“Real-life” Effectiveness Studies of Omalizumab in Adult Patients with Severe Allergic Asthma: Meta-analysis

After the approval of omalizumab for severe allergic asthma, a total of 25 studies have evaluated the effectiveness of omalizumab under "real-life" conditions of heterogeneity in patients, clinicians, sites, and treatment patterns.We conducted a meta-analysis to evaluate the effectiveness of omalizumab focusing on treatment response, lung function, quality of life, symptom control, corticosteroid use, and exacerbations and hospitalizations at 4-6, 12, and 24 months.We searched PubMed and Embase for real-life studies on omalizumab in severe asthma published up to 2015. Three effect size types were extracted: single-point proportions; mean ± SD of change relative to baseline as raw numbers and standardized as Cohen's d; and changes in proportions of patients as relative risk. Random-effects meta-analyses were performed to account for within- and between-study heterogeneity. Studies were weighted by the DerSimonian and Laird method.Per data available at the 3 time points, omalizumab therapy was consistently associated with large proportions of patients classified as "good" to "excellent" treatment responders (Global Evaluation of Treatment Effectiveness scale); improvements in forced expiratory volume in 1 second, quality of life (Asthma-related Quality-of-Life Questionnaire scale), and asthma symptom control (Asthma Control Test scale); reductions in oral and inhaled corticosteroid (ICS) use; and reductions in exacerbations and hospitalizations.This meta-analysis of noncontrolled studies documents the real-life pharmacotherapeutic effectiveness of omalizumab, as add-on treatment to ICS ± long-acting β2-agonists agents, in improving outcomes in patients with severe allergic asthma under conditions of heterogeneity in patients, clinicians, sites, and treatment patterns. The results mirror, complement, and extend the efficacy data from randomized controlled trials.