P187 Real-world evaluation of avacopan therapy in ANCA-associated vasculitis: a single-centre experience

Abstract Background/Aims ANCA-associated vasculitis (AAV) is a severe, multisystem autoimmune condition that traditionally requires prolonged corticosteroid use, often leading to significant toxicity. The landmark PEXIVAS trial demonstrated that reduced-dose steroid regimens were non-inferior to standard doses in preventing disease relapse, reinforcing the need for safer steroid-sparing strategies. Avacopan, an oral C5a receptor antagonist, has emerged as a targeted therapy to complement immunosuppression while minimising glucocorticoid exposure. Following the ADVOCATE trial results, avacopan was integrated into the British Society for Rheumatology (BSR) 2023 guidelines, which recommend its use in conjunction with cyclophosphamide or rituximab for induction therapy in AAV. However, real-world experience with avacopan remains limited, and its implementation in clinical practice warrants evaluation. This audit investigates the early experience of avacopan use at Royal United Hospital (RUH) Bath, focusing on efficacy, safety, and patterns of steroid tapering. The objectives of this audit were two-fold: assessment of steroid weaning regimens in patients receiving avacopan therapy, and evaluation of the safety and efficacy of avacopan in real-world practice. Methods A retrospective observational analysis was conducted on patients with AAV who were initiated on avacopan therapy at RUH Bath between 2023 and 2025. Inclusion criteria included patients who commenced avacopan alongside steroids at the point of diagnosis. Patients who refused steroids or who started avacopan ≥3 years after diagnosis were excluded. Clinical correspondence and laboratory data were reviewed. Efficacy was assessed using the Birmingham Vasculitis Activity Score (BVAS), and Vasculitis Damage Index (VDI) was recorded. Steroid tapering practices were compared with the PEXIVAS protocol and half-PEXIVAS protocol (twice the PEXIVAS tapering rate). Results A total of 9 patients were included (5 male, 4 female), with a mean age of 56.6 ± 14.8 years. Five were PR3-positive and four MPO-positive. Efficacy: Baseline BVAS averaged 16.9 ± 5.2. This reduced to 5.9 ± 4.9 at 3 months and 4.3 ± 3.7 at 6 months. VDI was recorded at 3.4 ± 2.9 at 3 months and 3.9 ± 3.0 at 6 months. By 6 months, two patients were in complete remission off steroids, and one remained in remission but still required steroids. Safety: Avacopan was discontinued in four cases due to toxicity, infection, or perceived lack of efficacy. Steroid weaning: Tapering regimens varied significantly and were tailored to individual patients. Some regimens were disrupted due to intercurrent illness or ICU admission. No standardized tapering protocol was used across the cohort. Conclusion Real-world use of avacopan at a UK national specialist centre revealed variability in weaning practices and challenges in standardisation. Avacopan showed good clinical response despite a low complete remission rate and appeared to be a generally safe option in the treatment of AAV. Further multi-centre, larger-scale studies are ongoing to develop national protocols and standardised practice. Disclosure I. Sen: None.