The study is about testing treatments for Crohn's Disease, a condition that causes inflammation in the digestive tract, usually affecting the intestines and leading to symptoms like stomach pain and diarrhea. Researchers want to see how well a drug called vedolizumab works when used with either adalimumab or ustekinumab in adults with moderate to severe Crohn's Disease. The study has two parts. In Part A, participants get treated with vedolizumab and either adalimumab or ustekinumab. In Part B, only those who improve in Part A will continue with just vedolizumab. Each participant will be monitored for at least 26 weeks after their last treatment dose. The study lasts about 76 weeks.

• Approximately 150 participants needed, taking place in the US and Canada.
• Participation involves multiple visits over about 1.5 years.
• Participants must not have other conditions like ulcerative colitis or certain infections.