A new study published in Advances in Therapy revealed a significant association between myasthenia gravis–activities of daily living (MG-ADL) improvements and higher EQ-5D-5L utility values in patients with generalized myasthenia gravis (gMG). Moreover, the MG-ADL scores alone are not sufficient to measure the effectiveness of efgartigimod treatment.
Generalized myasthenia gravis is a neurological condition causing muscle weakness and resulting in problems such as fatigue, vision impairment, swallowing difficulties, limb weakness, and breathing problem, the researchers noted. It is estimated that around 700,000 people worldwide and 103,000 people in the European Union (EU) are affected by MG, with approximately 85% of patients with MG progressing to gMG, they added.
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Patients with gMG experience significant impacts on their well-being, social function, psychological health, and physical health, which can lead to lower health-related quality of life (HRQoL) compared to the general population, the study team noted.
Various instruments have been validated to assess the symptom severity, functional status, and HRQoL of patients with gMG. However, limited information is available on the relationship between functional status (as measured by the MG-ADL) and utility values in patients with gMG, they continued.
The study used data from the phase 3 ADAPT clinical trial, which included adult patients with gMG who were randomly assigned to receive either efgartigimod + conventional therapy (EFG + CT) or placebo + CT (PBO + CT). Biweekly assessments of the patients’ MG-ADL total symptom scores and HRQoL using the EQ-5D-5L were conducted for up to 26 weeks.
The findings revealed that the patients treated with EFG + CT experienced greater improvements in most MG-ADL items and EQ-5D-5L dimensions, with the largest improvements seen in chewing, brushing teeth/combing hair, eyelid droop, self-care, usual activities, and mobility.
Moreover, the regression model showed that specific MG-ADL items had a greater impact on utility values, such as brushing teeth/combing hair, rising from a chair, chewing, and breathing. Additionally, the GEE model indicated that each unit improvement in MG-ADL led to a statistically significant increase in utility and that patients in the EFG + CT group had a significantly greater improvement in utility compared to the PBO + CT group.
“This analysis demonstrated that improvements in gMG symptoms were significantly associated with higher utility values,” the authors highlighted.
The authors acknowledged several limitations in the study, including the short follow-up period, which may not have captured the full impact of the treatment over time. Moreover, the assumptions made in the regression and GEE models might need to be revised, as the authors assumed an equal effect of each change in MG-ADL items on utility, but this may vary between items. Additionally, the study results might only be generalizable in a clinical trial setting, and it may be difficult to establish reference values in this patient population.
Reference
Dewilde S, Qi CZ, Phillips G. et al. Association between Myasthenia Gravis–activities of daily living (MG-ADL) and EQ-5D-5L utility values: the additional effect of efgartigimod on utilities. Adv Ther. Published online March 3, 2023. doi:10.1007/s12325-023-02437-w
