Clinical Impact of FDA's Expanded Efgartigimod Label: Josh Alpers, MD

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It may be that demonstration of clear clinical benefit may be adequate both to confirm the diagnosis of myasthenia and to establish that that's an ongoing treatment regimen.

The FDA expanded the indication for efgartigimod to include all adults with generalized myasthenia gravis (gMG), regardless of antibody status, marking the first approval of an FcRn-targeting therapy for patients with seronegative disease. The decision, supported by findings from the phase 3 ADAPT SERON study, broadens access to targeted treatment for a patient population that has historically had fewer evidence-based therapeutic options.¹

Beyond expanding access to treatment, the FDA's decision reflects the evolving understanding of seronegative gMG. As diagnostic assays continue to improve and previously undetectable antibodies become identifiable, experts more inclined to view many cases of so-called seronegative disease as antibody-mediated disorders that have simply eluded conventional testing. The approval may therefore influence not only treatment decisions, but also broader conversations surrounding diagnosis, patient selection, and the future classification of gMG.²

To gain further insight into the implications of the approval, NeurologyLive® sat down with Josh Alpers, MD, neuromuscular physician at Erlanger Health Systems in Chattanooga, Tennessee. In the interview, Alpers discussed the clinical implications of recent trial data supporting the label expansion in seronegative gMG, highlighting how the findings reinforce current understanding of antibody-mediated disease despite advances in antibody detection. He also explored how the evolving treatment landscape may shift targeted therapies earlier in the care paradigm, addressed the future of defining seronegative MG, and considered how treatment response itself may eventually play a role in confirming diagnosis.

REFERENCES
1. argenx Announces U.S. FDA Approval Expanding VYVGART and VYVGART Hytrulo for Use in All Adult Patients Living with gMG. Argenx. News Release. May 8, 2026. Accessed: June 26, 2026. https://argenx.com/news/2026/press-release-3291372
2. argenx Announces Positive Topline Results from ADAPT SERON Study of VYVGART in Patients with AChR-Ab Seronegative gMG. argenx. News Release. August 25, 2026. Accessed: June 26, 2026. https://argenx.com/news/2026/press-release-3291372