Week 2 Symptomatic Response with Vedolizumab as a Predictive Factor in Japanese Anti-TNFα-Naive Patients with Ulcerative Colitis: A post hoc Analysis of a Randomized, Placebo-Controlled Phase 3 Trial

<b><i>Background and Aim:</i></b> To evaluate the onset of symptomatic response with vedolizumab in patients with moderate-to-severe ulcerative colitis in Japan. <b><i>Methods:</i></b> Patients were randomized to receive vedolizumab 300 mg or placebo at Weeks 0, 2, and 6. Mayo subscores were analyzed in patients with baseline stool frequency (SF) ≥1 and rectal bleeding (RB) ≥1. In patients with baseline SF ≥2 and RB ≥1, the proportion who achieved SF ≤1 and RB = 0 was determined. <b><i>Results:</i></b> Patients were randomized to vedolizumab (<i>n</i> = 164) or placebo (<i>n</i> = 82). Decrease from baseline in mean SF subscore was greater with vedolizumab versus placebo from Week 2 (−6.6%; 95% confidence interval [CI], −16.2, 3.0), with a greater difference in anti-tumor necrosis factor (TNF)α-naive patients (vedolizumab vs. placebo, −13.2%; 95% CI, −29.7, 3.3). Mean percentage decrease from baseline RB subscore was numerically greater with vedolizumab versus placebo from Week 6 in anti-TNFα-naive patients (−10.7%; 95% CI, −33.0, 11.5). More patients in the anti-TNFα-naive subgroup achieved SF ≤1 and RB = 0 with vedolizumab versus placebo at Week 2 (14.8%; 95% CI, 2.5, 27.0) and Week 6 (20.3%; 95% CI, 4.4, 36.2). Patients with SF ≤1 and RB = 0 at Week 2 had higher clinical response, clinical remission, and mucosal healing rates at Week 10 than those without. <b><i>Conclusions:</i></b> Our results indicate that vedolizumab induces a rapid symptomatic response, particularly in anti-TNFα-naive patients, and suggest that early symptomatic improvement predicts treatment response at Week 10 (NCT02039505).