POS0357 BURDEN OF GLUCOCORTICOID USE AND ASSOCIATED TOXICITIES IN COMMERCIALLY INSURED ADULTS WITH IgG4-RELATED DISEASE IN THE UNITED STATES

Background: Immunoglobulin G4-related disease (IgG4-RD) is an immune-mediated fibroinflammatory disorder that often affects multiple organs. Glucocorticoids (GCs) are often used first-line for the treatment of IgG4-RD.[1] Despite their therapeutic benefits, long-term GC use is known to be associated with toxicities that can affect several organ systems.[1] While the association between GC exposure and toxicities has been well characterized in other conditions, little is known about the real-world use of GCs and the associated clinical burden in the context of IgG4-RD. Objectives: To describe real-world GC use and associated toxicities in patients with IgG4-RD using administrative claims data in the United States. Methods: Commercially insured adults (age ≥18 years) diagnosed with IgG4-RD were identified in the IQVIA PharMetrics Plus database (01/01/2011-06/30/2022) using a validated algorithm. This algorithm considered IgG4-RD-related diagnoses, prescription medication fills, and medical procedures.[2] The index date was defined as the first observed IgG4-RD-related diagnosis code, and the baseline and follow-up periods were defined as the 12 months before and after the index date, respectively. GC use during the follow-up period was calculated as the total cumulative prednisone equivalent dose divided by 365 days. Patients were classified into two mutually exclusive cohorts based on GC use. The low GC use cohort comprised patients with a mean GC dose of <5 mg/day, including patients with no GC use; the high GC use cohort comprised those with a mean GC dose of ≥5 mg/day. Incident GC toxicities were defined as toxicities with ≥1 diagnosis during the follow-up period and no diagnosis during the baseline period. Demographic characteristics were reported as of the index date; GC use and incident toxicities were reported during the follow-up period. Descriptive comparisons of incident toxicities between cohorts were analyzed using Chi-square tests. Results: A total of 295 patients with IgG4-RD were identified, with 150 (50.8%) included in the low GC use cohort (mean age 48.9 years, 55.3% female) and 145 (49.2%) in the high GC use cohort (mean age 50.8 years, 45.5% female). In the first year after diagnosis, most patients (84.1%) received ≥1 GC fill, with a mean of 4.1 fills, corresponding to 3.9 months of treatment. Patients in the low GC use cohort received a mean of 1.8 fills, corresponding to 1.4 months of treatment or a mean dose of 1.4 mg/day over the 12-month follow-up period. Patients in the high GC use cohort received 6.4 fills, corresponding to 6.5 months of treatments or a mean dose of 12.0 mg/day over the follow-up period. Higher GC use was associated with higher rates of incident GC toxicities, such that patients in the high GC use cohort had a greater mean number of GC toxicities (1.8 vs. 1.2; p<0.01) and were more likely to have ≥3 toxicities (29.0% vs. 13.3%; p<0.01) than the low GC use cohort. In particular, cardiovascular (29.0% vs. 18.7%; p=0.04), gastrointestinal (29.7% vs. 16.0%; p<0.01), and infectious (31.0% vs. 17.3%; p<0.01) toxicities were more commonly observed among patients with high GC use than low GC use. Conclusion: In the first year after diagnosis, patients with IgG4-RD experienced a substantial GC burden, as evidenced by nearly half of them exposed to high GC use. Higher GC use was associated with an increased incidence of GC toxicities across multiple organ systems. These findings suggest an unmet need for safe and effective treatments to mitigate prolonged exposure to GCs and improve patient outcomes, particularly in the absence of targeted approved therapies for IgG4-RD. REFERENCES: [1] Yasir M, et al. 2023. Available from: https://www.ncbi.nlm.nih.gov/books/NBK531462/. [2] Wallace ZS, et al. ACR Open Rheumatol. 2022;4(4):371–7. Acknowledgements: NIL. Disclosure of Interests: Zachary S. Wallace Amgen Inc., Jenny Y. Park Amgen Inc., Amgen Inc., Elizabeth Serra Employee of Analysis Group, Inc., which has provided paid consulting services to Amgen Inc., Annie Guérin Employee of Analysis Group, Inc., which has provided paid consulting services to Amgen Inc., Kristina R. Patterson Amgen Inc., Amgen Inc., Haridarshan Patel Amgen Inc., Amgen Inc., Vikesh K. Singh Amgen Inc.