Celiac disease (CeD), caused by immune reactions to cereal gluten, is treated with gluten -elimination diets. Within hours of gluten exposure, either perorally or extraorally by intradermal injection, treated patients experience gastrointestinal symptoms. To test whether gluten exposure leads to systemic cytokine production time -related to symptoms, series of multiplex cytokine measurements were obtained in CeD patients after gluten challenge. Peptide injection elevated at least 15 plasma cytokines, with IL-2, IL-8, and IL-10 being most prominent (fold-change increase at 4 hours of 272, 11, and 1.2, respectively). IL-2 and IL-8 were the only cytokines elevated at 2 hours, preceding onset of symptoms. After gluten ingestion, IL-2 was the earliest and most prominent cytokine (15-fold change at 4 hours). Supported by studies of patient-derived gluten-specific T cell clones and primary lymphocytes, our observations indicate that gluten-specific CD4+ T cells are rapidly reactivated by antigen -exposure likely causing CeD-associated gastrointestinal symptoms.

SUMMARY Background Gluten-free diet (GFD) is the only management available for celiac disease (CeD), a permanent immune intolerance to gluten. Nexvax2® is the first therapeutic vaccine designed to treat CeD. The adjuvant-free formulation of peptides is intended to engage and render gluten-specific CD4+ T cells unresponsive to further antigenic stimulation. We have assessed safety and pharmacodynamics of Nexvax2® in patients with CeD on GFD. Methods In two randomized, double-blind, placebo-controlled, phase 1 studies at 12 community sites in Australia, New Zealand and the United States, we screened for HLA-DQ2·5+ CeD patients (aged 18–70 years) on GFD. The screening and post-treatment periods included either a crossover, placebo-controlled, oral gluten challenge (OGC) to mobilize and assess T cells responsive to Nexvax2 or, for the final cohort in each study, endoscopy and duodenal histology without OGC. Participants and study staff were masked to the gluten content of food provided for each interval of the OGCs. One of two sequences of active and placebo challenges was assigned (1:1) by central randomization using a simple block method. The sequence of challenges was active/placebo then active/placebo, or placebo/active then active/placebo for the OGCs in the screening and post-treatment periods, respectively. Participants with a negative interferon (IFN)-γ release assay (IGRA) to Nexvax2 peptides after the screening OGC, or Marsh score >1 were discontinued before dosing. There was temporal allocation of participants to sequential cohorts assessing multiple fixed intradermal doses of Nexvax2 (60µg, 90µg, or 150µg weekly in the 3-dose study; or 150µg, or 300µg two-times weekly in the 16-dose study) in 0.1 mL 0.9% sodium chloride. A maximum tolerated dose (MTD) was administered in the final biopsy cohort in each study. Participants within each cohort were assigned to receive Nexvax2 or placebo by central randomization (2:1, respectively) using simple block method in SAS software Version 9·2. Participants, investigators, and study staff were masked to the treatment assignment, except for the study pharmacist. The primary endpoint was the number and percentage of adverse events in the treatment period. Other safety outcomes included duodenal histology, gastrointestinal symptoms, plasma cytokines, and immune cell frequencies. The main pharmacodynamic endpoint was IGRA to Nexvax2 peptides. All participants who received Nexvax2 or placebo, the safety population, were included in an intention to treat analysis for the primary endpoint. Additional post hoc analyses were also performed. Both trials were completed and closed before data analysis. Trials were registered with Australian New Zealand Clinical Trials Registry, numbers ACTRN12612000355875 and ACTRN12613001331729. Findings Participants were screened from November 28, 2012 to August 14, 2014, and August 3, 2012 to September 10, 2013, for the 3-dose and 16-dose studies respectively. Across both studies, 136 (80%) of 169 volunteers met initial eligibility crite...

Summary Background The prevalence and severity of duodenal injury in coeliac disease patients controlled on a gluten‐free diet is unclear. Aims To use quantitative histology to assess duodenal injury in treated coeliac disease. Methods Quantitative histology in pre‐treatment duodenal biopsies collected in clinical trials assessing an investigational immunotherapy for coeliac disease was analysed. Morphometric readings were converted to Marsh classifications. Results Ninety‐three patients had duodenal biopsies. For well‐oriented sections of second part biopsies, six (6%) patients were classified as Marsh 0 or 1, 30 (33%) as Marsh 2 and 56 (60%) as Marsh 3a or 3b. In second part biopsies from 78 seronegative patients on gluten‐free diet >2 years, 27 (35%) were Marsh 2 and 45 (58%) were Marsh 3a or 3b. Distal compared to proximal duodenal biopsies had significantly higher villus height to crypt depth ratios (median, third part: 2.1 vs bulb: 1.4; P < 0.0001) and higher intraepithelial lymphocyte density (44 vs 30; P = 0.0002). The sum of paired villus height and adjacent crypt depth measurements was correlated strongly with villus height (rs = 0.82, P < 10−10). At least one biopsy was graded Marsh 3a or worse in all 26 patients who had serial biopsies from the bulb, first, second and third part, but was overlooked in 20 patients by subjective histology. Conclusions Quantitative histology in well‐oriented biopsy sections reveals villus atrophy in the majority of patients with coeliac disease who appear well controlled on gluten‐free diet. Standardisation of biopsy collection, processing and evaluation could substantially improve the value of follow‐up biopsies in coeliac disease.

