The FDA has approved Argenx SE's (NASDAQ:ARGX) Vyvgart (efgartigimod alfa-fcab) for generalized myasthenia gravis (gMG) in adult patients who are anti-acetylcholine receptor (AChR) antibody positive.

• MG affects multiple muscle groups throughout the body.
• These patients represent approximately 85% of the total gMG population. With this regulatory milestone, Vyvgart is the first and only FDA-approved neonatal Fc receptor (FcRn) blocker.
• Related content: Benzinga's Full FDA Calendar.
• Zai Lab Limited (NASDAQ:ZLAB) has exclusive rights to develop and commercialize efgartigimod in Greater China and expects to file a marketing application in China by mid-2022.
• Under the terms of the strategic agreement with Zai Lab, Argenx will receive a $25 million milestone payment with this U.S. approval of Vyvgart.
• The approval is based on Phase 3 ADAPT trial results. The trial met its primary endpoint, demonstrating that significantly more anti-AChR antibody-positive gMG patients were responders following treatment with Vyvgart compared with placebo (68% vs. 30%).
• Vyvgart had a demonstrated safety profile in the ADAPT clinical trial.
• Marketing applications for efgartigimod for the treatment of gMG are currently under review in Japan and Europe, with anticipated decisions anticipated in Q1 and 2H of 2022, respectively.
• Price Action: ARGX shares are up 7.47% at $333.45 in premarket on Monday's last check.