Long-term Safety With Vedolizumab Intravenous (IV) in Pediatric Participants With Ulcerative Colitis (UC) or Crohn's Disease (CD)

Prior treatment

• Has a positive progressive multifocal leukoencephalopathy (PML) subjective symptom checklist prior to the administration of the first dose of study drug.
• Currently requires major surgical intervention for UC or CD (example, bowel resection), or is anticipated to require major surgical intervention for UC or CD during the study.

Other illness

• Has hypersensitivity or allergies to vedolizumab or any of its excipients.
• Has developed any new unstable or uncontrolled cardiovascular, heart failure moderate to severe (New York Class Association III or IV), pulmonary, hepatic, renal, gastrointestinal (GI), genitourinary, hematological, coagulation, immunological, endocrine/metabolic, neurological, or other medical disorder that, in the opinion of the investigator, would confound the study results or compromise participant safety.

Other

• Is female and is lactating or pregnant.
• Has withdrawn from Study MLN0002-2003.
• Has other serious comorbidities that will limit his or her ability to complete the study.

• Is male or female with UC or CD and was between 2 to 17 years, inclusive, at the time of randomization for Study MLN0002-2003.
  • (Note: A participant remains eligible to participate in this study after they reach 18 years of age if they continue to meet the inclusion criteria and do not meet any exclusion criteria.)
• Has completed Study MLN0002-2003 and, at Week 22, achieved clinical response as defined by a reduction of partial Mayo score of \>=2 points and \>=25% from Baseline, or a reduction of the Paediatric Ulcerative Colitis Activity Index (PUCAI) of \>=20 points from baseline for participants with UC; or a reduction of the CDAI as defined by a \>=70-point decrease from Baseline or a decrease of Pediatric Crohn's Disease Activity Index (PCDAI) of \>=15 points for participants with CD.
• May be receiving a therapeutic dose of the following drugs:
  • Oral 5-aminosalicylic acid (5-ASA) compounds.
  • Oral corticosteroid therapy (prednisone or equivalent steroid at a dose less than or equal to \[\<=\] 50 milligram per day \[mg/day\]) provided the participant was receiving this medication during prior participation in MLN0002-2003.
  • Topical (rectal) treatment with 5-ASA or corticosteroids.
  • Probiotics (example, Saccharomyces boulardii).
  • Antidiarrheals (example, loperamide, diphenoxylate with atropine) for control of chronic diarrhea.
  • Antibiotics used for the treatment of CD (i.e., ciprofloxacin, metronidazole).
  • Azathioprine (AZA) or 6-mercaptopurine (6-MP) or methotrexate (MTX), provided the participant was receiving this medication during prior participation in MLN0002-2003.
• The participant's vaccinations are up to date as per inclusion criteria number 10 in MLN0002-2003.