Risankizumab versus Ustekinumab for Moderate-to-Severe Crohn's Disease

BACKGROUND The efficacy and safety of risankizumab as compared with ustekinumab in patients with Crohn's disease are unknown. METHODS In this phase 3b, multicenter, open-label, randomized, controlled trial with blinded assessment of end points, patients with moderate-to-severe Crohn's disease who had had an inadequate response to anti-tumor necrosis factor (TNF) therapy or unacceptable side effects with such therapy were randomly assigned to receive risankizumab or ustekinumab at standard doses for 48 weeks. The two primary end points, which were tested sequentially, were clinical remission at week 24 (defined as a Crohn's Disease Activity Index score of <150 [range, 0 to 600, with higher scores indicating more severe disease activity]), which was analyzed in the first 50% of patients to complete the week 24 visit, with a noninferiority margin of 10 percentage points; and endoscopic remission at week 48 (defined as a score of <= 4, a decrease of >= 2 points from baseline, and no subscore >1 in any individual variable on the Simple Endoscopic Score for Crohn's Disease [range, 0 to 56, with higher scores indicating more severe disease]), which was analyzed for superiority in 100% of the patients. Safety was assessed in all patients who received at least one dose of risankizumab or ustekinumab. RESULTS In the full intention-to-treat population for the efficacy analysis, 230 of 255 patients (90.2%) who received risankizumab and 193 of 265 patients (72.8%) who received ustekinumab completed all the assigned treatments. Both primary end points were met; risankizumab was noninferior to ustekinumab with respect to clinical remission at week 24 (58.6% vs. 39.5%; adjusted difference, 18.4 percentage points; 95% confidence interval [CI], 6.6 to 30.3) and superior to ustekinumab with respect to endoscopic remission at week 48 (31.8% vs. 16.2%; adjusted difference, 15.6 percentage points; 95% CI, 8.4 to 22.9; P<0.001). The incidence of adverse events appeared to be similar in the two groups. CONCLUSIONS In this head-to-head clinical trial of risankizumab and ustekinumab involving patients with moderate-to-severe Crohn's disease who had had unacceptable side effects with anti-TNF therapy or an inadequate response to such therapy, risankizumab was noninferior to ustekinumab with respect to clinical remission at week 24 and superior with respect to endoscopic remission at week 48.