AstraZeneca’s Alexion posts 52-week PREVAIL data backing once-weekly self-injected C5 inhibitor gefurulimab in gMG

AstraZeneca’s Alexion posted new long-term trial results for gefurulimab in generalized myasthenia gravis, scheduled for presentation in late September 2026.

Data from the PREVAIL Phase 3 open-label extension indicated sustained symptom control through 52 weeks in treated adults.

Patients switching from placebo showed rapid improvement soon after starting therapy, with benefits maintained to one year.

The safety profile remained consistent, with no meningococcal infections reported, supporting positioning as a self-administered weekly injection.

Separate analyses due at the same meetings pointed to fewer hospitalizations and less rescue therapy use versus placebo earlier in the study.