Seeking a Cure: Seven New Drugs Approved for Myasthenia Gravis, Next-Generation Therapies on the Horizon

Looking Back at the First Half of 2025: New Progress in Myasthenia Gravis Drug Development

In May, Johnson & Johnson announced that the U.S. FDA had approved its antibody therapy Imaavy (nipocalimab) for marketing to treat anti-AChR and anti-MuSK antibody-positive generalized myasthenia gravis (gMG) in adults and children over 12 years old. This is the first FDA-approved treatment for this patient population.Neonatal Fc Receptor (FcRn) Blocker. This therapy was also listed by Evaluate as one of the top 10 therapies expected to launch this year.Potential BlockbusterOne of the therapies.

In the same month, Hansoh Pharma announced that the new indication application for its inebilizumab has been accepted by China's NMPA for the treatment of adult patients with generalized myasthenia gravis. This is aCD19-Targeted B-Cell Depleting Antibody, jointly developed by Hansoh Pharma and Amgen. The results of the global pivotal Phase 3 trial, MINT, were published in April this year in The New England Journal of Medicine.

Also in May, Rongchang BioBLyS/APRIL Dual-Target Fusion ProteinNew Indication for Innovative Drug Telitacicept Approved in China for the Treatment of Adult Patients with Generalized Myasthenia Gravis. The product can simultaneously target B-cell activating factor (also known as BLyS) and a proliferation-inducing ligand (APRIL), addressing the source of pathogenic antibody production—B cells and plasma cells.

In addition, in the field of CAR-T therapy, Cartesian Therapeutics announced in April this year that its research and developmentmRNA Cell Therapy12-Month Data from the Phase 2b Study of Descartes-08 for the Treatment of gMG. The study had previously achievedPositive Results, 80% of evaluable patients maintained a clinically significant response for up to one year. Descartes-08 is an investigational CAR-T cell therapy targeting BCMA, which has now entered phase 3 clinical trials. It is currently the fastest progressing CAR-T cell therapy in development for the MG field and has the potential to become the first cell therapy in the treatment of MG.

From these advances, it can be seen that the field of myasthenia gravis treatment drug development is welcoming diversified new breakthroughs in 2025.

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At Least 7 New Myasthenia Gravis Drugs Approved for Marketing in the Past Decade

Myasthenia Gravis is a chronic and rare autoimmune disease with no known cure. The pathogenic mechanism involves immunoglobulin G (IgG) antibodies in the patient's body.These antibodies disrupt synaptic transmission between nerves and muscles, leading to muscle fatigue and weakness, which in turn causes extreme fatigue and difficulties with facial expressions, speech, swallowing, and movement. In severe cases, it can even be life-threatening.Approximately 85% of patients with myasthenia gravis have generalized myasthenia gravis (gMG). According to literature data from 2021, the prevalence and incidence of gMG are increasing globally, with an estimated global prevalence of 2 to 36 cases per 100,000 people.

In the past decade, at least seven new drugs for myasthenia gravis have been approved for marketing worldwide, includingIncludeFcRn antagonists, complement inhibitors, and B-cell depleting agentsetc., have brought more treatment options for MG patients. C5 complement inhibitors include antibodies and macrocyclic peptide drugs, such as AstraZeneca's ravulizumab (Ravulizumab), eculizumab (Eculizumab), and UCB's macrocyclic peptide C5 complement inhibitor zilucoplan (Zilucoplan), etc.,These drugs can reduce neuromuscular junction injury mediated by complement activation.; FcRn inhibitors are mainly antibody-based drugs, such as Johnson & Johnson's nipocalimab, UCB's rozanolixizumab, and efgartigimod co-developed by Argenx and Zai Lab.They can reduce the levels of circulating IgG antibodies, thereby decreasing the circulation of pathogenic antibodies and improving MG symptoms.; The representative drug of B-cell depleting agents is Telitacicept, a BLyS/APRIL dual-target fusion protein developed by Rongchang Biopharmaceuticals.Targeting the source of pathogenic antibody production—B cells and plasma cells—to reduce the production of pathogenic autoantibodies and exert therapeutic effects.。

Searching for the "Cure" Dawn: Next-Generation Myasthenia Gravis Therapy Poised for New Breakthrough

A review of publicly available information reveals that, apart from the newly approved drugs, dozens of other new drugs are currently in clinical stages globally, exploring their potential for treating myasthenia gravis. Future breakthroughs are expected in multiple directions.

