IL5 and asthma: This study determined that the classification of patients with severe asthma into four subgroups according to FeNO and B-EOS contributed to show differences in frequency of future annual AEs, the heterogeneous prevalence of subclasses stratified by Sp-EOS and Sp-NEU rates, and particular patterns of clinical response to two classes of biologics, namely anti-IgE and anti-IL-5.