Evaluation of the Efficacy and Safety of Vonoprazan in Patients with Nonerosive Gastroesophageal Reflux Disease: A Phase III, Randomized, Double-Blind, Placebo-Controlled, Multicenter Study

Potassium-competitive acid blockers and acid-related disorders

PURPOSE OF REVIEW

Potassium-competitive acid blockers (PCABs) represent a new class of compounds for the treatment of acid-related disorders. Recent FDA approval of the PCAB vonoprazan for erosive esophagitis has started an important new approach to acid-related disorders.

RECENT FINDINGS

Compared to conventional proton pump inhibitors (PPIs), PCABs provide more rapid, potent, and sustained suppression of gastric acid with faster and more durable symptom relief. Studies have demonstrated the efficacy of PCABs for erosive esophagitis, nonerosive reflux disease, and peptic ulcer disease including H. pylori. However, the PCAB vonoprazan was only approved in the US as part of combination therapy for eradication of H. pylori. Clinical trials have now demonstrated noninferiority of vonoprazan to lansoprazole for treatment of erosive esophagitis, particularly noting superiority of vonoprazan in patients with severe esophagitis resulting in FDA approval of vonoprazan for treatment of erosive esophagitis. Emerging data suggests a possible utility of vonoprazan for PPI-resistant gastroesophageal reflux disease (GERD) and on-demand therapy for nonerosive reflux disease. Vonoprazan is generally well tolerated but long-term safety data is not well established.

SUMMARY

The PCAB vonoprazan is a newly FDA approved treatment option for erosive esophagitis. Its possible role in PPI-resistant GERD and nonerosive reflux disease warrants further investigation.

A Phase III Head-to-Head Study to Compare the Efficacy and Safety of Fexuprazan and Esomeprazole in Treating Patients with Erosive Esophagitis

Background: Fexuprazan (Fexuclue®; Daewoong Pharmaceutical Co., Ltd., Seoul, Korea) is a novel potassium-competitive acid blocker (P-CAB). This multi-center, randomized, double-blind, active-controlled, parallel-group, therapeutic confirmatory, phase III study was conducted to assess its efficacy and safety compared with esomeprazole (Nexium®; AstraZeneca, Gothenburg, Mölndal, Sweden) in Korean patients with erosive esophagitis (EE). Methods: This study evaluated patients diagnosed with EE at a total of 25 institutions in Korea between 13 December 2018 and 7 August 2019. After voluntarily submitting a written informed consent form, the patients were evaluated using a screening test and then randomized to either of the two treatment arms. The proportion of the patients who achieved the complete recovery of mucosal breaks at 4 and 8 weeks, the proportion of those who achieved the complete recovery of heartburn at 3 and 7 days and 8 weeks, and changes in the GERD-Health-Related Quality of Life Questionnaire (GERD-HRQL) scores at 4 and 8 weeks from baseline served as efficacy outcome measures. The incidence of treatment-emergent adverse events (TEAEs) and adverse drug reactions (ADRs) and the serum gastrin levels served as safety outcome measures. Results: The study population comprised a total of 231 patients (n = 231) with EE, including 152 men (65.80%) and 79 women (34.20%); their mean age was 54.37 ± 12.66 years old. There were no significant differences in the efficacy and safety outcome measures between the two treatment arms (p > 0.05). Conclusions: It can be concluded that the efficacy and safety of Fexuclue® are not inferior to those of esomeprazole in Korean patients with EE.

Efficacy and safety of potassium-competitive acid inhibitors in the treatment of gastroesophageal reflux: a systematic review and meta-analysis

BACKGROUND

Gastroesophageal reflux disease (GERD) is a common disease caused by reflux of gastric contents to the esophagus. Proton-pump inhibitors (PPIs) are recommended as a first-line therapy to treat GERD. Recently, the potassium-competitive acid inhibitors have been increasingly in use in clinical practice. We aimed to evaluate the efficacy and safety of P-CABs in GERD.

METHODS

We searched PubMed, the Cochrane Library, EMBASE and Web Of Science for publications regarding randomized controlled trials comparing potassium-competitive acid inhibitors to PPI monotherapy or Placebo with respect to efficacy and safety in GERD (until April 2023). The primary outcome was an absence or global symptom improvement and the incidence of adverse events in GERD. The quality of the included literature was assessed using the bias assessment tool recommended in the Cochrane Systematic Assessor's Handbook 5.1.0. We use RevMan 5.3 software for Meta-analysis, sensitivity analysis and publication bias analysis.

RESULTS

Of the 991 screened studies, 14 studies including 4868 participants were analyzed. The ORs for the healing rates of GERD with P-CABs versus PPI/Placebo were 2.10 (95% confidence interval [CI] 1.53-2.88), additionally, 1.09 (95% CI 1.05-1.14), 1.03 (95% CI 1.00-1.06) and 1.03 (95% CI 0.99-1.06) in Weeks 2, 4, and 8, respectively. The effectiveness rate of the experimental group was significantly higher than that of the control group (RR 1.73; 95% CI 1.27-2.36). The overall OR of Incidence of adverse events with P-CABs versus PPI/Placebo was 1.08 (95% CI 0.88-1.12). Overall, the risk of bias was low to some concerns. Furthermore, sensitivity analyses confirmed the robustness of the study's conclusion.

