Infliximab is indicated for the treatment of inflammatory bowel diseases (IBD).
Nevertheless, loss of response to infliximab is reported in up to 10% to 30% of patients within the first year of treatment.
Dr Claire Liefferinckx and colleagues evaluated the impact of the pharmacokinetics of infliximab at induction on treatment failure.
This is a longitudinal cohort study on 269 patients with IBD treated with infliximab in a single center.
A total of 2331 blood samples were prospectively collected from 2007 until 2015 with a retrospective analysis of clinical data.
|Median infliximab trough levels at induction was lower when patients had been previously exposed to anti–tumor necrosis factor|
|Inflammatory Bowel Diseases|
Infliximab trough levels were measured by enzyme-linked immunosorbent assay.
Antibodies to infliximab were measured by drug-sensitive bridging assay.
During follow-up, patients were defined according to treatment outcome.
At week 6, median infliximab trough levels in patients requiring a switch to another treatment due to loss of response was lower than in patients with long-term response, and in patients responding to optimization.
At week 2, median infliximab trough level was lower in the loss of response switched group compared with the long-term responders but no significant difference was reached with the loss of response optimized group.
In the loss of response switched group, median infliximab trough levels at induction was significantly lower when patients had been previously exposed to anti–tumor necrosis factor compared with naive patients.
Dr Liefferinckx's team concludes, "This study suggests that patients who do not respond to any optimization strategy have lower infliximab trough levels during induction at week 6."
"Infliximab trough levels measured early on at induction might predict treatment failure to infliximab during maintenance."