Proactive therapeutic drug monitoring is more effective than conventional management in inducing fecal calprotectin remission in inflammatory bowel disease.

Background: Proactive therapeutic drug monitoring (pTDM) may improve treatment outcomes in inflammatory bowel disease.

Aims And Methods: We compared 135 patients following a prospective pTDM protocol aiming at an infliximab trough level (IFXTL) between 5 and 10 μg/ml with sequential measurements of Fc, with 108 patients from a retrospective group under conventional management. We evaluated the rates of Fc remission (<250 μg/g) and other clinical outcomes at 2-year of follow-up.

Results: pTDM associated with higher rates of Fc remission (69.6% vs. 50.0%; P = 0.002), and steroid-free clinical remission (78.4% vs. 55.2%, P = 0.028) with a trend for clinical remission (79.3% vs. 68.5%, P = 0.075). There was no difference in treatment discontinuation (P = 0.195), hospitalization (P = 0.156), and surgery (P = 0.110). Higher IFXTL associated with Fc remission at week 14 (6.59 vs. 2.96 μg/ml, P < 0.001), and at the end of follow-up (8.10 vs. 5.03 μg/ml, P = 0.001). In patients reaching Fc remission after week 14, IFXTL increased from week 14 to the end of follow-up (2.71 vs. 8.54 μg/ml, P < 0.001). Fc remission associated with higher rates of clinical (85.8% vs. 56.8% P < 0.001) and steroid-free clinical remission (86.9% vs. 50.0% P < 0.001), lower IFX discontinuation (8.8% vs. 36.8%, P < 0.001), and hospitalization (13.5% vs. 33.7%, P < 0.001), without significance for surgery (6.1% vs. 12.6%, P = 0.101).

Conclusion: pTDM was more effective than conventional management in inducing Fc remission which was associated with improved outcomes.