Objective:

To evaluate real-world utilization of oral corticosteroids (OCS) among patients with generalized myasthenia gravis (gMG) over the first 6 months post-efgartigimod treatment initiation.

Background:

Design/Methods:

In this retrospective cohort study, patients with gMG using OCS who initiated efgartigimod treatment were identified from a US medical and pharmacy claims database (based on information licensed from IQVIA: Longitudinal Access and Adjudication Data [LAAD] for the period April 2016−April 2023, reflecting estimates of real-world activity [all rights reserved]). Average daily dose (ADD) of OCS was analyzed: (1) during the 3-month period immediately prior to efgartigimod initiation, (2) at 3-months post-efgartigimod initiation, and (3) at 6-months post-efgartigimod initiation. The proportion of patients whose ADD changed ≥5 mg between pre- and post-efgartigimod initiation and distribution of ADD at each timepoint were evaluated.

Results:

Among 576 patients with gMG who initiated efgartigimod between January 2022-September 2022, and continued efgartigimod treatment for ≥6 months, 231 (40%) were using OCS at baseline (pre-efgartigimod) and were included in the study. At baseline, 17 (7.4%), 109 (47.1%), 105 (45.5%) of patients had OCS AAD of 0-5mg, 5-20mg, and >20mg, respectively. At 3-months and 6-months post-efgartigimod, 82 (35%) and 99 (43%) patients experienced ≥5mg reduction in ADD, respectively. The proportion of patients with ADD of 0-5mg increased more than 3-fold (7% at baseline vs. 26% 6-months post-efgartigimod) and the proportion of patients with ADD of >20mg reduced by 35% (45% at baseline vs. 29% 6-months post-efgartigimod) following efgartigimod initiation.

Conclusions:

While additional data is required to assess longer-term patterns, early insights into OCS utilization post-efgartigimod initiation in patients with gMG indicate that a substantial proportion experienced reduction in OCS usage over the first 6 months post-efgartigimod initiation.