New tool shows difference in side effect severity for MG treatments

A scoring tool called the Adverse Event Unit (AEU) effectively measured side effects using data from an existing clinical trial.

Patients with myasthenia gravis (MG) involved in a recently published study who received both prednisone and azathioprine reported more treatment-related side effects than those who used prednisone alone.

The study used a scoring tool called the Adverse Event Unit (AEU) and was published recently in Muscle and Nerve.

MG is a chronic neuromuscular disease that often requires long-term immunosuppressive therapy, but medications can cause serious side effects. Researchers developed the AEU to better quantify and compare the burden of side effects across treatment options, using real patient and physician input to weigh adverse events.

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“Our data demonstrate that the AEU can be used to measure treatment-related AE retrospectively from clinical trial data,” explained this study’s authors. They continued, “In addition, we again observed that AEU scores increase with higher treatment exposure and with greater numbers of immunotherapies in MG.”

The AEU scoring system was applied to data from the MGTX trial, a large, randomized study that followed 117 adults with acetylcholine receptor-positive generalized MG. Over three years, researchers matched recorded side effects from the trial to AEU categories and compared those scores to prednisone exposure and treatment type. At least one adverse event was reported at 86% of study visits, and all recorded adverse events, including serious ones, were converted into AEU scores.

Patients who received both azathioprine and prednisone had higher AEU scores at all time points than those treated with prednisone alone. Only a weak correlation between higher prednisone doses and side effect burden occurred, suggesting that medication type and patient characteristics may play a larger role in determining side effects than dosage alone.

Interestingly, some patients who received high doses of prednisone had few or no reported side effects despite having more severe symptoms of MG. For example, in year one, 12 participants with high prednisone exposure had AEU scores of zero and a median Quantitative Myasthenia Gravis Score of 11. Similar patterns were observed in years two and three.

This study found no significant difference in AEU scores between men and women but did note a trend toward higher side effect scores in patients over age 50.

The ability to apply AEU scoring to existing clinical trial data may support its use in future research to help compare treatments and understand the real-world effects on patients.