argenx reports positive phase 3 ADAPT SERON results of VYVGART in AChR-Ab seronegative gMG

VYVGART was well tolerated, with a safety profile consistent with prior studies in AChR-Ab seropositive gMG and other indications

argenx announced positive topline results from the pivotal ADAPT SERON study of VYVGART in patients with AChR-Ab seronegative generalized myasthenia gravis (gMG). The study met its primary endpoint (p=0.0068), showing that patients treated with VYVGART achieved statistically significant and clinically meaningful improvement in MG-ADL (Myasthenia Gravis Activities of Daily Living) scores compared to placebo.

Based on these results, argenx plans to submit a supplemental Biologics License Application (sBLA) to the U.S. FDA to expand the VYVGART label to include adult AChR-Ab seronegative gMG patients across MuSK+, LRP4+, and triple seronegative subtypes. Full data will be presented at an upcoming medical meeting.

VYVGART was well tolerated, with a safety profile consistent with prior studies in AChR-Ab seropositive gMG and other indications. No new safety concerns were reported.

“The results of the ADAPT SERON study, the largest study to date of AChR-Ab seronegative gMG, confirm that VYVGART now has the potential to be a targeted, effective, safe, and necessary treatment for patients living with gMG, regardless of autoantibody status,” said James F. Howard Jr., M.D., Professor of Neurology, The University of North Carolina at Chapel Hill School of Medicine, and Principal Investigator of the trial. “Paired with our existing knowledge, these data demonstrate that pathogenic IgGs are underlying drivers of gMG across patient subtypes. This is a critical advancement in the management of this debilitating and unpredictable disease for patients with limited treatment options.”

“The ADAPT SERON study represents our longstanding commitment to the MG community and our ambition to help all MG patients address this debilitating condition and reach as many MG patients as we can,” said Luc Truyen, M.D., Ph.D., Chief Medical Officer, argenx. “The positive outcome of the ADAPT SERON study clearly shows VYVGART’s ability to provide meaningful benefit across all AChR-ab seronegative gMG subtypes.”

The randomized, double-blind, placebo-controlled Phase 3 study enrolled 119 patients across North America, Europe, China, and the Middle East. Patients received either 4 once-weekly infusions of VYVGART IV or placebo, followed by an open-label extension. The primary endpoint measured change in MG-ADL total score from baseline to day 29.