We used the ELEN index ( an algorithm to predict elevated sputum eosinophils ) or baseline fraction of exhaled nitric oxide to stratify patients by eosinophilic status , and with an interactive web-voice response system randomly assigned eosinophilic individuals in a 1:1:1:1 ratio to receive placebo , 2 mg benralizumab , 20 mg benralizumab , or 100 mg benralizumab , and non-eosinophilic individuals in a 1:1 ratio to receive placebo or 100 mg benralizumab .