CONCLUSIONS

Our findings suggest that potassium-competitive acid inhibitors is non-inferior to PPIs as therapy for patients with GERD. The safety outcomes for potassium-competitive acid inhibitors are similar to those for PPIs.

BRAZILIAN CLINICAL GUIDELINE FOR THE THERAPEUTIC MANAGEMENT OF GASTROESOPHAGEAL REFLUX DISEASE (BRAZILIAN FEDERATION OF GASTROENTEROLOGY, FBG)

BACKGROUND

Gastroesophageal Reflux Disease (GERD) is a prevalent condition in Brazil, affecting 12% to 20% of the urban population, with significant implications for patient quality of life and potential for complications.

OBJECTIVE

This paper focuses on the recent update of the Brazilian guidelines for GERD, a necessary revision due to advancements in knowledge and practice since the last publication over a decade ago. The update pays particular attention to the role and safety of proton pump inhibitors (PPIs), acknowledging the growing concerns about their long-term use, adverse events, and overprescription.

METHODS

The methodology of the guideline update involved an extensive literature review in multiple languages (English, French, Italian, Spanish, and Portuguese), drawing from major databases such as Medline, Embase, and SciELO-Lilacs.

RESULTS

This comprehensive approach resulted in a carefully curated selection of studies, systematic reviews, and meta-analyses, specifically focusing on PPIs and other therapeutic strategies for GERD. The updated guidelines are presented in a user-friendly question-and-answer format, adhering to the PICO system (Population, Intervention, Comparison, Outcomes) for clarity and ease of interpretation. The recommendations are supported by robust scientific evidence and expert opinions, enhancing their practical applicability in clinical settings. To ensure the reliability and clarity of the recommendations, the GRADE system (Grading of Recommendations Assessment, Development, and Evaluation) was employed. This system categorizes the strength of recommendations as strong, weak, or conditional and classifies evidence quality as high, moderate, low, or very low. These classifications provide insight into the confidence level of each recommendation and the likelihood of future research impacting these guidelines.

CONCLUSION

The primary aim of these updated guidelines is to offer practical, evidence-based advice for the management of GERD in Brazil, ensuring that healthcare professionals are equipped with the latest knowledge and tools to deliver optimal patient care.

BACKGROUND

•Gastrointestinal specialists rely heavily on guidelines to manage digestive pathologies effectively. The Brazilian clinical guideline for therapeutic management of gastroesophageal reflux disease (GERD) is an invaluable tool for these specialists.

BACKGROUND

•It critically analyzes practical aspects of therapy through 12 questions covering a wide range of topics, from behavioral measures to surgical and endoscopic indications.

BACKGROUND

•The recommendations in this guideline are justified using the GRADE system (Grading of Recommendations Assessment, Development, and Evaluation), and experienced experts provide comments and suggestions at the end of each question.

Different dosages of vonoprazan for gastroesophageal reflux disease: study protocol for a pragmatic, crossover-cluster, randomized controlled trial with patient preference arms

BACKGROUND

Vonoprazan results in more potent acid suppression for gastroesophageal reflux disease (GERD) than proton pump inhibitors. It has only been approved for treating erosive esophagitis in China, but 30-40% of GERD patients cannot achieve the goal of treatment with vonoprazan 20 mg daily. This study aims to investigate whether vonoprazan could relieve the symptoms of Chinese patients with non-erosive reflux disease (NERD) and whether increased dosage or different times of dosing could increase the response rate of GERD.

METHODS

This study is a pragmatic, open-label, crossover-cluster, randomized controlled trial with patient preference arms. Two thousand eight hundred eighty patients with GERD from 48 hospitals in China will be enrolled. These hospitals will be divided into a compulsory randomization cluster (24 hospitals) and a patient preference cluster (24 hospitals). Patients in the compulsory randomization cluster will be randomized to three regimens according to the crossover-cluster randomization. Patients in the patient preference cluster may choose to receive any regimen if they have a preference; otherwise, patients will be randomly assigned. The three treatment regimens will last 4 weeks, including (1) vonoprazan 20 mg p.o. after breakfast, (2) vonoprazan 20 mg p.o. after dinner, and (3) vonoprazan 20 mg p.o. after breakfast and after dinner. Patients will attend a baseline visit, a 4-week e-diary, a fourth-week visit, and a sixth-month visit online. The primary outcome is the symptom relief rate of all patients after 4-week therapy. Secondary outcomes include the healing rate of EE patients, the severity of symptoms, compliance with the therapy at the fourth-week follow-up visit, recurrent symptoms, and the frequency of self-conscious doctor visits at the sixth-month follow-up visit.

