Phase III, randomised, double-blind, multicentre study to evaluate the efficacy and safety of vonoprazan compared with lansoprazole in Asian patients with erosive oesophagitis

Potassium-Competitive Acid Blockers: Present and Potential Utility in the Armamentarium for Acid Peptic Disorders

Potassium-competitive acid blockers (PCABs) such as vonoprazan represent a novel class of acid suppressants that show tremendous promise to enhance care of acid peptic disorders. PCAB characteristics distinct from those of proton pump inhibitors-such as acid stability with dosing independent of food consumption, rapid onset of action, less variability with CYP2C19 polymorphisms, and extended half-lives-may add value in clinical practice. With recently reported data beyond Asian populations and expanding regulatory approval of PCABs, clinicians should be aware of these medications and their potential roles in the management of acid peptic disorders. This article provides an up-to-date summary of the evidence around PCABs for the treatment of gastroesophageal reflux disease (especially erosive esophagitis healing and maintenance), eosinophilic esophagitis, Helicobacter pylori infection, and peptic ulcer healing and secondary prophylaxis.

Randomized controlled trial to evaluate the efficacy and safety of fexuprazan compared with esomeprazole in erosive esophagitis

BACKGROUND

Fexuprazan, a novel potassium-competitive acid blocker, reversibly suppresses the K+/H+-ATPase enzyme in proton pumps within gastric parietal cells. Fexuprazan's suppression of gastric acid was maintained in healthy individuals for 24 h in a dose-dependent manner.

AIM

To compare fexuprazan to esomeprazole and establish its efficacy and safety in patients with erosive esophagitis (EE).

METHODS

Korean adult patients with endoscopically confirmed EE were randomized 1:1 to receive fexuprazan 40 mg or esomeprazole 40 mg once daily for eight weeks. The primary endpoint was the proportion of patients with healed EE confirmed by endoscopy at week 8. The secondary endpoints included the healing rate of EE at week 4, symptom response, and quality of life assessment. Safety profiles and serum gastrin levels were compared between the groups.

RESULTS

Of the 263 randomized, 218 completed the study per protocol (fexuprazan 40 mg, n = 107; esomeprazole 40 mg, n = 111). Fexuprazan was non-inferior to esomeprazole regarding the healing rate at week 8 [99.1% (106/107) vs 99.1% (110/111)]. There were no between-group differences in the EE healing rate at week 4 [90.3% (93/103) vs 88.5% (92/104)], symptom responses, and quality of life assessments. Additionally, serum gastrin levels at weeks 4 and 8 and drug-related side effects did not significantly differ between the groups.

CONCLUSION

Fexuprazan 40 mg is non-inferior to esomeprazole 40 mg in EE healing at week 8. We suggest that fexuprazan is an alternative promising treatment option to PPIs for patients with EE.

Efficacy and safety of proton pump inhibitors versus vonoprazan in treatment of erosive esophagitis: A PRISMA-compliant systematic review and network meta-analysis

BACKGROUND

Proton-pump inhibitors (PPIs) and vonoprazan are recommended as first-line therapies for erosive esophagitis (EE). However, it is uncertain how the magnitude of efficacy and safety of first-line therapy, the choice of individual PPIs or vonoprazan in the treatment of EE remains controversial. This study aimed to evaluate the efficacy and safety of vonoprazan and PPIs in healing esophageal mucosal injury in patients with EE.

METHODS

Relevant databases were searched to collect randomized controlled trials of proton pump inhibitors and vonoprazan in the treatment of reflux esophagitis up to December 2021. Studies on standard-dose PPIs or vonoprazan that were published in Chinese or English and assessed healing effects in EE were included in the analysis. Stata16.0 was used to conduct a network Meta-analysis to evaluate the efficacy and safety of the treatment.

RESULTS

A total of 41 literatures were included with 11,592 enrolled patients. For the endoscopic cure rate, all the PPIs and vonoprazan significantly improve compared to Placebo; Based on the surface under the cumulative ranking curve, Ilaprazole ranked first, followed by esomeprazole, vonoprazan, pantoprazole, lansoprazole, omeprazole, rabeprazole and placebo therapy ranked the last. For the rate of adverse events, there was no significant difference among all the PPIs, vonoprazan, and placebo.

CONCLUSIONS

Ilaprazole, esomeprazole and vonoprazan have more advantages in mucosal erosion healing, there was no significant difference in the comparative safety among all interventions.

Efficacy of keverprazan for duodenal ulcer: A phase II randomized, double-blind, parallel-controlled trial

BACKGROUND AND AIM

Considering the limitation of varying acid suppression of proton pump inhibitors, this study was aimed to assess the efficacy, safety, and dose-effect relationship of keverprazan, a novel potassium-competitive acid blocker, in the treatment of duodenal ulcer (DU) compared with lansoprazole.

METHODS

A randomized, double-blind, double-dummy, multicenter, low-dose, high-dose, and positive-drug parallel-controlled study was conducted to verify the non-inferiority of keverprazan (20 or 30 mg) to lansoprazole of 30 mg once daily for 4 to 6 weeks and dose-effect relationship of keverprazan in the treatment of patients with active DU confirmed by endoscopy.

