Omalizumab in eosinophilic granulomatosis with polyangiitis: friend or foe? A systematic literature review

OBJECTIVES: To systematically evaluate, through a Medline search, the role of omalizumab in eosinophilic granulomatosis with polyangiitis (EGPA). METHODS: A systematic review was performed with the following inclusion criteria: original articles and case reports written in English and reporting an association between omalizumab and EGPA. RESULTS: We found 18 papers on EGPA (14 case reports, 3 retrospective cohort studies, 1 prospective cohort study). Omalizumab showed to be effective as corticosteroid-sparing agent in EGPA patients with severe asthmatic manifestations. On the contrary, conflicting results concerned its use in refractory forms of EGPA. Plausible is the increased risk of EGPA onset among asthmatic patients treated with omalizumab, probably related to steroid reduction, even if it cannot be excluded that omalizumab might be occasionally directly involved in the pathogenesis. CONCLUSIONS: Our findings support the use of omalizumab in selected forms of EGPA, but caution in the tapering of corticosteroids is also recommended. Quality of evidence is limited, as the source of information was mainly case reports. Clinical trials are required in order to evaluate the role of omalizumab in EGPA and to ascertain the risk of asthmatic patients given omalizumab to develop EGPA.