Powered By
The U.S. Food and Drug Administration (FDA) has expanded the approval of efgartigimod alfa-fcab (Vyvgart) and efgartigimod alfa and hyaluronidase-qvfc (Vyvgart Hytrulo) to treat all adults with generalized myasthenia gravis (gMG).
The expanded approval includes gMG that is:
This expanded approval matters because some people with gMG don’t have detectable anti-AChR antibodies, meaning the antibodies don’t show up on blood tests. This can make diagnosis and treatment more complicated. About 20 percent of people with gMG don’t have detectable AChR antibodies.
“People living with seronegative generalized myasthenia gravis often face a longer, more complicated journey to diagnosis and treatment,” said Dr. Angela Lek, chief research officer at the Muscular Dystrophy Association. “The FDA’s approval reflects meaningful progress for a community that has historically had limited, targeted treatment options.”
Efgartigimod alfa-fcab, the main ingredient in Vyvgart and Vyvgart Hytrulo, is a type of antibody fragment. It’s designed to attach to a protein called the neonatal Fc receptor (FcRn). By blocking FcRn, the drug helps lower levels of immune system proteins called immunoglobulin G (IgG) antibodies in the blood.
In gMG, these antibodies can interfere with communication between nerves and muscles. That disruption can cause symptoms such as muscle weakness, fatigue, vision changes, trouble speaking, trouble swallowing, and breathing problems.
Vyvgart is given as an intravenous (IV) infusion. Vyvgart Hytrulo contains efgartigimod plus hyaluronidase, an ingredient that allows the medicine to be given as an injection under the skin. This injection option offers another way for adults with gMG to receive treatment.
The expanded approval was based on results from the phase 3 ADAPT SERON study. This randomized, double-blind trial included 119 adults with gMG who did not have detectable AChR antibodies.
Participants had anti-MuSK antibody-positive, anti-LRP4 antibody-positive, or triple seronegative gMG. Each received either efgartigimod alfa-fcab or a placebo (inactive treatment).
The study showed positive results. After four weeks, people treated with efgartigimod alfa-fcab had a statistically significant improvement in Myasthenia Gravis Activities of Daily Living (MG-ADL) scores compared with those who received a placebo.
The MG-ADL scale measures MG-related problems with:
Scores range from 0 to 24, with higher scores showing more severe symptoms. Across the full study group, people treated with efgartigimod alfa-fcab had an average 3.35-point improvement at week 4.
Improvements were also seen in later treatment cycles and across the serotypes studied.
The Muscular Dystrophy Association said the safety profile was consistent with earlier findings, with no new safety concerns identified.
This approval gives adults with gMG another treatment option. Before this expansion, some people without detectable AChR antibodies had fewer targeted options and were often left out of clinical trials. Now, healthcare providers may have another approved option to consider across gMG antibody types.
Not every treatment is right for every person. People with MG whose current treatment is not meeting their needs can talk with their MG specialist about whether newer options may be a good fit based on their diagnosis, symptoms, and overall health.
On MGteam, people share their experiences with myasthenia gravis, get advice, and find support from others who understand.
Are you satisfied with your current treatment plan for MG? Let others know in the comments below.
Get updates directly to your inbox.
Continue with Facebook
Continue with Email
Continue with Facebook
Continue with Email
Become a member to get even more
Join
Your Privacy Choices
This is a member-feature!
Sign up for free to view article comments.
We'd love to hear from you! Please share your name and email to post and read comments.
You'll also get the latest articles directly to your inbox.