RESULTS

Of the 180 subjects randomized, including 55 cases in the keverprazan_20 mg group, 61 cases in the keverprazan_30 mg group, and 64 cases in the lansoprazole_30 mg group, 168 subjects (93.33%) completed the study. The proportions of healed DU subjects in the keverprazan_20 mg, keverprazan_30 mg, and lansoprazole_30 mg groups were respectively 87.27%, 90.16%, and 79.69% at week 4 (P = 0.4595) and were respectively 96.36%, 98.36%, and 92.19% at week 6 (P = 0.2577). The incidence of adverse events in the keverprazan_20 mg group was lower than that in the lansoprazole_30 mg (P = 0.0285) and keverprazan_30 mg groups (P = 0.0398).

CONCLUSIONS

Keverprazan was effective and non-inferior to lansoprazole in healing DU. Based on the comparable efficacy and safety data, keverprazan of 20 mg once daily is recommended for the follow-up study of acid-related disorders. (Trial registration number: ChiCTR2100043455.).

The role of vonoprazan in patients with erosive esophagitis

Acid suppression is the primary therapy for erosive esophagitis (EE). Although proton pump inhibitors (PPIs) are considered as the first-line medication for EE, 10-20% of patients with Los Angeles C and D grade EE do not gain complete mucosal healing and symptom control despite 8-week double-dose PPI treatment. Vonoprazan is a novel potassium-competitive acid blocker (P-CAB), which blocks the H+, K+-adenosine triphosphatase enzymes in a K+-competitive and reversible manner. Vonoprazan exhibits different pharmacological and pharmacokinetic profiles from conventional PPIs, and has a rapid, potent and sustained acid inhibitory effect. In this review, we summarized and discussed current evidence regarding the role of vonoprazan in terms of mucosal healing, maintaining remission and symptom relief for the management of EE, including the initial and maintenance treatment of EE, as well as for PPI-resistant EE patients. Safety concerns and cost-effectiveness analysis of vonoprazan were also mentioned in the article. As a potent and well-tolerated acid blocker, vonoprazan has the potential to become a novel option for the management of EE.

British Society of Gastroenterology guidelines on the management of functional dyspepsia

Functional dyspepsia (FD) is a common disorder of gut-brain interaction, affecting approximately 7% of individuals in the community, with most patients managed in primary care. The last British Society of Gastroenterology (BSG) guideline for the management of dyspepsia was published in 1996. In the interim, substantial advances have been made in understanding the complex pathophysiology of FD, and there has been a considerable amount of new evidence published concerning its diagnosis and classification, with the advent of the Rome IV criteria, and management. The primary aim of this guideline, commissioned by the BSG, is to review and summarise the current evidence to inform and guide clinical practice, by providing a practical framework for evidence-based diagnosis and treatment of patients. The approach to investigating the patient presenting with dyspepsia is discussed, and efficacy of drugs in FD summarised based on evidence derived from a comprehensive search of the medical literature, which was used to inform an update of a series of pairwise and network meta-analyses. Specific recommendations have been made according to the Grading of Recommendations Assessment, Development and Evaluation system. These provide both the strength of the recommendations and the overall quality of evidence. Finally, in this guideline, we consider novel treatments that are in development, as well as highlighting areas of unmet need and priorities for future research.

Cost-Utility Analysis of CYP2C19 Genotype Detection for Selection of Acid-Suppressive Therapy with Lansoprazole or Vonoprazan for Patients with Reflux Esophagitis in China

BACKGROUND

The cytochrome P450 (CYP) 2C19 genotype has a profound effect on the efficacy of lansoprazole, with less of an influence on vonoprazan. Both are first-choice drugs for the treatment of reflux esophagitis in China.

OBJECTIVE

We aimed to estimate the cost-effectiveness of acid-suppressive treatments in Chinese patients with reflux esophagitis over 1 year from the societal perspective.

METHODS

We developed a decision-based Markov model with a 4-week cycle to simulate the economic benefits and quality-adjusted life-years between different treatment strategies for patients with reflux esophagitis: universal lansoprazole, universal vonoprazan, and CYP2C19 genotype-guided strategies. The primary outcome was the incremental cost-effectiveness ratio. Data sources were the published literature, clinical trials, documents, and local charges. We used sensitivity analyses to detect the robustness of the findings and explored subgroup analyses and scenario analyses to make further evaluations.

RESULTS

Compared to lansoprazole, vonoprazan and the CYP2C19 genotype-guided strategy were not preferable for Chinese patients with reflux esophagitis, with an incremental cost-effectiveness ratio of 222,387.1316 yuan/quality-adjusted life-year and 349,627.5000 yuan/quality-adjusted life-year, respectively. Sensitivity analyses showed the impact factors were the utility scores and the expenditures for the maintenance stage with lansoprazole and vonoprazan. When the willingness-to-pay threshold was 215,484 yuan/quality-adjusted life-year, 46.20% of the reflux esophagitis population was willing to pay for vonoprazan, compared with 8.30% for the CYP2C19 genotype-guided strategies. Vonoprazan and the CYP2C19 genotype-guided strategy were cost effective in the severe reflux esophagitis population, and in the reduction of the price of vonoprazan.

CONCLUSIONS

The health economic evaluations revealed that for Chinese patients with reflux esophagitis, vonoprazan and the CYP2C19 genotype-guided strategy were not cost-effective regimens compared with lansoprazole. However, we found that in certain conditions like a reduction in the price of vonoprazan and in patients with severe reflux esophagitis these could be cost-effective.

