Investigational Telitacicept Significantly Improves Myasthenia Gravis Outcomes in Phase 3 Study

Jianmin Fang

New late-breaking data from a randomized, double-blind, placebo-controlled phase 3 study (NCT05737160) showed that treatment with investigational telitacicept (RemeGen) led to sustained and significant improvement in clinical outcomes for patients with generalized myasthenia gravis (gMG). According to the RemeGen’s latest update, the company is planning to file a biologics license application (BLA) submission to the Center for Drug Evaluation of China’s National Medicinal Products Administration for the innovative treatment.^1,2

Presented at the 2025 American Academy of Neurology (AAN) Annual Meeting, held April 5-9, in San Diego, California, the study featured 114 patients with gMG who were randomly assigned to telitacicept 240 mg or placebo for a 24-week treatment phase, followed by an open-label extension. Coming into the study, patients had a score of at least 6 on Myasthenia Gravis-Activities of Daily Living (MG-ADL) and a score of at least 8 on Qualitative Myasthenia Gravis (QMG) score.

Led by Jian Yin, a professor at Beijing Hospital, results showed a change of –5.74 points on MG-ADL in the telitacicept group at 24 weeks vs a change of –0.91 for those on placebo. More notably, 98.1% and 12.0% of those in the telitacicept and placebo groups, respectively, achieved at least a 3-point reduction in MG-ADL. Telitacicept, a first-in-class recombinant B lymphocyte stimulator (BLyS) and a proliferation-inducing ligand (APRIL) dual-target novel fusion protein product, led to significant improvements in MG-ADL and QMG relative to placebo as early as 4 weeks into the study.

"Telitacicept demonstrated rapid and significant clinical improvement in the phase 3 trial, and was well tolerated,” Yin said in a statement. “Its dual-targeting mechanism not only inhibits abnormal B cells and plasma cells thoroughly and reduces the level of pathogenic antibodies, but also effectively slows down disease progression in the long term, and reduces steroid dosage as symptoms improve, providing a more precise, efficient, persistent, and safer option for gMG treatment."

After 24 weeks of treatment, those on telitacicept demonstrated changes of –8.66 on QMG score whereas those on placebo showed less impressive changes of –2.27. Overall, achievement of at least a 5-point reduction was found in 87.0% of those on telitacicept and 16.0% of those on placebo. In terms of safety, telitacicept was shown to be well tolerated over the treatment period, with an adverse event (AE) incidence that was similar to that in the placebo group and an incidence of infection-related AEs that was lower than that observed in the placebo group (45.6% vs 59.6%).

"The phase 3 data of Telitacicept for MG is clinically meaningful," Jianmin Fang, chief executive officer at RemeGen, said in a statement "There is a large unmet medical need in MG because the disease presents significant threat to patients' health and life-span. This breakthrough means that we have a new, effective treatment for MG as Telitacicept can significantly improve patients' symptoms and bring long term benefits to patients with MG. We look forward to working with global experts and scholars to overcome more complex autoimmune diseases and benefit more patients."

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Telitacicept previously demonstrated efficacy and safety in gMG in a phase 2 randomized, open-label study, published in the European Journal of Neurology. The study featured 29 patients who received telitacicept subcutaneously once a week for 24 weeks in addition to standard-of-care treatment using change in QMG score as the primary end point. Overall, after the treatment phase, investigators observed a mean reduction in QMG score of 7.7 (±5.34) and 9.6 (±4.29) in the 160 and 240 mg groups, respectively.

In the study, the mean reductions in QMG scores for these 2 groups were 5.8 (±5.85) and 9.5 (±5.03), respectively, indicating rapid clinical improvement. The mean reduction in the MG clinical absolutely score from baseline to week 24 was 13.8 (±7.30) in the 160 mg group and 14.1 (±9.78) in the 240 mg group (P = .931). At week 24, the cumulative percentage of patients achieving a QMG response, defined as a reduction of at least 3 or more points, was 92.9% in the 160 mg group and 100% in the 240 mg group.

In terms of safety, phase 2 data showed that AEs occurred in 78.6% of patients in the 160 mg group and 100% of patients in the 240 mg group; however, most of these were mild to moderate in severity. In the telitacicept 160 mg group, one patient (7.1%) experienced a Grade 3 AE (lymphocyte count decrease) and another had an SAE (pneumonia), both resolving without discontinuation, though the former required dosing interruption. In the 240 mg group, one patient (6.7%) had a dosing interruption due to an IgM decrease.

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REFERENCES
1. Remegen Announces Exciting Results of Telitacicept Phase 3 Clinical Trial for Patients with Generalized Myasthenia Gravis. News release. RemeGen. April 8, 2025. Accessed April 14, 2025. https://www.prnewswire.com/news-releases/remegen-announces-exciting-results-of-telitacicept-phase-3-clinical-trial-for-patients-with-generalized-myasthenia-gravis-302424073.html
2. BLA on Agenda: A Phase III Trial on Telitacicept for Myasthenia Gravis Achieves Primary Endpoint in China. News release. RemeGen. August 13, 2024. Accessed April 14, 2025. https://www.remegen.com/index.php?v=show&cid=105&id=2239
3. Yin J, Zhao M, Xu X, et al. A multicenter, randomized, open-label, phase 2 clinical study of telitacicept in adult patients with generalized myasthenia gravis. Eur J Neurol. 2024;31(8):e16322. doi:10.1111/ene.16322.