DISCUSSION

This trial will explore the effectiveness of different regimens of vonoprazan that will be implemented with GERD patients in China. The randomization with patient preferences considered and the crossover-cluster component may improve the robustness and extrapolation of study conclusions.

TRIAL REGISTRATION

https://www.chictr.org.cn ChiCTR2300069857. Registered on 28 March 2023.

PROTOCOL VERSION

February 18, 2023, Version 2.

Efficacy of Vonoprazan vs. Pantoprazole or Non-acid Suppression in Prevention of Post-variceal Ligation Ulcer Bleeding in Portal Hypertension: A Multi-arm Randomized Controlled Trial

Background

Up-to-date data about the role of acid suppression therapy e.g. proton-pump inhibitors; to reduce post-endoscopic variceal ligation (EVL) ulcer-bleeding are conflicting. Vonoprazan; a recently introduced potassium-competitor acid blocker, has not been studied to prevent post-EVL ulcer/bleeding. The aim was to evaluate the efficacy of vonoprazan vs. pantoprazole or non-acid suppression to prevent post-EVL ulcer/bleeding in portal hypertension patients.

Material and methods

We enrolled 275 portal hypertension patients undergoing EVL in a three-arm randomized, single-blind, controlled study. A clinico-laboratory baseline evaluation was performed. Following EVL, patients were randomly and equally assigned to receive vonoprazan 20mg once daily, pantoprazole 40 mg once daily, or no acid suppression therapy. Post-EVL ulcer bleeding, ulcer dimensions, odynophagia as well as vonoprazan safety were evaluated after 2 weeks of EVL.

Results

Post-EVL ulcer bleeding occurred among 2.15% of vonoprazan, 8.7% of pantoprazole, and 14.2% of the non-acid suppression groups (P < 0.001). Post-ligation ulcer frequency and dimensions were higher among non-acid suppression and pantoprazole groups vs. vonoprazan (P < 0.05). Chest pain and odynophagia were encountered among 73.6% and 54.9% of the non-acid suppression group vs. 39.6% and 45.1% in pantoprazole, and 17.2% and 21.5% in vonoprazan groups, respectively (P < 0.05). There were no vonoprazan-related adverse events. Non-use of vonoprazan was the strongest independent predictor for post-EVL bleeding.

Conclusion

Short course of vonoprazan 20 mg/day is safe and superior to pantoprazole 40 mg/day in the reduction of post-EVL ulcer dimensions at 2 weeks post-EVL, and prevention of ulcer-related bleeding. Acid suppression is superior to no acid suppression to prevent post-EVL complications.

Incidence and type of adverse events in patients taking vonoprazan: A systematic review and meta-analysis

Background

Vonoprazan, a novel acid-suppressive drug, is non-inferior to proton pump inhibitors (PPIs) for the management of gastric acid-related diseases. However, the safety of vonoprazan has not been systematically evaluated yet.

Objectives

To elucidate the incidence and type of adverse events (AEs) in patients taking vonoprazan.

Design

Systematic review and meta-analysis.

Data sources and methods

PubMed, EMBASE, and Cochrane Library databases were searched for all studies reporting the safety of vonoprazan. The incidences of any AEs, drug-related AEs, serious AEs, AEs leading to drug discontinuation, and common AEs were pooled. Odds ratios (ORs) were calculated to compare the incidence of AEs between patients taking vonoprazan and PPIs.

Results

Seventy-seven studies were included. The pooled incidences of any AEs, drug-related AEs, serious AEs, and AEs leading to drug discontinuation were 20, 7, 1, and 1%, respectively. The incidences of any AEs (OR = 0.96, p = 0.66), drug-related AEs (OR = 1.10, p = 0.44), serious AEs (OR = 1.14, p = 0.36), and AEs leading to drug discontinuation (OR = 1.09, p = 0.55) were not significantly different between patients taking vonoprazan and PPIs. In subgroup analyses, patients with peptic ulcer disease (PUD) had higher incidences of any AEs, serious AEs, and AEs leading to drug discontinuation than those with gastroesophageal reflux disease (GERD), Helicobacter pylori (H. pylori) infection, and artificial ulcer after gastric endoscopic submucosal dissection (ESD), but patients with H. pylori infection had a higher incidence of drug-related AEs than those with PUD, GERD, and artificial ulcer after gastric ESD. The incidence of AEs was higher in patients taking long-term use of vonoprazan than those taking short-term use of vonoprazan.

Conclusion

Vonoprazan is well tolerated and shows similar safety compared to PPIs. The safety of vonoprazan may be primarily influenced by its indications and duration.

Registration

PROSPERO CRD42022314982.

