FDA
FDA expands Vyvgart and Vyvgart Hytrulo approval in generalized myasthenia gravis
Generalized myasthenia gravis (gMG) remains challenging to diagnose and manage in patients who do not have detectable acetylcholine receptor antibodies (AChR-Ab), a group historically underrepresented in clinical trials and with limited evidence-based treatment options. Approximately 20% of patients with gMG are AChR-Ab negative, including patients who are MuSK-positive, LRP4-positive, or triple seronegative.
On May 8, 2026, FDA approved an expanded indication for Vyvgart (efgartigimod alfa-fcab) and Vyvgart Hytrulo (efgartigimod alfa and hyaluronidase-qvfc) for all adult patients with generalized myasthenia gravis, regardless of serotype. The expanded label makes the FcRn blocker the first approved therapy for all adult gMG serotypes.
The approval was based on findings from the phase 3 ADAPT SERON trial, which enrolled 119 adults with AChR-Ab negative gMG across anti-MuSK-Ab positive, anti-LRP4-Ab positive, and triple seronegative subgroups. Patients treated with Vyvgart achieved statistically significant improvement in MG-ADL scores compared with placebo at week 4 (P=.0068), with a mean 3.35-point improvement from baseline in the overall population.
Clinically meaningful improvements in Myasthenia Gravis Activities of Daily Living and Quantitative Myasthenia Gravis scores were observed across treatment cycles and across all serotypes studied. Investigators reported improvements in symptoms affecting speech, vision, swallowing, and physical function.
Safety findings were consistent with the established profile observed in AChR-Ab positive gMG. Common adverse effects included respiratory tract infection, headache, and urinary tract infection, while injection-site reactions were additionally reported with Vyvgart Hytrulo. Clinicians should continue monitoring for infections, hypersensitivity reactions, infusion or injection-related reactions, and decreased immunoglobulin-related complications.
“MG affects patients in various ways, and those with gMG who do not have detectable AChR antibodies need safe, effective treatments. Prior to the ADAPT SERON study, these patients were rarely included in clinical trials,” said James F. Howard Jr., MD, professor of neurology at the University of North Carolina at Chapel Hill School of Medicine. “The expanded indication of efgartigimod for use in all adult gMG patients enables healthcare providers to prescribe this targeted treatment more readily upon clinical diagnosis, irrespective of serotype.”
Source: argenx. (2026, May 8). Press release. argenx announces U.S. FDA approval expanding VYVGART and VYVGART Hytrulo for use in all adult patients living with gMG