Vedolizumab serum trough concentrations with and without thiopurines in ulcerative colitis: The prospective VIEWS pharmacokinetics study

Table 1 Baseline characteristics and comparison between thiopurine withdrawal and continuation groups, n (%)/mean ± SD/ median (interquartile range)

	Total (n = 62)	Withdrawal group (n = 42)	Continuation group (n = 20)
Demographics
Female sex	26 (41.9)	21 (50)	5 (25)
Age (years)	43.4 ± 18.0	43.7 ± 19.0	42.8 ± 16.1
Current/ex-smoker	16 (25.8)	11 (26.2)	5 (25)
Disease extent
Left sided colitis	41 (66.1)	27 (64.3)	14 (70)
Pancolitis	21 (33.9)	15 (35.7)	6 (30)
Disease duration (years)	7.5 (4-12)	8 (3-13)	6.5 (4-11.8)
Prior treatments
Corticosteroids	57 (91.9)	39 (92.9)	18 (90)
Immunomodulators	62 (100)	42 (100)	20 (100)
Anti-TNF	14 (22.6)	10 (23.8)	4 (20)
Baseline assessment
Partial mayo score	0 (0-0)	0 (0-0)	0 (0-0)
Mayo endoscopic score, 0-1 (n = 57)	57 (100)	42 (100)	20 (100)
Histologic remission (n = 54)	41 (75.9)	25 (69.4) (n = 36)	16 (88.9) (n = 18)
Laboratory values at baseline
Hemoglobin (g/L)	139.6 ± 12.9	137.8 ± 13.8	143.2 ± 10.5
Fecal calprotectin (µg/g)	23.7 (7.9-65)	17.7 (6.7-51.8)	44.3 (10.5-124.6)
Albumin (g/L)	41.4 ± 4.5	41.4 ± 5.0	41.2 ± 3.2
CRP (mg/L)	1.25 (0.5-3)	1.3 (0.5-3.3)	0.9 (0.2-2.5)
Vedolizumab serum trough concentrations
Week 0 (µg/mL)	15.6 (10.8-20.8)	16.2 (11.5-22.2)	15.2 (10.3-16.9)
Week 24 (µg/mL) (n= 57)	16.9 (12.0-22.1)	17.8 (10.5-25.7)	14.7 (12.2-19.7)
Week 48 (µg/mL) (n= 61)	15.4 (11.3-21.7)	15.9 (10.3-22.5)	14.7 (12.4-18.4)
Outcomes at week 48
Partial mayo score	0 (0-0)	0 (0-0)	0 (0-0)
Clinical remission	51 (82.3)	33 (78.6)	18 (90)
CRP (mg/L)	1.2 (0-3.4)	2.4 (0-6.4) (n = 32)	1.2 (0-2.8) (n = 17)
CRP remission	39 (79.6)	24 (75)	15 (88.2)
Fecal calprotectin (µg/g)	15.4 (5.5-47.7)	15.3 (5.5-43.2) (n = 31)	17.5 (6.4-48.2) (n = 16)
Fecal calprotectin remission	43 (91.5)	27 (87.1)	16 (100)
Endoscopic improvement (n = 57)	39 (68.4)	23 (62.6) (n = 37)	16 (80) (n = 20)
Histologic remission (n = 55)	32 (58.2)	18 (48.7) (n = 37)	14 (77.8) (n = 18)
Histo-endoscopic remission (n = 55)	25 (45.5)	12 (32.4) (n = 37)	13 (72.2) (n = 18)
Clinical remission at 2 years	48 (77.4)	30 (71.4)	18 (90)

Anti-TNF: Anti-tumor necrosis factor; CRP: C-reactive protein.

Table 2 Associations between vedolizumab serum trough concentrations and variable treatment endpoints, median (interquartile range)

Median vedolizumab serum trough concentrations (µg/mL)	No clinical remission	Clinical remission	P value	No endoscopic improvement	Endoscopic improvement	P value	No histologic remission	Histologic remission	P value
Week 01	14.0 (6.4-22.2)	15.7 (11.5-20.1)	0.47	13.9 (10.4-22.2)	15.9 (11.5-20.1)	0.69	16.0 (11.1-21.7)	15.5 (11.2-19)	0.44
Week 48	9.2 (5.4-21.7)	16.3 (12.5-22.4)	0.04	12.3 (8.1-21.9)	17.7 (13.5-21.1)	0.09	15.4 (9.8-21.9)	17 (12.6-21.0)	0.78
2 years2	12.4 (7.0-15.0)	17.7 (12.6-22.5)	0.02

¹Vedolizumab serum trough concentrations at week 0 vs remission rates at week 48.

²Vedolizumab serum trough concentrations at week 48 vs clinical remission at 2 years.

Table 3 Quartile analysis of vedolizumab serum trough concentrations and variable outcomes at week 48, n (%)

Quartile at week 0	Vedolizumab trough concentrations (µg/mL)	Clinical remission	CRP remission	Fecal calprotectin remission	Endoscopic improvement	Histologic remission	Histo-endoscopic remission (%)
1	5.19-10.75	11 (73.3)	8 (80.0)	8 (80.0)	8 (61.5)	7 (58.3)	6 (50.0)
2	10.75-15.60	14 (87.5)	12 (85.7)	13 (92.9)	10 (66.7)	10 (66.7)	7 (46.7)
3	15.60-20.85	14 (87.5)	9 (69.2)	12 (100)	12 (80.0)	9 (60.0)	7 (46.7)
4	20.85-41.50	12 (80.0)	10 (83.3)	10 (90.9)	9 (64.3)	6 (46.2)	5 (38.5)
Week 48
1	3.33-11.30	9 (60.0)	5 (62.5)	4 (57.1)	4 (33.3)	5 (45.5)	3 (27.3)
2	11.30-15.40	16 (94.1)	12 (75.0)	15 (100.0)	14 (82.4)	10 (62.5)	7 (43.8)
3	15.40-21.70	13 (86.7)	10 (90.9)	12 (100)	12 (80.0)	9 (60.0)	8 (53.3)
4	21.70-38.40	13 (86.7)	12 (85.7)	12 (92.3)	9 (69.2)	8 (61.5)	7 (53.9)