argenx Announces Positive Topline Results from ADAPT SERON Study of VYVGART in Patients with AChR-Ab Seronegative gMG

Core Insights - argenx SE announced positive topline data from the pivotal ADAPT SERON study of VYVGART, demonstrating significant improvement in AChR-Ab seronegative gMG patients compared to placebo with a p-value of 0.0068 [1][7] - The company plans to submit a supplemental Biologics License Application (sBLA) to the U.S. FDA to expand VYVGART's label to include adult AChR-Ab seronegative gMG patients across all three subtypes [2][7] - VYVGART was well tolerated and safe, with no new safety concerns identified, consistent with its established safety profile [3] Study Design and Results - The Phase 3 ADAPT SERON study was a randomized, double-blind, placebo-controlled trial involving 119 participants across North America, Europe, China, and the Middle East [5] - The primary endpoint was the change in MG-ADL total score from baseline to day 29, with participants receiving four once-weekly infusions of efgartigimod or placebo [5] - The study confirmed that VYVGART has the potential to be an effective treatment for gMG patients, regardless of autoantibody status [4] Implications for Treatment - The ADAPT SERON study is the largest to date for AChR-Ab seronegative gMG, indicating a critical advancement in treatment options for patients with limited alternatives [4][8] - Approximately 20% of gMG patients are AChR-Ab seronegative, and current treatments are lacking for those with anti-LRP4 antibodies or triple seronegative status [8] - The positive results from the study highlight VYVGART's ability to provide meaningful benefits across all AChR-Ab seronegative gMG subtypes [4][8] Company Overview - argenx is a global immunology company focused on improving the lives of individuals with severe autoimmune diseases, developing novel antibody-based medicines [18] - The company has developed VYVGART, the first approved neonatal Fc receptor blocker for treating generalized myasthenia gravis [18]