been of great interest for several years. Especially, transgenic silkworm has been studied intensively because of its ease in handling, low-cost, high-yield and unique glycosylation patterns. However, the physicochemical property of the therapeutic protein expressed in transgenic silkworm remains elusive. Here, we constructed an expression system for the TNFR-Fc fusion protein (Etanercept) using transgenic silkworm. The TNFR-Fc fusion protein was employed to N-glycan analysis, which revealed an increased amount of afucosylated protein. Evidence from surface plasmon resonance analysis showed that the TNFR-Fc fusion protein exhibit increased binding affinity for Fcγ receptor IIIa and FcRn compared to the commercial Etanercept, emphasizing the profit of expression system using transgenic silkworm. We have further discussed the comparison of higher order structure, thermal stability and aggregation of the TNFR-Fc fusion protein.