Myasthenia gravis (MG) is a chronic autoimmune disease of the neuromuscular junction causing fluctuating, fatigable weakness. Its treatment has been transformed in just a few years: alongside the traditional foundation of acetylcholinesterase inhibitors, corticosteroids, steroid-sparing immunosuppressants, and thymectomy, there is now a crowded field of approved targeted biologics working through three distinct mechanisms — FcRn blockade, complement inhibition, and B-cell depletion.
FcRn inhibitors: accelerating antibody clearance
These agents block the neonatal Fc receptor, which normally recycles IgG, thereby lowering levels of pathogenic autoantibodies. Efgartigimod (Vyvgart, and the subcutaneous Vyvgart Hytrulo) produces rapid, meaningful improvements in MG-ADL and QMG scores; the subcutaneous form is non-inferior to intravenous and adds convenience. The class has since expanded: rozanolixizumab (Rystiggo) gained approval in 2023 for both anti-AChR- and anti-MuSK-positive disease, and nipocalimab (Imaavy) was FDA-approved in 2025 — notably including adolescents aged 12 and older — on the strength of the Phase 3 Vivacity-MG3 trial. Common adverse events across the class include headache, infections, and infusion or injection reactions.
Complement (C5) inhibitors
By blocking terminal complement, these agents prevent complement-mediated damage at the neuromuscular junction in anti-AChR-positive disease. Eculizumab (REGAIN trial) and the longer-acting ravulizumab (CHAMPION-MG) both meaningfully reduce MG-ADL and QMG scores, with ravulizumab offering less frequent dosing. Zilucoplan (Zilbrysq), a self-injected C5 inhibitor approved in 2023, added a convenient daily subcutaneous option. All complement inhibitors carry a serious risk of meningococcal infection, so vaccination is mandatory.
B-cell depletion: inebilizumab
Inebilizumab (Uplizna), a CD19-targeting monoclonal antibody, depletes both antibody-secreting and precursor B cells. In the Phase 3 MINT trial it significantly improved MG-ADL and QMG scores (adjusted differences of roughly −1.9 and −2.5 versus placebo), and it was effective across both anti-AChR- and anti-MuSK-positive disease — MINT included the largest MuSK-positive cohort studied to date. It was FDA-approved for generalized MG in late 2025, with a twice-yearly maintenance schedule that markedly reduces treatment burden.
On the horizon
Telitacicept, a dual BLyS/APRIL inhibitor, has shown promising early results in refractory disease, and autologous hematopoietic stem-cell transplantation has produced prolonged remission in small, highly selected refractory cohorts.
| Class | Example agents | Mechanism | Key consideration |
|---|---|---|---|
| FcRn inhibitors | Efgartigimod, rozanolixizumab, nipocalimab | Lower pathogenic IgG | SC options; adolescents (nipocalimab) |
| C5 inhibitors | Eculizumab, ravulizumab, zilucoplan | Block terminal complement | Meningococcal vaccination required |
| B-cell depletion | Inebilizumab | CD19+ B-cell depletion | Twice-yearly dosing (MINT trial) |
| Investigational | Telitacicept, HSCT | BLyS/APRIL; immune reset | Refractory disease |
The practical upshot is that refractory generalized MG — once a therapeutic dead end — now has multiple mechanistically distinct, approved options, allowing genuinely individualized treatment.
Further reading: Inebilizumab MINT trial (Nowak et al., NEJM 2025); efgartigimod ADAPT and subcutaneous studies; rozanolixizumab MycarinG; nipocalimab Vivacity-MG3; ravulizumab CHAMPION-MG (Meisel et al., 2023); eculizumab REGAIN (Howard et al., Lancet Neurology 2017).