Mepolizumab in patients with eosinophilic granulomatosis with polyangiitis in remission: What is the right dose?

To the Editor: After the pivotal randomized controlled trial in which patients with eosinophilic granulomatosis with polyangiitis (EGPA) received 300 mg mepolizumab every 4 weeks, the US Food and Drug Administration expanded the approved use of mepolizumab to treat patients with EGPA. Conversely, in Europe, mepolizumab is not yet licensed for EGPA patients with severe asthma, and clinicians can use only the 100 mg/4 wk regimen that has already been approved in these patients. [...]we read with great interest the Clinical Communication by Caminati et al1 on the follow-up of 16 severely asthmatic patients with EGPA in remission, in whom mepolizumab 100 mg was administered monthly. [...]these data confirm that mepolizumab 100 mg/4 wk may be effective in treating severe asthma in many EGPA patients with vasculitis in remission, but that a higher dose may be needed for optimal outcomes in some patients.