Loss of efficacy and safety of the switch from infliximab original to infliximab biosimilar (CT-P13) in patients with inflammatory bowel disease

Table 1 Comparative baseline demographics and phenotypic characteristics of patients with Crohn's disease and ulcerative colitis in both groups n (%)

		Prospective cohort	95%CI	Retrospective cohort	95%CI	P value
Characteristics (n = 98)
Sex	men	51 (52)	41.6-62.4	56 (57.1)	46.8-67.4
	women	47 (48)	37.6-58.4	42 (42.9)	32.5-53.2	0.280
Smoking status	Never	67 (68.3)	58.7-78.1	69 (70.4)	60.9-79.9
	Previous	18 (18.4)	10.2-26.5	16 (16.3)	8.5-24.1	0.929
	Current	13 (13.3)	6.0-20.5	13 (13.3)	6.1-20.5
Crohn’s disease (n = 67)
Age at diagnosis	A1 (< 17)	7 (10.5)	2.4-18.5	10 (15)	5.6-24.2
	A2 (17-40)	49 (73.1)	61.8-84.5	48 (71.6)	60.1; 83.2	0.691
	A3 ( > 40)	11 (16.4)	6.8-26.0	9 (13.4)	4.5; 22.3
Location at diagnosis	L1 (ileal)	18 (26.9)	15.5-38.2	15 (22.4)	11.7-33.1
	L2 (colonic)	26 (38.8)	26.4-51.2	25 (37.3)	25.0-49.6	0.887
	L3 (ileocolonic)	21 (31.3)	19.5-43.2	25 (37.3)	25.0-49.6
	L4 (upper gastrointestinal tract)	2 (3.0)	0.3-10.4	2 (3.0)	0.4-10.4
Disease behavior	B1 (non-stricturing, non-penetrating)	38 (56.7)	44.169.3	39 (58.2)	45.7-70.8	0.860
	B2 (stricturing)	14 (20.9)	10.4-31.4	13 (19.4)	9.2-29.6
	B3 (penetrating)	15 (22.4)	11.7-33.1	15 (22.4)	11.7-33.1
Perianal disease	Yes	37 (55.2)	42.6-67.9	39 (58.2)	45.7-70.8	0.727
Extraintestinal manifestations	No	42 (62.7)	50.4-75.0	46 (68.7)	56.8-80.5	0.466
Ulcerative colitis (n = 31)
Extension
	E1 (proctitis)	13 (41.9)	22.9-60.9	12 (38.7)	19.9-57.5
	E2 (left colitis)	10 (32.3)	14,2-50.3	11 (35.5)	17.0-53.9	0.957
E3 (pancolitis)	8 (25.8)	8.8-42.9	8 (25.8)	8.8-42.9
Severity	S1 (mild)	11 (35.5)	17.0-53.9	10 (32.3)	14.2-50.3
	S2 (moderate)	16 (51.6)	32.4-70.8	17 (54.8)	35.7-74.0	0.962
	S3 (severe)	4 (12.9)	3.6-29.8	4 (12.9)	3.6-29.8
Extraintestinal manifestations	No	26 (83.9)	66.3-94.5	27 (87.1)	66.3-94.5	0.500
Prior treatment		75 (76.5)	67.6-85.4	85 (86.7)	79.5-94	0.097
Thiopurines		25 (25.5)	16.4-34.7	25 (25.5)	16.4-34.7	0.970
Methotrexate
Concomitant treatment		50 (51)	40.6-61.4	40 (40.8)	30.6-51.1	0.197
Thiopurines		8 (8)	2.2-14.1	7 (7,1)	1.1-10,1	0.999
Methotrexate

Table 2 Comparison of efficacy and loss of efficacy in both groups

	Infliximab original Group	95%CI	CT-P13 Group	95%CI	P value	Rate difference (95%CI)
Basal global remission	76/98 (77.6%)	66.8-86.3	81/98 (82.7%)	74.6-90.7	0.474	-0.173-0.071
Global remission 12 mo	66/93 (71%)	61.2-80.7	60/88 (68.2%)	51.1-71.4	0.806	-0.117-0.173
Basal remission CD	51/67 (76.1%)	65.2-87.1	56/67 (83.6%)	73.9-93.2	0.389	-0.225-0.076
Remission 12 mo CD	45/65 (69.2%)	57.2-81.2	42/62 (67.7%)	55.3-80.2	0.992	-0.163-0.192
Basal UC remission	25/31 (80.6%)	62.5-92.5	25/31 (80.6%)	62.5-92.5	0.748	-0.29-0.229
Remission 12 mo UC	21/28 (75%)	57.2-92.8	18/26 (69.2%)	49.6-88.9	0.866	-0.219-0.334

UC: Ulcerative colitis. CD: Crohn’s disease.

Table 3 Comparative of maintenance of remission at 12 mo in patients with initial remission in both groups

	Infliximab original group	95%CI	CT-P13group	95%CI	P value	Rate Difference (95%CI)
Maintained basal remission at 12 mo	62/74 (83.7%)	74.7-92.9	54/74 (72.9%)	62.2-83.5	0.162	-0.037-0.253
Maintained basal remission at 12 mo CD	42/51 (82.3%)	70.9-93.8	37/53 (69.8%)	56.5-83.1	0.205	-0.056-0.307
Maintained basal remission at 12 mo UC	20/23 (87%)	66.4-97.2	17/21 (81.0%)	62.5-92.5	0.890	-0.203-0.23

CD: Crohn's disease; UC: Ulcerative colitis.