Patient-reported data on disease progression could contribute to existing methods for measuring prognosis in subjects with myasthenia gravis (MG), according to a study recently published in Neurology and Therapy.
“With its modular nature and comprehensive content, the MG Symptoms PRO provides complementary information to the outcome measures widely used in MG,” the authors wrote.
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This retrospective, observational study included a total of 43 patients previously diagnosed with MG who formed the sample in phase 2a MG0003 study. Participants formed part of either the intervention or placebo group after randomization. The intervention consisted of administering rozanolixizumab 7 mg/kg. Simultaneously, all individuals completed the Quantitative MG (QMG), MG Symptoms Patient-Reported Outcome (PRO) questionnaire, MG-Activities of Daily Living (MG-ADL), and MG Composite (MGC) questionnaires during the study, for a total of 541 entries.
The researchers identified a meaningful continuum of severity of MG in all sections of the assessment, except for ocular muscles in all 4 instruments. Moreover, the QMG and MG Symptoms PRO showcased the greatest degree of coverage of the MG severity continuum. This finding suggests that ocular manifestations could reflect a completely different aspect of MG severity.
Bulbar weakness seemed to indicate disease severity in a more accurate manner than the other items. On the other hand, physical fatigability and muscle fatigability displayed a stronger association within low-severity MG.
“As the MG Symptoms PRO is the instrument measuring physical fatigue the most comprehensively, its coverage of the milder end of the continuum was improved compared to all other instruments, including the QMG,” noted Regnault and his colleagues.
The overall correlation varied from 0.56 to 0.74 for 4 questionnaires: MG Symptoms PRO Muscle Weakness Fatigability score, MG-ADL, MGC, and QMG. Only the MG Symptoms PRO that focused on independent muscle groups had a correlation between 0.20 and 0.71.
Reference
Regnault A, Morel T, de la Loge C, et al. Measuring overall severity of myasthenia gravis (MG): evidence for the added value of the MG Symptoms PRO. Neurol Ther. Published online May 11, 2023. doi:10.1007/s40120-023-00464-x