Potassium-competitive acid blockers and gastroesophageal reflux disease

Proton pump inhibitors (PPIs), the most commonly used antisecretory medi-cations in the management of reflux illness, virtually eliminate elective surgery for ulcer disease, and relegate anti-reflux surgery to patients with gastroesophageal reflux disease (GERD) who are inadequately managed by medical therapy. However, PPI medications still leave some therapeutic demands of GERD unmet. Furthermore, up to 40%-55% of daily PPI users have chronic symptoms, due to PPI refractoriness. Potassium-competitive acid blockers (P-CABs) transcend many of the problems and limits of PPIs, delivering quick, powerful, and extended acid suppression and allowing for treatment of numerous unmet needs. Recently, it has become clear that compromised mucosal integrity plays a role in the etiology of GERD. As a result, esophageal mucosal protection has emerged as a novel and potential treatment approach. An increasing body of research demonstrates that when P-CABs are used as primary drugs or add-on drugs (to regular treatment), they provide a considerable extra benefit, particularly in alleviating symptoms that do not respond to PPI therapy.

Acid Suppressive Drugs

Histamine H₂ receptor antagonists (H₂RAs) suppress gastric acid production by blocking H₂ receptors in parietal cells. Studies have shown that proton pump inhibitors (PPIs) are superior to H₂RAs as a treatment for acid-related disorders, such as peptic ulcer disease (PUD) and gastroesophageal reflux disease (GERD). PPIs reduce gastric acid production by irreversibly inhibiting the H⁺/K⁺ ATPase pump, and they also increase gastric emptying. Although PPIs have differing pharmacokinetic properties, each PPI is effective in managing GERD and PUDs. However, PPIs have some limitations, including short plasma half-lives, breakthrough symptoms (especially at night), meal-associated dosing, and concerns associated with long-term PPI use. Potassium-competitive acid blockers (P-CABs) provide more rapid and profound suppression of intragastric acidity than PPIs. P-CABs are non-inferior to lansoprazole in healing erosive esophagitis and peptic ulcers, and may also be effective in improving symptoms in patients with non-erosive reflux disease. Acid suppressive drugs are the most commonly used drugs in clinical practice, and it is necessary to understand the pharmacological properties and adverse effects of each drug.

The efficacy and safety of keverprazan, a novel potassium-competitive acid blocker, in treating erosive oesophagitis: a phase III, randomised, double-blind multicentre study

BACKGROUND

Keverprazan is a novel potassium-competitive acid blocker (P-CAB) with a strong acid-suppressive capacity that may provide clinical benefit in acid-related diseases.

AIMS

This study aimed to explore the non-inferior efficacy and safety of keverprazan to lansoprazole in treating erosive oesophagitis (EO).

METHODS

This was a phase III, randomised, double-blind multicentre study. Patients were randomised to receive keverprazan 20 mg once daily or lansoprazole 30 mg once daily for 4-8 weeks. EO healing rates and adverse events (AEs) were compared between the keverprazan group and the lansoprazole group.

RESULTS

A total of 238 patients comprised the full analysis set (FAS) while 221 patients comprised the per-protocol set (PPS). For FAS analysis, the EO healing rates at week 8 were 95.8% (114/119) and 89.9% (107/119) for keverprazan and lansoprazole respectively. For PPS analysis, the EO healing rates at week 8 were 99.1% (110/111) and 92.7% (102/110) for keverprazan and lansoprazole respectively. Non-inferiority of keverprazan compared with lansoprazole according to EO healing rates at 8 weeks was demonstrated in both FAS (difference: 5.8% [95% CI: -0.6% to 12.3%]; p = 0.081) and PPS (difference: 6.1% [95% CI: 1.1%-11.2%]; p = 0.018) analysis. Drug-related AEs were reported in 34.5% (41/119) patients of the keverprazan group and 25.2% (30/119) patients of the lansoprazole group with no significant difference (p = 0.156). No severe AE happened in the keverprazan group.

CONCLUSIONS

This study demonstrated the non-inferior efficacy of keverprazan to lansoprazole in treating EO. The incidences of drug-related AEs were comparable between keverprazan and lansoprazole.

A Population Pharmacokinetic Model of Vonoprazan: Evaluating the Effects of Race, Disease Status, and Other Covariates on Exposure

Vonoprazan, a potassium-competitive acid blocker, is under investigation in the United States and Europe for the treatment of erosive esophagitis and Helicobacter pylori infection. Population pharmacokinetic (popPK) analysis allows the identification of factors that could affect drug exposure in population subgroups. Here, we report a popPK model based on pooled data sets of available pharmacokinetic (PK) studies in healthy volunteers and patients with gastroesophageal reflux disease, including erosive esophagitis, from Asia and Europe. This model was used to evaluate the impact of different covariates, including race and disease status, on vonoprazan exposure. We analyzed PK data from 746 patients and 410 healthy volunteers from 15 clinical trials using a nonlinear mixed-effects approach to develop the popPK model. Model development focused on characterizing and quantifying the effects of clinical covariates of race (Asian vs non-Asian) and disease status (gastroesophageal reflux disease vs healthy volunteers) on vonoprazan exposure. Identified clinical covariates included fed/fasting status, race, sex, disease status, weight, serum creatinine, and age. The impact of variations in these clinical covariates on exposure to vonoprazan was smaller than the effect of halving or doubling the dose. PK parameters were similar in Asian and non-Asian populations. Variations in weight, age, and race are not predicted to have a clinically relevant impact on vonoprazan exposure or safety and require no changes in vonoprazan dosing. The limited impact of race on exposure suggests that efficacy and safety data for vonoprazan in Asian populations are translatable to non-Asian populations.

