Efficacy and Safety of Etrasimod in Patients with Moderately to Severely Active Isolated Proctitis: Results From the Phase 3 ELEVATE UC Clinical Programme

Background and Aims Pivotal trials in ulcerative colitis have historically excluded patients with isolated proctitis. Etrasimod is an oral, oncedaily, selective sphingosine 1phosphate1,4,5 receptor modulator for the treatment of moderately to severely active ulcerative colitis. This post hoc analysis assessed efficacy and safety of etrasimod 2 mg once daily in patients with isolated proctitis (centrally read) from the phase 3 ELEVATE UC 52 and ELEVATE UC 12 trials. Methods Patients, including those with isolated proctitis (<10 cm rectal involvement) who met all other inclusion criteria in ELEVATE UC 52 and ELEVATE UC 12, were randomised 2:1 to receive etrasimod or placebo. Primary, secondary and other identified efficacy endpoints and safety were assessed. Results We analysed data from 64 and 723 patients at Week 12 (both trials pooled), and 36 and 397 patients at Week 52 (ELEVATE UC 52 only) with isolated proctitis and more extensive colitis (≥10 cm rectal involvement), respectively. Patients with isolated proctitis receiving etrasimod demonstrated significant improvements versus placebo, including clinical remission rates at Weeks 12 (42.9% vs 13.6%) and 52 (44.4% vs 11.1%), endoscopic improvement (52.4% vs 22.7%) at Week 12 and bowel urgency numerical rating scale score at Week 12 (all p<0.01). Generally similar trends were observed in patients with more extensive colitis. Safety was consistent across subgroups, with no new findings. Conclusions Etrasimod demonstrated significant improvements versus placebo in patients with isolated proctitis, and those with more extensive disease, in most efficacy endpoints at Week 12 and 52.