Induction of endoscopic response: a network meta-analysis of induction studies comparing ontamalimab with other treatments for moderate-to-severe ulcerative colitis

Abstract Background Clinicians, patients, payers and policymakers require relevant, high-quality evidence to support decision-making regarding the treatment of ulcerative colitis (UC). In the absence of head-to-head trials, network meta-analysis (NMA) can be used to compare treatments. We conducted an NMA to compare the efficacy of ontamalimab (anti-MAdCAM-1) using its phase 2 data, with all biologics and novel small molecules for which induction study data on endoscopic response were available. Methods A systematic literature review was conducted in November 2017 to identify published randomised controlled trials of induction treatment in patients with moderate-to-severe UC. An NMA of the identified studies was performed using random-effects models and methods based on NICE guidance. Odds ratios and 95% credible intervals were calculated to describe the relative differences between treatments and placebo in terms of efficacy in inducing endoscopic response. Results were examined by anti-TNF status (naïve vs. experienced). Results In total, 15 phase 2 and phase 3 induction studies of the following agents were available and included: adalimumab (160/80mg), etrolizumab (100mg and 300mg), golimumab (200/100mg), infliximab (5mg), ontamalimab (22.5mg and 75mg), ozanimod (0.5mg and 1mg), tofacitinib (10mg) and vedolizumab (300mg). The definition of endoscopic response (improvement) in all trials was a Mayo endoscopic subscore of ≤1. Homogeneity between studies was good, enabling pooling of results. Figure 1 shows odds ratios for induction of endoscopic response with treatments relative to placebo in anti-TNF-naïve and -experienced patients. All treatments performed significantly better than placebo in anti-TNF-naïve patients, with the exception of both doses of etrolizumab and ozanimod 0.5 mg. Significant differences between some treatments were observed; specifically, ontamalimab 22.5 mg (p = 0.0277), tofacitinib 10 mg (p = 0.0233) and infliximab 5 mg (p = 0.0047) were all superior to adalimumab 160/80 mg. Conclusion This study suggests that ontamalimab, infliximab and tofacitinib could be superior to adalimumab in inducing endoscopic healing, although it was conducted before any large-scale head-to-head trials of these drugs. Furthermore, large variances due to differing endpoint timings, the combination of phase 2 and phase 3 data, and lack of control for placebo response rates preclude firm conclusions being drawn.