Alexion's Soliris misses mark in Phase III MG trial

Alexion Pharmaceuticals Inc. (NASDAQ:ALXN) sank $16.02 (10%) to $138.97 in early after-hours trading after it said Soliris eculizumab missed the primary endpoint of the Phase III REGAIN study to treat refractory generalized myasthenia gravis.

Alexion said Soliris did not significantly improve Myasthenia Gravis-Activities of Daily Living (MG-ADL) scores from baseline to week 26 vs. placebo (p=0.0698) as measured by a worst-rank analysis. The candidate met a secondary efficacy endpoint of change from baseline in Quantitative Myasthenia Gravis (QMG) score (p=0.0129). MG-ADL is a patient-reported assessment, while QMG is physician-assessed. ...