First Subcutaneous Injectable Approved to Treat Generalized Myasthenia Gravis
- By BSTQ Staff
The subcutaneous formulation of argenx’s Vyvgart has been approved by the U.S. Food and Drug Administration (FDA) to treat generalized myasthenia gravis (gMG). Vyvgart (efgartigimod) was the first in a new class of medication approved by FDA in 2021 as a one-hour intravenous infusion for gMG patients positive for the anti-acetylcholine receptor (AChR) antibody. The new subcutaneous formulation is a single injection for four weeks.
Approval was based on trial data that showed the new formulation to be similarly effective to the intravenous version. Previous data showed 68 percent of gMG patients on Vyvgart infusions had significant improvement to their daily function compared to 30 percent on placebo. Patients on argenx’s drug also had a superior response on a measure of muscle weakness compared to placebo.
Vyvgart is an antibody fragment that binds to the neonatal Fc receptor to prevent recycling of immunoglobulin G (IgG) back into the blood. Reduced overall levels of IgG includes a reduction in the abnormal AChR antibodies, which are present in approximately 85 percent of the gMG patient population. The AChR antibodies are what block the acetylcholine receptors from being able to receive signals from the nerve to stimulate a muscular response.
References
- Goodwin, K. FDA Approves First Subcutaneous Injectable for Muscle-Weakening Disease. BioSpace, June 21, 2023. Accessed at www.biospace.com/article/fda-approves-first-subcutaneous-injectable-for-muscle-weakening-disease-.
