Study of Vedolizumab in Patients With Moderate to Severe Crohn's Disease

Percentage of Participants in Clinical Remission at Week 10 in the Overall Population

Clinical remission is defined as a Crohn's Disease Activity Index (CDAI) score ≤ 150 points. The CDAI is used to quantify the symptoms of patients with Crohn's disease and consists of eight factors, each summed after adjustment with a weighting factor. The components of the CDAI are: * Number of liquid or soft stools each day for 7 days; * Abdominal pain (graded from 0-3 on severity) each day for 7 days; * General well-being, subjectively assessed from 0 (well) to 4 (terrible) each day for 7 days; * Presence of complications; * Taking Lomotil or opiates for diarrhea; * Presence of an abdominal mass (0 as none, 2 as questionable, 5 as definite); * Hematocrit of \< 0.47 in men and \< 0.42 in women; * Percentage deviation from standard weight. The total score ranges from 0 to approximately 600 and with higher scores indicating greater disease activity. All participants who prematurely discontinued for any reason were considered as not achieving clinical remission.

Time frame: Week 10

Percentage of Participants With Sustained Clinical Remission in the TNFα Antagonist Failure Population

Sustained clinical remission is defined as a CDAI score ≤ 150 points at both Week 6 and Week 10. The CDAI is used to quantify the symptoms of patients with Crohn's disease and consists of eight factors, each summed after adjustment with a weighting factor. The components of the CDAI are: * Number of liquid or soft stools each day for 7 days; * Abdominal pain (graded from 0-3 on severity) each day for 7 days; * General well-being, subjectively assessed from 0 (well) to 4 (terrible) each day for 7 days; * Presence of complications; * Taking Lomotil or opiates for diarrhea; * Presence of an abdominal mass (0 as none, 2 as questionable, 5 as definite); * Hematocrit of \< 0.47 in men and \< 0.42 in women; * Percentage deviation from standard weight. The total score ranges from 0 to approximately 600 and with higher scores indicating greater disease activity. All participants who prematurely discontinued for any reason were considered as not achieving sustained clinical remission.

Time frame: Week 6 and Week 10

Percentage of Participants With Sustained Clinical Remission in the Overall Population

Sustained clinical remission is defined as a CDAI score ≤ 150 points at both Week 6 and Week 10. The CDAI is used to quantify the symptoms of patients with Crohn's disease and consists of eight factors, each summed after adjustment with a weighting factor. The components of the CDAI are: * Number of liquid or soft stools each day for 7 days; * Abdominal pain (graded from 0-3 on severity) each day for 7 days; * General well-being, subjectively assessed from 0 (well) to 4 (terrible) each day for 7 days; * Presence of complications; * Taking Lomotil or opiates for diarrhea; * Presence of an abdominal mass (0 as none, 2 as questionable, 5 as definite); * Hematocrit of \< 0.47 in men and \< 0.42 in women; * Percentage deviation from standard weight. The total score ranges from 0 to approximately 600 and with higher scores indicating greater disease activity. All participants who prematurely discontinued for any reason were considered as not achieving sustained clinical remission.

Time frame: Week 6 and Week 10

Percentage of Participants With Enhanced Clinical Response at Week 6 in the TNFα Antagonist Failure Subpopulation

Enhanced clinical response is defined as a ≥ 100-point decrease in CDAI score from Baseline. The CDAI is used to quantify the symptoms of patients with Crohn's disease and consists of eight factors, each summed after adjustment with a weighting factor. The components of the CDAI are: * Number of liquid or soft stools each day for 7 days; * Abdominal pain (graded from 0-3 on severity) each day for 7 days; * General well-being, subjectively assessed from 0 (well) to 4 (terrible) each day for 7 days; * Presence of complications; * Taking Lomotil or opiates for diarrhea; * Presence of an abdominal mass (0 as none, 2 as questionable, 5 as definite); * Hematocrit of \< 0.47 in men and \< 0.42 in women; * Percent deviation from standard weight. The total score ranges from 0 to approximately 600 and with higher scores indicating greater disease activity. All participants who prematurely discontinued for any reason were considered as not achieving enhanced clinical response.

Time frame: Baseline and Week 6

Number of Participants With Adverse Events (AEs)

An AE was defined as any untoward medical occurrence in a patient administered a pharmaceutical product, which did not necessarily have a causal relationship with the treatment. A serious adverse event (SAE) was any AE, occurring at any dose and regardless of causality that resulted in death, was life-threatening, required inpatient hospitalization or prolongation of existing hospitalization, resulted in persistent or significant disability/incapacity, was a congenital anomaly/birth defect, was an important medical event based upon appropriate medical judgment that may have jeopardized the patient and may have required medical or surgical intervention to prevent 1 of the outcomes listed above, or any diagnosis of progressive multifocal leukoencephalopathy (PML). Relationship to study drug administration was determined by the investigator responding yes or no to the question: Is there a reasonable possibility that the AE is associated with the study drug?

Time frame: From the date of first study drug administration to Week 22, through the 14 March 2012 database lock date. At the time of this database lock, 7 patients had completed Week 10 or early termination assessments but not Week 22 assessments.