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

The drug being tested in this study is called Vedolizumab. Vedolizumab is being tested to
treat pediatric participants who have moderately to severely active UC or CD.

This study will look at the long-term safety profile in participants who take vedolizumab IV.
Participants will be randomly assigned (by chance, like flipping a coin) which will remain
undisclosed to the participant and investigator during this double blind study (up to Week
40) maintaining the dose at study entry and escalating the dose at disease worsening.

The dosing regimen selected for the long-term study is intended to maintain clinical response
at the lowest possible exposure.

At the discretion of the investigator, participants receiving the low dose (150 or 100 mg) of
vedolizumab IV may be escalated to the high dose (300 or 200 mg) if the participants
demonstrate disease worsening at 2 consecutive visits (scheduled or unscheduled).

Participants who experience continued disease worsening during the study despite being
administered vedolizumab 300 or 200 mg every 8 weeks (Q8W) will be discontinued from the
study.

Study duration is expected to be up to 5 years, depending on the enrollment rate in the
previous randomized double blind study (MLN0002-2003).

Inclusion Criteria:

1. Is male or female with Ulcerative Colitis or Crohn's Disease 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.)

2. 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.

3. 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], budesonide at a dose <= 9
mg/day).

- Topical (rectal) treatment with 5-ASAs 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.

4. The participant's vaccinations are up to date as per inclusion criteria number 10 in
MLN0002-2003.

Exclusion Criteria:

1. Is female and is lactating or pregnant.

2. Has hypersensitivity or allergies to vedolizumab or any of its excipients.

3. Has withdrawn from Study MLN0002-2003.

4. 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.

5. Has a positive progressive multifocal leukoencephalopathy (PML) subjective symptom
checklist prior to the administration of the first dose of study drug.

6. Currently requires major surgical intervention for ulcerative colitis (UC) or CD
(example, bowel resection), or is anticipated to require major surgical intervention
for UC or CD during the study.

7. Has other serious comorbidities that will limit his or her ability to complete the
study.