Efficacy and safety of gluten peptide-based antigen-specific immunotherapy (Nexvax2) in adults with coeliac disease after bolus exposure to gluten (RESET CeD): an interim analysis of a terminated randomised, double-blind, placebo-controlled phase 2 study

Evolution in coeliac disease diagnosis and management

The traditional gut-centric view of coeliac disease is evolving as immune and genetic insights underscore the central importance of a systemic, T cell immune response to gluten in disease pathogenesis. As the field increasingly recognize the limitations of small intestinal histology as the diagnostic standard, data supporting the accuracy of an immune (serologic) diagnosis of coeliac disease - well demonstrated in children - are growing for adults. Novel biomarkers such as interleukin-2 that identify the gluten-specific T cell demonstrate high sensitivity and specificity for coeliac disease and offer the potential for a diagnostic approach that avoids the need for gluten challenge. Asymptomatic disease and manifestations outside the gut pose considerable challenges for diagnosis using a case-finding strategy and enthusiasm for population screening is growing. The gluten-free diet remains a highly restrictive treatment and there is a paucity of controlled data to inform a safe gluten intake threshold. Ongoing symptoms and enteropathy are common and require systematic evaluation. Slowly-responsive disease is prevalent in the older patient diagnosed with coeliac disease, and super-sensitivity to gluten is an emerging concept that may explain many cases of nonresponsive disease. While there is great interest in developing novel therapies for coeliac disease, no drug has yet been registered. Efficacy studies are generally assessing drugs in patients with treated coeliac disease who undergo gluten challenge or in patients with nonresponsive disease; however, substantial questions remain around specific endpoints relevant for patients, clinicians and regulatory agencies and optimal trial design. Novel immune tools are providing informative readouts for clinical trials and are now shaping their design.

How Future Pharmacologic Therapies for Celiac Disease Will Complement the Gluten-Free Diet

The only proven treatment for celiac disease is adherence to a strict, lifelong, gluten-free diet. However, complete dietary gluten avoidance is challenging and a substantial number of patients do not respond fully, clinically, or histologically, despite their best efforts. As celiac disease is common and its central pathophysiology is well elucidated, it has become attractive for drug development to address the limitations of dietary treatment. Most efforts address nonresponsive celiac disease, defined as continued symptoms and/or signs of disease activity despite a gluten-free diet, and the more severe forms of refractory celiac disease, types I and II. An increasing spectrum of therapeutic approaches target defined mechanisms in celiac disease pathogenesis and some have advanced to current phase 2 and 3 clinical studies. We discuss these approaches in terms of potential efficiency, practicability, safety, and need, as defined by patients, regulatory authorities, health care providers, and payors.

Opportunities for Improving Biopsy and Non-Biopsy-Based Diagnosis of Celiac Disease

The accumulating data regarding a non-biopsy diagnosis of celiac disease has led to its adoption in certain scenarios, although debate on whether and when to use non-biopsy criteria in clinical practice is ongoing. Despite the growing popularity and evidence basis for a biopsy-free approach to diagnosis in the context of highly elevated serologies, there will continue to be a role for a biopsy in some groups. This review summarizes the current evidence supporting a non-biopsy approach and arguments supporting continued reliance on biopsy, and focuses on opportunities to improve both approaches.

A Look Into the Future: Are We Ready for an Approved Therapy in Celiac Disease?

As it appears that we are currently at the cusp of an era in which drugs that are new, re-purposed, or "supplements" will be introduced to the management of celiac disease, we need to reflect on whether the framework is set for celiac disease to be treated increasingly with pharmaceuticals as well as diet. This refers to reflecting on the rigor of current diagnostic practices; the limitations of the current standard of care, which is a gluten-free diet; and that we lack objective markers of disease severity. Investigating these issues will help us to identify gaps in technology and practices that could be critical for selecting patients with a well-defined need for an improved or alternative treatment. Both aspects, circumscribed limitations of the gluten-free diet and diagnostics helping to define celiac disease target groups, together with the guiding requirements by the responsible regulatory authorities, will contribute to defining the subgroups of patients with confirmed celiac disease eligible for distinct pharmacologic strategies. Because many patients with celiac disease are diagnosed in childhood, these aspects need to be differentially discussed for the pediatric setting. In this perspective, we aimed to describe these contextual issues and then looked ahead to the future. What might be the major challenges in celiac disease clinics in the coming years once drugs are an option alongside diet? And what will be the future objectives for researchers who further decipher the mucosal immunology of celiac disease? Speculating on the answers to these questions is as stimulating as it is fascinating to be part of this turning point.

