AstraZeneca (AZ) announced on 24 July that its dual-binding nanobody gefurulimab met primary endpoints in the Phase III PREVAIL trial for anti-acetylcholine receptor (AChR) antibody-positive generalized myasthenia gravis (gMG). The 25 kDa subcutaneous therapy, combining C5-targeting and albumin-binding domains, demonstrated statistically significant improvement in Myasthenia Gravis Activities of Daily Living (MG-ADL) scores at week 26 versus placebo. Gefurulimab's weekly dosing and self-administration potential could transform care for gMG patients, who currently require frequent infusions of conventional C5 inhibitors.

The trial enrolled participants across 20 countries, with safety data consistent with prior C5 inhibitor studies. AZ plans regulatory submissions based on these results, positioning gefurulimab as a first-line biologic option. PREVAIL's success follows rare disease subsidiary Alexion's legacy in complement inhibition, with gefurulimab offering improved convenience over biweekly intravenous therapies. Full data will be presented at an upcoming medical congress.