In the clinical pipeline for myasthenia gravis, there are a relatively large number of antibody-based drugs, including monoclonal antibodies, bispecific antibodies, and some antibody fusion proteins, with targets involving C5, FcRn, CD19/CD20, etc.For example, AstraZeneca's third-generation C5 complement inhibitor antibody gefurulimab, which is under development, has entered the phase 3 clinical stage. It has a smaller molecular weight and better permeability.Expected to be developed into a once-a-week subcutaneous injection therapy that can be self-administered by patients.Another example is the anti-CD19 monoclonal antibody Inebilizumab mentioned at the beginning. The marketing application for Myasthenia Gravis submitted by Hansoh Pharma has been accepted by China's NMPA. Two months ago, Amgen also announced the latest clinical data on the efficacy and safety of this product in treating adult patients with gMG: with twice-yearly dosing, it demonstrated sustained efficacy in acetylcholine receptor autoantibody-positive (AChR+) gMG patients.

CAR-T therapy has also demonstrated the potential to "cure" myasthenia gravis in clinical research.CAR-T therapy has made rapid progress in the field of autoimmune diseases in recent years. It can enable patients to achieve long-term drug-free remission and is considered to have the potential to bring about a transformative impact on the treatment of myasthenia gravis.In the clinical pipeline for myasthenia gravis, there are more than ten CAR-T therapies. These investigational pipelines mainly target B cells or plasma cells, primarily including BCMA and CD19.

In the MG clinical R&D pipeline, there are also multiple small-molecule drugs.For example, Novartis' oral complement B factor inhibitor iptacopan and BTK inhibitor remibrutinib have both entered Phase 3 clinical trials for the treatment of myasthenia gravis. Additionally, NMD Pharma’s chloride channel (ClC-1) inhibitor NMD670 is currently in Phase 2b clinical trials for myasthenia gravis, with a mechanism of action targeting non-immune modulation in skeletal muscles.

New breakthroughs have been made in the R&D pipeline of peptide and nucleic acid drugs.Zilucoplan as the first FDA-approved treatment for myasthenia gravisA Novel Macrocyclic Peptide C5 Complement Inhibitor Administered Once Daily via Subcutaneous Injection, which is an important breakthrough for peptide drugs in this therapeutic area.

In addition, the clinical study of siRNA therapy cemdisiran combined with antibody therapy pozelimab for the treatment of myasthenia gravis is already in progress.Phase 3Stage. The former, jointly developed by Alnylam and Regeneron, is an RNAi therapy targeting C5 complement. After entering the cell, cemdisiran binds to the target mRNA, leading to mRNA degradation and preventing the production of functional proteins. Pozelimab is a next-generation C5 complement inhibitor developed by Regeneron. It has previously received FDA approval for CD55-deficient protein-losing enteropathy. Regeneron is currently developing this...C5 Inhibitor "Antibody + siRNA" Combination TherapyFor the treatment of complement-mediated diseases, including myasthenia gravis. Among them,Cemdisiran can reduce the production of C5, and pozelimab can block the function of the remaining C5. Together, they inhibit terminal complement activity. This combination has the potential to achieve complete and sustained C5 suppression at a lower dose, reducing the frequency of administration, with subcutaneous delivery offering convenient clinical application.。

It is worth mentioning that the GalNAc delivery technology used by cemdisiran is currently the main strategy for nucleic acid therapies, especially for siRNA delivery to hepatocytes. Of the seven siRNA therapies approved by the FDA to date, six have utilized this technology.

Also benefiting from the continuous innovation of such delivery technologies, the global development of siRNA therapies is thriving, with over 350 products currently in the research pipeline. Amid this emerging trend in the industry, WuXi TIDES, a platform under WuXi AppTec that focuses on oligonucleotides, peptides, and related chemical conjugation drugs, has built a one-stop service platform covering custom synthesis, process development, and production to better meet the R&D needs of global partners for oligonucleotides and various chemical conjugates. Public information shows,In terms of customized GalNAc, the WuXi TIDES team has produced more than 100 GalNAc compounds covering different types of GalNAc molecules. By optimizing the GalNAc resin loading process, the yield of solid-phase synthesis has been increased by 50%. Meanwhile, with the help of a flow chemistry platform, the scaled-up production of high-purity GalNAc has been accelerated.。

On the journey of conquering diseases, the pace of scientific and technological exploration has never ceased. As an enabler of innovation, a trusted partner to customers, and a contributor to the global health industry, WuXi AppTec will continue to leverage its unique CRDMO business model to support global partners in developing innovative therapies across more disease areas, including myasthenia gravis, continuously benefiting patients!

References:

[1]Binks, S.N.M., Morse, I.M., Ashraghi, M. et al. Myasthenia gravis in 2025: five new things and four hopes for the future. J Neurol 272, 226 (2025). https://doi.org/10.1007/s00415-025-12922-7

[2]Dresser L., Wlodarski, R., Rezania, K., & Soliven, B. (2021). Myasthenia Gravis: Epidemiology, Pathophysiology and Clinical Manifestations. J Clin Med, 10(11):2235.

[3]Bubuioc, A. M., Kudebayeva, A., Turuspekova, S., Lisnic, V., & Leone, M. A. (2021). The epidemiology of myasthenia gravis. Journal of Medicine and Life, 14(1):7-16.