IL5 and Increased total eosinophil count: However, after targeting patients with severe asthma and refractory airway eosinophilia and choosing the correct primary outcome (i.e. asthma exacerbations), anti-IL-5 treatment has been shown to significantly reduce exacerbations and oral corticosteroid doses required to control symptoms, and it has been well tolerated during the study period of over a year (58).