Argenx shares climb as FDA reviews Vyvgart additional application

Shares in Argenx ARGX.BR are up around 4% as its immune disorder drug Vyvgart is reviewed in the U.S. for application to a broader patient population

The U.S. Food and Drug Administration accepted for priority review a supplemental biologics license application (sBLA) for Vyvgart for treatment of adults with acetylcholine receptor antibody-seronegative generalized myasthenia gravis (gMG)

David Seynnaeve from Degroof Petercam says the positive signal for potential drug approval is driving the share price higher

Currently 80% of gMG patients are AChR-Ab seropositive, and Vyvgart is approved for this population, but Argenx is seeking to cover the 20% that are AChR-Ab seronegative, Seynnaeve says

He adds that preliminary results in-line with consensus expectations, combined with 2026 strategic priorities announced by current CEO Tim Van Hauwermeiren at Monday's J.P. Morgan Healthcare Conference, have helped shares recover after they slipped following the CEO transition announced in early January

Shares are at the top of the BEL20 .BFX index; they will see their best day since October if gains hold