Efficacy and Safety of Abrilumab in a Randomized, Placebo-Controlled Trial for Moderate-to-Severe Ulcerative Colitis.

BACKGROUND & AIMS: The α4ß7 integrin is a validated target in inflammatory bowel disease. This randomized, phase 2b, placebo-controlled, double-blind study evaluated the efficacy and safety of the anti-α4ß7 antibody abrilumab in patients with moderate-to-severe ulcerative colitis despite treatment with conventional therapies. METHODS: Patients (total Mayo Score 6-12, recto-sigmoidoscopy score ≥2) with inadequate response or intolerance to conventional therapies were randomized to receive subcutaneous abrilumab (7, 21, or 70 mg) on day 1, weeks 2 and 4, and every 4 weeks; abrilumab 210 mg on day 1; or placebo. The primary end point was remission (total Mayo Score ≤2 points, no individual sub-score >1 point) for the 2 highest dosages at week 8. Key secondary end points were response and mucosal healing (centrally read) at week 8. RESULTS: For 354 patients who received ≥1 dose of investigational product (placebo, n = 116; 7 mg, n = 21; 21 mg, n = 40; 70 mg, n = 98; 210 mg, n = 79), non-adjusted remission rates at week 8 were 4.3%, 13.3%, and 12.7% for the placebo and abrilumab 70-mg and 210-mg groups, respectively (P < .05 for 70 and 210 mg vs placebo); odds of achieving remission were significantly greater with abrilumab 70 mg (odds ratio 3.35; 90% CI 1.41-7.95; P = .021) and 210 mg (odds ratio 3.33; 90% confidence interval 1.34-8.26; P = .030) than with placebo. Response and mucosal healing rates with these dosages also were significantly greater than with placebo. Higher baseline α4ß7 levels on naïve CD4+ T cells were a prognostic indicator for overall outcome, but not a predictive biomarker of abrilumab response. There were no cases of progressive multifocal leukoencephalopathy or deaths. CONCLUSIONS: Abrilumab treatment for 8 weeks induced remission, clinical response, and mucosal healing in patients with moderate-to-severe ulcerative colitis. ClinicalTrials.gov, number NCT01694485.

Safety, pharmacokinetics and pharmacodynamics of AMG 811, an anti-interferon-γ monoclonal antibody, in SLE subjects without or with lupus nephritis.

OBJECTIVE: To evaluate safety, pharmacokinetics and pharmacodynamics of anti-interferon (IFN)-γ monoclonal antibody AMG 811 in subjects with SLE without or with lupus nephritis (LN). METHODS: In this phase Ib, randomised, multiple-dose escalation study (NCT00818948), subjects without LN were randomised to subcutaneous AMG 811 (6, 20 or 60 mg) or placebo and subjects with LN were randomised to subcutaneous AMG 811 (20, 60 or 120 mg) or placebo every four weeks for three total doses. Outcomes included incidence of adverse events (AEs); pharmacokinetics; levels of serum proteins (CXCL-10, interleukin 18, monocyte chemotactic protein-1); changes in gene transcript profiles and clinical parameters (Safety of Estrogen in Lupus Erythematosus National Assessment-Systemic Lupus Erythematosus Disease Activity Index (SELENA-SLEDAI) scores, proteinuria, anti-double-stranded DNA (anti-dsDNA) antibodies, C3 complement, C4 complement). RESULTS: Fifty-six subjects enrolled (28 SLE without LN; 28 with LN). Baseline mean SELENA-SLEDAI scores were 2.2 and 12.0 for SLE subjects without and with LN, respectively. Most subjects reported an AE; no meaningful imbalances were observed between AMG 811 and placebo. Pharmacokinetic profiles were similar and mostly dose-proportional in subjects without or with LN. AMG 811 treatment reduced CXCL-10 protein levels and blood-based RNA IFN-γ Blockade Signature compared with placebo. Reductions were less pronounced and not sustained in subjects with LN, even at the highest dose tested, compared with subjects without LN. No effect on SELENA-SLEDAI scores, proteinuria, C3 or C4 complement levels, or anti-dsDNA antibodies was observed. CONCLUSION: AMG 811 demonstrated favourable pharmacokinetics and acceptable safety profile but no evidence of clinical impact. IFN-γ-associated biomarkers decreased with AMG 811; effects were less pronounced and not sustained in LN subjects. TRIAL REGISTRATION NUMBER: NCT00818948; results.

Brief Report: Pharmacodynamics, Safety, and Clinical Efficacy of AMG 811, a Human Anti-Interferon-γ Antibody, in Patients With Discoid Lupus Erythematosus.

