Why carry out this study?

Myasthenia gravis (MG) is a multi-faceted disease characterized by various cardinal symptoms, including muscle weakness and fatigability in various muscle groups (ocular, bulbar, respiratory, axial, and limb muscles), as well as physical fatigue; therefore, the measurement of overall severity of MG should account for these multiple manifestations.

These post hoc analyses of data from a Phase 2 clinical trial explored the definition of severity of MG based on all its manifestations, as captured by the existing outcome measures in MG. They also aimed to document the ability of a newly developed patient-reported outcome (PRO) measure, the MG Symptoms PRO, to bridge the gaps of the more established outcome measures in MG in their coverage of the overall MG severity.

What was learned from the study?

A meaningful continuum of overall MG severity was revealed, simultaneously reflecting muscle weakness in limbs, physical fatigue, bulbar, and respiratory muscle weakness. Ocular signs and symptoms appeared to represent a unique aspect in the overall picture of MG severity as they did not match well with this continuum.

The analyses also demonstrated the added value of the MG Symptoms PRO, which provides greater granularity and flexibility in the coverage of the overall MG severity compared with the more established outcome measures in MG.