Current advances in the diagnosis and management of gastroesophageal reflux disease

Gastroesophageal reflux disease (GERD) is very common and defined as troublesome symptoms owing to excessive acid reflux. The spectrum of GERD is broad, including not only erosive esophagitis and Barrett's esophagus but also nonerosive reflux disease (NERD), reflux hypersensitivity, and functional heartburn. Patients with reflux symptoms despite normal endoscopy remain common clinical presentation, can be heterogeneous overlapping with functional gastrointestinal disorders. Ambulatory esophageal pH monitoring with and without impedance helps the diagnosis of NERD. Metrics such as baseline impedance and postreflux swallow induced peristaltic wave enhance diagnostic accuracy in patients with inconclusive diagnoses. The major treatment of all manifestations of GERD is acid suppression with proton pump inhibitors, while other therapies, such as reflux-reducing agents and adjunctive medications, can be individualized where the response to traditional management is incomplete. GERD patients often need long-term treatment due to frequent relapses. Anti-reflux surgery can be effective too. Endoscopic therapies have some promising results, but long-term outcomes remain to be determined.

An update of pharmacology, efficacy, and safety of vonoprazan in acid-related disorders

INTRODUCTION

Patients with acid-related disorders (ARDs) of the upper digestive tract remain highly prevalent and need to be continuously investigated to improve their management.

AREAS COVERED

This review provides a summary of the most recent advancements in the treatment of ARDs with particular focus on the new drugs available to overcome the unmet needs of traditional therapies.

EXPERT OPINION

Proton pump inhibitors remain the best therapy in treating ARDs, but a consistent proportion of these patients continues to present mucosal lesions or to experience symptoms despite treatment. These cases pertain mainly to the most severe forms of erosive esophagitis or to non-erosive reflux disease. Also, the increasing rate of patients with H. pylori infection not responding to eradication therapy represents a difficult clinical condition. The recent advent of a new class of antisecretory drugs, such as the potassium competitive acid blockers and, among them the most studied vonoprazan, which are characterized by a better pharmacological profile than PPIs (rapid onset of action, longer lasting acid suppression, control of nocturnal acidity), has the potential to overcome the above-mentioned unmet needs. More research should be done to assess their efficacy in Western populations and their safety in patients treated in the long term.

Patient- and physician-reported satisfaction with gastroesophageal reflux disease (GERD) treatment in Chinese clinical practice

OBJECTIVE

The aim of this study was to assess the level of satisfaction with currently prescribed medications for gastroesophageal reflux disease (GERD) in patients and physicians in China.

METHODS

Physicians across China were invited to complete physician surveys concerning factors affecting the prescription of medication for GERD and their satisfaction through an online questionnaire. The enrolled physicians invited the first five GERD patients who visited them on the same day to complete online patient surveys concerning the satisfaction with medications for GERD and its influencing factors.

RESULTS

In total, 334 physician surveys (response rate 36.82%) and 1409 patient surveys (86.07%) were analyzed. Over half (62.57%) the physicians recommended taking a proton pump inhibitor (PPI) twice daily and the majority (88.02%) recommended taking a PPI for 1 week to 3 months. Factors affecting the prescription were how much it could improve quality of life (84.73%), followed by safety, medication compliance, and efficacy. Approximately 30% of patients reported taking a PPI twice daily and 47.20% reported taking a PPI for 1 week to 3 months. Factor affecting patients' adherence to medications was safety (64.30%), followed by medical insurance, efficacy and convenience. Approximately one-third of physicians and patients did not report "satisfied" or "very satisfied" with medications for GERD, including 10.51% of patients and 12.87% of physicians reporting "dissatisfied" or "very dissatisfied."

CONCLUSION

One-third of GERD patients and physicians were not satisfied or very satisfied with medications for GERD. Novel medications may help optimize the management of GERD.

Gastroesophageal reflux disease: When East meets West

Gastroesophageal reflux disease (GERD) is common worldwide and poses a huge challenge to health. Consensuses and guidelines on the diagnosis and management of GERD in China and the USA have recently been updated. The divergence between these guidelines indicates the differences in the conception of this disease by experts in different countries, and is influenced by available medications and interventional procedures. Prompt endoscopy has been advocated in China due to a high prevalence of upper gastrointestinal (GI) cancer, while endoscopy has been reserved for those who are at a risk of malignancy or who are reisitant to proton pump inhibitors (PPIs) in the USA. A potassium channel acid-blocker is widely used in Asian countries and has proven efficacy. Moreover, it has been recommended, together with PPIs, as a primary therapy for GERD in China; while PPI alone is recommended as a first-line treatment in the USA. Although more prokinetics are available in China than in the USA and can alleviate GERD symptoms when combined with PPI, the choice of prokinetics is limited in the USA, leading to completely opposite attitudes to prokinetics in the two countries. Novel anti-reflux procedures have been introduced in both countries. Transoral incisionless fundoplication (TIF) is recommended as an endoscopic anti-reflux procedure, and magnetic sphincter augmentation (MSA) is recognized as equivocal to conventional laparoscopic fundoplication in the USA. However, radiofrequency ablation is more popular in China, and clinical trials on TIF and MSA are not complete, which results in diverse opinions about suitable anti-reflux procedures in China. A comparison of the guidelines may therefore shed light on the multiple dimensions of GERD and thus deepen our understanding of the disease.