Celiac disease: Hope for new treatments beyond a gluten-free diet

BACKGROUND & AIMS

Celiac disease (CD) is a chronic inflammatory disease of the small intestine induced and maintained by gluten ingestion in susceptible individuals. Current treatment consists of strict adherence to a lifelong gluten-free diet (GFD) which is considered safe and effective in the large majority of patients. However, since adherence to a GFD is difficult and has a negative impact on quality of life, an increasing interest in other treatment options has emerged. Moreover, in some individuals a GFD is not sufficiently effective, necessitating alternative treatments.

METHODS

By performing a systematic search, we constructed a detailed narrative review. Only treatment options considered relevant and conducted in a phase I, II or III clinical trial were included.

RESULTS

Based on the pathophysiology of CD, four major therapeutic approaches can be distinguished: firstly, by focusing on intraluminal gluten detoxification before absorption occurs, secondly, by modulating intestinal permeability and preventing paracellular uptake, thirdly, by enhancing immunological tolerance to gluten and finally, by regulating gluten auto-immunity.

CONCLUSIONS

Despite significant efforts, no treatment has yet completed a phase III clinical trial. Future studies will likely focus on the use of supplemental drugs in conjunction to a GFD, with ALV003 and ZED-1227 currently being the most promising therapeutic options.

Clinical Presentation and Spectrum of Gluten Symptomatology in Celiac Disease

Views on the clinical presentation and symptomatology of celiac disease have evolved alongside advances in disease detection and understanding of disease pathogenesis. Although historically regarded as a pediatric illness characterized by malabsorption, it is now better viewed as an immune illness of gluten-specific T cells with systemic manifestations affecting all ages. Its broad presentation, including frequent extraintestinal manifestations and asymptomatic disease, contributes to suboptimal disease detection. Adverse symptoms greatly impact patient quality of life and can result from chronic gluten exposure in untreated disease or those poorly responsive to the gluten-free diet. They can also present as acute symptoms after episodic gluten exposure. Functional gastrointestinal disease is a common comorbidity. Biomarkers like interleukin-2 that are highly sensitive and specific for celiac disease highlight a role for gluten-specific T cells in acute gluten symptomatology. A mechanistic understanding of symptoms will inform approaches to better measure and treat them effectively.

Potential therapeutic options for celiac Disease: An update on Current evidence from Gluten-Free diet to cell therapy

Celiac disease (CD) is a chronic autoimmune enteropathy and multifactorial disease caused by inappropriate immune responses to gluten in the small intestine. Weight loss, anemia, osteoporosis, arthritis, and hepatitis are among the extraintestinal manifestations of active CD. Currently, a strict lifelong gluten-free diet (GFD) is the only safe, effective, and available treatment. Despite the social burden, high expenses, and challenges of following a GFD, 2 to 5 percent of patients do not demonstrate clinical or pathophysiological improvement. Therefore, we need novel and alternative therapeutic approaches for patients. Innovative approaches encompass a broad spectrum of strategies, including enzymatic degradation of gluten, inhibition of intestinal permeability, modulation of the immune response, inhibition of the transglutaminase 2 (TG2) enzyme, blocking antigen presentation by HLA-DQ2/8, and induction of tolerance. Hence, this review is focused on comprehensive therapeutic strategies ranging from dietary approaches to novel methods such as antigen-based immunotherapy, cell and gene therapy, and the usage of nanoparticles for CD treatment.

Tolerance-inducing therapies in coeliac disease - mechanisms, progress and future directions

Coeliac disease is an autoinflammatory condition caused by immune reactions to cereal gluten proteins. Currently, the only available treatment for the condition is a lifelong avoidance of gluten proteins in the diet. There is an unmet need for alternative therapies. Coeliac disease has a strong association with certain HLA-DQ allotypes (DQ2.5, DQ2.2 and DQ8), and these disease-associated HLA-DQ molecules present deamidated gluten peptides to gluten-specific CD4+ T cells. The gluten-specific CD4+ T cells are the drivers of the immune reactions leading to coeliac disease. Once established, the clonotypes of gluten-specific CD4+ T cells persist for decades, explaining why patients must adhere to a gluten-free diet for life. Given the key pathogenic role of gluten-specific CD4+ T cells, tolerance-inducing therapies that target these T cells are attractive for treatment of the disorder. Lessons learned from coeliac disease might provide clues for treatment of other HLA-associated diseases for which the disease-driving antigens are unknown. Thus, intensive efforts have been and are currently implemented to bring an effective tolerance-inducing therapy for coeliac disease. This Review discusses mechanisms of the various approaches taken, summarizing the progress made, and highlights future directions in this field.

