1-[5-(2-Fluorophenyl)-1-(pyridin-3-ylsulfonyl)-1H-pyrrol-3-yl]-N-methylmethanamine monofumarate (TAK-438), a novel and potent potassium-competitive acid blocker for the treatment of acid-related diseases

Turn over the new leaf of the treatment in peptic ulcer bleeding: a review of the literature

Peptic ulcer bleeding is the most common cause of upper gastrointestinal bleeding, which has a high mortality risk. The standard therapy for acute peptic ulcer bleeding combines medication administration and endoscopic therapies. Both pharmacologic and endoscopic therapies have developed continuously in the past few decades. Proton pump inhibitors (PPIs) already reached a high efficacy in ulcer healing and have been widely used in the past few decades. Endoscopic hemostasis, which includes local epinephrine injection, heater probe coagulation, use of hemostatic clips, and/or band ligation, is highly effective with an overall hemostatic success rate of 85%-90%. However, 10%-20% of patients could not be cured by the current standard combination treatment. Recurrent ulcer bleeding, despite an initial successful hemostasis, is also a big problem for longer hospitalization stays, higher mortality, and higher complication rates, especially for malignant ulcer bleeding. How to manage all types of peptic ulcer bleeding and how to prevent early recurrent peptic ulcer bleeding remain unresolved clinical problems. Recently, several novel medications and endoscopic methods have been developed. Potassium competitive acid blockers have shown a stronger and longer acid suppression than PPI. Hemostatic powder spray and hemostatic gel emulsion are novel hemostatic weapons with emerging evidence, which are potential missing pieces of the puzzle. This literature review will go through the development of endoscopic hemostasis to the prospects of novel endoscopic treatments.

Efficacy and Safety of Potassium-Competitive Acid Blockers vs Proton Pump Inhibitors for Peptic Ulcer Disease or Postprocedural Artificial Ulcers: A Systematic Review and Meta-analysis

INTRODUCTION

Peptic ulcer disease (PUD) and postprocedural artificial ulcers are common ulcer disease. For them, proton pump inhibitor (PPI) and potassium-competitive acid blocker (P-CAB) are commonly used in clinical practice. PPI requires acid, time, and multiple doses, but P-CAB has fewer limitations. We compared the efficacy, safety, and prevention of PPI and P-CAB in PUD or artificial ulcer.

METHODS

We searched PubMed, ClinicalTrials.gov , Embase, Cochrane Library, and Web of Science databases for all studies. All eligible randomized controlled trials up to August 5, 2023, were included. Healing rates, shrinking rates, treatment-emergent adverse events rates, and recurrence rates were measured. Risk of bias, sensitivity analyses, and heterogeneity were also performed.

RESULTS

Twenty researches that were selected from 926 screening studies and in total 6,551 participants were included. The risk ratio (RR) of healing rate with P-CABs vs PPIs of PUD at 4 weeks was RR 1.01 (95% confidence interval 0.98-1.04). In addition, the healing rate distinction of artificial peptic ulcer was RR 1.04 (0.89-1.22), and the shrinking rate was mean difference 0.10 (-1.30-1.51). The result of treatment-emergent adverse event rate of PUD was RR 1.11 (0.91-1.35), and the delayed bleeding rate of artificial ulcer was RR 0.35 (0.16-0.80). The RR for recurrence rate of drug-related ulcers was 0.45 (0.25-0.81).

DISCUSSION

P-CAB is noninferior in healing artificial ulcer and PUD, also the incidence of treatment-emergent adverse events. But, there may be a statistical advantage in holding back delayed bleeding and preventing drug-induced ulcers. More standardized experiments are needed for further applications and more precise conclusions.

Vonoprazan-associated Clostridioides difficile infection: an analysis of the Japanese Adverse Drug Event Report and the FDA Adverse Event Reporting System

Background

Prolonged or excessive use of acid suppressants may increase the risk of Clostridioides difficile infection (CDI) by altering the intestinal microecosystem. Vonoprazan, a novel potassium-competitive acid blocker, exhibits a faster and more sustained acid-suppressive effect than proton pump inhibitors (PPIs). Therefore, vonoprazan may have a greater impact on the gut microbiota, potentially resulting in CDI.

Objectives

This study aimed to explore the potential relationship between acid suppressants and CDI by the Japan Adverse Drug Event Report (JADER) and the FDA Adverse Event Reporting System (FAERS) databases.

Design

A retrospective analysis of the JADER and FAERS databases was examined by disproportionality analysis.

Methods

We performed signal detection analyses of CDI induced by vonoprazan and PPIs using the JADER and FAERS databases. The association between acid suppressants and CDI was calculated using the reporting odds ratio (ROR) and corresponding 95% confidence interval (95% CI). When the lower limit of the 95% CI is exceeded by 1, the association is considered statistically significant.

Results

In the JADER database, the ROR (95% CI) for vonoprazan and PPIs based on suspect drug reports was 15.84 (12.23-20.50) and 2.51 (1.92-3.28), respectively. In the FAERS database, the ROR (95% CI) for vonoprazan and PPIs based on primary and secondary suspect drug reports was 11.50 (6.36-20.82) and 1.42 (1.34-1.51), respectively. Subgroup analysis showed that elderly patients aged 60 years and older were more strongly associated with CDI. The ROR (95% CI) for vonoprazan and PPIs in patients aged 60 years and older in the JADER database was 15.35 (11.59-20.33) and 1.65 (1.14-2.39), respectively. Similarly, the ROR (95% CI) for vonoprazan and PPIs in the FAERS database was 12.56 (6.26-25.20) and 1.43 (1.31-1.57), respectively. Excluding the effect of Helicobacter pylori (H. pylori) infection, the use of acid suppressants was still associated with CDI.