Comparison of acid-lowering drugs for endoscopy negative reflux disease: Systematic review and network Meta-Analysis

BACKGROUND

The comparative efficacy and safety of medical therapies for gastro-esophageal reflux symptoms in endoscopy-negative reflux disease is unclear. We conducted a network meta-analysis to evaluate efficacy and safety of proton pump inhibitors (PPIs), histamine-2-receptor antagonists, potassium-competitive acid blockers (PCABs), and alginates in patients with endoscopy-negative reflux disease.

METHODS

We searched MEDLINE, EMBASE, EMBASE Classic, and the Cochrane central register of controlled trials from inception to February 1, 2022. We included randomized controlled trials (RCTs) comparing efficacy of all drugs versus each other, or versus a placebo, in adults with endoscopy-negative reflux disease. Results were reported as pooled relative risks with 95% confidence intervals to summarize effect of each comparison tested, with treatments ranked according to P-score.

KEY RESULTS

We identified 23 RCTs containing 10,735 subjects with endoscopy-negative reflux disease. Based on failure to achieve complete relief of symptoms between ≥2 and <4 weeks, omeprazole 20 mg o.d. (P-score 0.94) ranked first, with esomeprazole 20 mg o.d. or 40 mg o.d. ranked second and third. In achieving adequate relief, only rabeprazole 10 mg o.d. was significantly more efficacious than placebo. For failure to achieve complete relief at ≥4 weeks, dexlansoprazole 30 mg o.d. (P-score 0.95) ranked first, with 30 ml alginate q.i.d. combined with omeprazole 20 mg o.d., and 30 ml alginate t.i.d. second and third. In terms of failure to achieve adequate relief at ≥4 weeks, dexlansoprazole 60 mg o.d. ranked first (P-score 0.90), with dexlansoprazole 30 mg o.d. and rabeprazole 20 mg o.d. second and third. All drugs were safe and well-tolerated.

CONCLUSIONS & INFERENCES

Our results confirm superiority of PPIs compared with most other drugs in treating endoscopy-negative reflux disease. Future RCTs should aim to better classify patients with endoscopy-negative reflux disease, and to establish the role of alginates and PCABs in achieving symptom relief in both the short- and long-term.

[Treatment of Acid-related Diseases Using Potassium-competitive Acid Blockers]

Proton pump inhibitors (PPIs) have several limitations to their efficacy including insufficient acid suppression, slow onset of action, and variable efficacy among patients due to CYP2C19 metabolism. Potassium-competitive acid blockers inhibit H⁺-K⁺-ATPase in a reversible and K⁺-competitive manner, are novel acid suppressive drugs with rapid onset of action, meal independence, and prolonged control of intragastric acidity compared to PPIs. Potassium-competitive acid blockers exhibited non-inferior therapeutic efficacies on reflux esophagitis, gastric ulcers, and Helicobacter pylori eradication. The review is focused on the unmet needs across the acid-related diseases and recent updates on clinical studies using vonoprazan and tegoprazan.

Trends in gastroesophageal reflux disease research: A bibliometric and visualized study

Background

Gastroesophageal reflux disease (GERD), a disorder resulting from the retrograde flow of gastric contents into the esophagus, affects an estimated 10-30% of the Western population, which is characterized by multifactorial pathogenesis. Over the past few decades, there have been many aspects of uncertainty regarding GERD leading to an ongoing interest in the field as reflected by a large number of publications, whose heterogeneity and variable quality may present a challenge for researchers to measure their scientific impact, identify scientific collaborations, and to grasp actively researched themes in the GERD field. Accordingly, we aim to evaluate the knowledge structure, evolution of research themes, and emerging topics of GERD research between 2012 and 2022 with the help of bibliometric approaches.

Methods

The literature focusing on GERD from 2012 to 2022 was retrieved from the Science Citation Index Expanded of the Web of Science Core Collection. The overall publication performance, the most prolific countries or regions, authors, journals and resources-, knowledge- and intellectual-networking, as well as the co-citation analysis of references and keywords, were analyzed through Microsoft Office Excel 2019, CiteSpace, and VOSviewer.

Results

A total of 8,964 publications were included in the study. The USA published the most articles (3,204, 35.74%). Mayo Clin ranked first in the number of articles published (201, 2.24%). EDOARDO SAVARINO was the most productive author (86, 0.96%). The most productive journal in this field was SURGICAL ENDOSCOPY AND OTHER INTERVENTIONAL TECHNIQUES (304, 3.39%). AMERICAN JOURNAL OF GASTROENTEROLOGY had the most co-citations (4,953, 3.30%). Keywords with the ongoing strong citation bursts were transoral incision less fundoplication, eosinophilic esophagitis, baseline impedance, and functional heartburn.

Conclusion

For the first time, we obtained deep insights into GERD research through bibliometric analysis. Findings in this study will be helpful for scholars seeking to understand essential information in this field and identify research frontiers.

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.

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.

The views of African and Middle Eastern Gastroenterologists on the management of mild-to-moderate, non-erosive gastro-esophageal reflux disease (GERD)

INTRODUCTION

Gastro-esophageal reflux disease (GERD) is a common gastrointestinal disorder that occurs when backflow of the gastric contents into the esophagus results in troublesome symptoms. Though GERD has been extensively studied in Western populations, literature on the management of GERD in patients in Africa and Middle East (AME) is scarce.

