Patients with myasthenia gravis (MG) who have a shorter disease duration or more severe bulbar symptoms are more likely to have an early response to treatment with efgartigimod, according to a study recently published in the Journal of Neurology.
Efgartigimod is a relatively new therapy that has shown efficacy in treating a number of autoimmune conditions, including generalized MG. The study’s researchers sought to further investigate the efficacy of efgartigimod and assess factors associated with an early treatment response.
To do so, they looked through the clinical records of 115 patients with acetylcholine receptor (AChR)-antibody-positive generalized MG who were given an initial cycle of efgartigimod at four hospitals in China between September 2023 and June 2024.
Clinical assessments were performed prior to treatment and once weekly following weekly infusions until week four. Two clinical scoring systems were used: the Myasthenia Gravis Activities of Daily Living (MG-ADL) and the Quantitative Myasthenia Gravis (QMG) scores. Early responses were assessed at the first week after the first efgartigimod administration.
Read more about myasthenia gravis testing and diagnosis
Among patients who were scored according to the MG-ADL, 72.5% experienced an improvement of at least two points after the first infusion. By the fourth infusion, this rose to 93.3%. Among patients who were scored according to the QMG, 60.5% saw improvements after the first infusion and 87.5% by the fourth infusion; significant improvements were observed across all symptom categories (i.e., ptosis, diplopia, bulbar and limb), except for those involving the respiratory system. None of the patients had to discontinue treatment due to severe treatment side effects.
Patients who had a shorter disease duration and more severe bulbar symptoms were more likely to have an early response. The bulbar muscles are a group of muscles in the head, neck and jaw that impact speaking, swallowing and chewing. Previous research has indicated that bulbar symptoms respond more quickly to treatment, though the reason why is unclear.
“Disease duration and bulbar symptoms may serve as potential clinical markers for identifying patients likely to achieve early efficacy, which may help physicians select individuals who may benefit most from the treatment after the first infusion,” the study’s authors noted.
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