In patients with a baseline blood eosinophil cutoff of at least 300 cells per L , exacerbation rates in the benralizumab 20 mg group ( n = 70 ) and 100 mg group ( n = 97 ) were lower than in the placebo group ( n = 83 ; 030 vs 068 , reduction 57 % , 80 % CI 33 to 72 , p = 0015 for 20 mg dose ; 038 vs 068 , difference 43 % , 80 % CI 18 to 60 , p = 0049 for 100 mg dose ) .