Real-World Burden of Immunosuppressant-Treated Lupus Nephritis: A German Claims Database Analysis

Abstract

Introduction: This retrospective cohort study (GSK213737) aimed to characterize treatment patterns, healthcare resource utilization (HCRU), and costs in patients with lupus nephritis (LN) initiating immunosuppressant therapy in clinical practice in Germany, to better understand the full picture of the real-world burden of LN. Methods: Adult patients with LN who initiated mycophenolate mofetil (MMF), intravenous cyclophosphamide (CYC), azathioprine (AZA), tacrolimus, cyclosporin A, or rituximab therapy in 2011–2017 (index therapy) were identified from the Betriebskrankenkassen German Sickness Fund database. Treatment patterns, including immunosuppressant discontinuations, and therapy switches, were assessed (maximum follow-up 4 years). Corticosteroid use, HCRU, and total economic costs were also evaluated. HCRU and costs were compared with matched controls (individuals without systemic lupus erythematosus [SLE]/LN matched by age, sex, and baseline Charlson Comorbidity Index). Results: Among 334 patients with LN, the median (interquartile range) duration of index immunosuppressant therapy use was 380.5 (126, 1064) days. Of those patients with 4 years complete enrollment, 70.8% had ≥ 1 discontinuation and 28.8% switched therapy. While most patients (71.2%) received only one immunosuppressant, gaps in treatment were common. After 1 year of follow-up, 41.6% of patients had a prednisone-equivalent corticosteroid dose of ≥ 7.5 mg/day. Patients with LN had greater HCRU use for most categories assessed and increased mean total costs per person-year versus controls (€15,115.99 versus €4,081.88 in the first year of follow-up). Conclusions: This real-world analysis demonstrated the considerable burden of immunosuppressant-treated LN in Germany, with a high rate of discontinuations, frequent use of high-dose corticosteroids, and substantial HCRU/costs.