OBJECTIVE: Interferon-γ (IFNγ) is implicated in the pathogenesis of discoid lupus erythematosus (DLE). This study sought to evaluate a single dose of AMG 811, an anti-IFNγ antibody, in patients with DLE. METHODS: The study was designed as a phase I randomized, double-blind, placebo-controlled crossover study of the pharmacodynamics, safety, and clinical efficacy of AMG 811 in patients with DLE. Patients received a single subcutaneous dose of AMG 811 (180 mg) or placebo. The patients in sequence 1 received AMG 811 followed by placebo, while those in sequence 2 received placebo followed by AMG 811. Pharmacodynamic end points included global transcriptional analyses of lesional and nonlesional skin, IFNγ blockade signature (IGBS) transcriptional scores in the skin and blood, keratinocyte IFNγ RNA scores, and serum levels of CXCL10 protein. Additional end points were efficacy outcome measures, including the Cutaneous Lupus Erythematosus Disease Area and Severity Index, and safety outcome measures. RESULTS: Sixteen patients with DLE were enrolled in the study (9 in sequence 1 and 7 in sequence 2). AMG 811 treatment reduced the IGBS score (which was elevated in DLE patients at baseline) in both the blood and lesional skin. The keratinocyte IFNγ RNA score was not affected by administration of AMG 811. Serum CXCL10 protein levels (which were elevated in the blood of DLE patients) were reduced with AMG 811 treatment. The AMG 811 treatment was well tolerated but did not lead to statistically significant improvements in any of the efficacy outcome measures. CONCLUSION: AMG 811 treatment led to changes in IFNγ-associated biomarkers and was well tolerated, but no significant clinical benefit was observed in patients with DLE.

Gene expression profiles can predict panitumumab monotherapy responsiveness in human tumor xenograft models.

BACKGROUND: Epidermal growth factor receptor (EGFR)-targeted agents have demonstrated clinical benefit in patients with cancer. Identifying tissue-of-origin-independent predictive biomarkers is important to optimally treat patients. We sought to identify a gene array profile that could predict responsiveness to panitumumab, a fully human EGFR-binding antibody, using preclinical models of human cancer. METHODS: Mice bearing 25 different xenograft models were treated twice weekly with panitumumab or immunoglobulin G2 control to determine their responsiveness to panitumumab. Samples from these xenografts and untreated xenografts were arrayed on the Affymetrix human U133A gene chip to identify gene sets predicting responsiveness to panitumumab using univariate and multivariate analyses. The predictive models were validated using the leave-one-group-out (LOO) method. RESULTS: Of the 25 xenograft models tested, 12 were responsive and 13 were resistant to panitumumab. Unsupervised analysis demonstrated that the xenograft models clustered by tissue type rather than responsiveness to panitumumab. After normalizing for tissue effects, samples clustered by responsiveness using an unsupervised multidimensional scaling. A multivariate selection algorithm was used to select 13 genes that could stratify xenograft models based on responsiveness after adjustment for tissue effects. The method was validated using the LOO method on a training set of 22 models and confirmed independently on three new models. In contrast, a univariate gene selection method resulted in higher misclassification rates. CONCLUSION: A model was constructed from microarray data that prospectively predict responsiveness to panitumumab in xenograft models. This approach may help identify patients, independent of disease origin, likely to benefit from panitumumab.

Sources of variation in baseline gene expression levels from toxicogenomics study control animals across multiple laboratories.

BACKGROUND: The use of gene expression profiling in both clinical and laboratory settings would be enhanced by better characterization of variance due to individual, environmental, and technical factors. Meta-analysis of microarray data from untreated or vehicle-treated animals within the control arm of toxicogenomics studies could yield useful information on baseline fluctuations in gene expression, although control animal data has not been available on a scale and in a form best served for data-mining. RESULTS: A dataset of control animal microarray expression data was assembled by a working group of the Health and Environmental Sciences Institute's Technical Committee on the Application of Genomics in Mechanism Based Risk Assessment in order to provide a public resource for assessments of variability in baseline gene expression. Data from over 500 Affymetrix microarrays from control rat liver and kidney were collected from 16 different institutions. Thirty-five biological and technical factors were obtained for each animal, describing a wide range of study characteristics, and a subset were evaluated in detail for their contribution to total variability using multivariate statistical and graphical techniques. CONCLUSION: The study factors that emerged as key sources of variability included gender, organ section, strain, and fasting state. These and other study factors were identified as key descriptors that should be included in the minimal information about a toxicogenomics study needed for interpretation of results by an independent source. Genes that are the most and least variable, gender-selective, or altered by fasting were also identified and functionally categorized. Better characterization of gene expression variability in control animals will aid in the design of toxicogenomics studies and in the interpretation of their results.

Mixture modeling approach to flow cytometry data.

Flow Cytometry has become a mainstay technique for measuring fluorescent and physical attributes of single cells in a suspended mixture. These data are reduced during analysis using a manual or semiautomated process of gating. Despite the need to gate data for traditional analyses, it is well recognized that analyst-to-analyst variability can impact the dataset. Moreover, cells of interest can be inadvertently excluded from the gate, and relationships between collected variables may go unappreciated because they were not included in the original analysis plan. A multivariate non-gating technique was developed and implemented that accomplished the same goal as traditional gating while eliminating many weaknesses. The procedure was validated against traditional gating for analysis of circulating B cells in normal donors (n = 20) and persons with Systemic Lupus Erythematosus (n = 42). The method recapitulated relationships in the dataset while providing for an automated and objective assessment of the data. Flow cytometry analyses are amenable to automated analytical techniques that are not predicated on discrete operator-generated gates. Such alternative approaches can remove subjectivity in data analysis, improve efficiency and may ultimately enable construction of large bioinformatics data systems for more sophisticated approaches to hypothesis testing.