RESUMO
BACKGROUND: Omalizumab, an anti-IgE monoclonal antibody, is administered by injection once or twice monthly in offices and clinics. It offers a potential alternative intervention for patients with allergic asthma that is not well controlled because of recalcitrant poor adherence to inhaled corticosteroid therapy. OBJECTIVE: To assess the effect of omalizumab therapy by measuring airway responsiveness to adenosine, a marker of allergic airway inflammation, and resource use. METHODS: Patients (N = 17) aged 6 to 26 years (mean age, 16.4 years) with poorly controlled persistent allergic asthma, less than 50% adherence to inhaled corticosteroid therapy, a forced expiratory volume in 1 second (FEV1) of 60% predicted or higher, and adenosine provocation concentration that caused a decrease in FEV1 of 20% (PC20) of 60 mg/mL or less were randomized to receive 4 months of omalizumab or placebo in a double-blind, crossover trial with a 3- to 4-month washout between treatments. Patients were instructed to continue taking inhaled corticosteroids throughout the study. The PC20 was measured before and after each period. RESULTS: Fifteen patients completed the study. The mean baseline PC20 was 14.1 mg/mL (95% CI, 10.8-18.4 mg/mL). The fold change PC20 was 0.9 (95% CI, 0.5-1.7) during placebo and 3.1 (95% CI, 1.6-6.2) during omalizumab treatment; the estimated ratio was 3.4 (95% CI, 1.2-9.3; P = .02). Six patients required one or more short courses of oral corticosteroids for asthma exacerbations during placebo, but none required this intervention during omalizumab. During the study, the median prescription refills for inhaled corticosteroids was 0.15 (95% CI, 0.00-0.33) canisters per month. CONCLUSION: Omalizumab therapy is an alternative for patients with more severe poorly controlled asthma in whom adherence does not improve with conventional interventions. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT00133042.