A Study of Vedolizumab in Adult Participants With Moderate to Severe Crohn's Disease

Inclusion criteria:

1. The participant has a diagnosis of CD established at least 3 months before screeningby clinical and endoscopic evidence corroborated by a histopathology report. Casesof CD established at least 6 months before randomization for which a histopathologyreport is not available will be considered based on the weight of evidencesupporting the diagnosis and excluding other potential diagnoses, and must bediscussed with the sponsor on a case-by-case basis before randomization.

2. The participant has moderately to severely active CD as determined by a 2-componentpatient-reported outcome (PRO2) score of 14 to 34 points and a Simple EndoscopicScore for Crohn's Disease (SES-CD) score of ≥6 (or ≥4 in cases of isolated ileitis)on screening ileocolonoscopy.

3. The participant has CD involvement of the ileum and/or colon, at a minimum.

4. A participant with extensive colitis or pancolitis of >8 years duration or limitedcolitis of >12 years duration must have documented evidence that a surveillancecolonoscopy was performed within 12 months before initial screening (may beperformed during screening if not performed in previous 12 months).

5. A participant with a family history of colorectal cancer, personal history ofincreased colorectal cancer risk, age >50 years, or other known risk factor must beup-to-date on colorectal cancer surveillance (may be performed during screening).

6. The participant has demonstrated an inadequate response to, loss of response to, orintolerance of at least 1 of the following agents as defined below:

• Corticosteroids.

• Immunomodulators.

• TNF-α antagonists.

Exclusion Criteria:

I. Gastrointestinal (GI) Exclusion Criteria:

1. The participant has evidence of abdominal abscess at the initial screening visit.

2. The participant has had extensive colonic resection, subtotal or total colectomy.

3. The participant has a history of >3 small bowel resections or diagnosis of shortbowel syndrome.

4. The participant has received tube feeding, defined formula diets, or parenteralalimentation within 21 days before administration of the first dose of study drug.

5. The participant has had ileostomy, colostomy, known fixed symptomatic stenosis ofthe intestine, or evidence of fixed stenosis, or small bowel stenosis withprestenotic dilation.

6. Within 30 days before randomization, the participant has received any of thefollowing for the treatment of underlying disease:

• Nonbiologic therapies (eg, cyclosporine, thalidomide) other than thosespecifically listed in the Permitted Medications and Treatments section.

• An approved or investigational nonbiologic therapy in an investigationalprotocol.

7. The participant has received traditional Chinese medication (TCMs) within 30 daysbefore randomization.

8. The participant has had previous exposure to approved or investigationalanti-integrins including, but not limited to natalizumab, efalizumab, etrolizumab,or abrilumab (AMG-181), or mucosal vascular addressin cell adhesion molecule 1 (MAdCAM-1) antagonists, or rituximab.

9. The participant has had previous exposure to vedolizumab.

10. The participant has used topical (rectal) treatment with 5-aminosalicylic acid (5-ASA), corticosteroid enemas/suppositories or traditional Chinese medications forCD treatment within 2 weeks of the administration of the first dose of study drug.

11. The participant requires currently or is anticipated to require surgicalintervention for CD during the study.

12. The participant has a history or evidence of adenomatous colonic polyps that havenot been removed.

13. The participant has a history or evidence of colonic mucosal dysplasia including lowor high-grade dysplasia, as well as indeterminate for dysplasia. II. Infectious Disease Exclusion Criteria

14. The participant has evidence of active infection during the screening period.

15. The participant has evidence of treatment for Clostridioides difficile (C difficile)infection or other intestinal pathogen within, 28 days before first dose of studydrug.

16. The participant has chronic hepatitis B virus (HBV) infection or chronic hepatitis Cvirus (HCV) infection.

17. The participant has active or latent tuberculosis (TB).

18. The participant has any identified congenital or acquired immunodeficiency (eg,common variable immunodeficiency, human immunodeficiency virus [HIV] infection,organ transplantation).

19. The participants has received any live vaccinations within 30 days before screening.

20. The participant has a clinically significant active infection (eg, pneumonia,pyelonephritis, or coronavirus disease 2019 [COVID-19]) within 30 days beforescreening or during screening, or has an ongoing chronic infection or any ongoingCOVID-19-related symptom(s), if previously diagnosed as having COVID-19. III. General Exclusion Criteria

21. The participant has had any surgical procedure requiring general anesthesia within 30 days before enrollment or is planning to undergo major surgery during the studyperiod.

22. The participant has any history of malignancy, except for the following: (a)adequately-treated nonmetastatic basal cell skin cancer; (b) squamous cell skincancer that has been adequately treated and has not recurred for at least 1 yearbefore randomization; and (c) history of cervical carcinoma in situ that has beenadequately treated and has not recurred for at least 3 years before randomization.Participants with remote history of malignancy (eg, >10 years since completion ofcurative therapy without recurrence) will be considered based on the nature of themalignancy and the therapy received and must be discussed with the sponsor on acase-by-case basis before randomization.

23. The participant has a history of any major neurological disorders, including stroke,multiple sclerosis, brain tumor, or neurodegenerative disease.