An AE was any untoward medical occurrence without regard to causality in a participant who received study drug. An SAE was an AE resulting in any of the following outcomes or deemed significant for any other reason: death; initial or prolonged inpatient hospitalization; life-threatening experience (immediate risk of death); persistent or significant disability/incapacity; congenital anomaly. Lack of efficacy was reported as an AE when it was associated with a SAE. An AE was considered treatment emergent if it started for the first time in a participant on or after the first day of active treatment, or the event started before the first day of active treatment but increased in severity during active treatment. AEs included both SAEs and non-serious AEs.

Samples were analyzed using the semi-quantitative electrochemiluminescent (ECL) immunoassay method, a validated analytical method in compliance with sponsor's standard operating procedures. ADA positive is defined as ADA titer greater than or equal to (\>=) 4.32. Any positive ADA sample was further tested for NAbs.

CDAI-70 response was defined as a decrease in CDAI score of 70 or greater from baseline. The proportions of participants with CDAI-70 response at Week 8 were compared between placebo and PF-04236921 10 mg/50 mg. CDAI is used to quantify the symptoms of patients with Crohn's Disease. CDAI evaluates 8 Crohn's disease-related variables during a 1-week assessment period, yielding a composite score greater than or equal to (\>=) 0 and without an upper limit. Many clinical trials use the endpoint for response as a 70 or greater point decrease in CDAI and clinical remission is often defined as a CDAI score below 150. The Outcome included a Generalized linear mixed model analyses which incorporated longitudinal data for each subject, and the same model is used for estimate (least squares mean) and statistical analysis (mean difference).

CDAI-70 response was defined as a decrease in CDAI score of 70 or greater from baseline. The proportions of participants with CDAI-70 response at Week 8 were compared between placebo and PF-04236921 200 mg. CDAI is used to quantify the symptoms of patients with Crohn's Disease. CDAI evaluates 8 Crohn's disease-related variables during a 1-week assessment period, yielding a composite score \>=0 and without an upper limit. Many clinical trials use the endpoint for response as a 70 or greater point decrease in CDAI and clinical remission is often defined as a CDAI score below 150. The Outcome included a Generalized linear mixed model analyses which incorporated longitudinal data for each subject, and the same model is used for estimate (least squares mean) and statistical analysis (mean difference). Since the inputs in the model included different Analysis Population than in Outcome Measure 1, that will yield different estimates for placebo for the two different models.

CDAI-70 response was defined as a decrease in CDAI score of 70 or greater from baseline. The proportions of participants with CDAI-70 response at Week 12 were compared between placebo and and PF-04236921 10 mg/50 mg. CDAI is used to quantify the symptoms of patients with Crohn's Disease. CDAI evaluates 8 Crohn's disease-related variables during a 1-week assessment period, yielding a composite score \>=0 and without an upper limit. Many clinical trials use the endpoint for response as a 70 or greater point decrease in CDAI and clinical remission is often defined as a CDAI score below 150. The Outcome included a Generalized linear mixed model analyses which incorporated longitudinal data for each subject, and the same model is used for estimate (least squares mean) and statistical analysis (mean difference).

CDAI-70 response was defined as a decrease in CDAI score of 70 or greater from baseline. The proportions of participants with CDAI-70 response at Week 12 were compared between placebo and PF-04236921 200 mg. CDAI is used to quantify the symptoms of patients with Crohn's Disease. CDAI evaluates 8 Crohn's disease-related variables during a 1-week assessment period, yielding a composite score \>=0 and without an upper limit. Many clinical trials use the endpoint for response as a 70 or greater point decrease in CDAI and clinical remission is often defined as a CDAI score below 150. The Outcome included a Generalized linear mixed model analyses which incorporated longitudinal data for each subject, and the same model is used for estimate (least squares mean) and statistical analysis (mean difference). Since the inputs in the model included different Analysis Population than in Outcome Measure 3, that will yield different estimates for placebo for the two different models.