Diana Luca

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.

A randomised phase I study of etrolizumab (rhuMAb β7) in moderate to severe ulcerative colitis

Objective Etrolizumab (rhuMAb β7, anti-β7, PRO145223) is a humanised monoclonal antibody targeting the β7 subunit of the heterodimeric integrins α4β7 and αEβ7, which are implicated in leucocyte migration and retention in ulcerative colitis (UC). This randomised phase I study evaluated the safety and pharmacology of etrolizumab in patients with moderate to severe UC. Design In the single ascending dose (SAD) stage, etrolizumab (0.3, 1.0, 3.0, 10 mg/kg intravenous, 3.0 mg/kg subcutaneous (SC) or placebo) was administered 4:1 (n=25) in each cohort. In the multiple dose (MD) stage, new patients received monthly etrolizumab (0.5 mg/kg SC (n=4), 1.5 mg/kg SC (n=5), 3.0 mg/kg SC (n=4), 4.0 mg/kg intravenous (n=5)) or placebo (n=5). The pharmacokinetics was studied and Mayo Clinic Score evaluated at baseline, day 29 (SAD), and days 43 and 71 (MD). Results In the SAD stage, there were no dose limiting toxicities, infusion or injection site reactions. Two impaired wound healing serious adverse events occurred in two patients receiving etrolizumab. In the MD stage, there were no dose limiting toxicities, and no infusion or injection site reactions. Headache was the most common adverse event, occurring more often in etrolizumab patients. Antietrolizumab antibodies were detected in two subjects. The duration of β7 receptor full occupancy was dose related. A clinical response was observed in 12/18 patients, and clinical remission in 3/18 patients treated with etrolizumab in the MD stage, compared with 4/5 and 1/5 placebo patients, respectively. Conclusion Etrolizumab is well tolerated in moderate to severe UC. Further investigation is warranted.

Discovering Genetic Ancestry Using Spectral Graph Theory

As one approach to uncovering the genetic underpinnings of complex disease, individuals are measured at a large number of genetic variants (usually SNPs) across the genome and these SNP genotypes are assessed for association with disease status. We propose a new statistical method called Spectral‐GEM for the analysis of genome‐wide association studies; the goal of Spectral‐GEM is to quantify the ancestry of the sample from such genotypic data. Ignoring structure due to differential ancestry can lead to an excess of spurious findings and reduce power. Ancestry is commonly estimated using the eigenvectors derived from principal component analysis (PCA). To develop an alternative to PCA we draw on connections between multidimensional scaling and spectral graph theory. Our approach, based on a spectral embedding derived from the normalized Laplacian of a graph, can produce more meaningful delineation of ancestry than by using PCA. Often the results from Spectral‐GEM are straightforward to interpret and therefore useful in association analysis. We illustrate the new algorithm with an analysis of the POPRES data [Nelson et al., 2008]. Genet. Epidemiol. 34:51–59, 2010.

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.

Magnetic resonance enterography is feasible and reliable in multicenter clinical trials in patients with Crohn's disease, and may help select subjects with active inflammation

Reliable tools for patient selection are critical for clinical drug trials.

Safety, pharmacokinetics, and biologic activity of pateclizumab, a novel monoclonal antibody targeting lymphotoxin α: results of a phase I randomized, placebo-controlled trial

IntroductionPateclizumab (MLTA3698A) is a humanized mAb against lymphotoxin α (LTα), a transiently expressed cytokine on activated B and T cells (Th1, Th17), which are implicated in rheumatoid arthritis (RA) pathogenesis. This study was conducted to assess the safety, tolerability, < NOTE: For clarity and per AMA/S-W Style, please restore the use of Oxford/serial commas (ie: David likes vanilla, strawberry, and chocolate ice cream) throughout. and biologic activity of single and multiple doses of intravenous (IV) or subcutaneous (SC) pateclizumab in RA patients.MethodsThe single ascending dose (SAD) phase in patients with stable RA consisted of six cohorts (4:1 active:placebo at 0.3 mg/kg IV, 1.0 mg/kg IV, 1.0 mg/kg SC, 3.0 mg/kg IV, 3.0 mg/kg SC, and 5.0 mg/kg IV; n = 5/cohort). In the multiple ascending dose (MAD) phase, patients with prespecified RA disease activity received three doses of pateclizumab or placebo (4:1) every 2 weeks (1.0 mg/kg SC, n = 10; 3.0 mg/kg SC, n = 20; or 5.0 mg/kg IV, n = 5). Safety and tolerability were assessed throughout, and clinical activity was determined after three doses (Week 6).ResultsWe observed no serious adverse events (AEs) or dose-limiting toxicities, and the majority of AEs were mild to moderate. The pharmacokinetic profiles were linear, and clearance was independent of dose. Reductions in levels of serum CXCL13 were observed, supporting the biologic activity of pateclizumab on the LTα pathway. Patients receiving pateclizumab in the 3.0 mg/kg MAD group (3.0 mg/kg SC) demonstrated ACR20, ACR50, and ACR70 response rates at week 6 of 75%, 56% and 25%, respectively, compared with 57%, 29%, and 0% in the placebo group. The median Disease Activity Score in 28 joints, C-reactive protein, reduction was 28% for pateclizumab, versus 8.4% for placebo.ConclusionsPateclizumabwas generally well-tolerated in RA patients. Preliminary evidence of clinical activity was observed in active RA patients at the dose level targeted for clinical effect.