Conclusion

While signal detection analysis based on the JADER and FAERS databases could not establish causality, our study demonstrated that both vonoprazan and PPIs were significantly associated with CDI. Vonoprazan showed a stronger association with CDI in both databases.

Bismuth-Containing Quadruple Therapy for Helicobacter pylori Eradication: A Randomized Clinical Trial of 10 and 14 Days

BACKGROUND

Bismuth-containing quadruple therapy is the first-line treatment for eradicating Helicobacter pylori (H. pylori). The optimal duration for H. pylori eradication using bismuth-containing quadruple therapy remains controversial. Therefore, we aimed to compare the clinical effects of the 10- and 14-day bismuth-containing quadruple treatment regimen to eradicate H. pylori.

METHODS

Treatment-naïve patients with H. pylori infection (n = 1300) were enrolled in this multicenter randomized controlled study across five hospitals in China. They were randomized into 10- or 14-day treatment groups to receive bismuth-containing quadruple therapy as follows: vonoprazan 20 mg twice daily; bismuth 220 mg twice daily; amoxicillin 1000 mg twice daily; and either clarithromycin 500 mg twice daily or tetracycline 500 mg four times daily. At least 6 weeks after treatment, we performed a 13C-urea breath test to evaluate H. pylori eradication.

RESULTS

The per-protocol eradication rates were 93.22% (564/605) and 93.74% (569/607) (p < 0.001) and the intention-to-treat eradication rates were 88.62% (576/650) and 89.38% (581/650) (p = 0.007) for the 10- and 14-day regimens, respectively. Incidence of adverse effects was lower in patients who received 10- vs. 14 days of treatment (22.59% vs. 28.50%, p = 0.016). We observed no significant differences in the compliance to treatment or the discontinuation of therapy because of severe adverse effects between the groups.

CONCLUSION

Compared with the 14-day bismuth-containing quadruple regimens, the 10-day regimen demonstrated a non-inferior efficacy and lower incidence of adverse effects. Therefore, the 10-day regimen is safe and tolerated and could be recommended for H. pylori eradication (NCT05049902).

Potassium-competitive acid blockers and proton-pump inhibitors for healing of erosive esophagitis: a systematic review and network meta-analysis

Background

Proton-pump inhibitors (PPIs) and potassium-competitive acid blockers (P-CABs) are recommended for erosive esophagitis (EE), with good safety and tolerance. However, it is unclear which is the best treatment option for EE.

Objectives

This study aimed to evaluate the comparative efficacy of P-CABs and PPIs for healing EE patients, seeking an appropriate treatment choice in the 4- or 8-week treatment and standard or double dose.

Design

A systematic review and network meta-analysis.

Data sources and methods

Relevant databases were searched to collect randomized controlled trials of PPIs and P-CABs in the treatment of EE up to 31 May 2023. Studies on standard or double-dose PPIs or P-CABs which were published in English and assessed 4- or 8-week healing effects in EE were included. A network meta-analysis was performed to evaluate the efficacy of the treatments under the frequentist framework. Sensitivity and subgroup analyses of patients with different baseline EE were also conducted.

Results

In all, 34 studies involving 25,054 patients and 9 PPIs, 6 P-CABs, or placebo treatment interventions were included. The pooled 4-week healing rate was significantly statistically lower than the pooled 8-week healing rate for most treatments. Besides, the higher healing rate of double-dose treatment than standard-dose treatment was not observed in the initial treatment of most drugs. The main analysis only included studies conducted for both patients with and without severe EE at baseline, and the proportion of severe EE included in the study was >10%, Keverprazan 20 mg qd ranked best with a surface under the cumulative ranking curve (SUCRA) value of 84.7, followed by Ilaprazole 10 mg qd with a SUCRA value of 82.0, for the healing rate at 8 weeks. Sensitivity analysis showed that the results were robust. Subgroup analysis showed that most P-CABs had higher healing rates than PPIs, particularly for patients with severe EE. And the healing rate of Keverprazan 20 mg qd at 8 weeks ranked best in the subgroup without or with severe EE at baseline.

Conclusion

This study showed that an 8-week treatment seemed more effective than the 4-week treatment for healing EE patients. The healing effect of Keverprazan (20 mg qd) ranked best in 8-week treatment, for both severe and non-severe EE patients.

Trial registration

The study protocol was registered with INPLASY (registration number INPLASY2023120053).

Revolution of Helicobacter pylori treatment

Helicobacter pylori infection is a major global health concern, and its management has witnessed a revolutionary shift with the emergence of antibiotic resistance. In this review, I explore the mechanisms of H. pylori antibiotic resistance and highlight the critical need for susceptibility-based eradication treatments. The increasing prevalence of antibiotic-resistant strains requires innovative approaches to combat this resilient pathogen. I also delve into the importance of mass screening as a preventive strategy for early detection and intervention, describing my experience in Bhutan. Additionally, I explore promising alternatives, such as vaccination. The aim of this review is to provide insight into the evolving landscape of H. pylori treatment and highlight the need for a paradigm shift in the approach to combating this persistent bacterial infection.

Helicobacter pylori Diagnosis and Treatment in Africa: The First Lagos Consensus Statement of the African Helicobacter and Microbiota Study Group

BACKGROUND

Helicobacter pylori (H. pylori) infection is the most prevalent type of bacterial infection. Current guidelines from different regions of the world neglect specific African conditions and requirements. The African Helicobacter and Microbiota Study Group (AHMSG), founded in 2022, aimed to create an Africa-specific consensus report reflecting Africa-specific issues.

