BackgroundBenralizumab is effective in the treatment of eosinophilic asthma and is being investigated for the treatment of other eosinophil-associated diseases. Reports on the use of benralizumab for the treatment of eosinophilic granulomatosis with polyangiitis (EGPA) are limited to case reports and small case series.MethodsWe conducted a multicentre, retrospective study including EGPA patients treated with off-label benralizumab. The primary endpoint was the rate of complete response defined as no disease activity (Birmingham Vasculitis Activity Score=0) and a prednisone dose ≤4 mg/day. Partial response was defined as no disease activity and a prednisone dose ≥4 mg/day.ResultsSixty-eight patients were included, including 31 (46%) who had previously received mepolizumab. The use of benralizumab was warranted by uncontrolled asthma in 54 (81%), persistent ear, nose and throat (ENT) manifestations in 27 (40%) and persistent glucocorticoids (GCs) use in 48 (74%) patients. Median (IQR) follow-up after starting benralizumab was 23 (9–34) months. Thirty-three patients (49%) achieved a complete response, 24 (36%) achieved a partial response and 10 (15%) did not respond. Among the 57 patients who initially responded, 10 (18%) eventually required further line treatments. GCs were discontinued in 23 patients (38%). Prior mepolizumab use was associated with a higher rate of primary failure (26.7% vs 5.4%, p=0.034) and less frequent GCs discontinuation (14.8% vs 55.9%, p=0.001). Vasculitis flares occurred in 7 patients (11%) and were associated with histological evidence of vasculitis and/or antineutrophil cytoplasmic antibodies positivity at benralizumab initiation (p=0.004).ConclusionsBenralizumab appears to be an effective treatment for refractory asthma or ENT manifestations in EGPA and allows GC-sparing. However, its efficacy was lower after prior failure of mepolizumab.