Fedorak, R N

Summary Background Regulatory requirements for claims of mucosal healing in ulcerative colitis ( UC ) will require demonstration of both endoscopic and histologic healing. Quantifying these rates is essential for future drug development. Aims To meta‐analyse endoscopic and histologic placebo response and remission rates in UC randomised controlled trials ( RCT s) and identify factors influencing these rates. Methods MEDLINE , EMBASE and the Cochrane Library were searched from inception to March 2017 for placebo‐controlled trials of pharmacological interventions for UC . Endoscopic and histologic placebo rates were pooled by random effects. Mixed effects univariable and multivariable meta‐regression was used to evaluate the influence of patient, intervention and trial‐related study‐level covariates on these rates. Results Fifty‐six induction (placebo n = 4171) and 8 maintenance trials (placebo n = 1011) were included. Pooled placebo endoscopic remission and response rates for induction trials were 23% [95 confidence interval ( CI ) 19‐28%] and 35% [95% CI 27‐42%] respectively, and 20% [95% CI 16‐24%] for maintenance of remission. The pooled histologic placebo remission rate was 14% [95% CI 8‐22%] for induction trials. High heterogeneity was observed for all outcomes ( I 2 56.2%‐88.3%). On multivariable meta‐regression, central endoscopy reading was associated with significantly lower endoscopic placebo remission rates (16% vs 25%; OR = 0.52, [95% CI 0.29‐0.92], P = 0.03). On univariable meta‐regression, higher histologic placebo remission was associated with concomitant corticosteroids ( OR = 1.17 [95% CI 1.08‐1.26], P < 0.0001, per 10% increase in corticosteroid use). Conclusions Placebo endoscopic and histologic rates range from 14% to 35% in UC RCT s but are highly heterogeneous. Outcome standardisation may reduce heterogeneity and is needed in this field.

Summary Background Coeliac disease, an autoimmune disorder triggered by gluten ingestion, is managed by a gluten‐free diet ( GFD ), which is difficult for many patients. Larazotide acetate is a first‐in‐class oral peptide that prevents tight junction opening, and may reduce gluten uptake and associated sequelae. Aim To evaluate the efficacy and tolerability of larazotide acetate during gluten challenge. Methods This exploratory, double‐blind, randomised, placebo‐controlled study included 184 patients maintaining a GFD before and during the study. After a GFD run‐in, patients were randomised to larazotide acetate (1, 4, or 8 mg three times daily) or placebo and received 2.7 grams of gluten daily for 6 weeks. Outcomes included an experimental biomarker of intestinal permeability, the lactulose‐to‐mannitol ( LAMA ) ratio and clinical symptoms assessed by Gastrointestinal Symptom Rating Scale ( GSRS ) and anti‐transglutaminase antibody levels. Results No significant differences in LAMA ratios were observed between larazotide acetate and placebo groups. Larazotide acetate 1‐mg limited gluten‐induced symptoms measured by GSRS ( P = 0.002 vs. placebo). Mean ratio of anti‐tissue transglutaminase IgA levels over baseline was 19.0 in the placebo group compared with 5.78 ( P = 0.010), 3.88 ( P = 0.005) and 7.72 ( P = 0.025) in the larazotide acetate 1‐, 4‐, and 8‐mg groups, respectively. Adverse event rates were similar between larazotide acetate and placebo groups. Conclusions Larazotide acetate reduced gluten‐induced immune reactivity and symptoms in patients with coeliac disease undergoing gluten challenge and was generally well tolerated; however, no significant difference in LAMA ratios between larazotide acetate and placebo was observed. Results and design of this exploratory study can inform the design of future studies of pharmacological interventions in patients with coeliac disease.