Results Interpretation
- Drug levels required to improve clinical outcomes may vary between patients and depend on the desired therapeutic endpoint
- In patients with undetectable drug levels, anti-drug antibody (ADAb) quantification helps to identify how to improve patient response
- In patients with high anti-drug antibodies levels, a switch in-class may be necessary
- In patients with low anti-drug antibodies levels, the addition of an immunosuppressive drug may improve clinical outcomes


Please click below to display the details for each drug
Adalimumab
Adalimumab Level | Detectable Antibody | Clinical Evidence |
Not detected or ADA<6 µg/ml | Not detected |
|
Interpretation**/Action | ||
A higher dose of adalimumab or shortening the dosing interval may be appropriate. |
Adalimumab Level | Detectable Antibody |
|
Not detected or ADA<6 µg/ml | Detected | |
Interpretation**/Action | ||
In good responders, repeat test to see if antibodies resolve. In poor responders, a change to another anti-TNF drug and/or addition of concomitant immunosuppressant may be appropriate. |
Adalimumab Level | Detectable Antibody |
|
ADA>6 µg/ml | Not Detected | |
Interpretation**/Action | ||
In patients who do not have antibodies that do not respond or lose response, a change to another therapeutic class (not targeting TNFα) may be appropriate. |
Adalimumab Level | Detectable Antibody |
|
ADA>12 µg/ml | Not Detected | |
Interpretation**/Action | ||
In good responders, consider a reduction in dose to reduce potential AEs. |
** These findings are not diagnostic. They should be independently evaluated by the treating physician and used to supplement clinical findings in accordance with the treating physician’s independent medical judgment.
- 1 Sandborn W, van Assche G, Reinisch W, et al. Adalimumab induces and maintains clinical remission in patients with moderate-to-severe ulcerative colitis. Gastroenterology. 2012;142:257–265.
- 2 Roblin X, Marotte H, Rinaudo M, et al. Association between pharmacokinetics of adalimumab and mucosal healing in patients with inflammatory bowel diseases. Clin Gastroenterol Hepatol. 2014;12(1):80-84.
- 3 Mazor Y, Almog R, Kopylov U, et al. Evaluating adalimumab drug and antibody levels as predictors of clinical and laboratory response in Crohn’s disease patients. Aliment Pharmacol Ther. 2014 Sep;40(6):620-628.
- 4 Roblin X, Rinaudo M, Del Tedesco E, et al. Development of an algorithm incorporating pharmacokinetics of adalimumab in inflammatory bowel disease. Am J Gastroenterol. 2014 Aug;109(8):1250-6.
- 5 Karmiris K, Paintaud G, Noman M, et al. Influence of trough serum levels and immunogenicity on long-term outcome of adalimumab therapy in Crohn’s disease. Gastroenterology. 2009;137(5):1628-1640.
- 6 Yanai H, Lichtenstein L, Assa A, et al. Levels of drug and antidrug antibodies are associated with outcome of interventions after loss of response to infliximab or adalimumab. Clin Gastroenterol Hepatol. 2015 Mar;13(3):522-530.
- 7 Ungar B, Chowers Y, Yavzori M et al. The temporal evolution of antidrug antibodies in patients with inflammatory bowel disease treated with infliximab. Gut. 2014 Aug;63(8):1258-64.
- 8 Roblin X, Marotte H, Leclerc M, et al. Combination of C-reactive protein, infliximab trough levels and stable but not transient antibodies to infliximab are associated with loss of response to infliximab in inflammatory bowel disease. J Crohn’s Colitis. 2015 Jul;9(7):525-31.
- 9 Sandborn W. Crohn’s disease evaluation and treatment: Clinical decision tool. Gastroenterology. 2014;147:702-705.
- 10 Dassopoulos T, Cohen R, Scherl T, et al. Ulcerative colitis clinical care pathway. Gastroenterology. 2015 Jul;149(1):238-45.
- 11 Ungar B, Levy I, Yavne Y, et al. Optimizing anti-TNF-α therapy: serum levels of infliximab and adalimumab are associated with mucosal healing in patients with inflammatory bowel diseases. Clin Gastroenterol Hepatol. 2015 Oct 29.
