Telitacicept named orphan drug in EU as MG therapy
In Phase 3 trial, less impact on daily life seen for 98% of treated patients
Telitacicept, a B-cell-targeting therapy for myasthenia gravis (MG), has been granted orphan drug status in the European Union, according to its developer Remegen.
Orphan drug designation, or ODD, is awarded to medications that treat conditions affecting fewer than 5 in 10,000 people in the EU. The designation’s goal is to support companies developing treatments for rare diseases by providing regulatory and financial incentives, including protocol assistance, reduced regulatory fees, and easier market access.
Most notably, the designation — awarded by the European Medicines Agency (EMA) — will grant Remegen 10 years of market exclusivity in the EU if the therapy ultimately is approved.
“The ODD granted by EMA represents the recognition of telitacicept’s innovative mechanism of action and potential in treating MG,” Remegen said in a company press release.
The drug in 2022 received the same designation from the U.S. Food and Drug Administration (FDA). According to the company, this new award makes telitacicept “the first dual-target biologic drug for MG with ODD from both FDA and EMA worldwide.”
MG is an autoimmune disease in which self-reactive antibodies bind to proteins essential for sending chemical signals from nerves to muscles, thereby disrupting nerve-muscle communication. This leads to muscle weakness and other symptoms.
The most common antibodies causing MG target proteins known as the acetylcholine receptor, or AChR, and muscle-specific kinase, called MuSK. These antibodies are produced by B-cells, a type of white blood cell involved in immune responses. Telitacicept is designed to interfere with B-cell development and maturation by blocking two key proteins, BlyS (B-cell lymphocyte stimulator) and APRIL (A proliferation-inducing ligand). As such, treatment is expected to reduce the levels of MG-driving antibodies.
Telitacicept now approved in China as MG treatment
In a now-completed Phase 3 clinical trial (NCT05737160) conducted in China, telitacicept’s safety and efficacy were evaluated in 114 adults with generalized myasthenia gravis (gMG). The participants each had tested positive for antibodies against AChR or MuSK.
All were randomly assigned to receive weekly subcutaneous, or under-the-skin, injections of telitacicept or a placebo for about six months.
Trial data released earlier this year showed that patients treated with telitacicept experienced a mean reduction of 5.74 points in Myasthenia Gravis-Activities of Daily Living (MG-ADL) scores, compared with a 0.91 point reduction among those in the placebo group. The MG-ADL scale measures disease severity based on its impact on daily life.
More than 98% of patients receiving telitacicept showed an improvement of at least three points in MG-ADL, versus 12% in the placebo group. Similarly, 87% of treated patients achieved reductions of at least five points in Quantitative Myasthenia Gravis (QMG) score, which measures muscle weakness severity, compared with 16% of those on the placebo.
These gains were observed as early as four weeks into treatment and sustained throughout the six-month treatment period. The therapy was also well tolerated, with adverse event rates comparable to the placebo.
Based on these results, telitacicept was approved last month in China as an add-on treatment for adults with gMG positive for AChR antibodies. That decision came from the National Medical Products Administration.
Telitacicept now is being tested in a separate Phase 3 study, called RemeMG (NCT06456580), that’s recruiting adults with gMG at several clinical sites in the U.S. The study is also planned for sites in Poland, but as of January, recruitment hadn’t yet started. Similarly to the trial in China, participants will be given either telitacicept or a placebo, with the main goal of evaluating changes in MG-ADL scores. Secondary endpoints include changes in QMG scores.
In the press release, Remegen said the award of orphan drug status for telitacicept in the EU “[marks] a key milestone achieved in its global development.”
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