AREAS COVERED

In this review, we provide an overview of the management of mild-to-moderate GERD in AME. Here we focus on the efficacy and safety of currently available treatments for GERD to help physicians and community pharmacists appropriately manage patients with mild-to-moderate GERD in the primary healthcare setting, detailing specific situations and patient scenarios that are relevant to the region, including management of GERD during Ramadan and post-bariatric surgery.

EXPERT OPINION

Under-appreciation of the burden of GERD in the region has resulted in a lack of consensus on management. Barriers that currently prevent the adoption of treatment guidelines in the primary healthcare setting may include lack of availability of local guidelines and referral systems, a paucity of region-specific research, and dogmatic adherence to traditional practice. By increasing awareness, strengthening knowledge, and by more effective utilization of resources, physicians and pharmacists could optimize GERD management strategies to better support patients.

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).

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.

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.

Vonoprazan for treatment of gastroesophageal reflux disease: Research advances

Gastroesophageal reflux disease is a common gastrointestinal disease that can be effectively treated by drugs alone. Proton pump inhibitors are the currently mainstay drugs for the treatment of gastroesophageal reflux disease, but are insufficiently effective. Vonoprazan, which is a new type of drug that inhibits gastric acid secretion, has been employed for the management of gastroesophageal reflux disease. In this article, we comprehensively review the current evidence regarding clinical efficacy and safety of vonoprazan for the treatment of gastroesophageal reflux disease to guide the clinical decision.

Randomised clinical trial: comparison of tegoprazan and placebo in non-erosive reflux disease

BACKGROUND

Tegoprazan is a novel, fast- and long-acting potassium-competitive acid blocker that suppresses gastric acid secretion, which could benefit patients with non-erosive reflux disease (NERD), a type of gastroesophageal reflux disease.

AIM

To evaluate the efficacy and safety profiles of tegoprazan compared with those of a placebo in Korean patients with NERD.

METHODS

In this phase 3, double-blind, placebo-controlled, multicentre study, 324 Korean patients with NERD were randomised into three treatment groups: tegoprazan 50 mg, tegoprazan 100 mg and placebo. These drugs were provided once daily for 4 weeks. The primary endpoint was the proportion of patients with complete resolution of major symptoms (both heartburn and regurgitation) for the last 7 days of the 4-week treatment period. Other outcomes related to efficacy, safety and tolerability were also evaluated.

RESULTS

Among all, 42.5% (45/106), 48.5% (48/99) and 24.2% (24/99) of patients showed complete resolution of major symptoms at week 4 after receiving tegoprazan 50 mg, tegoprazan 100 mg, and placebo, respectively. Both doses of tegoprazan showed superior efficacy than the placebo (P = 0.0058 and P = 0.0004, respectively). The complete resolution rates of heartburn and proportions of heartburn-free days (as other efficacy outcomes) were significantly higher in both tegoprazan groups than in the placebo group (P < 0.05 for all). No significant difference in the incidence of treatment-emergent adverse events were noted.

CONCLUSIONS

Tegoprazan 50 and 100 mg showed superior therapeutic efficacy compared with the placebo, as well as a favourable safety profile in patients with NERD. Registration number: ClinicalTrials.gov identifier NCT02556021.

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.

Prevalence of behavioral disorders in patients with vonoprazan-refractory reflux symptoms

BACKGROUND

Behavioral disorders, such as supragastric belching (SGB) and rumination syndrome (RS), which may be treated by cognitive behavioral therapy, are common in patients with reflux symptoms refractory to proton pump inhibitors (PPI). Vonoprazan (VPZ) has been used as a new type of acid inhibitor in Japan since 2015. We herein investigated the prevalence of behavioral disorders in patients with VPZ-refractory reflux symptoms and attempted to identify predictive factors.

METHODS

We retrospectively analyzed esophagogastroduodenograms, high-resolution manometry, and 24-h multiluminal impedance pH-metry (MIIpH) in patients with VPZ-refractory reflux symptoms (heartburn or regurgitation) receiving 20 mg VPZ who underwent these tests at our hospital between January 2015 and April 2020. Patients were divided as follows: non-erosive reflux disease with pathological esophageal acid exposure (NERD), functional heartburn (FH), reflux hypersensitivity (RH), excessive (> 13 per day) SGB, and possible RS based on MIIpH parameters.

RESULTS

Among 49 patients, 6 (12.2%) had SGB, 4 (8.2%) possible RS, 29 (59.2%) FH, 9 (18.4%) RH, and 1 (2%) NERD. Possible RS patients had more postprandial non-acid reflux events than FH patients (p < 0.05). The multivariate logistic regression analysis did not identify any predictive factors with statistical significance.

