Expanded Label for Efgartigimod Offers Fast-Acting Treatment for gMG: James F. Howard, MD

The FDA announced on May 11, 2026, that they had approved efgartigimod for use in all adult patients with generalized myasthenia gravis (gMG).¹ The approval specifically targets patients with anti-acetylcholine receptor–positive, anti-muscle-specific tyrosine kinase antibody–positive, anti-low-density lipoprotein receptor-related protein 4 antibody–positive, and triple seronegative gMG. James F. Howard, MD, a professor of neurology at UNC School of Medicine, discussed the implications of this expanded use approval.

“All too long, payers have not recognized the need to treat those individuals [who] do not have antibodies to the acetylcholine receptor,” he said. Patients have dealt with numerous denials and peer-to-peer requests to use different therapies to treat their specific form of gMG. This approval, Howard said, represents a first in getting an approval that minimizes the barriers to treatment.

The adverse risk profile of standard of care treatments was also a consideration, as there are concerns about how long treatments such as corticosteroids would need to be taken for them to work in patients with gMG. The narrow adverse event profile is a plus for efgartigimod in this population.

The approval comes as a result of the phase 3 ADAPT SERON trial results, which Howard said were positive when compared with a placebo population.

“Individuals, when compared to a placebo population, had a steady improvement relative to those receiving a placebo over their first course…and then even accentuated through their second course and third course of therapy,” he explained.

The study enrolled 119 adults across North America, Europe, China, and the Middle East. Patients received once-weekly intravenous infusions of efgartigimod or placebo for 4 weeks in the first part of the study, with a primary end point of an improvement in Myasthenia Gravis Activities of Daily Living (MG-ADL) score.

Patients receiving efgartigimod had a statistically significant improvement in MG-ADL total score when compared with placebo, totaling a 3.35-point improvement at week 4. Disease activity also saw a clinically meaningful improvement.

Reference

Shaw M. FDA clears efgartigimod for all adult patients with myasthenia gravis. AJMC. May 11, 2026. Accessed May 21, 2026. https://www.ajmc.com/view/fda-clears-efgartigimod-for-all-adult-patients-with-myasthenia-gravis