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ABSTRACT Background Coeliac disease is due to an acquired, lifelong gluten‐specific immune response resulting in a gluten‐dependent chronic immune‐mediated enteropathy associated with gastrointestinal and extraintestinal morbidity. Strictly avoiding dietary gluten is the only available management but has never been subjected to rigorous efficacy assessment now required for a pharmaceutical agent. Gluten‐free diet (GFD) is partially and inconsistently effective, but it places a high burden on patients, families, the food industry, and regulators and is defined inconsistently around the world, highlighting the need for effective and convenient adjunctive pharmacological therapies. Aims To summarize key patient, scientific, and regulatory considerations for coeliac disease drug development based on a multi‐stakeholder meeting focused on accelerating clinical trials. Methods A pre‐competitive meeting convened by the Beyond Celiac Coalition (May 2024) included patients with coeliac disease, academic experts, pharmaceutical industry representatives, and participants from the US Food and Drug Administration. Moderated panel addressed patient priorities, symptom and histologic endpoints, biopsy and histology methods, gluten challenge design, clinical trial duration, and regulatory expectations. Themes were synthesized qualitatively with focus on trial design implications and unresolved questions. Results Participants described high symptom burden and psychosocial impact despite gluten‐free diet adherence underscoring unmet therapeutic need in coeliac disease. Regulatory perspectives emphasized the need for clinically meaningful improvement and evidence of intestinal benefit, framed as symptom and histology co‐primary endpoints in clinical trials. These expectations were discussed as most applicable to trial populations with both clinically meaningful symptoms and active histologic injury at baseline; for other phenotypes, it was emphasized that endpoint strategy, the role of gluten exposure, and trial duration should be tailored case by case to the population and mechanism of action. Practical challenges identified included endpoint selection and definition, discordance between symptoms and histology, selecting fit‐for‐purpose symptom measures; standardizing biopsy acquisition and central histology reads to address patchiness and variability, pre‐specifying definitions of meaningful histologic change given ongoing uncertainty about healing, and trial feasibility. Controlled gluten exposure was discussed as a tool to improve interpretability of efficacy outcomes, with careful consideration of dose, duration, patient burden and safety. Discussion addressed the ideal length of the double‐blind period, including a shorter 24‐week double‐blind study with an open‐label extension versus a 52‐week double‐blind design. Trial duration should balance scientific rigour, patient retention, and the need for longer‐term safety and durability data, with flexibility to tailor the approach to context. Conclusions Progress in coeliac disease drug development will require patient‐centred, scientifically robust but feasible trial designs with appropriate endpoints, justified use of gluten exposure, consideration of improved biomarkers to reduce patient burden and early regulatory engagement. Continued multi‐stakeholder collaboration, including dedicated consideration of paediatric drug development, is essential to advance effective therapies.

Dietary salt intake has significant effects on arterial blood pressure and the development of hypertension. Mechanisms underlying salt-dependent changes in blood pressure remain poorly understood. The goal of the present study was to utilize urine samples from the Dietary Approaches to Stop Hypertension (DASH)-Sodium trial and a targeted metabolomic approach to identify associations of urinary metabolites with blood pressure phenotypes on low- or high-sodium intake. We examined urinary levels of metabolites in 103 participants of the DASH-Sodium trial after 30 days on a defined diet containing high sodium (targeting 150 mmol sodium intake per day) or low sodium (50 mmol sodium per day). Systolic or diastolic pressure was 10 or more mmHg higher on the high-sodium intake in 51 of the 103 participants. Targeted chromatography/mass spectrometry analysis was performed in 24-h urine samples for 10 metabolites related to the tricarboxylic acid cycle and 47 amino metabolites. Urinary metabolite levels improved the prediction of classification of blood pressure salt-sensitivity based on race, age and sex. Random forest and generalized linear mixed model analyses identified significant (false discovery rate <0.05) associations between 24 h excretions of β-aminoisobutyric acid, cystine, citrulline, homocysteine and lysine and systolic blood pressure and between cystine and diastolic blood pressure. The differences of 24 h excretion of homocysteine between low- and high-sodium intakes were significantly associated with the differences in diastolic blood pressure. These associations were significant with or without considering demographic factors. Treatment with β-aminoisobutyric acid significantly attenuated high-salt-induced hypertension in Dahl salt-sensitive rats. These findings support the presence of new mechanisms of blood pressure regulation involving metabolic intermediaries.

The Dahl salt-sensitive rat is a widely used model of human salt-sensitive forms of hypertension. The kidney plays an important role in the pathogenesis of Dahl salt-sensitive hypertension, but the molecular mechanisms involved remain a subject of intensive investigation. Gene expression profiling studies suggested that 11β-hydroxysteroid dehydrogenase type 1 might be dysregulated in the renal medulla of Dahl salt-sensitive rats. Additional analysis confirmed that renal medullary expression of 11β-hydroxysteroid dehydrogenase type 1 was downregulated by a high-salt diet in SS-13BN rats, a consomic rat strain with reduced blood pressure salt sensitivity, but not in Dahl salt-sensitive rats. 11β-Hydroxysteroid dehydrogenase type 1 is known to convert inactive 11-dehydrocorticosterone to active corticosterone. The urinary corticosterone/11-dehydrocorticosterone ratio as well as urinary excretion of corticosterone was higher in Dahl salt-sensitive rats than in SS-13BN rats. Knockdown of renal medullary 11β-hydroxysteroid dehydrogenase type 1 with small-interfering RNA attenuated the early phase of salt-induced hypertension in Dahl salt-sensitive rats and reduced urinary excretion of corticosterone. Knockdown of 11β-hydroxysteroid dehydrogenase type 1 did not affect blood pressure in SS-13BN rats. Long-term attenuation of salt-induced hypertension was achieved with small hairpin RNA targeting renal medullary 11β-hydroxysteroid dehydrogenase type 1. In summary, we have demonstrated that suppression of 11β-hydroxysteroid dehydrogenase type 1 expression in the renal medulla attenuates salt-induced hypertension in Dahl salt-sensitive rats.