Real-world efficacy and safety of avacopan in ANCA-associated vasculitis: a retrospective comparative study

OBJECTIVES: Avacopan, an oral C5a receptor antagonist, is approved for treatment of severe antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) in combination with rituximab or cyclophosphamide. This study evaluated its real-world efficacy, safety and glucocorticoid-sparing effects. METHODS: This retrospective single-centre study included 35 patients with new-onset or relapsing AAV treated with avacopan plus standard induction therapy (rituximab, cyclophosphamide or both). Outcomes were compared with 70 matched controls receiving standard therapy. Primary endpoints were remission (Birmingham Vasculitis Activity Score (BVAS)=0, prednisolone ≤5 mg/day) at 6 and 12 months. Secondary endpoints included relapse, renal function, glucocorticoid exposure and adverse events. RESULTS: Baseline characteristics were generally comparable, although median estimated glomerular filtration rate (eGFR) was lower in the avacopan group (24 vs 49 mL/min). Induction therapy included rituximab (28%), cyclophosphamide (11%) or combination therapy (61%), reflecting severe disease. Remission rates were similar at 6 months (69% vs 68%) but tended to be higher with avacopan at 12 months (86% vs 68%; p=0.11). Relapses occurred less frequently with avacopan (16% vs 51%, p=0.003), including after treatment discontinuation. Avacopan was associated with accelerated glucocorticoid tapering (≤5 mg/day; 102 vs 164 days, p