Time to clinical response and remission for therapeutics in inflammatory bowel diseases: What should the clinician expect, what should patients be told?

Table 1 Expected time to clinical response for therapeutic agents used in the management of inflammatory bowel disease

Agent	Earliest published clinical response	Earliest published objective response	Time to response in most patients1	Time to futility	Use of therapeutic drug monitoring	Comments
Mesalazine (oral)	1 wk[21]	3 wk[148]	4 wk	> 12 wk	N	A higher dose may lead to a more rapid response
Prednisolone (oral)	2 wk[28]	2 wk[28]	3 to 7 wk	8 wk	N	May take longer for CD
Corticosteroids (IV)	3 d[31]	1 wk[127]	3-5 d	7-10 d	N
Infliximab (IV)	1 wk[48]	8 wk[149]	2-8 wk	> 6 mo	Y
Adalimumab (SC)	4 wk[59]	8 wk[59]	4-8 wk	> 6 mo	Y	Response time better with 160/80 mg vs 40/40 mg induction dosing
Certolizumab (SC)	2wk[61]	10 wk[64]	10 wk	> 16 wk	N
Golimumab (SC)	6 wk[65]	6 wk[65]	6 wk	> 14 wk	Y
Certolizumab (SC)	2 wk[61]	10 wk[64]	10 wk	> 16 wk	N
Vedolizumab (IV)	6 wk[78]	6 wk[78]	19 wk	12 mo	N2	Response time may be better for UC vs CD
Thiopurines (oral)	2 wk[80]	3 mo[88]		> 6-9 mo	Y	Endoscopic response may take much longer than clinical response
			10 to 12 wk
Methotrexate (oral or SC)	9 wk[111]	12 wk[110]	9 wk	> 6 mo	N	Response time and efficacy may be better in 1) CD vs UC, 2) SC vs oral
Cyclosporin (IV then oral)	1 wk[127]	1 wk[127]	4 to 5 d	> 14 d	Y
Tacrolimus (oral)	2 wk[122]	2 wk[122]	2 wk	4 wk	Y
EEN (oral)	10 d[131]	4 wk[139]	3 to 4 wk	8 wk	N

¹Clinical response reported in at least 50% of patients who achieve a response to therapy;

²Therapeutic drug monitoring is not yet widely available. EEN: Exclusive enteral nutrition; IV: Intravenous; SC: Subcutaneous; Y: Yes; N: No; CD: Crohn’s disease; UC: Ulcerative colitis.