Two-year efficacy and safety of anti-interleukin-5/receptor therapy for eosinophilic granulomatosis with polyangiitis

OBJECTIVES: To summarise the efficacy and safety of 2 years of anti-interleukin-5/receptor (anti-IL-5/R) therapy in patients with eosinophilic granulomatosis with polyangiitis (EGPA). METHODS: Patients were randomised 1:1 to receive benralizumab or mepolizumab every 4 weeks during the 52-week double-blind period of the MANDARA trial. Patients entered an open-label extension (OLE) in which they continued benralizumab (benralizumab/benralizumab) or switched from mepolizumab to benralizumab (mepolizumab/benralizumab). Remission (Birmingham Vasculitis Activity Score = 0 and oral glucocorticoid [OGC] dose ≤4 mg/d), OGC use, relapse, blood eosinophil count (bEOS), and safety up to year 2 (week 104) were reported. RESULTS: A total of 128 patients entered the OLE period (n = 66 benralizumab/benralizumab; n = 62 mepolizumab/benralizumab). At week 104, 41 (62.1%) benralizumab/benralizumab patients and 42 (67.7%) mepolizumab/benralizumab patients were in remission. During OLE year 1, 51 (77.3%) benralizumab/benralizumab patients and 42 (67.7%) mepolizumab/benralizumab patients had no relapses. By weeks 49 to 52, 27 (40.9%) benralizumab/benralizumab patients and 16 (25.8%) mepolizumab/benralizumab patients had withdrawn from OGCs, increasing to 29 (43.9%) and 27 (43.5%) at weeks 101 to 104, respectively; the median cumulative OGC dose was 950 mg and 791 mg during OLE year 1, respectively. The median bEOS among benralizumab/benralizumab-treated patients was 20 cells/µL (at weeks 52 and 100), and in mepolizumab/benralizumab-treated patients, it decreased from 70 cells/µL to 20 cells/µL 4 weeks after switching. Adverse events/serious adverse events were reported in 97.0%/22.7% of benralizumab/benralizumab and 100%/35.5% of mepolizumab/benralizumab patients. CONCLUSIONS: In patients with EGPA, treatment for 2 years with anti-IL-5/R therapies is associated with durable rates of remission, discontinuation of OGCs, bEOS depletion, and low relapse rates. Switching from mepolizumab to benralizumab enhances bEOS depletion and OGC sparing.