argenx showcases long-term Vyvgart data in Myositis and Sjogren’s disease
argenx (NASDAQ:ARGX) reported new clinical data for its neonatal Fc receptor (FcRn) blocker, Vyvgart (efgartigimod), demonstrating durable therapeutic benefits and a highly consistent safety profile for patients living with myositis and Sjogren’s disease.
The clinical findings, presented at the European Congress of Rheumatology (EULAR 2026) annual meeting, underscore argenx's ongoing efforts to transition its flagship asset into broader severe rheumatologic and systemic autoimmune conditions.
The immunology company highlighted 52-week results from its ALKIVIA+ open-label extension study evaluating Vyvgart in adult patients with myositis—a rare group of chronic autoimmune conditions causing progressive muscle inflammation and debilitating weakness.
The long-term analysis showed that patients successfully maintained their Total Improvement Scores (TIS) through a full year of continuous therapy, indicating stable and durable recovery in muscle function, strength, and overall quality of life.
Concurrently, argenx unveiled data from the RHO+ open-label extension trial evaluating the drug in Sjogren’s disease, a chronic autoimmune disorder characterized by systemic dryness and potential multi-organ involvement.
The RHO+ results demonstrated that patients experienced maintained or further improved disease activity metrics over extended periods.
Notably, this therapeutic stability was sustained under a flexible, biweekly maintenance dosing schedule, representing a meaningful convenience advantage for long-term patient care.
The cross-indication safety analysis pooled data from 834 patients across both pipelines, representing more than 1,300 cumulative patient-years of active clinical exposure.
The evaluation reinforced a highly favorable safety and tolerability profile, revealing no new or unexpected safety signals across the expanded cohorts.
The positive long-term readouts offer vital pipeline validation for argenx as it builds out its multi-indication commercial franchise.
Vyvgart is already widely approved for generalized myasthenia gravis (gMG) and chronic inflammatory demyelinating polyneuropathy (CIDP).
Management indicated that the sustained efficacy and clean safety signals from EULAR will anchor upcoming regulatory strategies and design protocols for subsequent late-stage clinical expansion.