Thailand guideline 2020 for medical management of gastroesophageal reflux disease

Gastroesophageal reflux disease (GERD) is one of the most prevalent and bothersome functional gastrointestinal disorders worldwide, including in Thailand. After a decade of the first Thailand GERD guideline, physician and gastroenterologist encountered substantially increase of patients with GERD. Many of them are complicated case and refractory to standard treatment. Concurrently, the evolution of clinical characteristics as well as the progression of investigations and treatment have developed and changed tremendously. As a member of Association of Southeast Asian Nations, which are developing countries, we considered that the counterbalance between advancement and sufficient economy is essential in taking care of patients with GERD. We gather physicians from university hospitals, as well as internist and general practitioners who served in rural area, to make a consensus in this updated version of GERD guideline focusing in medical management of GERD. This clinical practice guideline was constructed adhering with standard procedure. We categorized the guideline in to four parts including definition, investigation, treatment, and long-term follow up. We anticipate that this guideline would improve physicians' proficiency and help direct readers to choose investigations and treatments in patients with GERD wisely. Moreover, we wish that this guideline would be applicable in countries with limited resources as well.

A study for every second day administration of vonoprazan for maintenance treatment of erosive GERD (ESD von GERD): a multicenter randomized cross-over study

BACKGROUND

Vonoprazan is a potassium competitive acid blocker used to treat erosive gastroesophageal reflux disease (GERD) with stronger, more stable acid-suppressing effects than proton pump inhibitors (PPIs). This study clarified the usefulness and superiority of vonoprazan administered every second day over PPIs in the maintenance therapy of erosive GERD.

METHODS

This is a prospective, multicenter, open-label, two-period randomized cross-over study. Patients were randomized to either the vonoprazan-lansoprazole (VP-LZ) group, who were given vonoprazan 10 mg for the first 4 weeks and then lansoprazole 15 mg for the next 4 weeks both administered once every second day, or the lansoprazole-vonoprazan (LZ-VP) group, who were treated in reverse. GERD symptoms were compared using symptom diaries, the frequency scale for symptoms of GERD (FSSG), and the gastrointestinal symptom rating scale (GSRS).

RESULTS

We enrolled 122 patients between December 2017 and May 2019. Symptoms were well controlled in vonoprazan administration and lansoprazole administration were 93.6% and 82.1%, respectively, with a significant difference on McNemar's test (P = 0.003). During the second 4 weeks, 94.4% and 76.7% of patients in the VP-LZ and LZ-VP groups, respectively, were well controlled following for ≥ 6 consecutive days a week (P = 0.009). During the first 4 weeks, 96.7% and 80.0% of patients were well controlled with < 1 weekly in the VP-LZ and LZ-VP groups, respectively, during the first 4 weeks (P = 0.007). GERD symptoms, assessed via FSSG and GSRS, significantly decreased with vonoprazan administration once every second day.

CONCLUSIONS

Vonoprazan administered once every second day could be an effective alternative to PPIs in the maintenance treatment of erosive GERD (UMIN000030393).

Vonoprazan in the management of gastric/peptic ulcers: a systematic review of safety data

Introduction

Although potassium-competitive acid blockers (P-CABs) prompted safety concerns when first developed, they ultimately proved to have a favourable safety profile.

Aim

To assess the safety of vonoprazan in the management of gastroesophageal reflux disease (GERD), peptic ulcers, or gastroduodenal mucosal lesions induced by chronic use of aspirin or non-steroidal anti-inflammatory drugs (NSAIDs).

Material and methods

From March to June 2021, a literature search was conducted using Medline via PubMed, Cochrane library, Lilacs, SciELO, and Centre for Reviews and Dissemination (CRD) electronic databases. After applying the eligibility criteria, 10 studies were included in this review. Of these 10 articles, vonoprazan was used as initial therapy in 6 and as maintenance therapy in 4. Adverse event rates were similar for vonoprazan and proton-pump inhibitors (PPIs).

Conclusions

Our findings suggest that vonoprazan is a safe option for the management of erosive oesophagitis, gastric/peptic ulcers, or peptic ulcers induced by chronic use of aspirin or NSAIDs.

