Omalizumab in patients with chronic spontaneous urticaria: a systematic review and GRADE assessment

Chronic spontaneous urticaria (CSU) is characterized by the occurrence of hives, angio-oedema or both for a period of at least 6 weeks. Many patients remain symptomatic despite treatment with H1 antihistamines, even at higher doses. This systematic review assessed the quality of the evidence for the effects of omalizumab as treatment in patients with CSU. We searched PubMed, the Cochrane Database of Systematic Reviews and the Cochrane Central Register of Controlled Trials up to 7 August 2014. Three review authors independently carried out study selection, risk of bias assessment and data extraction. Two review authors analysed the data. Five randomized controlled trials (RCTs), which included 1116 participants, were evaluated. All the RCTs were judged as having a low risk of bias. There was a statistically significant improvement in measures of disease activity and quality of life following treatment with omalizumab when compared with placebo [mean difference (MD) -11·58, 95% confidence interval (CI) -13·39 to -9·77 and MD -13·12, 95% CI -16·30 to -9·95, respectively]. Complete response and partial response were more frequent after treatment with omalizumab [risk ratio (RR) 6·44, 95% CI 3·95-10·49 and RR 4·08, 95% CI 2·98-5·60, respectively]. There was no difference in the proportion of participants reporting adverse events between the omalizumab and placebo treatment groups (RR 1·05, 95% CI 0·96-1·16). There was high-quality evidence to support the effectiveness and safety of omalizumab 300 mg per month for the treatment of CSU for up to 6 months.