Optimal therapy and prospects for new medicines in eosinophilic granulomatosis with polyangiitis (Churg-Strauss syndrome).

INTRODUCTION: The prevalence of eosinophilic granulomatosis with polyangiitis (EGPA; previously known as Churg-Strauss syndrome) is lower than that of other antineutrophil cytoplasm antibody (ANCA)-associated vasculitides (AAV's), and only a few randomized controlled trials have been conducted for this rare disease. However, recent international efforts have helped delineate the best treatment approach. AREAS COVERED: At present, EGPA conventional therapy is by default similar to that of other AAVs. Limited, non-severe EGPA can initially be treated with glucocorticoids (GCs) alone. Patients with life-threatening manifestations and/or major organ involvement must receive a combination of GCs and an immunosuppressant, mainly cyclophosphamide. Remission can be achieved in >85% of patients with these first-line treatments, but vasculitis relapses occur in more than one-third of patients, and about 85% cannot stop GC treatment because of GC-dependent asthma and/or ENT manifestations. A few biologic agents, including rituximab or mepolizumab, are now under investigation after interesting preliminary results. Expert commentary: Treatment for EGPA still has several unmet needs. Several biologic agents are now under investigation in randomized controlled trials, but a few others should be considered soon. Their benefit should be demonstrated for devising more EGPA-tailored therapeutic strategies (ideally GC-free).