Etrolizumab as an Induction and Maintenance Therapy for Ulcerative Colitis: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Introduction: Etrolizumab is a gut-targeted, anti-integrin, biological therapeutic that selectively targets α4β7 and αEβ7 integrins to control immune cell trafficking and their inflammatory effects on the gut lining. We aim to assess the efficacy of etrolizumab as an induction and maintenance therapy for ulcerative colitis (UC). Methods: We conducted a systematic review and meta-analysis synthesizing randomized controlled trials (RCTs), which were retrieved by systematically searching: PubMed, Web of Science, SCOPUS, and Cochrane through April 18th, 2023. We used the fixed-effect model to pool dichotomous data using risk ratio (RR) with a 95% confidence interval (CI). Results: We included five RCTs with a total of 1,208 patients. Etrolizumab was significantly associated with increased clinical response (RR: 1.30 with 95% CI [1.09, 1.54], P= 0.003) and clinical remission rates during the induction phase (RR: 2.66 with 95% CI [1.69, 4.19], P= 0.0001), but not during the maintenance phase (RR: 1.31 with 95% CI [0.93, 1.85], P= 0.12). Etrolizumab was associated with increased endoscopic improvement rate during both induction (RR: 1.48 with 95% CI [1.17, 1.87], P= 0.001) and maintenance phases (RR: 1.69 with 95% CI [1.24, 2.30], P= 0.0008). Also, etrolizumab was associated with increased endoscopic remission rate during both induction (RR: 2.23 with 95% CI [1.43, 3.49], P= 0.0004) and maintenance phases (RR: 1.92 with 95% CI [1.29, 2.85], P= 0.001). Etrolizumab was associated with increased histologic remission rate during both induction (RR: 1.57 with 95% CI [1.17, 2.10], P= 0.002) and maintenance phases (RR: 2.04 with 95% CI [1.40, 2.98], P= 0.0002). Finally, there was no difference between etrolizumab and placebo regarding corticosteroid-free remission rate (RR: 1.94 with 95% CI [0.95, 3.94], P= 0.07). Conclusion: Etrolizumab was effective as an induction and maintenance therapy for moderate or severe UC based on clinical, endoscopic, and histologic remission. Further research is therefore warranted to investigate etrolizumab’s position in UC management guidelines by head-to-head comparisons with other validated drugs, such as vedolizumab (Figure 1).Figure 1.: Results of Etrolizumab vs placebo.