Early vedolizumab trough levels are not associated with short-term response in patients with inflammatory bowel disease
Abstract
Background: Data about the usefulness of monitoring vedolizumab therapy are sparse and conflicting. Here, the aim was to assess the association between early vedolizumab trough levels (VTLs) and responses to induction therapy in patients with inflammatory bowel disease (IBD).
Methods: The study population comprised consecutive IBD patients from a prospective cohort of vedolizumab treated individuals at our centre, in whom VTLs and anti-vedolizumab antibodies (AVAs) were measured during the induction phase of therapy. Included patients received vedolizumab (300 mg) at weeks 0, 2 and 6, with an extra dose at week 10 in cases of inadequate response after the third infusion.
Clinical response was evaluated by a physician at 1 month after the last induction dose (week 10 or 14). Measurement of VTL and AVA was performed by ELISA.
Results: Eighty-seven patients, 31 with Crohn's disease and 56 with ulcerative colitis, were included. Only 15% of patients were naïve to anti-tumour necrosis factor alpha therapy; 61% used concomitant systemic steroids and 26% used thiopurines.
An additional dose at week 10 was given to 39% of individuals. Clinical response to induction was reported in 77% of IBD patients.
The median VTL at week 6 was 30.6 µg/mL (range: 1.1-80.0). When comparing patients with and without a clinical response to vedolizumab, we found no significant difference in the median VTL at week 6 (29.4 vs. 34.4 µg/mL, respectively; p = 0.71).
Likewise, VTL did not differ significantly between individuals receiving an additional dose at week 10 and those receiving standard induction (40.0 vs. 28.5, respectively; p = 0.69). Seven per cent of patients developed positive AVA up until weeks 10-14.
Diagnosis type, concomitant immunosuppressants or previous biologic therapy had no impact on VTL. Conclusion: There was no association between early VTL and clinical response to induction therapy.
Further studies should address the clinical relevance of therapeutic drug monitoring during long-term vedolizumab treatment.