Alexion’s phase 3 study of eculizumab in refractory gMG fails to meet primary goal

The primary endpoint was a statistically significant change from baseline to week 26 compared to placebo in a patient-reported daily activity scale called Myasthenia Gravis-Activities of Daily Living Profile (MG-ADL).

However, there were clinically meaningful improvements in MG-ADL and Quantitative Myasthenia Gravis (QMG) measures in patients treated with eculizumab compared with placebo.

Secondary endpoints that were met in the study included the change from baseline in a physician-administered assessment of MG clinical severity called QMG, the proportion of patients achieving at least a three-point reduction in MG-ADL total score and the proportion of subjects with at least a five-point reduction in QMG score, all versus placebo.

Alexion said it will continue to analyze data from the study and present results on 7 July.

Alexion Pharmaceuticals executive vice president and global head of R&D Martin Mackay said: "The primary endpoint of the REGAIN study missed statistical significance, however the findings from this study underscore the pivotal role of complement inhibition in addressing the underlying pathophysiology of refractory gMG.

"Importantly, the totality of data reviewed to date, including the first three secondary endpoints and a series of prospectively defined sensitivity analyses, shows early and sustained substantial improvements over 26 weeks for patients treated with eculizumab compared to placebo."

Soliris is approved in the US, European Union, Japan and other countries as the first and only treatment for patients with paroxysmal nocturnal hemoglobinuria to reduce hemolysis.

Soliris is not indicated to treat patients with Shiga-toxin E. coli-related hemolytic uremic syndrome.