SUMMARY

Eighteen experts from nine African countries and two European delegates supported by nine African collaborators from eight other countries prepared statements on the most important African issues in four working groups: (1) epidemiology, (2) diagnosis, (3) indications and prevention, and (4) treatment. Limited resources, restricted access to medical systems, and underdeveloped diagnostic facilities differ from those of other regions. The results of the individual working groups were presented for the final consensus voting, which included all board members.

KEY MESSAGES

There is a need for further studies on H. pylori prevalence in Africa, with diagnosis hinged on specific African situation. Treatment of H. pylori in the African setting should be based on accessibility and reimbursement, while indication and prevention should be defined in specific African countries.

Vonoprazan: A Review in Helicobacter pylori Infection

Treatment for the eradication of Helicobacter pylori infection, a leading cause of peptic ulcer disease and an important risk factor for gastric cancer and mucosa-associated lymphoid tissue lymphoma, is indicated whenever infection is identified. However, treatment success rates with current guideline-recommended proton-pump inhibitor (PPI)-based regimens remain suboptimal, with one potential factor associated with treatment failure being inadequate acid suppression. Vonoprazan (Voquezna®) is a first-in-class potassium-competitive acid blocker with the potential to provide potent and sustained acid suppression. Following clinical trials conducted mainly in Asia (supported by post-marketing experience from Asia) and the phase III PHALCON-HP trial conducted in the USA and Europe, vonoprazan is now approved in the USA for use in combination with amoxicillin (dual therapy) or amoxicillin and clarithromycin (triple therapy) for the treatment of H. pylori infection in adults. The vonoprazan-based dual and triple therapy regimens were generally well tolerated in PHALCON-HP. In addition, vonoprazan has advantages including a rapid onset of action and no food effect, making vonoprazan-based dual and triple therapy regimens valuable alternatives to standard PPI-based triple therapy in the treatment of H. pylori infection.

Potassium-competitive acid blockers: rethinking acid suppression for gastroesophageal reflux disease and Helicobacter pylori

Gastroesophageal reflux disease (GERD) and Helicobacter pylori (H. pylori) infection are different disease states that are united by the core role of acid suppression in their management. In GERD, proton pump inhibitors (PPIs) have long been standard therapy based on abundant positive clinical trial data supporting their efficacy and safety. In H. pylori, PPIs are also a critical element of therapy in combination with 1 or more antibiotics to achieve and maintain a pH that maximizes the efficacy of therapy. Despite the considerable clinical success and widespread use of PPIs, room remains for agents with differentiated pharmacokinetic and pharmacodynamic profiles. The potassium-competitive acid blockers (PCABs) are mechanistically distinct from PPIs but are acid-stable and do not require activation of the proton pump by coadministration of food. In pharmacodynamic studies, these agents have shown greater durations of acid suppression above the critical threshold of pH 4 (for GERD) and pH 6 (for H. pylori), which have been shown to optimize therapeutic efficacy in these settings. These results have translated in clinical studies to similar and, in some cases, improved outcomes relative to PPIs in these disease states. This review summarizes current knowledge on the physiology of acid secretion, pathophysiology and management of GERD and H. pylori, and key characteristics and clinical trial data for PPIs and PCABs.

Predicting pharmacodynamic effects through early drug discovery with artificial intelligence-physiologically based pharmacokinetic (AI-PBPK) modelling

A mechanism-based pharmacokinetic/pharmacodynamic (PK/PD) model links the concentration-time profile of a drug with its therapeutic effects based on the underlying biological or physiological processes. Clinical endpoints play a pivotal role in drug development. Despite the substantial time and effort invested in screening drugs for favourable pharmacokinetic (PK) properties, they may not consistently yield optimal clinical outcomes. Furthermore, in the virtual compound screening phase, researchers cannot observe clinical outcomes in humans directly. These uncertainties prolong the process of drug development. As incorporation of Artificial Intelligence (AI) into the physiologically based pharmacokinetic/pharmacodynamic (PBPK) model can assist in forecasting pharmacodynamic (PD) effects within the human body, we introduce a methodology for utilizing the AI-PBPK platform to predict the PK and PD outcomes of target compounds in the early drug discovery stage. In this integrated platform, machine learning is used to predict the parameters for the model, and the mechanism-based PD model is used to predict the PD outcome through the PK results. This platform enables researchers to align the PK profile of a drug with desired PD effects at the early drug discovery stage. Case studies are presented to assess and compare five potassium-competitive acid blocker (P-CAB) compounds, after calibration and verification using vonoprazan and revaprazan.

Refractory Gastroesophageal Reflux Disease: Diagnosis and Management

Gastroesophageal reflux disease (GERD) is common, with increasing worldwide disease prevalence and high economic burden. A significant number of patients will remain symptomatic following an empiric proton pump inhibitor (PPI) trial. Persistent symptoms despite PPI therapy are often mislabeled as refractory GERD. For patients with no prior GERD evidence (unproven GERD), testing is performed off antisecretory therapy to identify objective evidence of pathologic reflux using criteria outlined by the Lyon consensus. In proven GERD, differentiation between refractory symptoms (persisting symptoms despite optimized antisecretory therapy) and refractory GERD (abnormal reflux metrics on ambulatory pH impedance monitoring and/or persistent erosive esophagitis on endoscopy while on optimized PPI therapy) can direct subsequent management. While refractory symptoms may arise from esophageal hypersensitivity or functional heartburn, proven refractory GERD requires personalization of the management approach, tapping from an array of non-pharmacologic, pharmacologic, endoscopic, and surgical interventions. Proper diagnosis and management of refractory GERD is critical to mitigate undesirable long-term complications such as strictures, Barrett's esophagus, and esophageal adenocarcinoma. This review outlines the diagnostic workup of patients presenting with refractory GERD symptoms, describes the distinction between unproven and proven GERD, and provides a comprehensive review of the current treatment strategies available for the management of refractory GERD.