Summary Background In patients with coeliac disease, FODMAPs in gluten‐containing foods, and participant anticipation of a harmful (‘nocebo’) effect, may contribute to acute symptoms after gluten challenge. Aim To establish acute gluten‐specific symptoms linked to immune activation in coeliac disease Methods We included 36 coeliac disease patients on a gluten‐free diet receiving placebo in the RESET CeD trial. Double‐blind, bolus vital wheat gluten (~6‐g gluten protein) and sham challenges low in FODMAPs were consumed 2 weeks apart. Assessments included daily Coeliac Disease Patient Reported Outcome (CeD PRO) symptom scores (0‐10), adverse events and serum interleukin‐2 (baseline and 4 hours). Results Median CeD PRO score for nausea increased most (sham: 0 vs gluten: 5.5; P < .001). Apart from tiredness (1 vs 4, P = .005) and headache (0 vs 2, P = .002), changes in other symptoms were small or absent. Only nausea increased significantly in occurrence with gluten (11% vs 69%, P < .001). Without nausea, only tiredness and flatulence were common after gluten. Nausea (6% vs 61%, P < .001; median onset: 1:34 hours) and vomiting (0% vs 44%, P < .001; 1:51 hours) were the only adverse events more common with gluten than sham. Interleukin‐2 was always below the level of quantitation (0.5 pg/mL) at baseline, and after sham. Interleukin‐2 was elevated after gluten in 97% of patients (median fold‐change: 20), and correlated with severity of nausea (rs = .49, P = .0025) and occurrence of vomiting (P = .0005). Conclusions Nausea and vomiting are relatively specific indicators of acute gluten ingestion, and correlate with immune activation. IBS‐like symptoms without nausea are unlikely to indicate recent gluten exposure.

BackgroundNexvax2® is a novel, peptide-based, epitope-specific immunotherapy intended to be administered by regular injections at dose levels that increase the threshold for clinical reactivity to natural exposure to gluten and ultimately restore tolerance to gluten in patients with celiac disease. Celiac disease patients administered fixed intradermal doses of Nexvax2 become unresponsive to the HLA-DQ2·5-restricted gluten epitopes in Nexvax2, but gastrointestinal symptoms and cytokine release mimicking gluten exposure, that accompany the first dose, limit the maximum tolerated dose to 150 μg. Our aim was to test whether stepwise dose escalation attenuated the first dose effect of Nexvax2 in celiac disease patients.MethodsWe conducted a randomized, double-blind, placebo-controlled trial at four community sites in Australia (3) and New Zealand (1) in HLA-DQ2·5 genotype positive adults with celiac disease who were on a gluten-free diet. Participants were assigned to cohort 1 if they were HLA-DQ2·5 homozygotes; other participants were assigned to cohort 2, or to cohort 3 subsequent to completion of cohort 2. Manual central randomization without blocking was used to assign treatment for each cohort. Initially, Nexvax2-treated participants in cohorts 1 and 2 received an intradermal dose of 30 μg (consisting of 10 μg of each constituent peptide), followed by 60 μg, 90 μg, 150 μg, and then eight doses of 300 μg over six weeks, but this was amended to include doses of 3 μg and 9 μg and extended over a total of seven weeks. Nexvax2-treated participants in cohort 3 received doses of 3 μg, 9 μg, 30 μg, 60 μg, 90 μg, 150 μg, 300 μg, 450 μg, 600 μg, 750 μg, and then eight of 900 μg over nine weeks. The dose interval was 3 or 4 days. Participants, care providers, data managers, sponsor personnel, and study site personnel were blinded to treatment assignment. The primary outcome was the number of adverse events and percentage of participants with adverse events during the treatment period. This completed trial is registered with ClinicalTrials.gov, number NCT02528799.FindingsFrom the 73 participants who we screened from 19 August 2015 to 31 October 2016, 24 did not meet eligibility criteria, and 36 were ultimately randomized and received study drug. For cohort 1, seven participants received Nexvax2 (two with the starting dose of 30 μg and then five at 3 μg) and three received placebo. For cohort 2, 10 participants received Nexvax2 (four with starting dose of 30 μg and then six at 3 μg) and four received placebo. For cohort 3, 10 participants received Nexvax2 and two received placebo. All 36 participants were included in safety and immune analyses, and 33 participants completed treatment and follow-up; in cohort 3, 11 participants were assessed and included in pharmacokinetics and duodenal histology analyses. Whereas the maximum dose of Nexvax2 had previously been limited by adverse events and cytokine release, no such effect was observed when dosing escalated from 3 μg up to 300 μg in HLA-DQ2·5 homozygotes or to 900 μg in HLA-D...