On October 27, 2024, RemeGen Co., Ltd (“RemeGen”) (688331.SH/09995.HK) announced that the Center for Drug Evaluation (CDE) of China’s National Medical Products Administration (NMPA) had officially accepted its Biologics License Application (BLA) of its innovative drug Telitacicept (RC18, trade name: Tai'ai®) for the treatment of generalized myasthenia gravis (gMG) and granted priority review. Telitacicept is a BLyS/APRIL dual-target fusion protein independently developed by RemeGen and has been approved for two indications in China, namely systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA).

Myasthenia gravis (MG) is a rare chronic autoimmune disease that has been included in China's First Batch of Rare Disease Catalog. According to a report by Frost & Sullivan, as of 2025, approximately 1.146 million individuals worldwide are predicted to be affected by MG, with around 217,000 in China. MG arises from immunoglobulin G (IgG) impairing the synaptic transmission at the neuromuscular junction which results in muscle weakness and threat to life in severe cases. Over 85% of patients will progress to generalized myasthenia gravis (gMG) within 24 months after disease onset and experience extreme fatigue and significant difficulties in facial expressions, speech, swallowing and physical movement.

Currently, there is no definitive treatment available for MG. However, targeted biological therapies have emerged as an area of special interest by virtue of their effectiveness, precision and safety. Among these, B cell targeted therapies stand out for their promising therapeutic potential. Researches have shown that these therapies can significantly lower the relapse rate and the drug discontinuation rate among MG patients, compared to conventional immunotherapy regimens. As a novel dual-target fusion protein directed at B cells, Telitacicept simultaneously targets B-lymphocyte stimulator (BLyS) and a proliferation-inducing ligand (APRIL). This mechanism can effectively inhibit the excessive activation of B cells and plasma cells, thereby reducing the production of pathogenic antibodies associated with MG and offering significant therapeutic benefits.

A Phase III clinical trial on gMG in China sponsored by RemeGen demonstrated favorable efficacy and safety profiles of Telitacicept, as evidenced by the continuous reduction of clinical symptoms among gMG patients in the treatment group. Additionally, RemeGen announced the achievement of First Patient In in the US for its global multi-center Phase III clinical trial on MG. Notably, for MG, Telitacicept has received breakthrough therapy designation from China’s NMPA, as well as orphan drug designation and fast track designation from the US FDA.