Gaik Wei Tew

Etrolizumab as induction therapy for ulcerative colitis: a randomised, controlled, phase 2 trial

BACKGROUND Etrolizumab is a humanised monoclonal antibody that selectively binds the β7 subunit of the heterodimeric integrins α4β7 and αEβ7. We aimed to assess etrolizumab in patients with moderately-to-severely active ulcerative colitis. METHODS In this double-blind, placebo-controlled, randomised, phase 2 study, patients with moderately-to-severely active ulcerative colitis who had not responded to conventional therapy were recruited from 40 referral centres in 11 countries. Eligible patients (aged 18-75 years; Mayo Clinic Score [MCS] of 5 of higher [or ≥6 in USA]; and disease extending 25 cm or more from anal verge) were randomised (1:1:1) to one of two dose levels of subcutaneous etrolizumab (100 mg at weeks 0, 4, and 8, with placebo at week 2; or 420 mg loading dose [LD] at week 0 followed by 300 mg at weeks 2, 4, and 8), or matching placebo. The primary endpoint was clinical remission at week 10, defined as MCS of 2 or less (with no individual subscore of >1), analysed in the modified intention-to-treat population (mITT; all randomly assigned patients who had received at least one dose of study drug, had at least one post-baseline disease-activity assessment, and had a centrally read screening endoscopic subscore of ≥2). This study is registered with ClinicalTrials.gov, number NCT01336465. FINDINGS Between Sept 2, 2011, and July 11, 2012, 124 patients were randomly assigned, of whom five had a endoscopic subscore of 0 or 1 and were excluded from the mITT population, leaving 39 patients in the etrolizumab 100 mg group, 39 in the etrolizumab 300 mg plus LD group, and 41 in the placebo group for the primary analyses. No patients in the placebo group had clinical remission at week 10, compared with eight (21% [95% CI 7-36]) patients in the etrolizumab 100 mg group (p=0·0040) and four (10% [0·2-24]) patients in the 300 mg plus LD group (p=0·048). Adverse events occurred in 25 (61%) of 41 patients in the etrolizumab 100 mg group (five [12%] of which were regarded as serious), 19 (48%) of 40 patients in the etrolizumab 300 mg plus LD group (two [5%] serious), and 31 (72%) of 43 patients in the placebo group (five [12%] serious). INTERPRETATION Etrolizumab was more likely to lead to clinical remission at week 10 than was placebo. Therefore, blockade of both α4β7 and αEβ7 might provide a unique therapeutic approach for the treatment of ulcerative colitis, and phase 3 studies have been planned. FUNDING Genentech.

EMerging BiomARKers in Inflammatory Bowel Disease (EMBARK) Study Identifies Fecal Calprotectin, Serum MMP9, and Serum IL-22 as a Novel Combination of Biomarkers for Crohn's Disease Activity: Role of Cross-Sectional Imaging

Objectives:In Crohns disease (CD), clinical symptoms correspond poorly to inflammatory disease activity. Biomarkers reflective of mucosal and bowel wall inflammation would be useful to monitor disease activity. The EMBARK study evaluated disease activity in patients with ulcerative colitis (UC) and CD, and used endoscopy with or without cross-sectional imaging for biomarker discovery.Methods:UC (n=107) and CD (n=157) patients were characterized and underwent ileocolonoscopy (ICO). A subset of CD patients (n=66) also underwent computed tomography enterography (CTE). ICO and CTE were scored by a gastroenterologist and radiologist who incorporated findings of inflammation into a single score (ICO-CTE) for patients that underwent both procedures. Serum and fecal biomarkers were evaluated for association with the Mayo Clinic endoscopy score in UC patients and with ICO alone or ICO-CTE in CD patients. Individual biomarkers with a moderate degree of correlation (P≤0.3) were evaluated using multivariate analysis with model selection using a stepwise procedure.Results:In UC, ordinal logistic regression using Mayo Clinic endoscopy subscore selected the combination of fecal calprotectin and serum matrix metalloproteinase 9 (MMP9; pseudo R2=0.353). In CD, we found that use of the ICO-CTE increased specificity of known biomarkers. Using ICO-CTE as the dependent variable for biomarker discovery, the selected biomarkers were the combination of fecal calprotectin, serum MMP9, and serum IL-22 (r=0.699).Conclusions:Incorporation of both ICO and CTE into a single measure increased biomarker performance in CD. Combinations of fecal calprotectin and serum MMP9 for UC, and combinations of fecal calprotectin, serum MMP9, and serum interleukin-22 in CD, demonstrated the strongest association with imaging/endoscopy-defined inflammation.

αEβ7 Integrin Identifies Subsets of Pro-Inflammatory Colonic CD4+ T Lymphocytes in Ulcerative Colitis.

