Efficacy and Safety of Ontamalimab in Treating Inflammatory Bowel Disease: a Systematic Review and Meta-Analysis of Randomized Controlled Trials

Ontamalimab is an anti-MAdCAM-1 monoclonal antibody. It directly restricts the binding of α4β7 + lymphocytes and does not affect the homing of lymphocytes in the central nervous system. Thus, it diminishes adverse effects while blocking their migration into the gut. Several clinical trials have validated the efficacy and safety of ontamalimab for Crohn's disease and ulcerative colitis. However, to date, there is no meta-analysis on the topic. Hence, we are conducting this meta-analysis. Using R version R.3.3, we reported outcomes as risk ratios (RRs) or mean difference (MD) and confidence intervals (CIs). A P-value ≤ 0.05 is considered as statistically significant.

The meta-analysis included a total of three studies with 1384 patients. In patients with ulcerative colitis, compared to placebo, ontamalimab had significantly improved clinical remission (RR = 2.17, 95% CI [1.42 to 3.32], P < 0.01), clinical response (RR = 1.79, 95% CI [1.35 to 2.38], P < 0.01), endoscopic response (RR = 2.27, 95% CI [1.55 to 3.31], P < 0.01) and mucosal healing (RR = 2.39, 95% CI [1.63 to 3.50], P < 0.01). No significant differences favoring ontamalimab or the placebo were found regarding safety outcomes. In patients with Crohn's disease, ontamalimab showed superiority over placebo in endoscopic response (RR = 2.00, 95% CI [1.08 to 3.70], P = 0.03). However, ontamalimab was associated with a higher incidence of serious adverse events, and study discontinuations were due to adverse events.

Ontamalimab has shown promising results, particularly in patients with moderate to severe ulcerative colitis, as evidenced by better clinical response and remission. However, questions remain about its long-term effectiveness and safety; hence, extended follow-up and more extensive studies are necessary.