Emerging Pharmaceutical Therapies to Address the Inadequacy of a Gluten-Free Diet for Celiac Disease

Celiac disease (CeD) is a chronic autoimmune disorder triggered by the ingestion of gluten, affecting around 1% of the global population. It is a multifactorial disease involving both genetics and environmental factors. Nowadays, the only available treatment for CeD is a life-long gluten-free diet (GFD), which can cause a significant burden for patients, since symptoms and mucosal injury can persist despite apparent compliance with a GFD. This could also lead to psychological consequences and affect the quality of life of these patients. Thankfully, recent advances in understanding the pathogenesis of CeD and the availability of various targets have made it feasible to explore pharmaceutical treatments specific to CeD. Recently, the FDA has highlighted the unmet needs of adult patients on a GFD who experience ongoing symptoms attributed to CeD and also show persistent duodenal villous atrophy. This review will outline the limitations of a GFD, describe the targets of potential novel treatment of CeD and provide an overview of the primary clinical trials involving oral and injectable agents for a non-dietary treatment of CeD.

Safety and tolerability of KAN-101, a liver-targeted immune tolerance therapy, in patients with coeliac disease (ACeD): a phase 1 trial

BACKGROUND

Coeliac disease management is limited to strict adherence to a gluten-free diet with no approved therapies. This first-in-human phase 1 study evaluated the safety and tolerability of KAN-101, a liver-targeting glycosylation signature conjugated to a deaminated gliadin peptide designed to induce immune tolerance to gliadin.

METHODS

Adults (aged 18-70 years) with biopsy-confirmed, HLA-DQ2.5 genotype coeliac disease were enrolled from clinical research units and hospitals in the USA. Part A of the trial was an open-label, single ascending dose study of intravenous KAN-101 using sentinel dosing in evaluation of the following cohorts: 0·15 mg/kg, 0·3 mg/kg, 0·6 mg/kg, 1·2 mg/kg, and 1·5 mg/kg. Following safety monitoring committee review of the 0·3 mg/kg dose level in part A, part B was initiated as a randomised, placebo-controlled, multiple ascending dose study. In part B, interactive response technology was used to randomly assign (5:1) patients to receive intravenous KAN-101 (0·15 mg/kg, 0·3 mg/kg, or 0·6 mg/kg) or placebo following a 1:1 assignment of the first two eligible patients in each cohort for sentinel dosing. Patients in part B received three administrations of KAN-101 or placebo followed by a 3-day oral gluten challenge (9 g per day) 1 week after completing dosing. Study personnel and patients were masked to treatment assignments in part B, and not in part A. The primary endpoint was the incidence and severity of adverse events with escalating doses of KAN-101, assessed in all patients who received any amount of study drug based on dose level received. The secondary endpoint was assessment of plasma concentrations and pharmacokinetic parameters of KAN-101 following single and multiple doses, assessed in all patients who received at least one dose and had one or more values for drug concentration. This study is registered with ClinicalTrials.gov, NCT04248855, and is completed.

FINDINGS

Between Feb 7, 2020, and Oct 8, 2021, 41 patients were enrolled at ten US sites. 14 patients were assigned to part A (four 0·15 mg/kg, three 0·3 mg/kg, three 0·6 mg/kg, three 1·2 mg/kg, one 1·5 mg/kg) and 27 patients to part B (six 0·15 mg/kg with two placebo, seven 0·3 mg/kg with two placebo, and eight 0·6 mg/kg with two placebo). Treatment-related adverse events were reported in 11 (79%) of 14 patients in part A and 18 (67%) of 27 in part B (placebo two [33%] of six patients; KAN-101 16 [76%] of 21 patients), were grade 2 or lower, and were mild to moderate in severity. The most commonly observed adverse events were nausea, diarrhoea, abdominal pain, and vomiting, consistent with symptoms had by patients with coeliac disease on gluten ingestion. No grade 3-4 adverse events, serious adverse events, dose-limiting toxicities, or deaths occurred. Pharmacokinetic analyses showed KAN-101 was cleared from systemic circulation within roughly 6 h with a geometric mean half-life of 3·72 min (CV% 6·5%) to 31·72 min (83·7%), and no accumulation with repeated dosing.

INTERPRETATION

KAN-101 has an acceptable safety profile in patients with coeliac disease with no dose-limiting toxicities and no maximum tolerated dose was observed. Rapid systemic clearance of KAN-101 was observed and no accumulation on repeated dosing. A future study will evaluate the safety and efficacy, including biomarker responses with a gluten challenge, of KAN-101 at doses 0·6 mg/kg and greater in patients with coeliac disease.

FUNDING

Kanyos Bio.