Defining and predicting deep remission in patients with perianal fistulizing Crohn’s disease on anti-tumor necrosis factor therapy

Table 1 Long-term outcomes of patients with perianal fistulizing Crohn’s disease on anti-tumor necrosis factor maintenance therapy

Type of anti-TNF therapy	n	Complex fistulas, %	Follow up, wk	Therapeutic outcome of interest	Therapeutic outcome, %	Ref.
IFX	68	75	52	Complete fistula closure & CDAI < 150	34	[4]
IFX	59	85	> 56	Complete fistula closure (PGA)	41	[5]
IFX	13	ND	951	Reduction of fistulas number (MRI)	15	[5]
IFX	156	82	2501	At least 1 fistula closure	69	[6]
IFX	12	ND	156	Clinical remission (PGA)	33	[7]
IFX	12	ND	156	Radiological healing (MRI)	42	[7]
IFX	19	ND	52	Absence of draining fistulas (PGA)	53	[8]
IFX	26	69	2552	Complete fistula closure	42	[9]
IFX (RCT)	96	ND	54	Complete fistula closure	36	[10]
IFX/ADM	49	ND	1602	Deep remission (PGA, MRI, endoscopy)	33	[11]
IFX/ADM	49	ND	1602	Absence of draining fistulas (PGA)	53	[11]
IFX/ADM	20	ND	52	Absence of draining fistulas (PGA)	35	[12]
IFX/ADM	78	67	1921	Absence of drainage with seton removal	53	[13]
IFX/ADM	20	ND	78	Radiological healing (MRI)	30	[8]
ADM	7	ND	156	Absence of draining fistulas (PGA)	0	[7]
ADM	7	ND	156	Radiological healing (MRI)	14	[7]
ADM	7	ND	52	Absence of draining fistulas (PGA)	29	[8]
ADM	39	ND	52	Clinical remission (FDAI)	41	[14]
ADM	14	ND	52	Radiological healing (MRI)	43	[14]
ADM	53	ND	40	Complete fistula closure	41	[15]
ADM (RCT)	70	ND	56	Absence of draining fistulas (PGA)	33	[16]
ADM (post hoc)	70	ND	116	Absence of draining fistulas (PGA)	31	[17]
CZP (RCT)	28	ND	26	Complete fistula closure	36	[18]

¹Median;

²Mean. CDAI: Crohn’s disease activity index; TNF: Tumor necrosis factor; ADM: Adalimumab; IFX: Infliximab; CZP: Certolizumab pegol; RCT: Randomized controlled trial; PGA: Physician global assessment; ND: Not defined; FDAI: Fistula drainage assessment index; MRI: Magnetic resonance imaging.

Table 2 Variables associated with improved therapeutic outcomes of anti-tumor necrosis factor maintenance therapy in patients with perianal fistulizing Crohn’s disease

Variables	Ref.
Clinical or phenotypic
Ileocolonic disease	[6]
Concomitant immunosuppressants	[6]
Duration of seton drainage (< 34 wk)	[6]
Duration of infliximab treatment (> 118 wk)	[6]
Number of infliximab infusions (> 19)	[6]
Absence of complex fistulas	[14]
Male gender	[26]
Absence of switch of anti-TNF therapy	[11]
Imaging
Absence of persisting fistulas on MRI	[5]
Absence of collections at baseline on MRI	[5]
Absence of rectal wall involvement on MRI	[5]
Absence of single-branched fistulas on MRI	[5]
Absence of rectal involvement on MRI	[11]
Serologic
Infliximab (maintenance) trough concentrations ≥ 10.1 μg/mL	[26]
Endoscopic
Absence of active proctitis	[11]

TNF: Tumor necrosis factor; MRI: Magnetic resonance imaging.