Abstract
BACKGROUND: Interleukin-23 (IL-23) plays a central role in the pathogenesis of ulcerative colitis (UC) by promoting Th17-mediated intestinal inflammation. While monoclonal antibodies targeting the IL-23p19 subunit have shown promise in clinical trials, the overall efficacy and safety of IL-23 inhibitors in moderate to severe UC remain to be comprehensively quantified. METHODS: We conducted a systematic review and meta-analysis of randomized controlled trials (RCTs) evaluating the efficacy and safety of IL-23p19 inhibitors-including mirikizumab, guselkumab, and risankizumab-in adults with moderate to severe UC. A comprehensive literature search was performed in PubMed, Embase, Web of Science, and Cochrane Library through February 2025. Primary outcomes included clinical remission and clinical response during induction; secondary outcomes included endoscopic remission and adverse events. Risk ratios (RRs) and 95% confidence intervals (CIs) were calculated using a random-effects model. RESULTS: Six RCTs encompassing 3,640 patients were included. IL-23 inhibitors significantly improved clinical remission during induction compared to placebo (RR = 2.45; 95% CI: 2.07-2.90; p < 0.001; I (2) = 0%), as well as clinical response (RR = 2.03; 95% CI: 1.74-2.38; p < 0.001). Endoscopic improvement was also significantly higher in the IL-23 group (RR = 2.49; 95% CI: 2.03-3.06; p < 0.001). Subgroup analyses demonstrated consistent efficacy in biologic-naïve and treatment-refractory populations. The incidence of any adverse events was comparable between IL-23 inhibitors and placebo (RR = 0.91; 95% CI: 0.85-0.98; p = 0.01), with no increase in serious infections. CONCLUSION: IL-23p19 inhibitors are effective and well tolerated in inducing and maintaining remission in patients with moderate to severe UC, including those with prior treatment failure. These findings support their use as a valuable therapeutic option in the evolving management landscape of UC.