A Study to Evaluate the Efficacy and Safety of AMG 714 in Adult Patients With Celiac Disease

Attenuation of the effects of gluten exposure was assessed by measuring the percent change from baseline in villous height to crypt depth ratio after 10 weeks of gluten challenge. Villi are the small fingerlike projections that line the small intestine and promote nutrient absorption and are often shortened in patients with celiac disease. Crypts are grooves between the villi that are often elongated in patients with celiac disease. A decreased VH:CD ratio indicates worsening disease. Small bowel biopsies were performed at baseline and week 12; histological assessments were performed by a blinded central pathologist.

Intraepithelial lymphocytes (IELS) are white blood cells interspersed between epithelial cells of the small and large intestine where they function to preserve the integrity of the mucosal barrier by protecting the epithelium against pathogen or immune-induced pathology. Increased intraepithelial lymphocytes is associated with celiac disease. Small bowel biopsies were performed at baseline and week 12; histological assessments were performed by a blinded central pathologist.

The Marsh classification system describes the stages of damage in the small intestine as seen under a microscope, with possible values of 0, 1, 2, 3a, 3b, or 3c. A score of 0 (best score) indicates that the intestinal lining is normal and celiac disease highly unlikely, a score of 3c (worst score) indicates increased intraepithelial lymphocytes, increased crypt hyperplasia and complete villi atrophy. Improvement is defined as a lower grade on the Marsh score scale compared to baseline.

Levels of anti-tTG IgA antibodies in serum were determined using an enzyme-linked immunosorbent assay (ELISA) immunoassay.

Levels of serum anti-DGP antibodies (immunoglobulin A [IgA] and immunoglobulin G [IgG]) were determined using ELISA immunoassay.

Participants were asked to record every bowel movement during the study using an electronic diary. If no bowel movements were experienced on any given day, the participant was required to document this using the electronic diary.

The Bristol Stool Form Scale (BSFS) is a pictorial aid to help study participants identify the shape and consistency of their bowel movements. Participants were asked to complete this form daily using an electronic diary at the time of each bowel movement. The BSFS categorizes bowel movements into 7 types, from Type 1 (separate hard lumps, like nuts; hard to pass) to Type 7 (watery, no solid pieces, entirely liquid). Diarrhoea was defined as at least one BSFS score >= 6 for the given week.

The GSRS is a 15-question 7-scale questionnaire used to assess 5 dimensions of gastrointestinal syndromes: diarrhea, indigestion, constipation, abdominal pain, and reflux. Questions are scored between 1 (no discomfort at all) and 7 (very severe discomfort). The total GSRS score is calculated as the sum of the scores of all 15 questions, and ranges from 15 (no discomfort at all) to 105 (very severe discomfort in all 5 dimensions of gastrointestinal syndromes).

The CeD-GSRS score is derived from a subset of questions from the GSRS questionnaire, including the diarrhea, indigestion, and abdominal pain domains (a total of 10 questions), which are each assessed on a scale of 1 (no discomfort at all) to 7 (very severe discomfort). The total CeD-GSRS score is calculated as the sum of the scores of all 10 questions, and ranges from 10 (no discomfort at all) to 70 (very severe discomfort in all celiac syndromes).