Revolutionizing gMG Treatment: Efgartigimod’s Triumph in Curtailing Oral Corticosteroid Dependence

• Efgartigimod (VYVGART/VYVGART Hytrulo) is a prescription medicine for the treatment of gMG in adults who are positive for antibodies directed toward a protein called acetylcholine receptor (anti-AChR antibody positive). It is designed as a first-in-class investigational antibody fragment to target the neonatal Fc receptor (FcRn).

Despite numerous adverse effects, including osteoporosis, weight gain, diabetes, and increased susceptibility to infections, oral corticosteroids (OCS) are frequently employed in the management of myasthenia gravis symptoms by suppressing the immune response. Therefore, reducing or tapering OCS usage is crucial to mitigate these risks while effectively managing generalized myasthenia gravis (gMG). To overcome the challenges associated with OCS several therapies including efgartigimod have emerged as promising alternatives for effectively managing gMG while minimizing adverse effects.

At the American Academy of Neurology conference 2024, Argenx presented the results of a retrospective cohort study aimed at assessing the real-world utilization of OCS among patients with gMG following initiation of efgartigimod treatment. The study utilized a retrospective cohort design and identified patients with gMG using OCS who initiated efgartigimod treatment from one of the US medical and pharmacy claims database. The analysis focused on the average daily dose (ADD) of OCS during three periods: 3 months before efgartigimod initiation, and at 3 months and 6 months post-initiation. The study assessed changes in ADD and the distribution of OCS dosage at each time point. Out of 576 gMG patients commencing efgartigimod treatment from January to September 2022, 231 (40%) were initially prescribed OCS. Before efgartigimod, a substantial 45.5% relied on high OCS doses (>20mg), 47.1% on moderate (5–20mg), and merely 7.4% on low (0–5mg) doses. Remarkably, within 3 months post-efgartigimod, 35% experienced a notable ≥5mg reduction in OCS dosage, rising to 43% at the 6-month mark. The paradigm shift was profound: the cohort with minimal OCS dependency surged over threefold from 7% to 26%, while those requiring >20mg witnessed a substantial 35% decline, dropping from 45% to 29%.

Conclusion: The findings of retrospective cohort study suggested that efgartigimod treatment may lead to a substantial reduction in OCS utilization among patients with gMG during the initial 6 months of treatment. This reduction in OCS dosage is promising, as it has the potential to mitigate the risks associated with long-term OCS use while effectively managing gMG symptoms. However, the researchers emphasize the need for additional data to assess longer-term patterns of OCS utilization and to better understand the sustained effects of efgartigimod on OCS usage in this patient population. This underscores the importance of ongoing research and monitoring to evaluate the real-world effectiveness of novel treatments like efgartigimod in managing gMG.