Evidence-based clinical practice guidelines for gastroesophageal reflux disease 2021

In Japan, with the increasing prevalence of gastroesophageal reflux disease (GERD) and growing public interest, the Japanese Society of Gastroenterology issued Evidence-based Clinical Practice Guidelines for GERD (1st edition) in 2009 and a revised 2nd edition in 2015. A number of studies on GERD were subsequently conducted in Japan and abroad, and vonoprazan, a potassium-competitive acid blocker (P-CAB), became available for the first time in Japan in February 2015. The revised 3rd edition (Japanese edition), which incorporates new findings and information, was published in April 2021. These guidelines are summarized herein, particularly sections related to the treatment of GERD. The important clinical issues addressed in the present revision are (i) the introduction of treatment algorithms that classify GERD into reflux esophagitis and non-erosive reflux disease, (ii) the clarification of treatment algorithms based on to the severity of reflux esophagitis, and (iii) the positioning of vonoprazan in the treatment for GERD. The present guidelines propose vonoprazan as the initial/maintenance treatment for severe reflux esophagitis. They also recommend vonoprazan or PPI as an initial treatment for mild reflux esophagitis and recommended PPI and proposed vonoprazan as maintenance treatment. These updated guidelines offer the best clinical strategies for GERD patients in Japan and hope that they will be of global use for the diagnosis and treatment for GERD.

Gastroesophageal reflux disease: key messages for clinicians

Gastroesophageal reflux disease (GERD) is a chronic common disorder for which patients often refer to specialists. In the last decades, numerous studies helped to clarify the pathophysiology and the natural history of this disease. Currently, in the clinical setting, GERD is defined by the presence of symptoms that, when endoscopic investigation is required, permit to distinguish between cases with or without associated esophageal mucosal injuries. These conditions are called erosive reflux disease and non-erosive reflux disease (NERD), respectively. The latter is the most common manifestation of GERD. Symptoms are defined typical, as heartburn and regurgitation, and atypical (also called extra-esophageal), as coughing and/or wheezing, hoarseness, sore throat, otitis media, and dental manifestations. In this context, it is crucial for clinicians to investigate the presence of features of suspected malignancy, as unexplained weight loss, anemia, dysphagia, persistent vomiting, familiar history of cancer, long history of GERD, and beginning of GERD symptoms after the age of 50 years. The presence of these risk factors should induce to perform an endoscopic examination. Particular attention should be given to functional conditions that can mimic GERD, such as functional heartburn and hypersensitive esophagus as well as, more rarely, eosinophilic esophagitis. The former ones have different pathophysiology and this explains the frequent non-response to proton pump inhibitor drugs. This narrative review provides to clinicians a useful and practical overview of the state-of-the-art on advancements in the knowledge of GERD.

2020 Seoul Consensus on the Diagnosis and Management of Gastroesophageal Reflux Disease

Gastroesophageal reflux disease (GERD) is a condition in which gastric contents regurgitate into the esophagus or beyond, resulting in either troublesome symptoms or complications. GERD is heterogeneous in terms of varied manifestations, test findings, and treatment responsiveness. GERD diagnosis can be established with symptomatology, pathology, or physiology. Recently the Lyon consensus defined the "proven GERD" with concrete evidence for reflux, including advanced grade erosive esophagitis (Los Angeles classification grades C and or D esophagitis), long-segment Barrett's mucosa or peptic strictures on endoscopy or distal esophageal acid exposure time > 6% on 24-hour ambulatory pH-impedance monitoring. However, some Asian researchers have different opinions on whether the same standards should be applied to the Asian population. The prevalence of GERD is increasing in Asia. The present evidence-based guidelines were developed using a systematic review and meta-analysis approach. In GERD with typical symptoms, a proton pump inhibitor test can be recommended as a sensitive, cost-effective, and practical test for GERD diagnosis. Based on a meta-analysis of 19 estimated acid-exposure time values in Asians, the reference range upper limit for esophageal acid exposure time was 3.2% (95% confidence interval, 2.7-3.9%) in the Asian countries. Esophageal manometry and novel impedance measurements, including mucosal impedance and a post-reflux swallow-induced peristaltic wave, are promising in discrimination of GERD among different reflux phenotypes, thus increasing its diagnostic yield. We also propose a long-term strategy of evidence-based GERD treatment with proton pump inhibitors and other drugs.

Consensus statements and recommendations on the management of mild-to-moderate gastroesophageal reflux disease in the Southeast Asian region

This paper reports the proceedings from the first consensus meeting on the management of mild-to-moderate gastroesophageal reflux disease (GERD) in the Southeast Asian (SEA) region. Seventeen statements were drawn up by a steering committee that focused on epidemiology, mechanism of action, diagnostic investigations, and treatment. Voting on the recommendations used the Delphi method with two rounds of voting among the 10 panel members. The consensus panel agreed that GERD is mostly a mild disease in the SEA region with predominantly non-erosive reflux disease (NERD). Complicated GERD and Barrett's esophagus are infrequently seen. The panel recommended endoscopy in patients with alarm or refractory symptoms but cautioned that the incidence of gastric cancer is higher in SEA. pH and impedance measurements were not recommended for routine assessment. The acid pocket is recognized as an important pathogenic factor in GERD. Lifestyle measures such as weight reduction, avoidance of smoking, reduction of alcohol intake, and elevation of the head of the bed were recommended but strict avoidance of specific foods or drinks was not. Alginates was recommended as the first-line treatment for patients with mild-to-moderate GERD while recognizing that proton-pump inhibitors (PPIs) remained the mainstay of treatment of GERD. The use of alginates was also recommended as adjunctive therapy when GERD symptoms were only partially responsive to PPIs.