A spectral graph approach to discovering genetic ancestry

Mapping human genetic variation is fundamentally interesting in fields such as anthropology and forensic inference. At the same time, patterns of genetic diversity confound efforts to determine the genetic basis of complex disease. Due to technological advances, it is now possible to measure hundreds of thousands of genetic variants per individual across the genome. Principal component analysis (PCA) is routinely used to summarize the genetic similarity between subjects. The eigenvectors are interpreted as dimensions of ancestry. We build on this idea using a spectral graph approach. In the process we draw on connections between multidimensional scaling and spectral kernel methods. Our approach, based on a spectral embedding derived from the normalized Laplacian of a graph, can produce more meaningful delineation of ancestry than by using PCA. The method is stable to outliers and can more easily incorporate different similarity measures of genetic data than PCA. We illustrate a new algorithm for genetic clustering and association analysis on a large, genetically heterogeneous sample.

A phase 1 study to evaluate the safety and LDL cholesterol–lowering effects of RG7652, a fully human monoclonal antibody against proprotein convertase subtilisin/kexin type 9

Proprotein convertase subtilisin/kexin type 9 (PCSK9) downregulates low‐density lipoprotein (LDL) receptors, thereby leading to a rise in circulating LDL cholesterol (LDL‐C). RG7652 is a fully human monoclonal antibody against PCSK9. This placebo‐controlled, phase 1 ascending‐dose study in healthy subjects evaluated the safety of RG7652 and its efficacy as a potential LDL‐C–lowering drug.

995 Feasibility, Precision and Reproducibility of MR Enterography for Detection of Inflammation in Crohn's Disease in a Multicenter Clinical Trial

Conclusions: The majority of strictures in CD patients treated by surgery are consistent with a mixed type inflammation (acute inflammation plus fibrosis). The presence of stratified BS pattern shows a significantly higher degree of fibrosis while the evidence of high mural signal intensity on T2-weighted fatsaturated images on MRI reflects histological features of acute inflammation. Even if the ideal definition of the type of the strictures in CD still remains significantly far to be obtained, the combined use of BS and MRI can offer useful information in a sub-group of patients needing surgery for complicating CD.

Mo1680 Assessing Crohn's Disease Inflammatory Biomarker Diagnostic Accuracy Using Ileocolonoscopy or a Combined Ileocolonoscopy-CTE Score in the Embark Study

Background: Crohns disease (CD), a transmural inflammation of the bowel wall, presents most commonly in the terminal ileum and ascending colon, resulting in challenges in the accurate diagnosis of intestinal inflammation. Non-invasive biomarkers are attractive alternatives to ileocolonoscopy (Ico) to monitor inflammatory CD activity. We assessed the performance of two well-characterized biomarkers, fecal calprotectin and serum CRP, for diagnosis of active mucosal inflammation as measured by Ico alone or a score deduced from combination of Ico and CT enterography (CTE). Methods: 153 CD patients enrolled in the EMBARK study underwent Ico and a subset of patients (n=65) also underwent CTE. Previous intestinal resection rates and disease activity were similar between the groups (resection in 52% and median HBI of 8 in both groups). Both Ico and CTE were scored separately by central read then a novel scoring system that incorporates disease activity visible by either Ico or CTE was developed by both central readers to jointly assess disease activity in IcoCTE patients. Disease severity and length scores were assigned for individual bowel segments based on ulcer size, hyperenhancement and wall thickening. ELISA was used to measure CRP and calprotectin. Results: Active CD was observed in 22% (34/153) of patients by Ico alone using ulcerated area ≥2 and 34% (52/153) of patients using SES-CD>4. CRP was significantly higher in patients using either definition of CD activity, while calprotectin was increased only when SES-CD>4 was used to identify active CD. In the cohort of patients where both Ico and CTE were performed, more patients were observed to have active CD by Ico-CTE score ≥4 (42 of 65, 65%) than by Ico alone using ulcerated area (9 of 65, 14%) or SES-CD>4 (13 of 65, 20%). Patients with ileal disease by Ico-CTE were likely to have missed CD activity by Ico alone (12 out of 22, 55%). Calprotectin was significantly different at the 1% level between active and inactive CD patients when the combined IcoCTE was used (p=0.004) but not by Ico alone using ulcerated area (p=0.26) or SES-CD≥4 (p=0.06). Use of the combined Ico-CTE score also increased specificity of calprotectin in detecting inflammation using a 100 μg/g cutoff. Calprotectin performed similarly in detecting CD activity in the ileum as ileocolonic or colonic disease (77/79 vs. 68/85 sensitivity/ specificity) measured by Ico-CTE. Conclusion: The use of a novel Ico-CTE scoring system increases the detection of mucosal inflammation, particularly in patients with ileal disease. Calprotectin had increased performance in active CD patients when mucosal activity was measured by a combination of Ico and CTE. Ico alone is likely to underestimate the number of active CD patients and therefore the performance of calprotectin as a biomarker of inflammation.