CONCLUSION

More than 20% patients with VPZ-refractory reflux symptoms had behavioral disorders. The use of HRM and MIIpH may be clinically relevant for a better diagnosis and more specific treatment.

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.

Novel Therapies for Gastroesophageal Reflux Disease: Beyond Proton Pump Inhibitors

PURPOSE OF REVIEW

Despite the many areas of unmet needs in gastroesophageal reflux disease (GERD), proton pump inhibitors (PPIs) remain the cornerstone of medical therapy. However, since their introduction, the therapeutic limitations of PPIs in GERD management have been increasingly recognized.

RECENT FINDINGS

In this review we discuss the new medical, endoscopic, and surgical therapeutic modalities that have been developed over the last decade. They include the potassium-competitive acid blockers (P-CABs) which provide a rapid onset, prolonged, and profound acid suppression, mucosal protectants which promote the physiological protective barrier of the esophageal mucosa, new prokinetics and neuromodulators. There are growing numbers of novel therapeutic endoscopic techniques that are under investigation or were recently introduced into the market, further expanding our therapeutic armamentarium for GERD. The development of diverse therapeutic modalities for GERD, despite the availability of PPIs, suggests that there are many areas of unmet need in GERD that will continue and drive future exploration for novel therapies.

Efficacy and Safety of Vonoprazan in Patients With Nonerosive Gastroesophageal Reflux Disease: A Randomized, Placebo-Controlled, Phase 3 Study

OBJECTIVES

To assess the efficacy and safety of vonoprazan on heartburn symptoms in patients with nonerosive reflux disease (NERD) (ClinicalTrials.gov: NCT02954848).

METHODS

This phase 3, double-blind, placebo-controlled study included Japanese patients aged 20 years and older with grade N/M NERD and recurrent heartburn. Patients received placebo (n = 245) or vonoprazan 10 mg (n = 238) for 4 weeks. The primary efficacy outcome was frequency of heartburn experienced by patients during the treatment period (proportion of days without heartburn). Other outcomes included cumulative improvement rates of heartburn, proportion of patients with complete heartburn resolution in the fourth week of treatment, and safety.

RESULTS

Compared with placebo, the proportion of days without heartburn was not significantly higher in the vonoprazan group in the full analysis (primary end point, 72.55% vs 61.50%, vonoprazan vs placebo, P = 0.0643) but was significantly higher in the per-protocol-set sensitivity analysis (P = 0.0341). Early onset of response and significantly greater cumulative improvement rates of heartburn were observed in the vonoprazan group (P = 0.0003). In a post hoc analysis, a greater proportion of patients with complete heartburn resolution in the fourth week of treatment were reported in the vonoprazan group (P = 0.0023). Incidence of treatment-emergent adverse events was similar between treatment groups (23.5% vs 23.3%); most treatment-emergent adverse events were mild in severity.

DISCUSSION

Although vonoprazan 10 mg was not superior to placebo with respect to proportion of days without heartburn in Japanese patients with NERD, vonoprazan had a significantly higher cumulative rate of heartburn resolution and was well tolerated.

The potential role of potassium-competitive acid blockers in the treatment of gastroesophageal reflux disease

PURPOSE OF REVIEW

Gastroesophageal reflux disease (GERD) is primarily a motor disorder, but its pathogenesis is multifactorial. Although gastric acid secretion is usually normal in GERD patients, treatment with proton pump inhibitors (PPIs) has become the standard of care, despite increasing awareness of their shortcomings. In this article, a new class of antisecretory drugs (namely potassium-competitive acid blockers, P-CABs), developed to overcome these limitations, is discussed.

RECENT FINDINGS

P-CABs block the K exchange channel of the proton pump, resulting in rapid, competitive, reversible inhibition of acid secretion. These drugs offer a more rapid elevation of intragastric pH than PPIs, while maintaining similar antisecretory effect, the duration of which is dependent on half-life and can be prolonged with extended release formulations. Thus, P-CABs offer advances in the treatment of GERD including rapid heartburn relief, faster and more reliable healing of severe grades of erosive esophagitis, as a consequence of better control of nighttime acid secretion than PPIs.

SUMMARY

P-CABs overcome many of the drawbacks of PPIs. The unique antisecretory effects of vonoprazan might be especially useful in the long-term treatment of patients with Barrett's esophagus.

Recognition of Helicobacter pylori by protein-targeting aptamers

BACKGROUND

Helicobacter pylori (H pylori) is a disease-causing pathogen capable of surviving under acidic conditions of the human stomach. Almost half of the world's population is infected with H pylori, with gastric cancer being the most unsatisfactory prognosis. Although H pylori has been discovered 30 years ago, the effective treatment and elimination of H pylori continue to be problematic.