Proton pump inhibitors and potassium competitive acid blockers decrease pembrolizumab efficacy in patients with metastatic urothelial carcinoma

We elucidated the efficacy of gut microbiome-altering drugs on pembrolizumab efficacy in patients with metastatic urothelial carcinoma (mUC). Clinical data were analyzed retrospectively from 133 patients with mUC who received second-line pembrolizumab therapy between January 2018 and January 2021, following failed platinum-based chemotherapy. We evaluated the effects of gut microbiome-altering drugs (proton pump inhibitors [PPI]/potassium-competitive acid blockers [P-CAB], H2 blockers, antibiotics, non-steroidal anti-inflammatory drugs [NSAIDs], metformin, antipsychotics, steroids, and opioids), taken by patients within 30 days before/after pembrolizumab treatment, on progression-free survival (PFS) and overall survival (OS). Fifty-one patients received PPI/P-CAB (37/14, respectively); H2 blockers, 7; antibiotics, 35; NSAIDs, 22; antipsychotics, 8; metformin, 3; steroids, 11; and opioids, 29. Kaplan-Meier curves revealed PPI or P-CAB users showed shorter PFS than non-PPI-P-CAB users (p = 0.001, p = 0.005, respectively). Multivariate analysis highlighted PPI/P-CAB use as the only independent prognostic factor for disease progression (hazards ratio: 1.71, 95% confidence interval: 1.14-2.07, p = 0.010) but not death (p = 0.177). Proton pump inhibitors/potassium-competitive acid blockers may decrease the efficacy of pembrolizumab therapy for mUC, possibly via gut microbiome modulation.

The Efficacy and Safety of Regimens for Helicobacter pylori Eradication Treatment in China: A Systemic Review and Network Meta-Analysis

BACKGROUND

With Helicobacter pylori's increasing antibiotic resistance, evidence of more effective treatments is lacking in China, where H. pylori prevalence is nearly 50%. Thus, we performed a network meta-analysis to compare therapeutic regimens.

METHODS

Data extracted from eligible randomized controlled trials from January 2000 to September 2021 were entered into a Bayesian hierarchical random-effects model to evaluate the efficacy and safety of H. pylori eradication regimens.

RESULTS

This study included 101 trials involving 21,745 patients. Vonoprazan-bismuth-containing quadruple therapy (VBQT) ranked the highest [surfaces under cumulative ranking curve (SUCRA), 83.64%], followed by high-dose amoxicillin dual therapy (HDDT) [SUCRA, 79.70%, odds ratio (OR)=1.31, 95% credible interval (CrI) (0.36, 4.72)] and proton pump inhibitor-based bismuth-containing quadruple therapy (BQT) [SUCRA, 63.59%, OR=1.59, 95% CrI (0.48, 5.24)]. HDDT [OR=2.47, 95% CrI (1.51, 4.06)], BQT [OR=2.04, 95% CrI (1.69, 2.47)], concomitant quadruple nonbismuth therapy (CT) [OR=1.93, 95% CrI (1.19, 3.15)], and sequential therapy (ST) [OR=1.86, 95% CrI (1.50, 2.32)] had higher eradication rates than standard triple therapy (TT). ST (SUCRA, 82.52%) and VBQT (SUCRA, 83.89%) had the highest eradication rate before and after 2010 in the effectiveness ranking, respectively. Furthermore, the H. pylori eradication rate of patients receiving 14-day BQT treatment was higher than that of 10-day BQT regimen [OR=2.55, 95% CI (1.84, 3.53)] and 7-day BQT regimen [OR=3.64, 95% CI (2.64, 5.01)].

CONCLUSIONS

The TT regimen was not an optimal choice in China for H. pylori eradication; VBQT, HDDT, and BQT showed better efficacy. After 2010, there is a trend toward significance that VBQT provided a higher H. pylori eradication rate in China, but with only 1 randomized controlled trial. Thus, more supportive real-world data are needed to confirm its effectiveness.

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.

Neuroendocrine mechanism of gastric acid secretion: Historical perspectives and recent developments in physiology and pharmacology

The physiology of gastric acid secretion is one of the earliest subjects in medical literature and has been continuously studied since 1833. Starting with the notion that neural stimulation alone drives acid secretion, progress in understanding the physiology and pathophysiology of this process has led to the development of therapeutic strategies for patients with acid-related diseases. For instance, understanding the physiology of parietal cells led to the developments of histamine 2 receptor blockers, proton pump inhibitors (PPIs), and recently, potassium-competitive acid blockers. Furthermore, understanding the physiology and pathophysiology of gastrin has led to the development of gastrin/CCK2 receptor (CCK2 R) antagonists. The need for refinement of existing drugs in patients have led to second and third generation drugs with better efficacy at blocking acid secretion. Further understanding of the mechanism of acid secretion by gene targeting in mice has enabled us to dissect the unique role for each regulator to leverage and justify the development of new targeted therapeutics for acid-related disorders. Further research on the mechanism of stimulation of gastric acid secretion and the physiological significances of gastric acidity in gut microbiome is needed in the future.

