Vedolizumab is a gut-selective monoclonal anti-α₄β₇ integrin antibody treatment for Crohn's disease (CD). A multicenter, randomized, double-blind, placebo-controlled, phase 3 trial (NCT03234907) assessed vedolizumab efficacy and safety in Chinese patients with moderate-to-severe CD and inadequate/loss of response/intolerance to previous conventional or anti-tumor necrosis factor-α therapy.

Eligible patients aged ≥18 to ≤80 years with moderate-to-severe CD (CD Activity Index [CDAI] total score 220–400) were randomized 2:1 to vedolizumab 300 mg intravenous infusion or placebo at Weeks 0, 2, 6 of induction, and every 4/8 weeks during Week 14-58 maintenance treatment. Primary and secondary endpoints at Week 10 were enhanced clinical response (≥100-point decrease from baseline CDAI score), and clinical remission (CDAI score ≤150), respectively. Additional Week 10 and/or Week 60 assessments included endoscopic and biomarker (C-reactive protein and fecal calprotectin) measurements.

The study was conducted at 30 centers (August 2017 through August 2020). Enrolled patients (n = 215) were randomized to vedolizumab (n =144) or placebo (n = 71). By Week 10, 19.4% vedolizumab-treated versus 24.3% placebo-treated patients achieved an enhanced clinical response. The Cui-Hung-Wang-adjusted p-value for the primary endpoint was 0.347. After maintenance treatment at Week 60, rates of enhanced clinical response, clinical remission, endoscopic response, mucosal healing, and biomarker improvements appeared greater for vedolizumab-treated than placebo-treated patients.

There were no new safety findings for vedolizumab treatment of Chinese patients with CD. Although the primary endpoint was not met, vedolizumab-treated patients showed improvements in other disease activity measures at Weeks 10 and 60.