MATERIALS AND METHODS

In our study, we screened nucleic acid aptamers using H pylori surface recombinant antigens as targets. Trypsin was used for separating aptamers that were bound to proteins. Following nine rounds of screening, we performed sequence similarity analyses to assess whether the aptamers can recognize the target protein. Two sequences with desirable recognition ability were selected for affinity detection. Aptamer Hp4 with the strongest binding ability to the H pylori surface recombinant antigen was chosen. After optimization of the binding conditions, we conducted specificity tests for Hp4 using Escherichia coli, Staphylococcus aureus, Vibrioanguillarum, and H pylori.

RESULTS

The data indicated that the aptamer Hp4 had an equilibrium dissociation constant (K_d ) of 26.48 ± 5.72 nmol/L to the target protein. This aptamer was capable of exclusively detecting H pylori cells, without displaying any specificity for other bacteria.

CONCLUSIONS

We obtained a high-affinity aptamer for H pylori, which is expected to serve as a new molecular probe for detection of H pylori.

Randomised phase 3 trial: tegoprazan, a novel potassium-competitive acid blocker, vs. esomeprazole in patients with erosive oesophagitis

BACKGROUND

Tegoprazan is a novel potassium-competitive acid blocker that has a fast onset of action and can control gastric pH for a prolonged period, which could offer clinical benefit in acid-related disorders.

AIM

To confirm the non-inferiority of tegoprazan to esomeprazole in patients with erosive oesophagitis (EE).

METHODS

In this multicentre, randomised, double-blind, parallel-group comparison study, 302 Korean patients with endoscopically confirmed EE (Los Angeles Classification Grades A-D) were randomly allocated to either tegoprazan (50 or 100 mg) or esomeprazole (40 mg) treatment groups for 4 or 8 weeks. The primary endpoint was the cumulative proportion of patients with healed EE confirmed by endoscopy up to 8 weeks from treatment initiation. Symptoms, safety and tolerability were also assessed.

RESULTS

The cumulative healing rates at week 8 were 98.9% (91/92), 98.9% (90/91) and 98.9% (87/88) for tegoprazan 50 mg, tegoprazan 100 mg and esomeprazole 40 mg, respectively. Both doses of tegoprazan were non-inferior to esomeprazole 40 mg. The incidence of adverse events was comparable among the groups, and tegoprazan was well-tolerated.

CONCLUSION

Once daily administration of tegoprazan 50 or 100 mg showed non-inferior efficacy in healing EE and tolerability to that of esomeprazole 40 mg.

Potassium-competitive acid blockers - are they the next generation of proton pump inhibitors?

The modern lifestyle caters to an increase in the incidence of peptic ulcer disease, gastroesophageal reflux disease and several other acid-related conditions of the gut. The drugs to prevent these conditions work either through H2 receptor blockade or inhibition of the H⁺, K⁺ ATPase enzyme. Although proton pump inhibitors have been proven to be efficacious, they have a slow onset of action with limited resolution of symptoms in most patients. Potassium-competitive acid blockers (P-CABs) are novel drugs that bind reversibly to K⁺ ions and block the H⁺, K⁺ ATPase enzyme, thus preventing acid production. P-CABs have a fast onset of action and have dose-dependent effects on acid production. Animal studies exist that differentiate the better results of P-CABs from proton pump inhibitors; further human trials will give a comprehensive picture of the results and will help to elucidate the therapeutic benefits of this new group of drugs.

New Medical Approach to Functional Dyspepsia, from Core Symposium 3, Japan Gastroenterological Association 2015-2017

In the annual meeting of the Japan Gastroenterological Association (JGA), the scientific organizing committee selected the serial topics for the core symposium. One of the core symposia held during 2015-2017 was entitled "New medical approach to functional dyspepsia (FD)." In 2015, the subtitle of this symposium was "Helicobacter pylori gastritis and FD." In 2016, the subtitle of this symposium was "overlap with other functional GI disorders." In 2017, the subtitle was "therapeutic approach to FD." During these 3 years, a total of 24 presentations were included in Core Symposium 3 and deep and intensive discussions were carried out.

Vonoprazan versus proton pump inhibitors for the management of gastroesophageal reflux disease: A protocol for a systematic review with meta-analysis

BACKGROUND AND AIM

Vonoprazan, a novel potassium-competitive acid blocking agent, is used in the management of gastroesophageal reflux disease (GERD). We aim to perform a systematic review and meta-analysis for the comparison of the effects of vonoprazan and proton pump inhibitors (PPIs) in GERD in randomized controlled trials (RCTs).

METHODS

A systematic and comprehensive search will be performed using MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials (CENTRAL), Google Scholar, and clinical trial registries, for studies published up to September 2018. Only randomized clinical trials will be included. Primary outcomes of symptoms and esophageal erosion improvement in the intention-to-treat analysis, and secondary outcomes of symptoms and esophageal erosion improvement rate in the per protocol analysis, the comparative efficacy in terms of healing rate of esophageal erosion on endoscopy, the comparative efficacy in terms of improvement of esophageal impedance-pH study, adverse events, long-term safety, and the comparative efficacy in terms of CYP2C19 metabolite levels will be studied. The quality of included studies will be assessed using the modified risk of bias tool. Heterogeneity of estimates across studies as well as publication bias will be assessed. This systematic review and meta-analysis will be performed according to the protocol recommended by the Cochrane Collaboration and reported according to the preferred reporting items for systematic reviews and meta-analysis (PRISMA) guidelines. All statistical analyses will be conducted using Stata SE version 15.0.

