Clinical efficacy and safety of efgartigimod for treatment of myasthenia gravis

Plain language summaryTherapies for myasthenia gravis (MG) have been directed at removing or suppressing autoantibodies that cause disease. Despite advances in immunotherapy, the treatment of MG is challenging, especially in the case of worsening symptoms and refractory disease (disease that does not respond to treatment). The neonatal Fc receptor (FcRn), which is a protein in the blood, facilitates the recycling of a type of antibody called IgG. IgG autoantibodies are versions of IgG that mistakenly target and react with a person's own tissues or organs and are thought to play a role in MG. Blocking the FcRn receptor with a drug causes IgG autoantibodies to break down, stopping them from causing disease. Clinical trials have shown improvements in disease severity associated with a reduction in the autoantibodies that cause MG. Efgartigimod is a well-tolerated drug that inhibits IgG autoantibodies with minor side effects such as headache and upper respiratory (lung) and urinary tract infections. Efgartigimod may be a potential treatment strategy in patients with MG. Studies are now being carried out to determine how efgartigimod works in a real-world setting. Treatment of acute exacerbations and refractory myasthenia gravis (MG) remains challenging despite advances in immunotherapy. Frequent use of plasmapheresis and immunoglobulins are associated with adverse events and strain on resources. The neonatal Fc receptor (FcRn) facilitates IgG recycling and FcRn antagonism enhances the degradation of IgG pathogenic autoantibodies without compromising adaptive and innate immunity. Efgartigimod, an FcRN antagonist, has been shown in well-designed clinical trials to improve clinical status and reduce autoantibody levels without significant safety concerns. Efgartigimod has received approvals for use in the United States, Japan and Europe. It is plausible that efgartigimod is effective across different subgroups and varied spectrums of MG severity. Novel strategies involving FcRn modulation and long-term follow-up studies will help provide further insights and expand the therapeutic repertoire.