1. Induction studies' characteristics.

Study ID	Numbers randomised group	Trial registration number	Published protocol	Do the outcomes reported match the protocol or trial register?
Feagan 2008	185 participants randomised into 3 arms. IV placebo (n = 58) at days 1 and 29 IV vedolizumab (MLN0002) 0.5 mg/kg (n = 62) at days 1 and 29 IV vedolizumab (MLN0002) 2 mg/kg (n = 65) at days 1 and 29	Not found	Not found	N/A
Sandborn 2013 – Induction Phase	368 participants randomised into 2 arms in a 3:2 ratio (intervention:placebo) IV placebo (n = 148) at weeks 0 and 2 IV vedolizumab 300 mg (n = 220) at weeks 0 and 2	ClinicalTrials.gov number: NCT00783692	Yes	Yes
Sands 2014	315 participants randomised into 2 arms IV placebo (n = 207) at weeks 0, 2 and 6 IV vedolizumab 300 mg (n = 209) at weeks 0, 2 and 6	ClinicalTrials.gov number: NCT01224171	Not found	N/A
Watanabe 2020 – Induction Phase	157 participants randomised into 2 arms IV placebo (n = 78) at weeks 0, 2 and 6 IV vedolizumab 300 mg (n = 79) at weeks 0, 2 and 6	ClinicalTrials.gov number: NCT02038920	Not found	N/A

IV: intravenous; n: number of participants; N/A: not applicable.