Therapeutic Drug Monitoring (TDM) and biomarkers such as faecal calprotection (FC) can be useful tools in helping to support clinical decision making to optimsie treatment. Treatment optimisation can involve changing the dosing, infusion interval or stopping treatment. 

Please note that Inflectra®/infliximab is not licensed for dose escalation in ulcerative colitis, ankylosing spondylitis, psoriasis, psoriatic arthritis, paediatric ulcerative colitis or paediatric Crohn's disease.

What is TDM? 

TDM is a measurement of serum drug concentrations and anti-drug antibodies (ADA) to allow more accurate adjustments of drug levels in an indiviudal patient64,65,66.

TDM Trough Levels and Therapeutic Range

TDM can provide clinical insight in either:

  • Primary non-response (PNR): lack of improvement in clinical signs and symptoms with induction therapy67
  • Secondary loss of response (LOR): loss of response during maintenance treatment after intial response to induction therapy67

Why are infliximab trough levels and ADA measured for TDM in IBD?

Montioring of infliximab trough levels is associated with improved clinical outcomes during induction therapy and maintenance therapy68,69. Detectable ADA is associated with decreased serum concentration of infliximab70,73,74 and understanding ADA status is important to inform clinical decision making in induction and maintenance therapy70-72

Why use TDM?

Personalised medicine can be particularly effective in infliximab treatment as patients can require different strategies to optimsie their therapy68.  A personalised approach using TDM can lead to improved clinical outcomes and more effective use of infliximab, which has potential cost-savings75-78.  

Limited therapeutic options are available for patients with IBD79 and maximising anti-TNF drug persistence may help to avoid hospitalisation and surgery80.

Applying TDM in clinical practice

Even minimal information can inform treatment strategy . The simple algorithm below can be used to interpret TDM results in clinical practice81,82

Applying TDM in Clinical Practice

+ IS, Immunosuppression
* Please note that Inflectra/infliximab is not licensed for dose escalation in ulcerative colitis, ankylosing spondylitis, psoriasis, psoriatic arthritis, paediatric ulcerative colitis or paediatric Crohn's disease.

Suggested infliximab threshold level for maintenance therapy ranges from >0.5 µg/ml to ≥10.1 µg/ml83.

Watch Dr Walter Reinisch discuss the benefits of using TDM in clinical practice:


What is Faecal Calprotectin?

Faecal calprotectin (FC) is a biomarker of disease activity in IBD.

FC correlates with inflammatory activity in CD and UC85

It is stable in stool for up to 3 days at room temperature so it is readily mesaurable84

FC levels can be used to: 

  • Confirm active disease (when clinical symptoms are present)86 
  • Evaluate efficacy of current thearpy (mucosal healing)14
  • Predict disease course15 
  • Stratify treatment (modulating disease course)16

Listen to KOLs discuss the use of biomarkers in IBD:


Prescribing Information 

Inflectra® Summary of Product Characteristics   |   Legal Category: POM  Basic NHS Price: 1 vial £377.66

PP-IFA-GBR-0313. December 2018