Gefurulimab Shows Positive Results in Global Phase III Trial for gMG

Alexion, AstraZeneca Rare Disease, announced encouraging top-line results from the global Phase III PREVAIL trial evaluating gefurulimab in adults with AChR antibody-positive generalised myasthenia gravis (gMG). The study enrolled 260 patients across 20 countries and met its primary and all secondary endpoints. Gefurulimab significantly improved MG-ADL scores at week 26 versus placebo, demonstrating rapid and sustained disease control. The treatment was well-tolerated with a consistent safety profile and no new safety signals. gMG is a rare, chronic autoimmune condition marked by fluctuating muscle weakness that can severely impair daily functioning. Gefurulimab, a novel dual-binding C5 inhibitor nanobody, is optimised for weekly subcutaneous self-administration, offering enhanced convenience. It works by inhibiting the complement cascade to prevent immune system overactivation. With orphan drug designation in the U.S., gefurulimab could become a first-line biologic for gMG, offering patients improved control and independence in managing this debilitating disease.

25-07-2025