Efficacy and Safety of Potassium-Competitive Acid Blockers Versus Proton Pump Inhibitors as Helicobacter pylori Eradication Therapy: A Meta-Analysis of Randomized Clinical Trials

Helicobacter pylori is a gram-negative bacterium that chronically infects the gastric epithelium. Potassium-competitive acid blockers (P-CABs) are a promising alternative, being more potent than standard proton pump inhibitors (PPIs). The meta-analysis followed Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Inclusion criteria were randomized controlled trials (RCTs) comparing P-CAB and PPI-based therapy, confirmed H. pylori infection, and measured eradication rates after at least four weeks. Subgroup analyses were conducted based on therapy type and trial location. Quality assessment used the Cochrane risk-of-bias tool, RoB 2.0, and statistical analysis was performed using ReviewManager (RevMan) 5.4 (2020; The Cochrane Collaboration, London, United Kingdom). A p-value of <0.05 is considered statistically significant. In the intention-to-treat (ITT) analysis, P-CABs demonstrated superior overall efficacy, consistently observed in the first-line treatment subgroup. However, no significant difference was found in the subgroup receiving salvage therapy. Another ITT subgroup analyzed the impact of geographical location, favoring P-CABs in the overall study population and the Japanese subgroup. However, no statistically significant differences were found in the subgroups of other countries. In the PPA, P-CABs showed superior efficacy overall, consistently seen in the first-line treatment subgroup. However, no significant difference was found in the subgroup receiving salvage eradication therapy. Another PPA subgroup analysis considered the geographical impact on eradication rates, revealing P-CABs as superior to PPIs in the overall study population and the Japanese subgroup, but not in other countries. No significant adverse event outcomes were observed. P-CAB-based triple therapy is more effective than PPI-based triple therapy as the primary treatment for H. pylori eradication, particularly in Japanese patients. Nevertheless, regarding salvage therapy, both treatments show comparable efficacy. Additionally, the tolerability of P-CAB-based and PPI-based triple therapy is similar, with a similar occurrence of adverse events.

Vonoprazan With Amoxicillin or Amoxicillin and Clarithromycin for the Treatment of Helicobacter pylori Infection

OBJECTIVES

To describe the pharmacology, efficacy, safety, and potential role of vonoprazan with amoxicillin or amoxicillin and clarithromycin for the treatment of Helicobacter pylori infection in adults.

DATA SOURCES

PubMed, Embase, Cochrane Library, and ClinicalTrials.gov were searched using the terms: (vonoprazan OR voquezna) AND ("H. pylori" OR "Helicobacter pylori") AND amoxicillin with no date limitations up to November 3, 2022.

STUDY SELECTION AND DATA EXTRACTION

Studies assessing the efficacy and safety of vonoprazan with amoxicillin and/or clarithromycin were included and divided into 3 groups based on different comparisons between treatment regimens used in each group.

DATA SYNTHESIS

Ten clinical trials and 17 observational studies were included. Vonoprazan-based therapy demonstrated greater acid inhibition and similar or higher efficacy than proton-pump inhibitor (PPI)-based therapy in treatment-naïve patients and with clarithromycin-resistant infections.

RELEVANCE TO PATIENT CARE AND CLINICAL PRACTICE

Proton-pump inhibitor-based therapies have not reached the desired successful eradication rate of 90% for H. pylori infection. Vonoprazan-based therapies being at least as effective as PPI-based therapies offer an alternative for patients with H. pylori infection.

CONCLUSION

Vonoprazan-based therapies were effective and well tolerated for the treatment of H. pylori infection in adults. These regimens provide an important alternative with prolonged acid inhibition, lower potential for CYP2C19 polymorphism, and at least comparable efficacy and safety versus PPI-based therapies in patients with H. pylori infections. Thus, vonoprazan-based therapy should be considered for certain patients, for example, those with failure to PPI-based treatments.

Long-term potassium-competitive acid blockers administration causes microbiota changes in rats

BACKGROUND

Vonoprazan is a new potassium-competitive acid blocker (P-CAB) that was recently approved by the FDA. It is associated with a fast onset of action and a longer acid inhibition time. Vonoprazan-containing therapy for helicobacter pylori eradication is highly effective and several studies have demonstrated that a vonoprazan-antibiotic regimen affects gut microbiota. However, the impact of vonoprazan alone on gut microbiota is still unclear.Please check and confirm the authors (Maria Cristina Riascos, Hala Al Asadi) given name and family name are correct. Also, kindly confirm the details in the metadata are correct.Yes they are correct.  METHODS: We conducted a prospective randomized 12-week experimental trial with 18 Wistar rats. Rats were randomly assigned to one of 3 groups: (1) drinking water as negative control group, (2) oral vonoprazan (4 mg/kg) for 12 weeks, and (3) oral vonoprazan (4 mg/kg) for 4 weeks, followed by 8 weeks off vonoprazan. To investigate gut microbiota, we carried out a metagenomic shotgun sequencing of fecal samples at week 0 and week 12.Please confirm the inserted city and country name is correct for affiliation 2.Yes it's correct.

RESULTS

For alpha diversity metrics at week 12, both long and short vonoprazan groups had lower Pielou's evenness index than the control group (p = 0.019); however, observed operational taxonomic units (p = 0.332) and Shannon's diversity index (p = 0.070) were not statistically different between groups. Beta diversity was significantly different in the three groups, using Bray-Curtis (p = 0.003) and Jaccard distances (p = 0.002). At week 12, differences in relative abundance were observed at all levels. At phylum level, short vonoprazan group had less of Actinobacteria (log fold change = - 1.88, adjusted p-value = 0.048) and Verrucomicrobia (lfc = - 1.76, p = 0.009).Please check and confirm that the author (Ileana Miranda) and their respective affiliation 3 details have been correctly identified and amend if necessary.Yes it's correct. At the genus level, long vonoprazan group had more Bacteroidales (lfc = 5.01, p = 0.021) and Prevotella (lfc = 7.79, p = 0.001). At family level, long vonoprazan group had more Lactobacillaceae (lfc = 0.97, p = 0.001), Prevotellaceae (lfc = 8.01, p < 0.001), and less Erysipelotrichaceae (lfc = - 2.9, p = 0.029).

