MGFA Session 2025: Telitacicept eases gMG symptoms long term
New data show substantial reductions in symptom severity for trial participants
Nearly one year of treatment with Remegen’s telitacicept in a clinical trial in China led to substantial and sustained reductions in symptom severity among adults with generalized myasthenia gravis (gMG).
That’s according to new results from the Phase 3 trial, which were shared during the Myasthenia Gravis Foundation of America (MGFA) scientific session at the American Association of Neuromuscular & Electrodiagnostic Medicine (AANEM) annual meeting, held last week in San Francisco.
George Li, MD, who serves as a scientific consultant for Remegen, presented the new data in a talk titled “Efficacy and safety of telitacicept in patients with generalized myasthenia gravis: Results from a Phase 3 study” that detailed the trial’s methods and findings.
“Telitacicept showed sustained efficacy for up [to] 48 weeks [and] was well tolerated in gMG patients in this … Phase 3 trial from China,” Li said, adding that “a global Phase 3, multicenter, … placebo-controlled trial with [a] long-term open-label extension study is going on to evaluate [the] efficacy and safety of telitacicept in patients worldwide.”
That trial will randomly assign participants to either telitacicept or a placebo, and neither the researchers nor the patients will know who is receiving the therapy. Following the initial trial period, the study will continue in an extension, with a goal of assessing the medication’s effects during follow-up.
Regulators in China have approved telitacicept as an add-on treatment for adults with gMG who are positive for antibodies targeting the acetylcholine receptor (AChR). Vor Bio recently partnered with Remegen to develop and market telitacicept outside of China, Hong Kong, Macau, and Taiwan.
New larger trial to test Telitacicept in people with gMG worldwide
The partners now hope to expand on these positive trial results in the global Phase 3 RemeMG study (NCT06456580), which is underway at sites across the U.S., Australia, Europe, South America, and the Asia-Pacific region. Study locations in Canada are not yet recruiting.
“With our global Phase 3 trial now enrolling across 14 countries, we are excited to build on this momentum and work toward delivering the same transformative benefits to patients worldwide,” Jean-Paul Kress, MD, Vor’s CEO and chairman of the board, said in a company press release.
In gMG, the immune system mistakenly attacks proteins involved in the communication between nerve and muscle cells. This leads to the development of the disease’s hallmark symptoms of widespread muscle weakness and fatigue.
Immune B-cells are responsible for producing the self-reactive antibodies that drive these autoimmune attacks. For most people with gMG, these antibodies target AChR, a key protein in nerve-muscle communication. More rarely, antibodies may target muscle specific kinase (MuSK) or other proteins.
Telitacicept is designed to reduce the activity of B-cells by targeting two proteins involved in their development and maturation: one called B-cell stimulator (BLyS) and another known as A proliferation-inducing ligand (APRIL). This is expected to help lower the levels of the self-reactive antibodies driving gMG and thereby ease disease symptoms.
With our global Phase 3 trial now enrolling across 14 countries, we are excited to build on this momentum and work toward delivering the same transformative benefits to patients worldwide.
The Remegen-sponsored Phase 3 study (NCT05737160) tested telitacicept against a placebo in 114 adults with gMG. Four had antibodies targeting MuSK, while the remaining 110 tested positive for anti-AChR antibodies. All remained on stable, previously prescribed therapies for gMG during the study.
Patients were randomly assigned to receive weekly under-the-skin (subcutaneous) injections of telitacicept or a placebo for 24 weeks, or about six months. Following this randomized period, there was a 24-week open-label period during which all participants were given telitacicept.
During the first 24 weeks, participants in the telitacicept group saw a rapid improvement in their scores on the MG Activities of Daily Living (MG-ADL), a standardized measure of disease severity that assesses the extent to which symptoms affect everyday activities. MG-ADL scores dropped — meaning improved — by a mean of 6.4 points in individuals treated with telitacicept and by 1.6 points in those given the placebo during this time.
In the open-label period, participants in the placebo group who switched to telitacicept also experienced rapid and sustained decreases in MG-ADL scores. After 24 weeks of treatment with telitacicept in the study’s open-label portion, their MG-ADL scores dropped by a mean of 6.3 points. Participants who continued treatment with telitacicept also experienced further improvements, with MG-ADL scores dropping by a mean of 7.5 points after 48 weeks.
Similar patterns emerged with the scores of the Quantitative MG (QMG) scale, another common metric of gMG symptom severity.
Over 90% of participants still saw improvements at 1 year
At week 48, more than 90% of patients — both those who remained on telitacicept for the entire duration of the trial and those who were initially treated with the placebo — saw their MG-ADL scores improve by at least three points. More than 90% of patients in both groups also saw their QMG scores improve by at least five points at the 48-week mark.
“The strength and consistency of these results with telitacicept in China mark a major step forward as we look to redefine long-term disease control for patients living with generalized myasthenia gravis,” Kress said. “Achieving sustained and meaningful improvements across both treatment and crossover groups sets a new standard of care expectation globally.”
Investigators also assessed the effects of treatment on the levels of several classes of antibodies, including immunoglobulin G (IgG), which encompasses most antibodies that cause gMG. The decrease in IgG antibody levels mirrored MG-ADL and QMG improvements, with participants originally given a placebo seeing similar declines after switching to telitacicept.
Most adverse events that occurred during the study were mild or moderate in severity. Some participants who switched from the placebo to telitacicept had mild injection site reactions, but these resolved and did not lead to discontinuation.
The ongoing RemeMG trial has a similar design to the China-based study. Its primary goal is to assess changes in MG-ADL scores after 24 weeks of treatment.
Note: The Myasthenia Gravis News team is providing virtual coverage of Myasthenia Gravis Foundation of America’s scientific session at the American Association of Neuromuscular & Electrodiagnostic Medicine Annual Meeting Oct. 29. Go here to see the latest stories from the conference.
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