To evaluate the efficacy and safety of omalizumab on the treatment of chronic spontaneous urticaria (CSU) by systemic review and meta-analysis.

Electronic databases, such as PubMed, Clinicaltrials.gov, the Cochrane Database of Systematic Reviews, and the Cochrane Central Register of Controlled Trials, were searched to collect randomized controlled trials (RCTs) about the efficacy and safety of omalizumab in the treatment of CSU. Two reviewers independently screened RCTs according to the inclusion and exclusion criteria, extracted data, and assessed the quality of the included RCTs. And then, a meta-analysis was carried out by using RevMan 5.3 software for comparisons of the efficacy and safety of the 75-, 150-, 300-, 600-mg omalizumab groups versus the placebo group after 1-month treatment, as well as the total omalizumab group versus the placebo group.

A total of 7 RCTs involving 1 365 patients were included in this meta-analysis. The results showed that the total omalizumab group and different omalizumab subgroups were superior in improving the urticaria activity score of 7 days (UAS7) and wheal number score of 7 days to the placebo group (all P < 0.05) . For the improvement in the itch severity score (ISS) of 7 days and complete response rate for main symptoms (UAS7= 0) , the total omalizumab group, 75-, 150- and 300-mg omalizumab groups were superior to the placebo group (all P < 0.05) , but there were no significant differences between the 600-mg omalizumab group and the placebo group (P= 0.07) . The dermatology life quality index (DLQI) was better in the total omalizumab group, 150- and 300-mg omalizumab groups than in the placebo group (all P < 0.05) , but no significant difference was observed between the 75-mg omalizumab group and the placebo group (P= 0.50) . There were no significant differences in the incidence of common adverse events or serious adverse events between the total omalizumab group as well as the 75-, 150- and 300-mg omalizumab subgroups and the placebo subgroup (all P>0.05) .

Omalizumab can improve clinical symptoms and life quality of patients with CSU, and is effective in improving the UAS, ISS, wheal number score, DLQI and complete response rate for main symptoms (UAS= 0) with high safety. Subcutaneous injection of omalizumab at a dose of 150 or 300 mg/month shows the best efficacy in improving the clinical symptoms and life quality of patients with CSU.

Urticaria; Antibodies, monoclonal, humanized; Meta-analysis; Randomized controlled trial; Omalizumab