The comparative safety of biological treatment in patients with axial spondylarthritis: a meta-analysis of randomized controlled trials with placebo.

OBJECTIVE To evaluate the comparative safety of biological treatment in patients with axial spondyloarthritis (axSpA) enrolled in randomized controlled trials (RCTs) with placebo. MATERIALS AND METHODS Studies were systematically retrieved from the Web of Science, PubMed, Cochrane Library, and Embase databases. The last search was performed on 8 June 2020. The primary outcome measures were adverse events (AEs), serious AEs, infection, serious infection, and discontinuation due to AEs. This study was performed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. RESULTS A total of twenty-two trials, including 2599 participants treated with biologics and 1547 participants treated with placebo, met the inclusion criteria. There was a significantly higher risk of infection, AEs, and discontinuation due to AEs in the biologics groups compared to the placebo groups [risk ratio (RR) = 1.38, 95% confidence interval (95% CI) = 1.22-1.57, p < 0.01; RR = 1.17, 95% CI = 1.10-1.25, p < 0.01; and RR = 1.72, 95% CI = 1.03-2.87, p = 0.04, respectively], and low heterogeneity was found among the included studies (I2 = 0%, p = 0. 49; I2 = 29%, p = 0.10; and I2 = 0%, p = 0.79, respectively). The risk of serious infection and serious AEs was not significantly different between axSpA patients treated with biologics and those treated with placebo [RR = 1.62, 95% CI = 0.54-4.90, p = 0.39 and RR = 1.17, 95% CI = 0.79-1.73, p = 0.44]. Low heterogeneity was found among the included studies (I2 = 0%, p = 0.94 and I2 = 0%, p = 0.69). The subgroup analyses based on tumour necrosis factor inhibitors and interleukin antagonists did not yield significant differences. CONCLUSIONS This meta-analysis is the first comprehensive assessment of the safety of various biological agents in axSpA patients. The use of biological agents in axSpA is generally safe and tolerable.