Potent Acid Suppression With Vonoprazan vs Proton Pump Inhibitors Does Not Have Higher Association With Clostridioides difficile Infection

INTRODUCTION

Proton pump inhibitors (PPIs) are associated with the onset of Clostridioides difficile infection (CDI). Although a new potassium-competitive acid blocker, vonoprazan, consistently shows a more potent acid inhibitory effect in comparison to PPIs, the risk of CDI in vonoprazan-treated patients relative to those treated with PPIs is unknown. In this retrospective case-control study, using a nationwide hospital-based administrative database in Japan, we investigated the association of the onset of CDI in patients treated with vonoprazan.

METHODS

A CDI case was defined as a case in which a patient was diagnosed and treated for CDI. For each CDI case, 3 non-CDI patients were extracted as controls. Information on the usage of acid suppressants in the 2 months before the onset of CDI and other confounding factors was collected. Relative associations of gastric acid suppressants with the onset of CDI were estimated.

RESULTS

A total of 4,466 CDI cases and 13,220 of non-CDI controls were extracted. A multivariate conditional regression analysis revealed that PPI or vonoprazan use was modestly, but significantly associated with CDI (odds ratio [95% confidence interval]: PPI, 1.3 [1.2-1.4]; vonoprazan, 1.4 [1.2-1.7]). With PPI users as a reference, vonoprazan did not show a stronger association with CDI (odds ratio [95% confidence interval]: 1.07 [0.91-1.26]).

DISCUSSION

We found a significant positive association between vonoprazan use and CDI; however, the magnitude of the association was not beyond that in PPI users. This is the first report on any potential adverse effects of vonoprazan.

Gastro-oesophageal reflux disease

Gastro-oesophageal reflux disease (GERD) is a common disorder in adults and children. The global prevalence of GERD is high and increasing. Non-erosive reflux disease is the most common phenotype of GERD. Heartburn and regurgitation are considered classic symptoms but GERD may present with various atypical and extra-oesophageal manifestations. The pathophysiology of GERD is multifactorial and different mechanisms may result in GERD symptoms, including gastric composition and motility, anti-reflux barrier, refluxate characteristics, clearance mechanisms, mucosal integrity and symptom perception. In clinical practice, the diagnosis of GERD is commonly established on the basis of response to anti-reflux treatment; however, a more accurate diagnosis requires testing that includes upper gastrointestinal tract endoscopy and reflux monitoring. New techniques and new reflux testing parameters help to better phenotype the condition. In children, the diagnosis of GERD is primarily based on history and physical examination and treatment vary with age. Treatment in adults includes a combination of lifestyle modifications with pharmacological, endoscopic or surgical intervention. In refractory GERD, optimization of proton-pump inhibitor treatment should be attempted before a series of diagnostic tests to assess the patient's phenotype.

Prevention of delayed bleeding with vonoprazan in upper gastrointestinal endoscopic treatment

BACKGROUND

Delayed bleeding is the major adverse event in upper gastrointestinal endoscopic treatment (UGET). We aimed to investigate the efficacy of vonoprazan, which is the novel strong antisecretory agent, to reduce the risk for delayed bleeding in comparison with proton pump inhibitors (PPIs) in UGET.

METHODS

This retrospective population-based cohort study used the Diagnosis Procedure Combination database in Japan. We included patients on vonoprazan or PPI in UGET between 2014 and 2019. The primary outcome was delayed bleeding. We conducted propensity score matching to balance the comparison groups, and logistic regression analyses to compare the bleeding outcomes.

RESULTS

We enrolled 124,422 patients, in which 34,822 and 89,600 were prescribed with vonoprazan and PPI, respectively. After propensity score matching, the risk for delayed bleeding was lower in vonoprazan than in PPI (odds ratio [OR], 0.75; 95% confidence interval [CI], 0.71-0.80), consistent with sensitivity analysis results. In the subgroup analyses of seven UGET procedures, vonoprazan was significantly advantageous in esophageal endoscopic submucosal dissection (E-ESD) (OR, 0.71; 95% CI, 0.54-0.94) and gastroduodenal endoscopic submucosal dissection (GD-ESD) (OR, 0.70; 95% CI, 0.65-0.75), although correction for multiple testing of the outcome data removed the significance in E-ESD. These results were also consistent with sensitivity analysis results. In the five other procedures, no significant advantage was found.

CONCLUSIONS

This nationwide study found that, compared with PPI, vonoprazan can reduce delayed bleeding with approximately 30% in GD-ESD. Vonoprazan has the possibility to become a new treatment method for preventing delayed bleeding in this procedure.

Direct Comparison of the Efficacy and Safety of Vonoprazan Versus Proton-Pump Inhibitors for Gastroesophageal Reflux Disease: A Systematic Review and Meta-Analysis

BACKGROUND

Gastroesophageal reflux disease (GERD) is a common disorder, and is typically treated with proton-pump inhibitors (PPIs) as the recommended first-line therapy. Recently, a new potassium-competitive acid blocker, vonoprazan, was launched in Japan. It is uncertain whether the standard dose of vonoprazan 20 mg is superior to that of PPIs for GERD, so a direct comparison of the therapeutic effects and adverse events between vonoprazan 20 mg and PPIs is needed.

METHODS

MEDLINE, the Cochrane Central Register of Controlled Trials, and Embase were chosen as the literature sources. Randomized controlled trials for vonoprazan 20 mg and PPIs published in English were searched. Data from studies meeting the eligibility criteria were extracted individually by two researchers and compared to maintain consistency.

