Effectiveness of Low-Dose Mepolizumab in the Treatment of Eosinophilic Granulomatosis with Polyangiitis (EGPA): A Real-Life Experience

Data showing effectiveness of mepolizumab in patients with eosinophilic granulomatosis with polyangiitis (EGPA) are limited.This is a single-center retrospective chart review of patients with EGPA treated with mepolizumab. Clinical, laboratory, functional parameters and asthma, rhinitis control, and quality of life scores (Asthma Control Test [ACT], Asthma Quality of Life Questionnaire [AQLQ], Rhinoconjunctivitis Quality of Life Questionnaire [RQLQ], and SinoNasal Outcome Test [SNOT]-22) were evaluated at the baseline, 6th month, and 12th month. Complete response was defined as the absence of asthma and/or ear, nasal symptoms and exacerbations with a prednisone of ≤7.5 mg/day, partial response if it was achieved with a prednisone of >7.5 mg/day.Overall, 25 patients (18 F/7 M) with a median age of 47 years (23-76) were enrolled. Mepolizumab 100 mg/month was administered (dose increased to 300 mg/month in 3 patients). Mepolizumab significantly decreased daily dose of oral corticosteroid (OCS) from 11.04 mg to 3.65 mg together with a significant improvement in ACT, AQLQ, RQLQ, and SNOT-22 scores and a significant reduction in asthma exacerbations and blood eosinophil count at the 6th and 12th month (all p values <0.05). The mean forced expiratory volume in 1 s increased (at baseline: 1.88 L to 2.46 L at the 12th month [p = 0.037]). Seventy-six percent of patients responded completely at the 6th month and 81.25% at the 12th month. The complete responders at the 6th and 12th month were older than partial responders and nonresponders (p = 0.030 and p = 0.057, respectively). Patients with complete response at the 6th month were on lower doses of OCS than partial responders and nonresponders (p = 0.029).Low-dose mepolizumab was effective in EGPA patients by improving sinonasal and asthma outcomes, while reducing the need for OCS.