CONCLUSION

This study provides evidence that vonoprazan impacts the gut microbiota and permits a precise delineation of the composition and relative abundance of the bacteria at all different taxonomic levels.

Vonoprazan versus lansoprazole in erosive esophagitis - A systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Proton-pump inhibitors (PPIs) are the mainstay of treatment in erosive esophagitis (EE). An alternative to PPIs in EE is Vonoprazan, a potassium competitive acid blocker. We conducted a systematic review and meta-analysis of randomized controlled trials (RCTs) comparing vonoprazan to lansoprazole.

METHODS

Multiple databases searched through November 2022. Meta-analysis was performed to assess endoscopic healing at two, four and eight weeks, including for patients with severe EE (Los Angeles C/D). Serious adverse events (SAE) leading to drug discontinuation were assessed. The quality of evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) methodology.

RESULTS

Four RCTs with 2208 patients were included in the final analysis. Vonoprazan 20 mg once-daily was compared to lansoprazole 30 mg once-daily dosing. Among all patients, at two and eight weeks post-treatment, vonoprazan resulted in significantly higher rates of endoscopic healing as compared to lansoprazole, risk ratios (RR) 1.1, p<0.001 and RR 1.04, p=0.03. The same effect was not observed at four weeks, RR 1.03 (CI 0.99-1.06, I2=0%) following therapy. Among patients with severe EE, vonoprazan resulted in higher rates of endoscopic healing at two weeks, RR 1.3 (1.2-1.4, I2=47%), p=<0.001, at four weeks, RR 1.2 (1.1-1.3, I2=36%), p=<0.001 and at eight weeks post-treatment, RR 1.1 (CI 1.03-1.3, I2=79%), p=0.009. We found no significant difference in the overall pooled rate of SAE and pooled rate of adverse events leading to drug discontinuation. Finally, the overall certainty of evidence for our main summary estimates was rated as high (grade A).

CONCLUSION

Based on limited number of published non-inferiority RCTs, our analysis demonstrates that among patients with EE, vonoprazan 20 mg once-daily dosing achieves comparable and in those with severe EE, higher endoscopic healing rates as compared to lansoprazole 30 mg once-daily dosing. Both drugs have a comparable safety profile.

Targeting ATP12A, a Nongastric Proton Pump α Subunit, for Idiopathic Pulmonary Fibrosis Treatment

Idiopathic pulmonary fibrosis (IPF) is a pathological condition of unknown etiology that results from injury to the lung and an ensuing fibrotic response that leads to the thickening of the alveolar walls and obliteration of the alveolar space. The pathogenesis is not clear, and there are currently no effective therapies for IPF. Small airway disease and mucus accumulation are prominent features in IPF lungs, similar to cystic fibrosis lung disease. The ATP12A gene encodes the α-subunit of the nongastric H+, K+-ATPase, which functions to acidify the airway surface fluid and impairs mucociliary transport function in patients with cystic fibrosis. It is hypothesized that the ATP12A protein may play a role in the pathogenesis of IPF. The authors' studies demonstrate that ATP12A protein is overexpressed in distal small airways from the lungs of patients with IPF compared with normal human lungs. In addition, overexpression of the ATP12A protein in mouse lungs worsened bleomycin induced experimental pulmonary fibrosis. This was prevented by a potassium competitive proton pump blocker, vonoprazan. These data support the concept that the ATP12A protein plays an important role in the pathogenesis of lung fibrosis. Inhibition of the ATP12A protein has potential as a novel therapeutic strategy in IPF treatment.

JP-1366: A novel and potent potassium-competitive acid blocker that is effective in the treatment of acid-related diseases

The global prevalence of GERD is substantially increasing each year, and GERD is a chronic disease that reduces the quality of life of patients. The efficacy of conventional drugs is diverse, and most require long-term or lifetime administration; thus, the development of more effective therapeutic agents is needed. Herein, a more effective treatment for GERD was tested. We investigated whether JP-1366 affected gastric H+/K+-ATPase activity and used the Na+/K+-ATPase assay to confirm the selectivity of H+/K+-ATPase inhibition. To clarify the mechanism of enzyme inhibition, JP-1366 and TAK-438 were analyzed by Lineweaver-Burk. Also, we investigated the effects of JP-1366 in various models involving reflux esophagitis. We found that JP-1366 mediates strong, selective, and dose-dependent inhibition of H+/K+-ATPase. We found that JP-1366 significantly suppressed gastric acid secretion in histamine-treated pylorus-ligated rats in a dose-dependent manner. Additionally, we confirmed that JP-1366 inhibited histamine-stimulated gastric acid secretion in the HPD model. JP-1366 exhibited a more than 2-fold higher inhibitory effect on esophageal injury than TAK-438 in GERD lesions and had a more potent inhibitory effect in indomethacin- or aspirin-induced gastric ulcer rat models than TAK-438. Additionally, JP-1366 inhibited gastric ulcers. These results support the possibility that JP-1366 is a good candidate drug for treating acid-related diseases.

