Introduction: We describe the use of Mepolizumab in children/adolescents with severe eosinophilic asthma at the Royal Hospital for Children, Glasgow, UK.

Methods: Mepolizumab offered to children/adolescents with severe eosinophilic asthma not eligible for Omalizumab. Eosinophilic asthma confirmed (blood eosinophil count >300 cells/?L or exhaled nitric oxide concentration (FeNO) ?50 ppb) in previous year. Data collected from case-notes, evaluated from the 12 months before and 12 months after Mepolizumab. Forced expiratory volume in 1s (FEV1), FeNO, blood eosinophil count and Asthma Control Test (ACT) scores recorded. Pre and post-Mepolizumab incidence rate ratios (IRR) calculated for courses of oral steroids received and hospital admissions, and two-side, two tailed t-tests used to compare FeNO levels, FEV1, eosinophils counts, ACT scores.

Results: 16 children/adolescents (median age 13, interquartile range 2.25; 8M:8F) received Mepolizumab monthly, no serious adverse reactions. All received high-dose inhaled corticosteroids + long-acting beta agonists with low ACT scores (mean 11.69±4.83). Eleven on daily oral steroids. Three weaned off oral steroids and 3 patients? daily oral steroid dose reduced. Eosinophil count fell by mean of 0.85 x 109/L (p<0.001). No change in ACT, FEV1 z-scores, FeNO, or number of courses of oral steroids for attacks (IRR 0.71, p=0.09). Incidence of hospital admissions fell 1.33 to 0.44 per patient year in 12 months following Mepolizumab (IRR 0.33,p=0.007). 

Conclusion: Mepolizumab appeared to be associated with a reduction in the hospitalisation rate for asthma and a reduction in daily steroid burden.