Treatment of Antineutrophil Cytoplasmic Antibody–Associated Vasculitis With Diffuse Alveolar Hemorrhage With Avacopan

Objective Avacopan, an activated complement factor 5 receptor antagonist, has been approved as adjunct therapy for severe active antineutrophil cytoplasmic antibody–associated vasculitis (AAV). Current evidence supports the management of AAV presenting with diffuse alveolar hemorrhage (DAH) by administering glucocorticoids combined with either rituximab or cyclophosphamide in addition to supportive care. The role of avacopan in patients with DAH as a primary severe disease manifestation of AAV has not been well established. Furthermore, concerns remain regarding timely access to avacopan, the best glucocorticoid tapering regimen, and long‐term efficacy and safety of the drug. We sought to identify clinical features and outcomes of patients presenting with DAH secondary to AAV who received avacopan in addition to glucocorticoids and rituximab or cyclophosphamide. Methods We performed a retrospective cohort study of all consecutive patients presenting with DAH as part of active severe granulomatosis with polyangiitis or microscopic polyangiitis. Demographic and clinical characteristics were collected at presentation and follow‐up. Results Fifteen patients met inclusion criteria and were observed for a median time of 17 weeks (interquartile range IQR 6–37 weeks) after initiation of avacopan. Patients were predominantly female and White, had never smoked, and were a median age of 66 years (IQR 52–72 years) at diagnosis. The majority had newly diagnosed severe AAV with renal involvement. Three patients progressed to respiratory failure. The timing of avacopan introduction and patterns of glucocorticoid tapers varied widely in this cohort. Two serious adverse events related to infection were observed, including one opportunistic infection leading to the patient's death, although neither was directly attributed to avacopan administration. Conclusion We describe the clinical course of patients who presented with the severe AAV disease manifestation of DAH and received avacopan as adjunct therapy. Most patients achieved remission during follow‐up, and adverse events, including infection, were observed.