Telitacicept now under priority review in China as gMG treatment
Therapy eased disease severity in 2 clinical trials in China: Developer
The China National Food and Drug Administration has accepted and placed under priority review an application from Remegen seeking approval of telitacicept as a treatment for generalized myasthenia gravis (gMG).
That’s according to a press release from Remegen, a commercial-stage biotechnology company that’s developing the treatment for worldwide use. Remegen is a subsidiary of Yantai Rongchang Pharmaceutical, a traditional Chinese medicine company.
The injection therapy is already approved in China for systemic lupus erythematosus, the most common form of lupus, and rheumatoid arthritis, two other autoimmune diseases.
In two clinical trials in China, one of which was recently completed, telitacicept was found to ease disease severity in adults with gMG, according to Remegen.
In the U.S., telitacicept was granted orphan drug status in 2022 as a potential treatment for myasthenia gravis (MG). That designation, awarded by the U.S. Food and Drug Administration, helps to accelerate the clinical development and regulatory review of treatments for rare disorders.
Global Phase 3 trial now testing telitacicept for gMG
Autoimmune diseases are marked by the body’s mistaken production of self-reactive antibodies against healthy cells, which result in cell death and tissue damage. In MG, these abnormal antibodies disrupt the communication between nerves and muscles, leading to symptoms such as muscle weakness. The most prevalent type of MG-causing antibodies targets a protein called acetylcholine receptor, or AChR.
Telitacicept, formerly known as RC18, is designed to dampen the inflammatory activity of B-cells by simultaneously blocking two proteins essential for these cells’ development: B-cell lymphocyte stimulator, or BLyS, and a proliferation-inducing ligand, or APRIL.
Administered via under-the-skin, or subcutaneous, injections, the therapy was developed by combining a fragment of an antibody with a portion of the TACI receptor — a protein that modulates B-cell development.
In a Phase 2 clinical trial (NCT04302103) in China, completed in 2022, 29 gMG patients with anti-AChR antibodies were randomly assigned to receive weekly injections of either one of two doses of telitacicept for 24 weeks, or nearly six months. The two tested doses were 160 and 240 mg.
Data showed that both doses led to a lessening of disease severity, as assessed with the Quantitative MG (QMG) scale, a measure of MG severity in which higher scores indicate more disability.
Specifically, the low dose was associated with a mean score reduction of 7.7 points on the QMG scale, and the high dose with a mean drop of 9.6 points. This group difference in terms of QMG score changes was statistically significant, indicating that the high dose was more effective.
A more recent China-based Phase 3 clinical trial (NCT05737160), completed in August, evaluated telitacicept at that 240 mg dose, versus a placebo. The study involved approximately 100 adults with gMG who tested positive for MG-driving self-reactive antibodies.
The results showed that “telitacept can continuously and effectively improve the clinical status of patients with generalized myasthenia gravis,” Remegen stated in the release.
Meanwhile, earlier this year, the company launched a global, placebo-controlled Phase 3 clinical trial — dubbed RemeMG (NCT06456580) — with a similar design to the China-based study. An estimated 180 gMG patients with self-reactive antibodies, ages 18 and older, are being recruited. The first patient in the U.S. was enrolled earlier this year.
The new study’s main goal is to determine whether telitacicept is superior to the placebo at lessening disease severity, as assessed with the MG Activities of Daily Living (MG-ADL) scale, after about six months. Higher scores on the MG-ADL scale indicate worse symptom severity, with a greater effect on daily activities. Secondary goals include score changes in the QMG scale and a measure of quality of life known as the MG Quality of Life scale.
The trial is expected to be completed in 2027.
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