- 12 Vande Casteele N, Ferrante M, Van Assche G, et al. Trough concentrations of infliximab guide dosing for patients with inflammatory bowel disease. Gastroenterology. 2015;148(6):1320-1329.
Certolizumab
Certolizumab Level | Detectable Antibody | Literature Findings** |
Week 6: Not detected or CZP </= 43 µg/ml Week 12: Not detected or CZP </= 18 µg/ml | Not detected |
|
Interpretation**/Action | ||
Check patient compliance to treatment. A higher dose of certolizumab or shortening the dosing interval may be appropriate. |
Certolizumab Level | Detectable Antibody |
|
Week 6: Not detected or CZP </= 43 µg/ml Week 12: Not detected or CZP </= 18 µg/ml | Detected | |
Interpretation**/Action | ||
In good responders, repeat test to see if antibodies resolve. In poor responders, a change to another anti TNF drug and/or addition of concomitant immunosuppressant may be appropriate. |
Certolizumab Level | Detectable Antibody |
|
Week 6: Not detected or CZP > 43 µg/ml Week 12: Not detected or CZP > 18 µg/ml | Not Detected | |
Interpretation**/Action | ||
In poor responders who do not have antibodies, a change to another therapeutic class (not targeting TNFα) may be appropriate. |
Certolizumab Level | Detectable Antibody |
|
Upper range trough level | Not Detected | |
Interpretation**/Action | ||
In good responders, consider a reduction in dose to reduce potential AEs. |
** These findings are not diagnostic. They should be independently evaluated by the treating physician and used to supplement clinical findings in accordance with the treating physician’s independent medical judgment.
- 1 Colombel J, Sandborn W, Allez M, et al. Association between plasma concentrations of certolizumab pegol and endoscopic outcomes of patients with Crohn’s disease. Clin Gastroent Hep. 2014;12:423–431.
- 2 Sandborn W, Hanauer S, Pierre-Louis, B, et al. Certolizumab pegol plasma concentration and clinical remission in Crohn’s Disease [abstract Su2079]. Gastroenterology. 2012;142: S563.
- 3 Paul S, Smeraglia J, de Longueville M, et al. Comparison of two enzyme-linked immunosorbent assays used for drug concentration monitoring in psoriatic arthritis patients treated with certolizumab pegol. Arthritis Rheumatol. 2016;68 (Suppl 10):A2589.
- 4 Vande Casteele N, Mould D, Kosutic G, et al. Refinement of population pharmacokinetic model of certolizumab pegol in Crohn’s disease patients to account for time varying nature of covariates. IBD. 2016 Mar;22 (Supp 1):P103.
- 5 Data on File UCB.
- 6 Schreiber S, Rutgeerts P, Fedorak R, et al. A randomized, placebo-controlled trial of certolizumab pegol (CDP870) for treatment of Crohn’s disease. Gastroenterology. 2005;129: 807–818.
- 7 Schreiber S, Khaliq-Kareem, M, Lawrance I, et al. Maintenance therapy with certolizumab pegol for Crohn’s disease. N Engl J Med. 2007;357: 239–250.
- 8 Sandborn W, Abre M, D’Haen G, et al. Certolizumab pegol in patients with moderate to severe Crohn’s disease and secondary failure to infliximab. Clin Gastroenterol Hepatol. 2010;8: 688–695.
- 9 Lichtenstein G. Comprehensive review: antitumor necrosis factor agents in inflammatory bowel disease and factors implicated in treatment response. Ther Adv Gastro. 2013;6(4):269-293.
- 10 Lin K, Mahadevan U. Pharmacokinetics of biologics and the role of therapeutic monitoring. Gastroenterol Clin N Am. 2014;43:565-579.
- 11 Yanai H, Lichtenstein L, Assa A, et al. Levels of drug and antidrug antibodies are associated with outcome of interventions after loss of response to infliximab or adalimumab. Clin Gastroenterol Hepatol. 2015 Mar;13(3):522-530.
