Efficacy and safety of omalizumab in patients with refractory allergic asthma: a meta-analysis

Abstract

Objective: To evaluate the efficacy and safety of omalizumab in patients with refractory allergic asthma using meta-analysis. Methods: We searched databases including PubMed, Web of Science, Embase and the website of ClinicalTrials. gov registry for randomized controlled trials (RCTs), using the search terms: ("anti-IgE" OR "anti-immunoglobulin E" OR "anti-IgE antibody" OR "omalizumab" OR "rhuMAb-E25" OR "Xolair") AND ("allergic asthma"). The time was up to September 19th 2020. Review Manager 5.4 software and Stata16 software were used to calculate pooled RR or WMD, perform heterogeneity test, and assess publication bias. Results: Fifteen RCTs with 6 316 patients in total (omalizumab, n=3 469; placebo, n=2 847) met our selection criteria. Comparing with placebo, omalizumab reduced the risk of asthma exacerbations during both stable-inhaled corticosteroid (ICS) phase (RR=0.69, 95%CI: 0.63-0.75, P<0.001; I2=39.0%, P=0.090) and ICS-reduction phase (RR=0.55, 95%CI: 0.46-0.66, P<0.001; I2=41.0%, P=0.180), reduced emergency visits (RR=0.53, 95%CI: 0.38-0.73, P<0.001; I2=0, P=0.420), made a significant reduction in dosage of ICS (RR=1.35, 95%CI: 1.25-1.45, P<0.001; I2=22.0%, P=0.280) and even withdrew from ICS completely (RR=1.80, 95%CI: 1.41-2.31, P<0.001; I2=57.0%, P=0.070). Omalizumab significantly improved asthma-related quality of life (RR=1.81, 95%CI: 1.51-2.17). The use of rescue bronchodilators was significantly reduced in the omalizumab group (RR=0.78, 95%CI: 0.67-0.92) but there was no significant difference in the dosage of rescue bronchodilators (puff per day) (WMD=-0.32, 95%CI: -0.77-0.13). Patients taking omalizumab did not increase the frequency of any adverse events (RR=1.01, 95%CI: 0.98-1.03) and serious adverse events (RR=0.89, 95%CI: 0.74-1.06). Conclusions: Omalizumab is an ideal adjunctive treatment for refractory allergic asthma with good efficacy and safety. Further randomized controlled trials are needed to determine the appropriate duration of treatment.