On April 2, 2024, RemeGen Co., Ltd. (“RemeGen”) announced that the United States FDA had granted Fast Track Designation to Telitacicept for treatment of Primary Sjögren's Syndrome after the relevant phase 3 multicenter global clinical trial was approved to proceed at the end of 2023.

Primary Sjögren's Syndrome (pSS) is a chronic inflammatory autoimmune disorder that mainly affects lacrimal, salivary, and other secretory glands. The most common symptoms among patients include dry mouth, dry eyes, and dry skin. The currently available treatment options for pSS are far less than satisfying. No medication has been proven effective by an evidence-based medicine methodology in relieving dryness, fatigue, pain or visceral organ damage. Prevailing therapies are mainly from experience in this field or regimens for similar diseases.

The B cell receptor signaling pathway is vital in the pathogenesis of pSS. B-lymphocyte stimulator (BLyS) and a proliferation-inducing ligand (APRIL) are critical factors in B cell maturation and differentiation. Telitacicept is a novel humanized TACI-Fc fusion protein constructed with the extracellular domain of TACI (a B cell receptor), and the fragment crystallizable (Fc) domain of IgG1 via DNA recombination technology. By binding to BLyS and APRIL simultaneously, the reagent can inhibit B cell maturation and differentiation and reduce autoantibody production, helping control disease activity more effectively.

The data of a randomized, double-blinded, placebo-controlled phase 2 clinical trial for Telitacicept in the treatment of adult pSS patients was published in Rheumatology, one of the top journals in this field globally, showed Telitacicept had favorable clinical benefits for patients with pSS. According to the study, compared with the placebo group, patients in the Telitacicept group achieved significant improvement in ESSDAI and MFI-20 scores and lower Ig levels at Week 12 and 24 with no serious adverse event reported, demonstrating good safety profile. No death was observed in either group throughout the study.

By now, no biological medication has been approved for pSS treatment worldwide. Telitacicept is a promising candidate for a breakthrough medication for pSS, to narrow the gap in this field and bring a better recovery outlook for more patients.