Vonoprazan: A New Potassium-Competitive Acid Blocker

Objective: To review the safety, efficacy, and tolerability of vonoprazan for the treatment of Helicobacter pylori infection in adults. Data Sources: A literature search was performed through PubMed using the following key terms: vonoprazan, Voquezna, TAK-438, potassium-competitive acid blocker, H pylori, and gastrointestinal. Study Selection and Data Extraction: Selected articles included those which described clinical studies of the pharmacology, pharmacokinetics, efficacy, safety, or tolerability of vonoprazan. Data Synthesis: Vonoprazan works by competing with potassium on the proton pump to inhibit gastric acid secretion. Phase 3 clinical trials have shown that vonoprazan is noninferior to proton pump inhibitors (PPIs) as a component of H pylori eradication regimens. Vonoprazan has also shown promise in duodenal ulcer-healing rates and in reducing symptoms of heartburn. Common adverse effects associated with vonoprazan include nasopharyngitis, diarrhea, constipation, flatulence, dyspepsia, headache, and abdominal pain. Conclusion: Clinical practice guidelines recommend PPIs as the antisecretory agent of choice in H pylori eradication regimens with histamine-2 receptor antagonists (H2RAs) as potential alternatives. However, the use of either class of medications may be limited by adverse effects, drug interactions, and tolerability. Potassium-competitive acid blockers (P-CABs), like vonoprazan, may be safe and effective alternative antisecretory agents for H pylori eradication regimens, as well as other gastrointestinal disorders.

The efficacy and mechanism of vonoprazan-containing triple therapy in the eradication of Helicobacter pylori

Purpose: Vonoprazan (VPZ) produces a strong acid-inhibitory effect, which can potentially eradicate Helicobacter Pylori (H. pylori). We aimed to assess whether a 14-day VPZ-containing triple therapy was safe and effective in the Chinese population and the potential mechanism. Methods: Enrolled patients confirmed to be infected with H. pylori were randomly divided into four groups: VPZ + doxycycline + furazolidone, VPZ + doxycycline + amoxicillin, esomeprazole (EPZ) + bismuth + doxycycline + furazolidone, and EPZ + colloidal bismuth + doxycycline + amoxicillin for 14 days. The eradication rate, medication adherence, and incidence of adverse events (AEs) were evaluated. Inhibition of H. pylori by VPZ and EPZ in vitro was assessed. H. pylori treated with appropriate concentrations of VPZ and EPZ were sequenced by transcriptome analysis to explore the antibacterial mechanism. Results: A higher eradication rate were observed in VPZ-containing triple therapy. No obvious differences were observed in medication adherence or the incidence of AEs. VPZ had no direct inhibitory effect on H. pylori, whereas EPZ directly inhibited H. pylori may through downregulated genes related to the ribosome. Conclusion: In the Chinese population, 14-day VPZ-containing triple therapy was safe and more effective and can be used clinically as first-line H. pylori treatment. Clinical Trial Registration: ClinicalTrials.gov, identifier NCT05097846.

Randomised clinical trial: 3-year interim analysis results of the VISION trial to evaluate the long-term safety of vonoprazan as maintenance treatment in patients with erosive oesophagitis

BACKGROUND

VISION is a randomised, phase 4, open-label, parallel-group, multicentre study conducted in 33 centres in Japan. The aim of this study was to assess the long-term safety of vonoprazan for maintenance treatment of healed erosive oesophagitis versus lansoprazole.

METHODS

Patients with endoscopically diagnosed erosive oesophagitis were randomised 2:1 to once-daily vonoprazan 20 mg or lansoprazole 30 mg, for a 4- to 8-week healing phase. Patients with endoscopically confirmed healing entered a 260-week maintenance phase with a once-daily starting dose of vonoprazan 10 mg or lansoprazole 15 mg. Primary endpoint was change in gastric mucosal histopathology.

RESULTS

Of 208 patients (vonoprazan, n = 139; lansoprazole, n = 69) entering the healing phase, 202 entered the maintenance phase (vonoprazan, n = 135; lansoprazole, n = 67). At 3 years, 109 vonoprazan-treated and 58 lansoprazole-treated patients remained on treatment. Histopathological evaluation of gastric mucosa showed that hyperplasia of parietal, foveolar and G cells was more common with vonoprazan than lansoprazole at week 156 of the maintenance phase. There was no marked increase in the occurrence of parietal, foveolar and G cell hyperplasia among patients in the vonoprazan group from week 48 to week 156. Histopathological evaluation of the gastric mucosa also showed no neoplastic changes in either group. No new safety issues were identified.

CONCLUSIONS

In this interim analysis of VISION, no new safety concerns were identified in Japanese patients with healed erosive oesophagitis receiving vonoprazan or lansoprazole as maintenance treatment for 3 years. (CT.gov identifier: NCT02679508; JapicCTI-163153; Japan Registry of Clinical Trials: jRCTs031180040).

Size reduction of gastric fundic gland polyposis by de-escalation of acid-suppressive therapy

The patient, a 73-year-old woman, had been taking acid-suppressive therapy for refractory reflux esophagitis for 10 years. A potassium-competitive acid blocker was administered to strengthen acid-suppressive therapy for worsening symptoms of gastroesophageal reflux disease. Esophagogastroduodenoscopy showed an increase in the number and size of fundic gland polyposis (FGPs). When acid-suppressive therapy was changed from potassium-competitive acid blocker to proton pump inhibitor, the FGPs showed reduced size 1 year later. Furthermore, when acid-suppressive therapy was changed from proton pump inhibitor to histamine-2 receptor antagonist, FGPs were even smaller after 1 and 2 years. The patient, who had no flare-up of gastroesophageal reflux disease symptoms, continues to be treated medically with histamine-2 receptor antagonist. This case report describes changes in endoscopic findings of a patient with FGPs caused by acid-suppressive therapy for refractory gastroesophageal reflux disease.

