Background: Eosinophilic granulomatosis with polyangiitis (EGPA) is a rare vasculitis characterized by asthma, systemic manifestations, blood and tissue eosinophilia.

Aim: To assess the effectiveness and safety of mepolizumab (anti-IL-5) and benralizumab (anti-IL-5R?) in patients with EGPA for 24 months.

Material and Methods: We conducted a multicenter observational study, including 49 patients (31 females, 63.3%) with EGPA treated with anti-IL-5/R? biologics at 9 Italian outpatients? facilities. Remission rates [Birmingham Vasculitis Activity Score (BVAS) =0 and prednisone (or equivalent) of ?4.0 mg/day], corticosteroids (OCS) intake and respiratory outcomes were assessed.

Results: Overall, BVAS score dropped from 6 (4-10) to 0 (0-0) (p<0.0001) at 24 months; 57.1% achieved remission after 24 months. The median OCS dose was reduced from 10 mg/day (5-20) to 2.5 mg/day (0.0-5) (p<0.0001) at 24 months; 69.6% of OCS-dependent patients lowered their daily dose by 75% and 28.3% discontinued these drugs. Multivariate analysis found that lower OCS intake [OR 0.8 (95% CI 0.67-0.93), p=0.0040] and higher blood eosinophil count [OR 1.002 (95% CI 1.0-1.003), p=0.0180] at baseline were independently associated with remission at 24 months. Asthma exacerbation dropped from 4 (3-5.8) to 0 (0-0.5) at 24 months (p<0.0001). The ACT score increased from 13.5 (10-17) to 22 (20-24) (p<0.0001) after 24 months. The pre-bronchodilator FEV₁% improved from 77% (59.3-89.5) to 81.5% (71.5-100.5) (p<0.0001) at 24 months.

Conclusions: These real-world data suggest that anti-IL-5/R? biologics are effective and safe in the management of EGPA.