Recombinant Protein Therapy for Generalized Myasthenia Gravis Demonstrates Efficacy in Phase 3 Study

RC18 (telitacicept; RemeGen, Beijing, China), a novel recombinant protein therapy that targets both the B lymphocyte stimulator (BLyS) and proliferation-inducing ligand (APRIL) pathways, may provide rapid, significant, and sustained improvements in people with generalized myasthenia gravis (gMG), according to new data. The positive efficacy results from a phase 3 clinical trial (NCT05737160) were presented at the American Academy of Neurology (AAN) 2025 Annual Meeting.

The multicenter, randomized, double-blind, placebo-controlled trial included 114 people in China with gMG, baseline myasthenia gravis activities of daily living (MG-ADL) scores ≥6, and quantitative myasthenia gravis (QMG) scores ≥8. Participants were randomized 1:1 to receive either RC18 240 mg or placebo over 24 weeks, followed by an open-label extension (OLE).

Key results from the double-blind treatment period include the following:

• At week 24, 98.1% of RC18-treated participants achieved a ≥3-point reduction in MG-ADL score compared with only 12.0% of those who received placebo; mean QMG reductions were 8.66 points with RC18 and 2.27 points with placebo.
• At week 24, 87.0% of RC18-treated participants achieved a ≥5-point reduction in QMG compared with 16.0% of those who received placebo; mean MG-ADL reductions were 5.74 points with RC18 and .91 points with placebo.
• Clinical improvements were observed as early as week 4 and continued throughout the study.
• RC18 demonstrated a favorable safety profile with an adverse event (AE) profile similar to placebo and fewer infection-related events (45.6% vs 59.6%).

“Telitacicept demonstrated rapid and significant clinical improvement in the phase 3 trial, and was well tolerated,” said Professor Yin Jiang of Beijing Hospital, Principal Investigator for the phase 3 study. “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.”

RemeGen has submitted a biologics license application (BLA) to China's regulatory authorities with anticipated approval in the second quarter of 2025, and the company is also advancing a global multicenter phase 3 trial to validate these promising results in a wider patient population.

Source: Remegen announces exciting results of telitacicept phase 3 clinical trial for patients with generalized myasthenia gravis. Press release. PR Newswire. https://www.prnewswire.com/news-releases/remegen-announces-exciting-results-of-telitacicept-phase-3-clinical-trial-for-patients-with-generalized-myasthenia-gravis-302424073.html