Abstract Background and Aims: The αEβ7 integrin is crucial for retention of T lymphocytes at mucosal surfaces through its interaction with E-cadherin. Pathogenic or protective functions of these cells during human intestinal inflammation, such as ulcerative colitis [UC], have not previously been defined, with understanding largely derived from animal model data. Defining this phenotype in human samples is important for understanding UC pathogenesis and is of translational importance for therapeutic targeting of αEβ7–E-cadherin interactions. Methods: αEβ7+ and αEβ7− colonic T cell localization, inflammatory cytokine production and expression of regulatory T cell-associated markers were evaluated in cohorts of control subjects and patients with active UC by immunohistochemistry, flow cytometry and real-time PCR of FACS-purified cell populations. Results: CD4+αEβ7+ T lymphocytes from both healthy controls and UC patients had lower expression of regulatory T cell-associated genes, including FOXP3, IL-10, CTLA-4 and ICOS in comparison with CD4+αEβ7− T lymphocytes. In UC, CD4+αEβ7+ lymphocytes expressed higher levels of IFNγ and TNFα in comparison with CD4+αEβ7− lymphocytes. Additionally the CD4+αEβ7+ subset was enriched for Th17 cells and the recently described Th17/Th1 subset co-expressing both IL-17A and IFNγ, both of which were found at higher frequencies in UC compared to control. Conclusion: αEβ7 integrin expression on human colonic CD4+ T cells was associated with increased production of pro-inflammatory Th1, Th17 and Th17/Th1 cytokines, with reduced expression of regulatory T cell-associated markers. These data suggest colonic CD4+αEβ7+ T cells are pro-inflammatory and may play a role in UC pathobiology.

Prognostic and predictive biomarkers for patients with idiopathic pulmonary fibrosis treated with pirfenidone: post-hoc assessment of the CAPACITY and ASCEND trials

BACKGROUND Heterogeneity in the progression of idiopathic pulmonary fibrosis (IPF) might reflect diversity in underlying pathobiology, and represents a major challenge in the prediction of clinical progression and treatment benefit. Previous studies have found peripheral blood concentrations of several protein biomarkers to be prognostic for overall survival duration in patients with IPF, but these findings have generally not been directly compared and replicated between cohorts. We aimed to use the pivotal trials for pirfenidone to evaluate prognostic and predictive properties of biomarkers across multiple endpoints, and whether they are modulated by pirfenidone treatment. METHODS We did post-hoc analyses of test and replication cohorts from CAPACITY 004 (NCT00287716), CAPACITY 006 (NCT00287729), and ASCEND (NCT01366209) trials for the plasma proteins CCL13, CCL17, CCL18, CXCL13, CXCL14, COMP, interleukin 13, MMP3, MMP7, osteopontin, periostin, and YKL40. Eligible participants had IPF and received pirfenidone 2403 mg/day or placebo in CAPACITY (test cohort) or ASCEND (replication cohort), were aged 40-80 years, and without missing biomarker data at baseline. To identify biomarkers that were consistently prognostic for clinical outcome measures, the primary analysis was the association between biomarker concentrations at baseline and absolute change in percentage of predicted forced vital capacity (FVC%pred) at 12 months (CAPACITY week 48, ASCEND week 52) in the placebo group. Biomarkers within the test cohort that met predefined success criteria of a prognostic p value less than 0·10 from multivariate analysis were further assessed in the replication cohort. Furthermore, the predictive effect size (ie, biomarkers that were predictive for benefit from pirfenidone) was calculated as the difference in FVC%pred treatment effect (pirfenidone in relation to placebo) between high versus low biomarker subgroups at week 48 (test cohort) or week 52 (replication cohort). FINDINGS Several baseline biomarkers (CCL13, CCL18, COMP, CXCL13, CXCL14, periostin, and YKL40) were prognostic for progression outcomes in the placebo groups of the test cohort. However, only CCL18 was consistently prognostic for absolute change in percentage of FVC%pred in both the test (p=0·032) and replication (p=0·004) cohorts. Pirfenidone treatment benefit was consistent regardless of baseline biomarker concentration. INTERPRETATION Blood CCL18 concentrations were the most consistent predictor of disease progression across IPF cohorts with potential to inform new target discovery and clinical trial design. Future validation of these findings in prospective studies is warranted. FUNDING Genentech Inc.

microRNA–mRNA regulatory networks underlying chronic mucus hypersecretion in COPD

