Proposal for an anti-TNF-exit strategy based on trough serum level.

BACKGROUND AND AIMS: The aim of the study was to evaluate, if the strategy to stop anti-TNF treatment after determination of low trough serum levels and exclusion of inflammation is associated with lower relapse rates. METHODS: Since 2013 we followed an exit strategy in patients treated with anti-TNF treatment for inflammatory bowel disease based on trough serum levels. The relapse rates were observed prospectively, data analysis was performed in a retrospective manner of the collected clinical data. RESULTS: Forty patients were enrolled, who stopped anti-TNF therapy. 13 Patients followed the clinical algorithm, 27 patients were used as control group (13 patients with ulcerative colitis and 14 patients with Crohn's disease). 19 patients received Infliximab, 21 Adalimumab. The median follow-up time after discontinuation was 19 months (IQR 18). Relapses were observed in 22/40 patients (55%). Among the 13 patients with a targeted discontinuation of therapy based on the algorithm, three relapses were observed (23%), compared to 19/27 (70%) from the non-algorithm group (OR: 7.9; 95%-CI: 1.7-36.5). Relapse-free-survival after anti-TNF discontinuation was significantly higher in patients treated by the algorithm compared to the non-algorithm group (p = 0.032). CONCLUSION: An exit strategy based on trough serum levels significantly reduces the relapse rate.

CT-P13 (Inflectra™, Remsima™) monitoring in patients with inflammatory bowel disease.

The approval of infliximab biosimilars Remsima™ and Inflectra™ (CT-P13) for patients with inflammatory bowel disease (IBD) is a promising step to reduce treatment costs. Since monitoring of Remicade™ serum trough levels and anti-Remicade™ immunogenicity hold an important significance in treatment modalities, no data about monitoring of drug serum trough levels or anti-drug antibody levels in IBD patients treated with Remsima™ or Inflectra™ are present to date. Therefore, in this study we applied a Remicade™-validated ELISA to determine drug serum levels of Remsima™ or Inflectra™. Serum concentrations were measured at identical levels compared to Remicade™ at multiple time points over 38 weeks, suggesting that the monitoring of serum trough levels is equally feasible for patients receiving Remsima™ or Inflectra™ and Remicade™. Additionally, anti-drug antibody levels were not significantly different in patients treated with Remsima™ or Inflectra™ compared to patients treated with Remicade™. To our knowledge this is the first real-life experience demonstrating the feasibility of drug monitoring in IBD patients treated with the infliximab biosimilars Remsima™ and Inflectra™.