Mepolizumab reduced the number of blood and sputum eosinophils and allowed prednisone sparing in patients who had asthma with sputum eosinophilia despite prednisone treatment. (ClinicalTrials.gov number, NCT00292877.)

Our findings suggest that ILC2s can promote the persistence of airway eosinophilia in patients with severe asthma through uncontrolled localized production of the type 2 cytokines IL-5 and IL-13, despite high-dose oral corticosteroid therapy.

Weight-adjusted IV reslizumab was superior to fixed-dose SC mepolizumab in attenuating airway eosinophilia in prednisone-dependent patients with asthma, with associated improvement in asthma control. Clinical trial registered with www.clinicaltrials.gov (NCT 02559791).

This study identifies an autoimmune endotype of severe asthma that can be identified by the presence of sputum autoantibodies against EPX and autologous cellular components.