argenx's VYVGART Study Meets Primary Endpoint, sBLA to be Submitted by End of 2025

The article reports on positive topline data from the ADAPT SERON study of VYVGART (efgartigimod alfa-fcab) in patients with myasthenia gravis (MG). The study met its primary endpoint, demonstrating a statistically significant and clinically meaningful improvement in MG-ADL total score compared to placebo. The results will be used to submit a Supplemental Biologics License Application to the FDA by the end of 2025.

Title: Argenx Reports Positive Topline Results from ADAPT SERON Study of VYVGART in Myasthenia Gravis

Amsterdam, the Netherlands – July 2, 2025 – Argenx SE (Euronext & Nasdaq: ARGX), a global immunology company, announced positive topline results from its pivotal ADAPT SERON study of VYVGART® (efgartigimod alfa-fcab) in patients with myasthenia gravis (MG). The study met its primary endpoint, demonstrating a statistically significant and clinically meaningful improvement in MG-ADL (Myasthenia Gravis Activities of Daily Living) total score compared to placebo [1].

The ADAPT SERON study, a Phase 3 randomized, double-blind, placebo-controlled, multi-center trial, enrolled 119 adults with AChR-Ab seronegative generalized MG (gMG) across North America, Europe, China, and the Middle East. Participants received 4 once-weekly infusions of efgartigimod or placebo, followed by a 5-week follow-up and primary analysis. The primary endpoint, MG-ADL total score change from baseline to day 29, was achieved with a p-value of 0.0068, indicating robust efficacy [1].

The study's success marks the first global Phase 3 trial to show meaningful improvements across all three seronegative subtypes: MuSK+, LRP4+, and triple seronegative patients. This breakthrough expands the market potential of VYVGART significantly, as it effectively treats AChR-Ab seronegative gMG patients, a population with historically limited treatment options [1].

Argenx plans to submit a Supplemental Biologics License Application (sBLA) to the FDA by the end of 2025, seeking expansion of VYVGART's label to include adult AChR-Ab seronegative gMG patients across all three subtypes. This expansion could allow the company to target the entire gMG patient population, regardless of antibody status [1].

The drug maintained its established safety profile with no new concerns identified, strengthening VYVGART's competitive position. The study's results validate argenx's mechanistic approach targeting pathogenic IgGs as underlying drivers of gMG across all patient subtypes, potentially establishing VYVGART as a foundational therapy for the broader MG population [1].

References:
[1] https://www.stocktitan.net/news/ARGX/argenx-announces-positive-topline-results-from-adapt-seron-study-of-ogpvuzfr98mp.html