Mepolizumab in children and adolescents with severe eosinophilic asthma not eligible for omalizumab: a single Center experience.

BACKGROUND: Mepolizumab is an anti-interleukin-5 monoclonal antibody shown to reduce asthma exacerbations in adults and adolescents with severe eosinophilic asthma.

AIM: To assess the impact of mepolizumab on children and adolescents over 12 months by examining steroid usage, asthma-related hospitalizations, Asthma Control Test (ACT) scores, fractional exhaled nitric oxide concentration (FeNO), forced expiratory volume in 1 s (FEV1 ), mid expiratory flow (FEF25-75% ), and blood eosinophil count.

METHODS: Retrospective analysis performed between October 2015 and December 2022. Data was reviewed 12 months before and after commencing mepolizumab. Mepolizumab was offered if the patient had severe eosinophilic asthma and were unresponsive to or ineligible for omalizumab.

RESULTS: Sixteen participants (age 7-17, 8 males, 8 females) received subcutaneous mepolizumab monthly with no serious adverse reactions. Incidence of hospital admissions fell significantly (IRR 0.33, p  = 0.007). Among the 11 patients receiving daily oral corticosteroids, 3 were weaned off daily oral steroids and 3 patients' daily dose was significantly reduced (mean Δ-0.095 ± 0.071 mg/kg, p  = 0.0012). Eosinophil count was decreased (mean Δ-0.85 x 109 /L, p  < 0.001). There was no significant change in mean overall steroid burden per patient (mean Δ-1445.63 ± 1603.18 mg, p  = 0.10), ACT scores (mean Δ2.88 ± 6.71, p  = 0.17), FEV1 z-scores (mean Δ-0.99 ± 1.88, p  = 0.053), FEF25-75% z-scores (mean Δ-0.65 ± 1.61, p  = 0.13), FeNO (mean Δ-20.09 ± 80.86, p  = 0.34), or number of courses of oral steroids given for asthma attacks (IRR 0.71, p  = 0.09).

CONCLUSION: Among children and adolescents with severe eosinophilic asthma ineligible for or not responsive to omalizumab, mepolizumab therapy exhibited significant reduction in rate of asthma-related hospitalizations and significant decrease in daily steroid dosage.