- 12 Ungar B, Chowers Y, Yavzori M et al. The temporal evolution of antidrug antibodies in patients with inflammatory bowel disease treated with infliximab. Gut. 2014 Aug;63(8):1258-64.
- 13 Roblin X, Marotte H, Leclerc M, et al. Combination of C-reactive protein, infliximab trough levels and stable but not transient antibodies to infliximab are associated with loss of response to infliximab in inflammatory bowel disease. J Crohn’s Colitis. 2015 Jul;9(7):525-31.
- 14 Prescribing information, certolizumab pegol. Smyrna, GA:UCB;2006.
- 15 Sandborn W. Crohn’s disease evaluation and treatment: Clinical decision tool. Gastroenterology. 2014;147:702-705.
- 16 Vande Casteele N, Ferrante M, Van Assche G, et al. Trough concentrations of infliximab guide dosing for patients with inflammatory bowel disease. Gastroenterology. 2015;148(6):1320-1329.
Infliximab
Infliximab Level | Detectable Antibody | Clinical Evidence |
Not detected or IFX<3.5 µg/ml | Not detected |
|
Interpretation**/Action | ||
A higher dose of infliximab or shortening the dosing interval may be appropriate. |
Infliximab Level | Detectable Antibody |
|
Not detected or IFX<3.5 µg/ml | Detected | |
Interpretation**/Action | ||
In good responders, repeat test to see if antibodies resolve. In poor responders, a change to another anti-TNF drug and/or addition of concomitant immunosuppressant may be appropriate. |
Infliximab Level | Detectable Antibody |
|
IFX>3.5 µg/ml | Not Detected | |
Interpretation**/Action | ||
In patients who do not have antibodies that do not respond or lose response, a change to another therapeutic class (not targeting TNFα) may be appropriate. |
Infliximab Level | Detectable Antibody |
|
IFX>10 µg/ml | Not Detected | |
Interpretation**/Action | ||
In good responders, consider a reduction in dose to reduce potential AEs. |
** These findings are not diagnostic. They should be independently evaluated by the treating physician and used to supplement clinical findings in accordance with the treating physician’s independent medical judgment.
- 1 Cornillie F, Hanauer S, Diamond R, et al. Post induction serum infliximab trough level and decrease of C-reactive protein level are associated with durable sustained response to infliximab: a retrospective analysis of the ACCENT I trial. Gut. 2014; Mar 4.
- 2 Adedokun O, Sandborn W, Feagan B, et al. Association between serum concentration of infliximab and efficacy in adult patients with ulcerative colitis. Gastroenterology. 2014;147:1296-1307.
- 3 Paul S, Tedesco E, Marotte H, et al. Therapeutic Drug Monitoring of infliximab and mucosal healing in inflammatory bowel disease: a prospective study. Inflamm Bowel Disease. 2013;(0):1-9.
- 4 Colombel J, Sandborn W, Reinisch W, et al. Infliximab, azathioprine, or combination therapy for Crohn’s disease. N Engl J Med. 2010;362(15):1383-1395.
- 5 Vande Casteele N, Ferrante M, Van Assche G, et al. Trough concentrations of infliximab guide dosing for patients with inflammatory bowel disease. Gastroenterology. 2015;148(6):1320-1329.
- 6 Afif W, Loftus E, Faubion W, et al. Clinical utility of measuring infliximab and human anti-chimeric antibody concentrations in patients with inflammatory bowel disease. Am J Gastroenterol. 2010;105:1133-1139.
- 7 Vande Casteele N, Khanna R, Levesque B, et al. The relationship between infliximab concentrations, antibodies to infliximab and disease activity in Crohn’s disease. Gut. 2015;64:1539 -1545.
- 8 Nanda K, Cheifetz A, Moss A. Impact of antibodies to infliximab on clinical outcomes and serum infliximab levels in patients with inflammatory bowel disease (IBD): a metaanalysis. Am J Gastroenterol. 2013; 108: 40-47.
