The purpose of this study is to compare the effectiveness and safety of Risankizumab versus Ustekinumab and compare how well these drugs work in patients with moderate to severe Crohn's disease. Participants who are aged 18 to 80 years with moderately to severely active Crohn's disease and have intolerance or inadequate response to one or more anti-TNF (tumor necrosis factor) therapies may be eligible. Anti-TNF drugs include Etanercept (Enbrel) and Infliximab (Remicade).
Participants will either take Risankizumab or Ustekinumab for 48 weeks and see if their Crohn's disease get improved. The chance of being randomized (like drawing names out of a hat) into Risankizumab group and receiving Risankizumab is 50%. The chance of being randomized into Ustekinumab group and receiving Ustekinumab is 50%.
Participants in the Risankizumab group will receive three IV infusions at week 0, week 4, and week 8 respectively, and then subcutaneous (under the skin) injection every 8 weeks. Participants in the Ustekinumab group will receive 1 IV infusion at week 0, and then subcutaneous injection every 8 weeks.
Part 2 will continue up to an additional 220 weeks of study participation (which includes the 4-week period between Week 48 and Week 52 [the first dosing visit in Part 2] and 216 weeks of study participation), or until the study is discontinued, whichever is earlier. In addition to the 220 weeks of study participation, subjects will be contacted by the study doctor 140 days after last dose to assess adverse events. This is an open label access to study drug.