Longitudinal associations of corticosteroid dose with corticosteroid toxicity in patients with myasthenia gravis in the USA

Topic:

Clinical Management

Poster Number: P348

Author(s):

Thomas Ragole, MD, University of Colorado Hospital, USA, Michael Blackowicz, MD, Alexion, AstraZeneca Rare Disease, Boston, MA, USA, Emma Weiskopf, MD, Alexion, AstraZeneca Rare Disease, Boston, MA, USA, Ashwin Anand, MPH, Forian Inc., Newtown, Mike Sicilia, BSc, Forian Inc., Newtown, Gil I. Wolfe, MD, Jacobs School of Medicine and Biomedical Sciences, University Buffalo/State University of New York

Corticosteroids remain a common treatment for myasthenia gravis (MG) but are associated with notable adverse effects, particularly with long-term use. The aim of this study is to quantify corticosteroid-related toxicity in a real-world population of adults with MG. This retrospective cohort study included patients with MG who received corticosteroids after MG diagnosis, using linkage of a large multipayer claims database with electronic health records (CHRONOS, Forian Inc.), between January 1, 2016, and September 30, 2024. Eligible patients were aged ≥18 years, had ≥2 MG claims separated by ≥30 days, and had ≥1 post-baseline measurement of Glucocorticoid Toxicity Index – Metabolic Domains (GTI-MD; Copyright © 2016, 2018. Massachusetts General Hospital, licensed with permission; defined by BMI, blood pressure, LDL cholesterol, and hemoglobin A1c parameters, or concomitant medication changes) ≥6 months after their first MG claim. Patients were excluded if they received corticosteroids within 6 months of their first MG claim. Data were included from first MG claim to end of follow-up. Dose–response relationships of cumulative and average corticosteroid dose with aggregate improvement score (AIS) and cumulative worsening score (CWS) were estimated using mixed effects regression models with repeated measures. In total, 69,588 patients were eligible, excluding the GTI-MD requirement; 31,021 (44.6%) received corticosteroids at least once. After limiting eligibility to patients with valid GTI-MD scores, the analytic sample included 300 patients with and 441 patients without corticosteroid use. Corticosteroid-related toxicity was higher in patients with ≥3 months’ continuous use (CU) versus those with <3 months’ CU, or no use at all. At 24 months, CWS was 40.5, 28.7 and 23.2, respectively, and AIS was 17.2, 5.3 and 3.6, respectively. This large retrospective analysis will quantify the burden of corticosteroid toxicity in patients with MG and establish a reliable estimate of the longitudinal dose–response relationship of corticosteroid dose with toxicity.