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6 The clinical and financial impact of measuring infliximab levels and antibodies to infliximab in inflammatory bowel disease patients
  1. S O’Reilly,
  2. D Keegan,
  3. K Byrne,
  4. J Sheridan,
  5. HE Mulcahy,
  6. GA Doherty,
  7. G Cullen
  1. Centre for Colorectal Disease, St Vincent’s University Hospital, Elm Park, Dublin, Ireland


Background Approximately 150 IBD patients are currently on infliximab (IFX) at our centre, costing over €2 million in 2016. IFX drug and antibody level measurement was introduced in 2015.

Aim To analyse the clinical and financial impact of measurement of IFX levels and antibodies to IFX (ATI) in 2016.

Method IBD patients with IFX levels and ATI measured between Dec 2015 and Dec 2016 were identified from laboratory records and an IBD database. The results and clinical reaction to the levels were recorded.

Results 93 (55 Crohn’s, 38 UC) patients had levels checked. More than one measurement was made in 25. 37 had subtherapeutic levels (<3 mg/ml), five with ATI. 10 had dose escalation and seven stopped IFX. The remainder were in clinical remission and maintained on current dose. 34 had supertherapeutic levels (>7 mg/ml): 12 had dose reduction and six stopped IFX. The remainder were maintained on current dose. 22 had therapeutic levels (3-7mg/ml): 13 were maintained on current dose, two dose escalated, five dose reduced and two stopped IFX. 76% of IBD patients on IFX had supertherapeutic or subtherapeutic levels. Of these, 41% had a medication/dose change in response to these results. 11% stopped IFX. Projected savings in our centre are €85 000 in 2016.

Conclusions Initial analysis suggests significant cost savings with IFX level measurement, although decisions on IFX dosing are not made on levels in isolation and alternative treatment options may be equally or more expensive. A prospective study would help clarify the true cost savings.

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