P368 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 potentially improve disease control and treatment outcomes in inflammatory bowel disease. Methods Using a prospectively maintained database we compared 135 patients following a pTDM protocol aiming at an Infliximab trough level (IFXTL) between 5-10 µg/mL with sequential measurements of Fc, with 108 patients from a retrospective group under conventional management (noTDM). We evaluated the rates of Fc remission (<250 µg/g), and other clinical outcomes at 2-years 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 follow-up (8.10 vs 5.03 μg/mL, P=0.001). Fc remission associated with higher rates of clinical remission (85.8% vs 56.8% P<0.001), steroid-free clinical remission (86.9% vs 50.0% P<0.001), and lower rates of IFX discontinuation (8.8% vs 36.8%, P<0.001), and hospitalization (13.5% vs 33.7%, P<0.001) with a non-significant trend for surgery (6.1% vs 12.6%, P=0.101). Conclusion PTDM was more effective than conventional management in inducing Fc remission which associated with improved clinical outcomes.