Abstract

Goals: To valorate whether therapeutic drug monitoring (TDM) of anti-TNF? drugs may improve clinical control of patients with inflammatory bowel disease (IBD) in a treat to target approach and its economic impact on direct costs. Study: Prospective single center cohort study based on algorithm decision-making in IBD patients on maintenance therapy with anti-TNF?. Remission/active IBD status was defined based on a combination of clinical, laboratory and image techniques data. Anti-TNF? trough levels (TL) and anti-drug antibodies (ADA) levels in baseline and 6 months apart taking algorithm-based therapeutic decisions in a treat to target approach with a subsequent follow-up. The economic impact on direct costs of this approach was also calculated. Results: We included 67 patients. Mean follow-up was 15.3 months. Adequacy to decisions recommended by algorithm was 91% and 86,7% after first and second TDM. At baseline therapeutic TL were seen in 79,1% of patients, with ADA being positive in 3% of patients. At 6 months and at the end of follow-up, 97,4% and 89,5% of those in remission at baseline continued in remission, and most of them with the same scheme of therapy, 5 de-escalated, 5 stopped biologics and 1 escalated dose. Of those with active-IBD at baseline, 44,8% and 48,3% of them achieved remission at 6 months and at the end of follow-up (dose escalation in 13 patients, switch to another anti-TNF? and surgery in 3 patient each). Globally, while 56,7% of patients were in remission at baseline, they accounted 74,6% at 6 months (p:0,002) and 71,6% at the end of protocol (p:0,031). Direct cost of anti-TNF was reduced in 15,7%. Conclusion: TDM allows an efficient decision-making and associates a reduction in direct costs of anti-TNF?.