P71 Mepolizumab in adolescents with severe eosinophilic asthma not eligible for omalizumab: one centre’s experience

Introduction Mepolizumab is an anti-interleukin-5 monoclonal antibody shown to reduce asthma exacerbations in adults and adolescents with severe eosinophilic asthma. 1 The Scottish Medicines Commission has accepted it for restricted use in adults as an add-on treatment for severe refractory eosinophilic asthma. Here we describe the use of Mepolizumab as an unlicensed medicine with local approval for use in adolescents with severe asthma. Methods Mepolizumab was offered to adolescents with severe eosinophilic asthma not eligible for Omalizumab because of previous allergic reaction (n=2) or failure to respond (n=1) to Omalizumab, or excessively high IgE (n=4). Eosinophilic asthma was confirmed: blood eosinophil count ≥300 cells/µL or exhaled nitric oxide concentration (FeNO) ≥50 ppb in the previous year. All received high-dose ICS +LABA and had low ACT scores (mean 10.4±2.88). Four were on daily oral steroids. Mean exacerbations requiring oral steroids in the previous year were 4.9±1.68. Prior to commencing and before each monthly injection, pulmonary function (FeNO and forced expiratory volume in 1 s (FEV 1 )), blood eosinophil count, Asthma Control Test (ACT) and Paediatric Asthma Quality of Life Questionnaire (PAQLQ) were measured. Long-term medications not adjusted. Data from clinical case notes. Results Seven adolescents (mean age 13.9±1.9, range 11–17 years; 5 males, 2 females) each received 4 Mepolizumab doses (100 mg sc) at monthly intervals with no serious adverse reactions. Blood eosinophil count decreased in all (mean pre-treatment 0.8±0.62 × 10 9 cells/L,0.1±0.06 × 10 9 cells/L after 4 doses). ACT score improved in 6/7 patients (86%) (mean pre-treatment 10.4±2.88, 13.6±5.16 after 4 doses). PAQLQ improved in 4/7 patients (57%) (mean pre-treatment 3.8±1.30, 4.4±1.41). We did not demonstrate improvement in FEV 1 . Mean FeNO was −15±29 ppb (figure 1). During treatment, none required hospitalisation for asthma attacks, 2/7 patients (29%) were attack free, 5/7 patients (71%) had reduced attack frequency. Conclusion In adolescents with refractory eosinophilic asthma not eligible for Omalizumab, these data suggest that Mepolizumab is well tolerated, reduces risk of exacerbations, may improve asthma control and quality of life but does not improve lung function. Reference Pavord ID, et al. Mepolizumab for severe eosinophilic asthma (DREAM): a multicentre, double-blind, placebo-controlled trial. Lancet2012;380(9842):651–9.