2026 American Academy of Neurology Abstract Website

Objective:

To characterize the indications and experiences of patients with seropositive generalized myasthenia gravis (gMG) treated with biologic therapy.

Background:

Biologic therapies are recently available treatment options for gMG, but data regarding their uses and outcomes outside of clinical trials is limited.

Design/Methods:

Chart review of adult seropositive gMG patients treated with biologic therapy at the University of Pennsylvania between October 2020–July 2025 was conducted. Indication for initiating biologic therapy, outcome of therapy, ability to wean from biologic, and ability to wean from corticosteroids were recorded. Data were summarized descriptively using medians and interquartile ranges (IQR) for continuous variables, and percentages for categorical variables.

Results:

Among 588 persons with seropositive gMG, 87 (14.8%) received biologic therapy. The median age at diagnosis was 61 years (IQR: 16-91), and 55.1% were female. Biologics were primarily initiated due to inadequate response to first-line therapies (79.3%), less frequently for steroid sparing purposes (25.3%) or as bridge to other non-steroidal immunosuppressants (12.6%), and rarely for long-term maintenance (3.4%). More than one-third (40.2%) of patients had more than one indication for initiation. Use of biologic therapy was as follows: efgartigimod 57.5%, eculizumab 17.2%, ravulizumab 13.8%, rituximab 8.1%, and rozanolixizumab 3.4%. Approximately half (58.6%) of patients had success with the first biologic. 23.0% tried a second or third biologic, of whom 80.0% had success. 27.9% had started to wean from the biologic therapy. Among patients on steroids at the time they started therapy (N=58), 81.0% were able to start weaning from steroids.

Conclusions:

While only a subset of patients with MG are prescribed biologic therapy, the most common indication in this study was lack of adequate response to first line therapies. Our results suggest that the majority of patients experience symptomatic improvement and the ability to start weaning from steroids. Biologics were rarely used for long term maintenance treatment of seropositive gMG.