- 9 Yanai H, Lichtenstein L, Assa A, et al. Levels of drug and antidrug antibodies are associated with outcome of interventions after loss of response to infliximab or adalimumab. Clin Gastroenterol Hepatol. 2015 Mar;13(3):522-530.
- 10 Ungar B, Chowers Y, Yavzori M et al. The temporal evolution of antidrug antibodies in patients with inflammatory bowel disease treated with infliximab. Gut. 2014 Aug;63(8):1258-64.
- 11 Roblin X, Marotte H, Leclerc M, et al. Combination of C-reactive protein, infliximab trough levels and stable but not transient antibodies to infliximab are associated with loss of response to infliximab in inflammatory bowel disease. J Crohn’s Colitis. 2015 Jul;9(7):525-31.
- 12 Vande Casteele N, Compernolle G, Ballet V, et al. OP11 Individualised infliximab treatment using therapeutic drug monitoring: a prospective controlled Trough level Adapted Infliximab Treatment (TAXIT) trial. J Crohns Colitis. 2012;6:S6.
- 13 Sandborn W. Crohn’s disease evaluation and treatment: Clinical decision tool. Gastroenterology. 2014;147:702-705.
- 14 Dassopoulos T, Cohen R, Scherl T, et al. Ulcerative colitis clinical care pathway. Gastroenterology. 2015 Jul;149(1):238-45.
- 15 Velayos F, Kahn J, Sandborn W, et al. A test-based strategy is more cost effective than empiric dose escalation for patients with Crohn’s disease who lose responsiveness to infliximab. Clin Gastroenterol Hepatol. 2013;11: 654-666.
- 16 Steenholdt C, Brynskov J, Thomsen O, et al. Individualised therapy is more cost-effective than dose intensification in patients with Crohn’s disease who lose response to anti-TNF treatment: a randomised, controlled trial. Gut. 2014;63(6):919-927.
- 17 Ungar B, Levy I, Yavne Y, et al. Optimizing anti-TNF-α therapy: serum levels of infliximab and adalimumab are associated with mucosal healing in patients with inflammatory bowel diseases. Clin Gastroenterol Hepatol. 2015 Oct 29.
Vedolizumab
Vedolizumab Level | Detectable Antibody | Literature Findings** |
VDZ<40 µg/ml* | Not detected |
|
Interpretation**/Action | ||
In poor responders, shortening the dosing interval may be appropriate. |
Vedolizumab Level | Detectable Antibody |
|
VDZ<40 µg/ml* | Detected | |
Interpretation**/Action | ||
In poor responders, shortening the dosing interval may be appropriate. |
Vedolizumab Level | Detectable Antibody |
|
VDZ>40 µg/ml* | Not Detected | |
Interpretation**/Action | ||
In poor responders who do not have antibodies, a change to another drug regimen may be appropriate. |
** These findings are not diagnostic. They should be independently evaluated by the treating physician and used to supplement clinical findings in accordance with the treating physician’s independent medical judgment.
- 1 Feagan B, Rutgeerts P, Sands B, et al. Vedolizumab as induction and maintenance therapy for ulcerative colitis. NEJM. 2013 Aug;369(8):699-710.
- 2 Sandborn W, Feagan B, Rutgeerts P, et al. Vedolizumab as induction and maintenance therapy for Crohn’s disease. NEJM. 2013 Aug;369(8):699-710.
- 3 Rosario M, Abhyankar B, Sankoh S, et al. Relationship between Vedolizumab pharmacokinetics and endoscopic outcomes in patients with ulcerative colitis. ECCO Abstract. 2015. Session 5: DOP 040.
- 4 Williet N, Fovet M, Claudez P, et al. Serum Vedolizumab assay at week 6 predicts sustained clinical remission and lack of recourse to optimization in IBD. ECCO abstract. 2016.
- 5 Sands B, Dubinsky M, Vermeire S, et al. Effects of increased Vedolizumab dosing frequency on clinical remission and response in ulcerative colitis and Crohn’s disease. Inflamm Bowel Dis. 2014;20:S67.
