Eosinophilic Granulomatosis with Polyangiitis (EGPA) is a rare multisystemic disease classified both amongst hypereosinophilic disorders and ANCA-associated vasculitis. Vessel inflammation and eosinophilic proliferation are the hallmarks of the disease and main effectors of organ damage. Two distinct disease phenotypes have classically been described according to ANCA-status: the ANCA-negative subset with eosinophil-driven manifestation and the ANCA-positive one with vasculitic manifestations. An analogous dichotomization has also been backed by histological findings and a distinct genetic background. EGPA is typically consider a Th2-mediated disease and blood and tissue eosinophilia represent the cornerstone of diagnosis. Besides, ANCA are known for inducing endothelial injury and vascular inflammation by activating the circulating neutrophils. Thus, the pathogenesis of EGPA seems to be mediated by two coexisting mechanisms. However, the verbatim application of this strict dualism cannot always be translated into routine clinical practice. In the present review we describe the current knowledge on the eosinophilic and ANCA-mediated aspects of EGPA pathogenesis. Finally, we review the rationale of the currently proposed EGPA dichotomy and future research perspectives.

Objective Mepolizumab proved to be an efficacious treatment for eosinophilic granulomatosis with polyangiitis (EGPA) at a dose of 300 mg every 4 weeks in the randomized, controlled MIRRA trial. In a few recently reported studies, successful real‐life experiences with the approved dose for treating severe eosinophilic asthma (100 mg every 4 weeks) were observed. We undertook this study to assess the effectiveness and safety of mepolizumab 100 mg every 4 weeks and 300 mg every 4 weeks in a large European EGPA cohort. Methods We included all patients with EGPA treated with mepolizumab at the recruiting centers in 2015–2020. Treatment response was evaluated from 3 months to 24 months after initiation of mepolizumab. Complete response to treatment was defined as no disease activity (Birmingham Vasculitis Activity Score [BVAS] = 0) and a prednisolone or prednisone dose (or equivalent) of ≤4 mg/day. Respiratory outcomes included asthma and ear, nose, and throat (ENT) exacerbations. Results Two hundred three patients, of whom 191 received a stable dose of mepolizumab (158 received 100 mg every 4 weeks and 33 received 300 mg every 4 weeks) were included. Twenty‐five patients (12.3%) had a complete response to treatment at 3 months. Complete response rates increased to 30.4% and 35.7% at 12 months and 24 months, respectively, and rates were comparable between mepolizumab 100 mg every 4 weeks and 300 mg every 4 weeks. Mepolizumab led to a significant reduction in BVAS score, prednisone dose, and eosinophil counts from 3 months to 24 months, with no significant differences observed between 100 mg every 4 weeks and 300 mg every 4 weeks. Eighty‐two patients (40.4%) experienced asthma exacerbations (57 of 158 [36%] who received 100 mg every 4 weeks; 17 of 33 [52%] who received 300 mg every 4 weeks), and 31 patients (15.3%) experienced ENT exacerbations. Forty‐four patients (21.7%) experienced adverse events (AEs), most of which were nonserious AEs (38 of 44). Conclusion Mepolizumab at both 100 mg every 4 weeks and 300 mg every 4 weeks is effective for the treatment of EGPA. The 2 doses should be compared in the setting of a controlled trial.

No abstract

No abstract

Purpose of reviewThe link between severe asthma and eosinophilic granulomatosis with polyangiitis (EGPA) in terms of pathophysiological background, clinical manifestations and disease evolution has leaded to investigate the relevance of anti T2 monoclonal antibodies licensed for severe asthma patients as a treatment option for EGPA. The present review aimed to provide un update on EGPA pathophysiology and to critically summarize the most robust evidence coming from trials and real-life setting on the use of anti T2 biologics in EGPA patients.Recent findingsMepolizumab, an anti-interleukin-5 monoclonal antibody, is the only biologic drug targeting eosinophilic inflammation currently approved for EGPA treatment at the dose of 300 mg/4 weeks. Its use is restricted by the American College of Rheumatology guidelines to specific diseases phases and severity grades. However the most appropriate mepolizumab positioning and dose is still under investigation in the real life practice, which is providing an increasing amount of evidence confirming its efficacy, alone or in combination with other options in different disease stages. The relevance of other monoclonal antibodies interfering with T2 inflammation, including omalizumab and benralizumab, is under investigation but the evidence is still scarceSummaryTaking into account the suboptimal medium-long term safety profile of conventional EGPA treatments, the opportunity of selectively targeting eosinophilic inflammation certainly represents a revolutionary approach. However, further real-word evidence is required to effectively position the new treatments in the light of the disease complexity, including different immunological drivers, and individual variability.