Table 1.

Main characteristics of the included studies

Ref.	Study duration	Treatment	Age (mean, yr)	Disease duration (yr)	Baseline CDAI (mean)	Jadad score
Gordon et al[12], 2001	12	Natalizumab 3 mg/kg intravenous infusion at 0 wk, n = 18	36	8.5	258	5
		Placebo intravenous infusion at 0 wk, n = 12	34	8.4	273
Ghosh et al[10], 2003	12	Natalizumab 6 mg/kg intravenous infusion at 0, 4 wk, n = 51	35	7.8	298	5
		Natalizumab 3 mg/kg intravenous infusion at 0, 4 wk, n = 66	36	8.1	300
		Natalizumab 3 mg/kg intravenous infusion at 0 wk, n = 68	36	8.4	288
		Placebo intravenous infusion at 0, 4 wk, n = 63	34	8.9	300
Targan et al[13], 2007	12	Natalizumab 300 mg intravenous infusion at 0, 4, 8 wk, n = 259	38	10.1	304	5
		Placebo intravenous infusion at 0, 4, 8 wk, n = 250	38	10	300
Feagan et al[11], 2008	8	Vedolizumab 2 mg/kg intravenous infusion at 0, 4 wk, n = 65	39	8	297	5
		Vedolizumab 0.5 mg/kg intravenous infusion at 0, 4 wk, n = 62	36	8.8	288
		Placebo intravenous infusion at 0, 4 wk, n = 58	35	9	288
Sandborn et al[14], 2013	6	Vedolizumab 300 mg intravenous infusion at 0, 2 wk, n = 220	36	9.2	327	5
		Placebo intravenous infusion at 0, 2 wk, n = 148	39	8.2	325

CDAI: Crohn’s disease activity index.