Histological Outcomes And Jak-Stat Signalling In Ulcerative Colitis Patients Treated With Tofacitinib.

BACKGROUND AND AIMS: Histological outcomes and JAK-STAT signaling 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). Twenty-six of 40 (65%) patients had severe endoscopic disease (endoscopic Mayo score 3) and 31/40 (78%) failed prior 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 to 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 to responders (0.4%, IQR 0.1-2.1). CONCLUSIONS: Tofacitinib treatment resulted in histological improvement in the majority of UC patients and a substantial decrease of STAT1, STAT3 and STAT5 expression. HEMI was associated with more profound suppression of STAT1.

Tyrosine Kinase 2 Signalling Drives Pathogenic T cells in Colitis.

BACKGROUND AND AIMS: Tyrosine kinase 2 [TYK2] is required for the signalling of key cytokines in the pathogenesis of inflammatory bowel disease [IBD]. We assessed the efficacy of a novel selective TYK2 inhibitor [TYK2i] in experimental colitis, using pharmacological and genetic tools. METHODS: At onset of T cell transfer colitis, RAG1-/- mice received vehicle or TYK2i daily by oral gavage. T cells lacking TYK2 kinase activity [TYK2KE] were used to confirm selectivity of the inhibitor. To this end, RAG1-/- or RAG1-/-TYK2KE animals were transferred with either wild type [WT] or TYK2KE-CD45RBhigh colitogenic T cells. Loss of body weight, endoscopic disease, the disease activity index [DAI], and histopathology scores were recorded. Tissues were analysed ex vivo for lymphocyte populations by flow cytometry. The impact of TYK2 inhibition on human DC-T cell interactions were studied using autologous Revaxis specific T cell assays. RESULTS: TYK2i [70 mg/kg] prevented weight loss and limited endoscopic activity during T cell transfer colitis. TYK2i [70 mg/kg] decreased DAI. Whereas transfer of WT T cells into RAG-/-TYK2KE hosts induced colitis, TYK2KE T cells transferred into RAG1-/-TYK2KErecipients failed to do so. Ex vivo analysis showed a decrease in colon tissue Th1 cells and an increase in Th17 cells upon transfer of TYK2KE-CD45RBhigh cells. In human antigen-triggered T cells, TYK2i displayed reduced Th1 differentiation, similar to murine Th1 cells. CONCLUSIONS: Oral administration of TYK2i, as well as transfer of T cells lacking TYK2 activity, reduced human Th1 differentiation and ameliorated the course of murine T cell transfer colitis. We conclude that TYK2 is a promising drug target for the treatment of IBD.

GSK2586184, a JAK1 selective inhibitor, in two patients with ulcerative colitis.

Tofacitinib, a non-selective Janus kinase (JAK) inhibitor, is effective in inducing clinical and endoscopic remission in patients with active ulcerative colitis (UC). Tofacitinib inhibits cytokine signalling through blockade of JAK1, JAK2, JAK3 and tyrosine kinase 2 (TYK2). Adverse events including neutropenia and anaemia resulting from JAK2 inhibition have been observed in actively treated patients. By selectively targeting JAK1, such adverse events could be expected to be avoided. This open label study was designed to enrol 15 patients with UC, however the trial was discontinued after two inclusions due to safety concerns with the agent in a parallel trial for systemic lupus erythematosus. GSK2586184 was administered in two patients with moderate-to-severe UC. The JAK1 selective inhibitor GSK2586184 was well tolerated and induced clinical and endoscopic response in two patients with moderate-to-severe UC. In addition, treatment with GSK2586184 decreased histology scores and faecal calprotectin levels at early withdrawal.

Exercise training improves exercise capacity in adult patients with a systemic right ventricle: a randomized clinical trial.

OBJECTIVE: To assess whether exercise training in adult patients with a systemic right ventricle (RV) improves exercise capacity and quality of life and lowers serum N-terminal prohormone brain natriuretic peptide (NT-proBNP) levels. DESIGN: Multi-centre parallel randomized controlled trial. PARTICIPANTS: Patients with a systemic RV due to congenitally or surgically corrected transposition of the great arteries. METHODS: Fifty-four adult patients with a systemic RV, were randomized using unmarked opaque envelopes to an intervention group (n = 28) with three training sessions per week for 10 consecutive weeks, and a control group (n = 26). Randomization was stratified by participating centre. At baseline, and follow-up, we determined maximal exercise capacity (V'O(2peak)), serum NT-proBNP levels, and quality of life by means of the SF-36, and the TAAQOL Congenital Heart Disease questionnaires. The final analysis was performed by linear regression, taking into account the stratified randomization. RESULTS: Forty-six patients were analysed (male 50%, age 32 ± 11 years, intervention group n = 24, control group n = 22). Analysis at 10 weeks showed a significant difference in V'O(2peak) (3.4 mL/kg/min, 95% CI: 0.2 to 6.7; P = 0.04) and resting systolic blood pressure (-7.6 mmHg, 95% CI: -14.0 to -1.3; P = 0.03) in favour of the exercise group. No significant changes were found in serum NT-proBNP levels or quality of life in the intervention group or in the control group nor between groups. None of the patients in the intervention group had to discontinue the training programme due to adverse events. CONCLUSION: In adult patients with a systemic RV exercise training improve exercise capacity. We recommend to revise restrictive guidelines, and to encourage patients to become physically active. ( TRIAL REGISTRATION: The study was registered at http://trialregister.nl. Identifier: NTR1909.).