- 6 Yanai H, Lichtenstein L, Assa A, et al. Levels of drug and antidrug antibodies are associated with outcome of interventions after loss of response to infliximab or adalimumab. Clin Gastroenterol Hepatol. 2015 Mar;13(3):522-530.
- 7 Ungar B, Chowers Y, Yavzori M et al. The temporal evolution of antidrug antibodies in patients with inflammatory bowel disease treated with infliximab. Gut. 2014 Aug;63(8):1258-64.
- 8 Roblin X, Marotte H, Leclerc M, et al. Combination of C-reactive protein, infliximab trough levels and stable but not transient antibodies to infliximab are associated with loss of response to infliximab in inflammatory bowel disease. J Crohn’s Colitis. 2015 Jul;9(7):525-31.
- 9 Dassopoulos T, Cohen R, Scherl T, et al. Ulcerative colitis clinical care pathway. Gastroenterology. 2015 Jul;149(1):238-45.
Ustekinumab
Ustekinumab Trough Level | Detectable Antibody | Clinical Evidence |
UST<1 µg/ml | Not detected |
|
Interpretation**/Action | ||
In poor responders, shortening the dosing interval may be appropriate. |
Ustekinumab Trough Level | Detectable Antibody |
|
UST < 1 µg/ml | Detected | |
Interpretation**/Action | ||
In poor responders, a change to another drug regimen may be appropriate. |
Ustekinumab Trough Level | Detectable Antibody |
|
UST >/ 1 µg/ml | Not Detected | |
Interpretation**/Action | ||
In patients who do not have antibodies that do not respond or lose response, a change to another drug regimen may be appropriate. |
** These findings are not diagnostic. They should be independently evaluated by the treating physician and used to supplement clinical findings in accordance with the treating physician’s independent medical judgment.
- 1 Adedokun O, Xu Z, Gasink C, et al. Pharmacokinetics and exposure-response relationships of ustekinumab during IV induction and SC maintenance treatment of patients with Crohn’s disease with ustekinumab: results from the UNITI-1, UNITI-2, and IM-UNITI studies. Program and abstracts of Digestive Disease Week 2016; May 21-24, 2016; San Diego, California. Abstract Sa1934.
- 2 Sandborn W, Gasink C, Gao L, CERTIFI Study Group, et al. Ustekinumab induction and maintenance therapy in refractory Crohn’s disease. N Engl J Med. 2012 Oct18;367(16):1519-28.
- 3 Feagan B, Sandborn W, Gasink C, et al. Ustekinumab as induction and maintenance therapy for Crohn’s disease patients. N Engl J Med. Nov 2016;375:1946-1960.
- 4 Sandborn W, Feagan B, Gasink C, et al. A randomized multicenter, double blind, placebo-controlled study of ustekinumab maintenance therapy in moderate-to-severe Crohn’s disease patients: Results from IM-UNITI. Gastroenterology. April 2016;150(4):S157-S158.
- 5 Battat R, Kopylov U, Bessissow T, et al. Association of ustekinumab trough concentrations with clinical, biochemical and endoscopic outcomes. Program and abstracts of Digestive Disease Week 2016; May 21-24, 2016; San Diego, California. Abstract 696.
- 6 Data on file, Janssen.
- 7 Yanai H, Lichtenstein L, Assa A, et al. Levels of drug and antidrug antibodies are associated with outcome of interventions after loss of response to infliximab or adalimumab. Clin Gastroenterol Hepatol. 2015 Mar;13(3):522-530.
- 8 Ungar B, Chowers Y, Yavzori M et al. The temporal evolution of antidrug antibodies in patients with inflammatory bowel disease treated with infliximab. Gut. 2014 Aug;63(8):1258-64.
- 9 Roblin X, Marotte H, Leclerc M, et al. Combination of C-reactive protein, infliximab trough levels and stable but not transient antibodies to infliximab are associated with loss of response to infliximab in inflammatory bowel disease. J Crohn’s Colitis. 2015 Jul;9(7):525-31.
