Telitacicept found to reduce gMG severity in Phase 3 trial in China
Decision on therapy’s approval in country expected by end of June
Treatment with Remegen’s telitacicept over nearly six months safely reduced disease severity in adults with generalized myasthenia gravis (gMG) and helped ease these patients’ symptoms.
That’s according to new data from a Phase 3 clinical trial (NCT05737160) that was presented in a late-breaking session at this year’s American Academy of Neurology (AAN) Annual Meeting, held April 5-9, in San Diego and online.
“The Phase 3 data of telitacicept for MG is clinically meaningful,” Jianmin Fang, PhD, CEO of Remegen, said in a company press release. “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 MG patients.”
The treatment is under priority review for gMG by China’s National Medical Products Administration, with a decision expected in the second quarter of the year.
New data from trial testing treatment vs. a placebo
An autoimmune disease, MG is caused by self-reactive antibodies that disrupt nerve-muscle communication. These autoantibodies are produced by a type of immune cells called B-cells.
Telitacicept works to reduce the activity of B-cells by blocking two proteins involved in their development: B-cell stimulator, or BLyS, and A proliferation-inducing ligand, known as APRIL. It combines an antibody protein fragment with a part of the BLyS/APRIL receptor TACI, preventing both proteins from interacting with receptors on B-cells. This is expected to reduce the production of MG-driving antibodies and thus ease disease symptoms.
In an earlier Phase 2 study (NCT04302103) in Beijing that enrolled 29 adults with gMG, the therapy was found to be safe and to reduce disease severity.
The ongoing Phase 3 trial is a multicenter placebo-controlled study in China involving 114 adults with gMG. Participants were randomly assigned to receive 240 mg of telitacicept or a placebo, given by subcutaneous, or under-the-skin, injection, once weekly for 24 weeks, or about six months. All patients who completed this part of the trial then received telitacicept for an additional period of 24 weeks.
The study’s main goal was to assess changes in the scores of the MG Activities of Daily Living (MG-ADL) scale, a measure of MG severity that assesses the disease’s impact on daily life, after the 24 weeks. Secondary outcomes included assessing changes in the scores of the Quantitative MG (QMG), another measure of MG severity, and MG-ADL for up to 48 weeks, or about one year.
Phase 3 trial in US, Poland now testing telitacicept in gMG
The newly presented results, from the first part of the trial, demonstrated that patients treated with telitacicept saw a significant improvement — signaling a reduction in severity — in MG-ADL and QMG scores after four weeks of treatment compared with those on the placebo.
After six months, MG-ADL scores had decreased by 5.74 points in patients treated with telitacicept and by 0.91 points in those given the placeb0. Additionally, nearly all patients (98.1%) in the telitacicept group saw their MG-ADL scores drop by at least three points; that reduction was seen in 12% of those in the placebo group.
Similarly, a reduction in QMG scores was more striking in the treatment group (8.66 vs. 2.27 points), with a higher proportion of patients treated with telitacicept seeing their QMG scores drop by at least five points compared with those receiving the placebo (87% vs. 16%).
Telitacicept demonstrated rapid and significant clinical improvement in the Phase 3 trial, and was well tolerated.
Telitacicept was well tolerated, with the incidence of adverse events being similar between the treatment and placebo groups. The incidence of infection-related adverse events was lower in patients treated with telitacicept than in those given the placebo (45.6% vs. 59.6%).
Yin Jian, the principal investigator of the trial at Beijing Hospital, noted that the therapy’s “dual-targeting mechanism not only inhibits abnormal B cells and plasma cells thoroughly and reduces the level of pathogenic [disease-causing] antibodies, but also effectively slows down disease progression in the long term.”
According to Jian, “telitacicept demonstrated rapid and significant clinical improvement in the Phase 3 trial, and was well tolerated.”
Meanwhile, the therapy is also being tested in the multicenter Phase 3 RemeMG trial (NCT06456580), which is assessing its efficacy and safety in up to 180 gMG patients at several sites in the U.S. and Poland.
The treatment has received orphan drug and fast-track status from the U.S. Food and Drug Administration for MG. These designations are intended to support and accelerate a therapy’s development.
In China, telitacicept is approved for the treatment of the autoimmune disease lupus, and is in clinical testing for several other conditions.
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