Histological Outcomes and JAK-STAT Signalling in Ulcerative Colitis Patients Treated with Tofacitinib.

BACKGROUND AND AIMS: Histological outcomes and JAK-STAT signalling were assessed in a prospective ulcerative colitis [UC] patient cohort after 8 weeks treatment with tofacitinib, an oral Janus kinase [JAK] inhibitor. METHODS: Forty UC patients received tofacitinib 10 mg twice daily for 8 weeks. Treatment response was defined as histo-endoscopic mucosal improvement [HEMI]. Histological remission was defined as a Robarts Histopathology Index [RHI] ≤3 points and histological response as 50% decrease in RHI. Mucosal expression of JAK1-3, tyrosine kinase 2 [TYK2], and total signal transducer and activator of transcription [STAT] 1-6 were assessed using immunohistochemistry [IHC]. RESULTS: At baseline, the median RHI was 14 (interquartile range [IQR] 10-19). Of 40 [65%] patients, 26 had severe endoscopic disease [endoscopic Mayo score 3] and 31/40 [78%] failed prior anti-tumour necrosis factor [anti-TNF] treatment. At Week 8, 15 patients [38%] had HEMI, 23 patients [58%] histological remission, and 34 [85%] histological response. RHI decreased by a median of 14 points [IQR 9-21] in responders [p <0.001] and by 6 points [IQR 0-13] in non-responders [p = 0.002]. STAT1, STAT3, and STAT5 expression levels decreased significantly in the whole cohort. Responders had lower Week 8 STAT1 expression levels compared with non-responders [0.2%, IQR 0.1-2.8 vs 4.3%, IQR 1.2-11.9, p = 0.001], suggesting more profound STAT1 blockade. A trend of higher baseline JAK2 expression was observed in tofacitinib non-responders [2.7%, IQR 0.1-7.7] compared with responders [0.4%, IQR 0.1-2.1]. CONCLUSIONS: Tofacitinib treatment resulted in histological improvement in the majority of UC patients and in a substantial decrease of STAT1, STAT3, and STAT5 expression. HEMI was associated with more profound suppression of STAT1.

Assessment of endoscopic response using pan-enteric capsule endoscopy in Crohn's disease; the Sensitivity to Change (STOC) study.

BACKGROUND: The potential use of pan-enteric capsule endoscopy (pan-CE) to evaluate mucosal changes during treatment has not been evaluated. We aimed to assess the ability of pan-CE to measure changes in mucosal disease activity before and after starting biologic treatment in Crohn's disease patients. METHODS: In this two-center prospective study, patients with clinical and biochemical signs of active Crohn's disease underwent pan-CE before and 8 to 12 weeks after treatment initiation with infliximab, adalimumab or vedolizumab. Endoscopic disease activity was assessed using the simple endoscopic score for Crohn's disease (SES-CD) and the Crohn's disease endoscopic index of severity (CDEIS), expanded with two segments (i.e., the jejunum and pre-terminal ileum). Occurrence of endoscopic remission (i.e., absence of ulcers) and endoscopic response (i.e., 50% decrease in SES-CD and CDEIS scores compared to baseline) was assessed and the standardized effect size was calculated. RESULTS: Twenty-two patients (50% females) completed the study. Endoscopic remission was observed in 6 out of 22 (27%) patients and 13/22 patients (59%) showed an endoscopic response for both the SES-CD and CDEIS score. Median SES-CD and CDEIS scores decreased from 16.0 (IQR 10.0 - 24.0) to 6.0 (IQR 2.8 - 12.0, p = .001) and from 7.1 (IQR 4.6 - 11.2) to 3.0 (IQR 0.9 - 6.0, p = .001), respectively. The standardized effect size was 1.44 and 1.24 for the SES-CD and CDEIS, respectively. No adverse events related to pan-CE were reported. CONCLUSION: Pan-CE was a useful technique to assess changes in mucosal disease activity in Crohn's disease patients.