Clinical Context
Generalized myasthenia gravis is an autoimmune disorder characterized by fluctuating muscle weakness due to the immune system's production of antibodies that disrupt communication between nerves and muscles. In the United States, the incidence of gMG is estimated to be around 20 cases per 100,000 people, with many patients experiencing significant impairment in daily activities. Current treatment options include immunotherapies like corticosteroids and B-cell depleting agents, which can be effective but often come with severe side effects and variable responses. The approval of efgartigimod alfa represents a new therapeutic approach that targets the neonatal Fc receptor, thereby reducing pathogenic IgG levels, including those responsible for muscle weakness in gMG.
Q: What is efgartigimod alfa (Vyvgart) approved for?
A: Efgartigimod alfa is approved for the treatment of seronegative generalized myasthenia gravis in adults. The FDA approved this treatment on May 10, 2026, based on clinical trial data demonstrating significant efficacy in improving muscle strength and daily function.
Q: How does efgartigimod work?
A: Efgartigimod is a neonatal Fc receptor blocker that reduces levels of immunoglobulin G (IgG) antibodies, including those that contribute to muscle weakness in myasthenia gravis. By preventing the recycling of IgG, it helps alleviate symptoms associated with the disease.
Q: What is the recommended dose of efgartigimod?
A: Efgartigimod is administered subcutaneously, with specific dosing guidance available in the prescribing information. Clinicians should consult the current label before prescribing to ensure proper administration.
Q: What are the most common side effects of efgartigimod?
A: Common side effects include respiratory tract infections, headache, and urinary tract infections. Hypersensitivity reactions may also occur, and patients should be monitored for signs of infection during treatment.