The treatment of myasthenia gravis (MG) has seen a significant shift from broad immunosuppressants to targeted biologic therapies. These newer medications offer more precise action, faster symptom control, and are often better tolerated. This is an important advancement for the many individuals living with this chronic autoimmune disease.
IMAAVY™ (Nipocalimab): The Newest Addition
The FDA approved nipocalimab (IMAAVY™) in April 2025 for generalized myasthenia gravis (gMG) in adults and adolescents (12+) who are antibody-positive (AChR+ or MuSK+). This approval was based on data from the Vivacity-MG3 study.
IMAAVY™ is a neonatal Fc receptor (FcRn) blocker that reduces pathogenic IgG antibodies responsible for muscle weakness. By targeting FcRn, it prevents antibody recycling and increases their destruction.
- Administration: Intravenous (IV) infusion every two weeks.
- Efficacy: Clinical trials showed nipocalimab improved daily abilities and reduced autoantibody levels.
- Key Advantage: Studied as a chronic maintenance therapy for consistent symptom control.
How FcRn Inhibitors Work
FcRn inhibitors block the protein responsible for recycling IgG antibodies. In MG, pathogenic IgG antibodies attack nerve-muscle communication. By blocking FcRn, these inhibitors lower the number of circulating IgG antibodies, improving muscle strength.
Other FDA-approved FcRn inhibitors include:
- Vyvgart (efgartigimod alfa): Approved in 2021 for anti-AChR antibody-positive gMG. Available as IV infusion and subcutaneous self-injection (Vyvgart Hytrulo).
- Rystiggo (rozanolixizumab-noli): Approved in 2023 for adults with anti-AChR or anti-MuSK antibody-positive gMG. It is the first FDA-approved treatment for patients with MuSK antibodies and is given as a weekly subcutaneous infusion.
Complement Inhibitors: Another Targeted Approach
Complement inhibitors target the complement system, which can damage the neuromuscular junction.
- Zilbrysq (zilucoplan): Approved in 2023 for adults with anti-AChR antibody-positive gMG. Zilucoplan is a C5 complement inhibitor and the first once-daily, self-administered subcutaneous therapy for gMG.
- Ultomiris (ravulizumab) and Soliris (eculizumab): Also C5 complement inhibitors. Ultomiris has less frequent dosing than Soliris.
A Comparison of Recent Myasthenia Gravis Drugs
| Feature | IMAAVY™ (Nipocalimab) | Rystiggo (Rozanolixizumab) | Zilbrysq (Zilucoplan) |
|---|---|---|---|
| Mechanism of Action | FcRn Blocker | FcRn Blocker | C5 Complement Inhibitor |
| Targeted Antibodies | Anti-AChR+ and Anti-MuSK+ | Anti-AChR+ and Anti-MuSK+ | Anti-AChR+ |
| Administration | IV infusion, every 2 weeks | SC infusion, once weekly for 6 weeks | Once-daily SC self-injection |
| Approval Year | 2025 | 2023 | 2023 |
| Key Benefit | Long-lasting disease control, broadest population of FcRn blockers | First to target both AChR and MuSK antibodies | First once-daily, self-administered C5 inhibitor |
Emerging and Pipeline Therapies
Research continues to explore new MG treatments, including other FcRn inhibitors like Batoclimab, advanced CAR-T Cell Therapy, and Small-Molecule Degraders.
Conclusion: A New Era in Myasthenia Treatment
The approval of several targeted therapies, including the recent IMAAVY™ (nipocalimab), marks a significant advance in myasthenia gravis treatment. These drugs offer more precise methods to manage the autoimmune attack compared to older, broader immunosuppressants. FcRn blockers and complement inhibitors provide new options, especially for those not responding to conventional treatments or experiencing unmanageable side effects. Ongoing research into therapies like CAR-T cells promises further personalization of MG care. With increasing options, treatment strategies can be better tailored to individual patient needs. The Myasthenia Gravis Foundation of America is a good resource for more information.
