FcRn antagonist and C5 complement inhibitor as early rescue strategies in severe Myasthenia Gravis: a two-case report

Background: Myasthenia gravis (MG) is an autoimmune neuromuscular disorder in which approximately 10-15% of patients with generalized AChR antibody-positive MG develop refractoriness to standard immunosuppressive therapies. Advanced therapeutic strategies, including FcRn antagonists and C5 complement inhibitors, have demonstrated early and sustained clinical efficacy in pivotal phase 3 trials. However, evidence supporting their early use in complex clinical scenarios remains limited. Case report: We report two cases of severe generalized MG in which early initiation of advanced therapies was associated with rapid clinical stabilization. In the first case, a 75-year-old man with thymoma-associated MG and severe bulbar involvement refractory (MG-ADL: 11) to plasma exchange (PLEX) and intravenous immunoglobulins (IVIg), and unable to continue azathioprine due to adverse events, received off-label efgartigimod preoperatively. Near-complete resolution of bulbar symptoms was observed within 48 hours, enabling robot-assisted thymectomy on day 4 following the first infusion, with sustained neurological improvement at one-month follow-up (MG-ADL score: 2). In the second case, a 74-year-old man with severe refractory bulbar MG requiring nasogastric tube feeding (MG-ADL: 13) and subsequent percutaneous endoscopic gastrostomy (PEG) was treated with ravulizumab after an incomplete response to PLEX, IVIg, corticosteroids, and azathioprine. MG-ADL decreased from 9 at treatment initiation to 5 after two infusions of ravulizumab, and complete recovery of swallowing function allowed PEG removal at 18-week follow-up, with achievement of minimal symptom expression (MG-ADL score: 0). Discussion: These cases highlight the potential role of early and targeted use of advanced immunotherapies in severe, refractory MG, including as a bridging strategy to thymectomy. Further prospective studies are needed to define optimal criteria and timing for early integration of these agents into the therapeutic algorithm.