IL5 and asthma: Specific biological medications have been developed primarily for T2 severe asthma phenotype (eg, early-onset allergic and late-onset eosinophilic asthma): anti-interleukin 5 (IL5) (mepolizumab, reslizumab), anti-IL5 receptor (anti-IL5R) (benralizumab), anti-IL4 (dupilumab), and anti-IgE therapy (omalizumab) (1).