Observational study of tofacitinib in ulcerative colitis in Sweden (ODEN) - Interim analysis of clinical and biomarker data

Background: Tofacitinib is a Janus kinase (JAK) inhibitor for the treatment of moderate to severe ulcerative colitis (UC). ODEN is an ongoing Swedish multicentre prospective observational study regarding effectiveness of tofacitinib in UC. In this interim analysis, we aimed to assess the clinical outcomes during the first 16 weeks. Methods: Patients with active UC were enrolled 2020-2023 when starting tofacitinib as per clinical indication. Inclusion criteria were fecal (F) calprotectin >250 mg/kg or Mayo endoscopic score ≥2. Data were collected using an electronic case report form linked to the Swedish National Quality Registry for Inflammatory Bowel Disease (SWIBREG). Data concerning inflammatory markers, endoscopic activity, partial (p) Mayo, extra intestinal manifestations, health-related quality of life measures, corticosteroid use, and colectomy rates were collected regardless of tofacitinib discontinuation. Information collected at week 8 and 16 is presented here. Intention-to-treat (ITT) analysis was applied and tofacitinib discontinuation was considered as treatment failure (i.e., no tofacitinib-induced clinical or laboratory response or remission). McNemar’s test was used for proportion differences. Results: The proportion of patients who previously had failed at least one biologic was 95% and at least two biologics, 62%. At inclusion, median p-Mayo was 5 and 39% of patients were on corticosteroids (Table 1a). Patients’ survival on drug is shown in Figure 1a. At week 8 and 16, 42% and 43%, respectively, achieved corticosteroid free clinical remission, Figure 1b. A 50% reduction in F-calprotectin was seen in 54% and 49% at week 8 and 16, respectively. The endpoint of Mayo endoscopic score 0 and/or F-calprotectin <100 mg/kg was achieved by 30% and 38% at week 8 and 16, respectively. Arthralgia frequency decreased significantly from baseline from 29% at inclusion to 13% and 11% at week 8 and 16 respectively. Three patients underwent colectomy the first