Golimumab
Golimumab Trough Level | Detectable Antibody | Clinical Evidence |
Week 6 – GLM<2.5μg/ml Maintenance – GLM<1.4 μg/ml | Not detected |
|
Response Interpretation/Action | ||
In poor responders, shortening the dosing interval may be appropriate. |
Golimumab Trough Level | Detectable Antibody |
|
GLM<2.5μg/ml Maintenance – GLM<1.4 μg/ml | Detected | |
Response Interpretation/Action | ||
In poor responders, addition of immunomodulators or a change to another drug regimen may be appropriate. |
Golimumab Trough Level | Detectable Antibody |
|
GLM >/= 2.5μg/ml | Not Detected | |
Response Interpretation/Action | ||
In patients who do not have antibodies that do not respond or lose response, a change to another drug regimen may be appropriate. |
** These findings are not diagnostic. They should be independently evaluated by the treating physician and used to supplement clinical findings in accordance with the treating physician’s independent medical judgment.
- 1 Hanauer S. Still in pursuit. Gastroenterology.. 2014 Jan;146(1):13-15.
- 2 Sandborn W, Feagan B, Marano C, et al. PURSUIT-SC Study Group. Subcutaneous golimumab induces clinical response and remission in patients with moderate-to-severe ulcerative colitis. Gastroenterology. 2014 Jan;146(1):85-95.
- 3 Rutgeerts P, Reinisch W, Feagan B, et al. How long should golimumab treatment be continued in patients with ulcerative colitis who do not respond to initial induction therapy? United European Gastro J. 2014, 2(Supp1):OP208:67-68.
- 4 Sandborn W, Feagan B, Marano C, et al. PURSUIT-Maintenance Study Group. Subcutaneous golimumab maintains clinical response in patients with moderate-to-severe ulcerative colitis. Gastroenterology. 2014 Jan;146(1):96-109.
- 5 Adedokun O, Xu Z, Marano C, et al. Pharmacokinetics and exposure-response relationship of golimumab in patients with moderately-to-severely active ulcerative colitis: Results from phase 2/3 PURSUIT induction and maintenance studies. J Crohns Colitis. 2016 Jul 20.
- 6 Detrez I, Dreesen E, Van Stappen T, et al. Variability in golimumab exposure: A ‘real-life’ observational study in active ulcerative colitis. J Crohns Colitis. 2016 May;10(5):575-81.
- 7 Roblin X, Marotte H, Rinaudo M, et al. Association between pharmacokinetics of adalimumab and mucosal healing in patients with inflammatory bowel diseases. Clin Gastroenterol Hepatol. 2014;12(1):80-84.
- 8 Ungar B, Levy I, Yavne Y, et al. Optimizing anti-TNF-α therapy: serum levels of infliximab and adalimumab are associated with mucosal healing in patients with inflammatory bowel diseases. Clin Gastroenterol Hepatol. 2015 Oct 29.
- 9 Detrez I, Gils A. Pharmacokinetics and exposure-response relationship of golimumab in patients with moderately-to-severely active ulcerative colitis: Results from phase 2/3 PURSUIT induction and maintenance studies. J Crohns Colitis. 2016 Jul 31.
- 10 Gilardi D, Fiorino G, Allocca M, et al. Golimumab: clinical update on its use for ulcerative colitis. Drugs Today. 2015 Mar;51(3):171-84.
- 11 Yanai H, Lichtenstein L, Assa A, et al. Levels of drug and antidrug antibodies are associated with outcome of interventions after loss of response to infliximab or adalimumab. Clin Gastroenterol Hepatol. 2015 Mar;13(3):522-530.
- 12 Ungar B, Chowers Y, Yavzori M et al. The temporal evolution of antidrug antibodies in patients with inflammatory bowel disease treated with infliximab. Gut. 2014 Aug;63(8):1258-64.
- 13 Roblin X, Marotte H, Leclerc M, et al. Combination of C-reactive protein, infliximab trough levels and stable but not transient antibodies to infliximab are associated with loss of response to infliximab in inflammatory bowel disease. J Crohn’s Colitis. 2015 Jul;9(7):525-31.
ADAb* = Anti-Drug Antibodies