Chronic mucus hypersecretion (CMH) is a common feature in chronic obstructive pulmonary disease (COPD) and is associated with worse prognosis and quality of life. This study aimed to identify microRNA (miRNA)–mRNA regulatory networks underlying CMH. The expression profiles of miRNA and mRNA in bronchial biopsies from 63 COPD patients were associated with CMH using linear regression. Potential mRNA targets of each CMH-associated miRNA were identified using Pearson correlations. Gene set enrichment analysis (GSEA) and STRING (search tool for the retrieval of interacting genes/proteins) analysis were used to identify key genes and pathways. 20 miRNAs and 539 mRNAs were differentially expressed with CMH in COPD. The expression of 10 miRNAs was significantly correlated with the expression of one or more mRNAs. Of these, miR-134-5p, miR-146a-5p and the let-7 family had the highest representation of CMH-associated mRNAs among their negatively correlated predicted targets. KRAS and EDN1 were identified as key regulators of CMH and were negatively correlated predicted targets of miR-134-5p and let-7a-5p, let-7d-5p, and let-7f-5p, respectively. GSEA suggested involvement of MUC5AC-related genes and several other relevant gene sets in CMH. The lower expression of miR-134-5p was confirmed in primary airway fibroblasts from COPD patients with CMH. We identified miR-134-5p, miR-146a-5p and let-7 family, along with their potential target genes including KRAS and EDN1, as potential key miRNA–mRNA networks regulating CMH in COPD. miR-134, miR-146a and the let-7 family as regulators of chronic mucus hypersecretion in COPD http://ow.ly/1RWl30kWcWF

PTU-074 Ulcerative Colitis: The Alpha-e-beta-7 Integrin Is Associated With A High Frequency Of Th17, Th1 And Th17/th1 Cd4 Lymphocytes

Introduction T lymphocytes expressing the αEβ7 integrin are highly enriched within human intestinal epithelium and lamina propria. Studies exploring pathogenic or protective functions of αEβ7 expressing cells are lacking. Defining this phenotype is critical for our understanding of IBD pathogenesis and of translational importance with the development of etrolizumab, a humanised antibody specific to the β7 integrin that blocks α4β7:MAdCAM-1 and αEβ7:E-cadherin interactions. Methods Lymphocytes within colonic biopsies from a total of 43 UC and 35 non-disease control patients were studied. Multi-colour FACS was optimised to determine surface and intracellular protein expression (CD45, CD3, CD4, CD8, αE, β7, CD161, IL-17A, TNFα, IFNγ and IL-10). qPCR was performed on TCRαβ+ lymphocytes, FACS sorted into CD4+αEβ7+, CD4+αEβ7-, CD8+αEβ7+ and CD8+αEβ7- prior to gene expression assay. Dual stain IHC for αE, plus CD3, CD4, CD8 and FOXP3 was performed using a Ventana Benchmark XT autostainer. Severity of UC was stratified using the Mayo endoscopic score for ulcerative colitis. Results Ulcerative colitis was associated with a significantly increased frequency of T lymphocytes in the intestinal mucosa (p < 0.05). IHC revealed the highest expression of αE on CD4 and CD8 intraepithelial lymphocytes, although a substantial number of lamina propria lymphocytes also expressed this integrin. In UC, FACS demonstrated CD4+αEβ7+ lymphocytes had a higher potential to produce the pro-inflammatory cytokines IFNγ(p < 0.01), TNFα(p < 0.001) and IL-17A(p < 0.0001) than CD4+αEβ7- lymphocytes. In addition, a mean of 31.5% of the CD4+αEβ7+ lymphocytes produced both IL-17A and IFNγ compared to a mean of only 7.7% in the CD4+αEβ7- compartment (p < 0.001). IL-10 was not differentially expressed between CD4+αEβ7+ and CD4+αEβ7- lymphocytes in controls or UC, and a low frequency of αEβ7+FOXP3+ cells was observed by IHC. qPCR array confirmed higher mRNA levels of IFNγ(p < 0.001), TNFα(p < 0.01) and IL-17A(p < 0.01), and lower transcription of FOXP3 (p < 0.0001) in CD4+αEβ7+ cells compared to CD4+αEβ7- cells. Conclusion αEβ7 expression was associated with an enrichment of pro-inflammatory Th17, Th1 and Th17/Th1 T lymphocytes, and not associated with a regulatory phenotype. These data suggest therapeutic interventions targeting αE expressing T cells and the αEβ7 integrin itself may be viable approaches for reducing aberrant inflammatory responses in UC. Disclosure of Interest C. Lamb Grant/research support from: Genentech, J. Mansfield Grant/research support from: Genentech, G. Tew Employee of: Genentech, D. Gibbons Grant/research support from: Genentech, A. Long Grant/research support from: Genentech, P. Irving Grant/research support from: Genentech, L. Deihl Employee of: Genentech, J. Eastham Anderson Employee of: Genentech, G. O’Boyle Grant/research support from: Genentech, D. Jones Grant/research support from: Genentech, A. Hayday Grant/research support from: Genentech, M. Keir Employee of: Genentech, J. Egen Employee of: Genentech, J. Kirby Grant/research support from: Genentech.