RESULTS

Fifty-six articles were identified in the databases, and one study was manually searched and added to the analysis, ultimately yielding six eligible studies. For the main analysis, the risk ratios (RR) of efficacy and adverse events between vonoprazan and PPIs were 1.06 (0.99-1.13) and 1.08 (0.96-1.22), respectively. Subgroup analysis for patients with severe esophagitis at baseline showed significantly higher results for vonoprazan than lansoprazole, with an RR of 1.14 (1.06-1.22).

CONCLUSIONS

Our findings suggest that vonoprazan is non-inferior to PPIs as therapy for patients with GERD. Subgroup analysis indicates that vonoprazan is more effective than PPIs for patients with severe erosive esophagitis. The safety outcomes for vonoprazan are similar to those for PPIs.

The pharmacotherapeutic management of gastroesophageal reflux disease (GERD)

INTRODUCTION

Gastroesophageal reflux disease (GERD) is a very common worldwide condition, affecting about 15-20% of the whole population, and representing a major burden for health-care systems. Because of its frequency, health physicians - family doctors as well as specialists - should be aware of the different pharmacotherapeutic approaches in managing GERD, according to disease severity.

AREAS COVERED

Authors summarize the pharmacological management of GERD in adults, present the different pharmaceutical classes, and review the evidence on efficacy for each treatment according to the most common clinical scenarios: non-erosive gastroesophageal reflux disease (NERD), erosive esophagitis (EE), and proton-pump inhibitor (PPI) refractory GERD. They also provide an overview of treatments under development.

EXPERT OPINION

To date, PPIs remain the most effective treatment option for both NERD and EE. However, Potassium-Competitive Acid blockers (PCAB) may be considered, with at least similar efficacy in Asian populations. Preliminary data suggest that PCABs could be superior to classic PPIs in patients with severe EE, and may also be of particular interest in the management of PPI-refractory GERD patients. Their definitive role in GERD management, however, still remains to be determined based on properly designed and conducted randomized clinical trials.

Current knowledge on non-steroidal anti-inflammatory drug-induced small-bowel damage: a comprehensive review

Recent advances in small-bowel endoscopy such as capsule endoscopy have shown that non-steroidal anti-inflammatory drugs (NSAIDs) frequently damage the small intestine, with the prevalence rate of mucosal breaks of around 50% in chronic users. A significant proportion of patients with NSAIDs-induced enteropathy are asymptomatic, but some patients develop symptomatic or complicated ulcers that need therapeutic intervention. Both inhibition of prostaglandins due to the inhibition of cyclooxygenases and mitochondrial dysfunction secondary to the topical effect of NSAIDs play a crucial role in the early process of injury. As a result, the intestinal barrier function is impaired, which allows enterobacteria to invade the mucosa. Gram-negative bacteria and endogenous molecules coordinate to trigger inflammatory cascades via Toll-like receptor 4 to induce excessive expression of cytokines such as tumor necrosis factor-α and to activate NLRP3 inflammasome, a multiprotein complex that processes pro-interleukin-1β into its mature form. Finally, neutrophils accumulate in the mucosa, resulting in intestinal ulceration. Currently, misoprostol is the only drug that has a proven beneficial effect on bleeding small intestinal ulcers induced by NSAIDs or low-dose aspirin, but its protection is insufficient. Therefore, the efficacy of the combination of misoprostol with other drugs, especially those targeting the innate immune system, should be assessed in the next step.

Cytochrome P450-Based Drug-Drug Interactions of Vonoprazan In Vitro and In Vivo

Background

Vonoprazan fumarate is a potassium-competitive acid blocker that was developed as a novel acid-suppressing drug for multiple indications. As a potential alternative to proton-pump inhibitors, the determination of the drug-drug interactions is vital for further applications. Probe drug cocktails are a type of rapid, economical, and efficient approach for evaluating cytochrome P450 enzyme activities. Since vonoprazan is metabolized partly by cytochrome P450, cocktails were used to study CYP-based drug-drug interactions.

Methods

This study was conducted both in vitro and in vivo. In the in vitro study of rat liver microsomes, ultra-performance liquid chromatography coupled to tandem mass spectrometry was utilized to assess the reversible inhibition of cytochrome P450 by vonoprazan by determining the concentration of probe drugs (phenacetin, bupropion, tolbutamide, dextromethorphan, midazolam, chlorzoxazone). The differences in the levels of probe drugs between the rat groups with or without vonoprazan administration were also tested in the rats.

Results

In vitro analysis revealed that the IC₅₀ values of midazolam, tolbutamide, dextromethorphan, and bupropion in rat microsomes were 22.48, 18.34, 3.62, and 3.68 μM, respectively, while chlorzoxazone and phenacetin displayed no inhibition. In vivo analysis revealed that midazolam, bupropion, dextromethorphan, and tolbutamide showed significant (P < 0.05) differences in distinct pharmacokinetic parameters after vonoprazan administration, while those of chlorzoxazone and phenacetin were not significantly different.

Conclusion

The in vitro and in vivo results indicated that vonoprazan can inhibit CYP3A4, CYP2C9, CYP2D6, and CYP2B6, suggesting that the coadministration of vonoprazan with cytochrome P450 substrates should be performed cautiously in clinical settings.