argenx wins FDA label expansion for VYVGART and Hytrulo across four gMG serotypes
FDA approves VYVGART and VYVGART Hytrulo label expansion to treat adult generalized myasthenia gravis across anti-AChR-Ab, anti-MuSK-Ab, anti-LRP4-Ab and triple seronegative subtypes. Phase 3 ADAPT SERON data showed a 3.35-point mean MG-ADL score improvement at week 4 (p=0.0068) with rapid, sustained symptom relief and consistent safety across serotypes.
1. FDA Label Expansion
The FDA approved a supplemental biologics license application expanding VYVGART and VYVGART Hytrulo to all adult generalized myasthenia gravis patients, covering anti-AChR-Ab positive, anti-MuSK-Ab positive, anti-LRP4-Ab positive and triple seronegative subtypes, marking the first U.S. approval for this full gMG population.
2. Phase 3 ADAPT SERON Results
The Phase 3 ADAPT SERON study enrolled gMG patients without detectable AChR antibodies and met its primary endpoint with a mean 3.35-point improvement in MG-ADL total score at week 4 (p=0.0068). Patients experienced rapid, sustained symptom relief—including improvements in speech, vision, physical function and swallowing—and a safety profile consistent across all serotypes.
3. Clinical and Market Implications
This label expansion simplifies treatment selection for clinicians by eliminating serotype testing barriers, broadens access to approximately 20% of gMG patients previously excluded from targeted therapy, and positions argenx to expand its market share while advancing development in ocular and pediatric gMG populations.