#2533 Real-world challenges associated with the use of systemic glucocorticoids in a US IgAN cohort
Authors: Patel Mit , Gusto Gaelle , Pesce Giancarlo , Madison Terri 
Published: May 2024

Abstract

Background and Aims
Immunoglobulin A nephropathy (IgAN) is the most common primary glomerular disease and up to 50% of patients progress to kidney failure within 10-20 years. Until early 2022, management of IgAN was primarily focused on supportive care. As outlined in the Kidney Disease: Improving Global Outcomes (KDIGO) guidelines, patients at high risk of progressive chronic kidney disease despite maximal supportive care can be considered for a 6-month course of systemic glucocorticoids (SGC), although important risks of toxicity and contraindications must be considered. There is currently limited real-world evidence describing the impact of the use of SGC on treatment‑emergent toxicity and healthcare resource utilization (HCRU) in patients with IgAN. We report the incidence of adverse events (AEs) commonly associated with SGC, as well as HCRU rates and costs, in a real-world cohort of IgAN patients, comparing new initiators of SGC with patients who have never initiated SGC.

Method
This non-interventional, retrospective cohort study was conducted in the TriNetX Dataworks - United States of America Network, a database of de-identified, patient-level electronic medical records (EMR) of approximately 100 million patients. The cohort was selected from a total of 19, 687 patients with IgAN, identified using proxy ICD‑10 codes N02.8 (recurrent and persistent hematuria with other morphologic changes) or N04.1 (nephrotic syndrome) between January 1, 2011, and May 4, 2022. Eligible patients were required to have: an incident diagnosis of IgAN with the same diagnosis within 30-180 days; at least 12 months of EMR history available prior to and after initial IgAN diagnosis; not experienced kidney failure prior to or on the initial date of IgAN diagnosis; and not received SGC prior to the date of diagnosis. Data assessed included demographic and clinical characteristics, IgAN-directed medications, AEs, and HCRU. To promote balance between cohorts, new initiators of SGC (dexamethasone, prednisone, prednisolone, methylprednisolone) were matched with patients who did not receive SGC using a propensity score (PS) approach based on their characteristics at diagnosis. To avoid immortal-time bias, the index date was set as the time of SGC initiation in patients in the SGC cohort; for the non-SGC cohort, a pseudo-index date was assigned using the same lag from diagnosis to index date as their 1:1 PS-matched patient in the SGC cohort. Differences in the cumulative incidence of individual AEs were analyzed using the chi-square test or Fisher's exact test, and differences in HCRU rates and costs were analyzed using the Kruskal-Wallis test.

Results
After implementing the PS approach, the final analysis included 802 patients (401 PS-matched pairs), with a mean age of 41.2 years and 55% being male. Median duration of follow-up was 3.5 and 3.1 years for the SGC and non-SGC cohorts, respectively. Of AEs that occurred in at least ten of the 802 patients, patients who received SGC experienced a significantly increased incidence of all AEs except for fractures, new onset of diabetes, and reported onset of glaucoma (Table 1). Patients who received SGC had a 12-fold increased incidence of severe infections requiring hospitalization compared with the non-SGC cohort. Annualized mean HCRU rates and costs were significantly greater across all HCRU types for patients who received SGC vs those who did not receive SGC, including an 8-fold increase in inpatient visits, a 4-fold increase in emergency department admissions, and twice as many ambulatory visits (Fig. 1). Results were consistent when the cohort was restricted to patients with IgAN identified using only the ICD-10 code N02.8 (recurrent and persistent hematuria with other morphologic changes).

Conclusion
The findings of this real-world analysis demonstrate significant side effects and costs for IgAN patients treated with SGC compared with patients not treated with SGC, underscoring the recommendation in the 2021 KDIGO guidelines to carefully consider treatment-emergent toxicity before treating IgAN patients with SGC.