Real-world effectiveness of omalizumab in severe allergic asthma: a meta-analysis of observational studies.

Abstract Background Assessment of clinical outcomes in the real-world corroborates findings from randomized controlled trials (RCTs). Objective This meta-analysis evaluated real-world data of omalizumab on treatment response, lung function, exacerbations, oral corticosteroid (OCS) use, patient-reported outcomes (PROs), healthcare resource utilization (HCRU), and school/work absenteeism at 4, 6 and 12 months post-treatment. Methods Observational studies in severe allergic asthma patients (≥6 years) treated with omalizumab for ≥16 weeks, published from January 2005 to October 2018 were retrieved from PubMed, Embase and Cochrane. A random effects model was used to assess heterogeneity. Results In total, 86 publications were included. Global evaluation of treatment effectiveness (GETE) was good/excellent in 77% patients at 16 weeks (risk difference: 0.77; 95% CI: 0.70–0.84; I2=96%) and in 82% patients at 12 months (0.82, 0.73–0.91; 97%). The mean improvement in FEV1 was 160, 220 and 250 mL at 16 weeks, 6 months and 12 months, respectively. There was a decrease in ACQ score at 16 weeks (−1.14), 6 months (−1.56) and 12 months (−1.13) following omalizumab therapy. Omalizumab significantly reduced annualized rate of severe exacerbations (risk ratio [RR]: 0.41, 95% CI: 0.30–0.56; I2=96%), proportion of patients receiving OCS (RR: 0.59, 95% CI: 0.47–0.75; I2=96%), and number of unscheduled physician visits (mean difference: −2.34, 95% CI: −3.54–−1.13; I2=98%) at 12 months versus baseline. Conclusion The consistent improvements in GETE, lung function and PROs, and reductions in asthma exacerbations, OCS use and HCRU with add-on omalizumab in real-life confirms and complements the efficacy data of RCTs.