A recent analysis of 18 clinical trials published in the European Journal of Neurology found that older patients with myasthenia gravis (MG) experience smaller treatment benefits than younger patients when treatment is rated using the quantitative myasthenia gravis (QMG) score — but not when it’s rated using the myasthenia gravis activities of daily living (MG-ADL) score.
The QMG is conducted by physicians, and is meant to be an objective measure of a patient’s symptoms at a single visit. In contrast, the MG-ADL reflects a patient’s perception of their daily symptoms over a set period. The study’s authors said that the difference between these two scores could be due to many reasons — from biological differences in late-onset MG to older patients naturally having more limitations — but that the need to include age when evaluating treatment is clear.
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Older adults with MG are at greater risk of developing comorbidities and may face changes in immune system function and drug response. Current clinical trials do not consistently report age-stratified analyses, which may uncover clinically meaningful subgroup differences.
The study included 1,823 participants in clinical trials published between 2017 and 2025. The most common therapies under investigation included neonatal Fc receptor (FcRn) inhibitors (seven trials), complement C5 inhibitors (four trials), and B-cell targeted therapies (four trials). The average age at the start of the trials ranged from 39.1 years to 63.0 years.
Overall, participants in the treatment groups exhibited greater improvements in QMG and MG-ADL scores compared with controls.
For every 10-year increase in average age, however, the difference in QMG improvement between treated and untreated patients declined by 1.21 points. Across clinical trials, age explained 25.4% of the variability in treatment effect measured via QMG score. The association between age and QMG score appeared to be most influenced by the FcRn trials.
On the other hand, each 10-year increase in mean age was not associated with a change in treatment effect when using the MG-ADL score. Additionally, no associations were observed within the individual treatment classes, and 0% of the variability in treatment effect measured via MG-ADL score was explained by age.
“These findings suggest that age may contribute to differences in observed treatment effects across MG trials and support patient-level analyses to determine whether age modifies treatment response and, if so, through which biological or clinical pathways,” the authors concluded.
Limitations included the lack of data on individual patient ages and small number of trials included in treatment class analyses.