RESULTS

The results of this systematic review and meta-analysis will be published in a peer-reviewed journal.

CONCLUSION

To our knowledge, this systematic review and meta-analysis will be the first to evaluate existing research comparing Vonoprazan and PPIs in GERD. Our study will provide information about the effect of vonoprazan and PPIs in GERD in RCTs. The review will benefit patients, healthcare providers, and policymakers.

Efficacy of Vonoprazan for Gastroesophageal Reflux Symptoms in Patients with Proton Pump Inhibitor-resistant Non-erosive Reflux Disease

Objective Clinically, patients with proton pomp inhibitor (PPI)-resistant gastroesophageal reflux disease (GERD) are very challenging to treat. The aim of this study was to determine the rates of symptom relief and adverse events among PPI-resistant GERD patients that changed their therapy from a PPI to vonoprazan. Methods Patients with severe gastroesophageal reflux symptoms (total GERD-Q score ≥8) without endoscopic findings of mucosal breaks who changed their medication from a PPI to vonoprazan during a 12-week period from 2015 to 2016 at 2 hospitals were selected. The primary outcome was the self-reported relief of gastroesophageal reflux symptoms. The odds ratio (OR) for the improvement of symptoms was calculated based on an exact binomial distribution using a matched-pair analysis. The secondary outcome was the GERD-Q score and adverse events. Results Twenty-six patients (6 men) with a mean age of 67.5 years were analyzed. After the therapy was changed from a PPI to vonoprazan, 18 patients (69.2%) reported an improvement, 6 (23.1%) reported no change, and 2 (7.7%) reported an exacerbation of symptoms. A change in therapy was significantly associated with improved self-reported symptoms (OR 9.0, p<0.001). The mean total GERD-Q score during vonoprazan treatment was significantly lower than that during PPI therapy (11.96 vs. 8.92). There were no significant differences in the incidence of adverse events between the therapies. Conclusion Changing the medication from a PPI to vonoprazan was significantly associated with an improvement in gastroesophageal reflux symptoms. Vonoprazan is one of the most promising treatment options for patients with PPI-resistant GERD.

Vonoprazan fumarate, a novel potassium-competitive acid blocker, in the management of gastroesophageal reflux disease: safety and clinical evidence to date

Potassium-competitive acid blocker (P-CAB) is a class of drug that competitively blocks the potassium-binding site of H⁺, K⁺-adenosine triphosphate (ATP)ase. Although the history of this class of drugs started over 30 years ago, clinical use of two P-CABs, revaprazan and vonoprazan, were only recently approved in Korea and Japan, respectively. Among them, vonoprazan has several advantages over conventional proton-pump inhibitors (PPIs), including rapid onset of action, long duration of acid suppression, fewer interindividual variations in terms of acid suppression, and minimum dietary influence on its action. These advantages of vonoprazan have been proved in clinical trials conducted for license approvals for several acid-related diseases. In this review article, current evidence of vonoprazan in the management of gastroesophageal reflux disease (GERD) will be summarized. Since the clinical trial data, as well as postmarketed clinical data, have consistently demonstrated superiority of vonoprazan over conventional PPIs in terms of achieving healing of mucosal breaks and maintaining the healing, it may provide an excellent, if not complete, option for fulfilling some of the unmet needs for current GERD therapy. The safety problem of vonoprazan is also discussed, as more pronounced hypergastrinemia inevitably ensues with its use.

Vonoprazan fumarate for the management of acid-related diseases

INTRODUCTION

Proton pump inhibitors (PPIs) display a number of limitations and unmet clinical needs that have prompted the development of novel drugs to improve the outcomes of acid-related diseases, including the eradication of H. pylori. In this context, a new synthesized potassium-competitive acid blocker (P-CAB), vonoprazan, showed higher suppression of gastric acid secretion. Areas covered: This review discusses the current knowledge regarding the efficacy of vonoprazan in the treatment of acid-related diseases, with a particular focus on its use in Helicobacter pylori eradication. Expert opinion: Vonoprazan showed some advantages over PPIs in terms of the pharmacokinetic and pharmacodynamic profile: fast onset of action without requiring acid activation and specific administration timing, more potent and prolonged inhibition of acid secretion, including a better nighttime acid control, and a less antisecretory variability. Recent evidence suggests that vonoprazan can be preferred to PPIs as maintenance therapy for reflux esophagitis and eradication of Helicobacter pylori owing to its stronger antisecretory effect. Moreover, vonoprazan displays favorable safety and tolerability profiles, even though long-term studies on the effects of vonoprazan are required.