Table 2.

Biologic induction TDM thresholds and associated therapeutic outcomes for vedolizumab and ustekinumab.

IBD type	Study type and sample size	Total N	Threshold concentration [µg/mL]	Associated therapeutic outcome and time point	Reference
Vedolizumab
Week 2
CD/UC	Retrospective cohort	179	>28.9	Clinical response in UC at week 14	Dreesen et al.83
CD/UC	Retrospective cohort	179	>35.2	Biochemical remission in CD at week 6	Dreesen et al.83
Week 6
UC	Post-hoc analysis of RCT [GEMINI1]	693	>37.1	Clinical response at week 6	Osterman et al80
CD/UC	Retrospective cohort	179	>20.8	Clinical response in UC at week 14	Dreesen et al.83
CD/UC	Retrospective cohort	81	>28	Sustained clinical response	Liefferinckx et al84
CD/UC	Prospective cohort	82	>18	Mucosal healing within 52 weeks	Yacoub et al81
CD/UC	Prospective cohort	47	<18.5	Need for dose-escalation within 24 weeks	Willett et al82
Week 14
UC	Post-hoc analysis of RCT [GEMINI1]	693	>18.4	Clinical response at week 14	Osterman et al80
CD/UC	Retrospective cohort	179	>12.6	Clinical response in UC at week 14	Dreesen et al.83
CD/UC	Retrospective cohort	179	>17	Mucosal healing in UC at week 14	Dreesen et al.83
Ustekinumab
Week 4
CD	Prospective cohort	86	>15.9	50% decrease in FC at week 8	Verstockt et al94
CD	Prospective cohort	51	>13	Clinical and biochemical response at week 16	Soufflet et al.95
Week 8
CD	Post-hoc analysis of RCTs [UNITI-1 and 2]	701	>3.3	Clinical remission at week 8	Adedokun et al.91
CD	Prospective cohort	86	>7.2	Biological remission at week 8	Verstockt et al.94
CD	Prospective cohort	86	>4.2	50% decrease in FC at week 8	Verstockt et al.94
CD	Prospective cohort	51	>2	Clinical and biochemical response at week 16	Soufflet et al.95

Abbreviations: CD, Crohn’s disease; UC, ulcerative colitis; RCT, randomized controlled trial; AAA, anti-adalimumab antibodies; FC, faecal calprotectin.

^aCT-P13.