Differential effects of proton pump inhibitors and vonoprazan on vascular endothelial growth factor expression in cancer cells

Proton pump inhibitors (PPIs) are potent inhibitors of gastric acid secretion, used as first-line agents in treating peptic ulcers. However, we have previously reported that PPIs may diminish the therapeutic effect of anti-vascular endothelial growth factor (VEGF) drugs in patients with cancer. In this study, we explored the effects of vonoprazan, a novel gastric acid secretion inhibitor used for the treatment of peptic ulcers, on the secretion of VEGF in cancer cells and attempted to propose it as an alternative PPI for cancer chemotherapy. The effects of PPI and vonoprazan on VEGF expression in cancer cells were compared by real-time reverse transcription-polymerase chain reaction and ELISA. The interaction of vonoprazan and PPIs with transcriptional regulators by docking simulation analysis. In various cancer cell lines, including the human colorectal cancer cell line (LS174T), PPI increased VEGF messenger RNA expression and VEGF protein secretion, while this effect was not observed with vonoprazan. Molecular docking simulation analysis showed that vonoprazan had a lower binding affinity for estrogen receptor alpha (ER-α), one of the transcriptional regulators of VEGF, compared to PPI. Although the PPI-induced increase in VEGF expression was counteracted by pharmacological ER-α inhibition, the effect of vonoprazan on VEGF expression was unchanged. Vonoprazan does not affect VEGF expression in cancer cells, which suggests that vonoprazan might be an alternative to PPIs, with no interference with the therapeutic effects of anti-VEGF cancer chemotherapy.

Cost-Effectiveness of Vonoprazan Compared With Proton Pump Inhibitors in Patients Taking Low-Dose Aspirin for Secondary Prevention of Cardiovascular Events in Japan

BACKGROUND

Low-dose aspirin (LDA) is used to prevent recurrent cardiovascular (CV) events, but is associated with upper gastrointestinal (GI) bleeding; concomitant use of a proton pump inhibitor (PPI) reduces this risk. This study aimed to assess the cost-effectiveness of vonoprazan compared with PPIs (lansoprazole and esomeprazole) in patients taking LDA for secondary prevention of CV events.

METHODS AND RESULTS

A Markov simulation model was developed to predict the number of GI bleeding and acute CV events using 3 strategies (vonoprazan+LDA, esomeprazole+LDA, and lansoprazole+LDA), which were translated into quality-adjusted life-years (QALYs) and costs. Transition probabilities and utilities were derived from the results of published literature, and medical costs were based on the Japanese National Health Insurance fee table and claims databases in 2020. Outcomes were projected over 30 years starting at age 65 years and discounted at 2% annually. Expected costs with esomeprazole 20 mg, lansoprazole 15 mg and vonoprazan 10 mg were JPY 1,225,657, JPY 943,930, and JPY 1,059,510, respectively. The QALY gain for vonoprazan vs. esomeprazole was 0.35, thus vonoprazan was dominant against esomeprazole. The QALY gain for vonoprazan vs. lansoprazole was 0.29 and the incremental cost-effectiveness ratio (ICER) was JPY 398,551, thus, vonoprazan was more cost-effective than lansoprazole.

CONCLUSIONS

Vonoprazan is dominant or cost-effective compared with esomeprazole and lansoprazole in patients taking LDA for secondary prevention of CV events.

Long-term safety and effectiveness of vonoprazan for prevention of gastric and duodenal ulcer recurrence in patients on nonsteroidal anti-inflammatory drugs in Japan: a 12-month post-marketing surveillance study

BACKGROUND

This study assessed the safety and effectiveness of vonoprazan for prevention of duodenal and gastric ulcer recurrence in patients on long-term nonsteroidal anti-inflammatory drugs (NSAIDs) in routine clinical practice.

RESEARCH DESIGN AND METHODS

This 12-month, prospective, observational study (145 sites, Japan, September 2016-April 2020) analyzed patients with a history of gastric or duodenal ulcer who started once-daily vonoprazan and were receiving NSAIDs for pain or low-dose aspirin for thrombosis/embolism suppression. The primary outcome was the incidence of adverse drug reactions (ADRs).

RESULTS

Most patients (86.7% [1099/1268]) received vonoprazan for at least 6 months. Most patients (98.6% [1250/1268]) received the 10-mg dose of vonoprazan, 38.3% (486/1268) received cyclooxygenase-2 inhibitors, and 61.7% (782/1268) received other NSAIDs. The overall incidence of ADRs was 0.71% (9/1268). Most commonly reported ADRs were gastrointestinal (0.32%), nervous system (0.16%), and hepatobiliary system (0.16%) disorders. The overall incidence of gastric or duodenal ulcer recurrence was 1.04% (95% CI 0.56-1.78).

CONCLUSIONS

No new safety concerns were reported for vonoprazan for prevention of secondary ulcer or bleeding in patients receiving long-term NSAIDs. Vonoprazan was effective for preventing NSAID-related peptic ulcer recurrence in this real-world study.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT03214198; Japan Pharmaceutical Information Center Clinical Trials Information: JapicCTI-163436.

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.

Novel Cocrystals of Vonoprazan: Machine Learning-Assisted Discovery

Vonoprazan (VPZ) is the first-in-class potassium-competitive acid blocker (P-CAB), and has many advantages over proton pump inhibitors (PPIs). It is administered as a fumarate salt for the treatment of acid-related diseases, including reflux esophagitis, gastric ulcer, and duodenal ulcer, and for eradication of Helicobacter pylori. To discover novel cocrystals of VPZ, we adopted an artificial neural network (ANN)-based machine learning model as a virtual screening tool that can guide selection of the most promising coformers for VPZ cocrystals. Experimental screening by liquid-assisted grinding (LAG) confirmed that 8 of 19 coformers selected by the ANN model were likely to create new solid forms with VPZ. Structurally similar benzenediols and benzenetriols, i.e., catechol (CAT), resorcinol (RES), hydroquinone (HYQ), and pyrogallol (GAL), were used as coformers to obtain phase pure cocrystals with VPZ by reaction crystallization. We successfully prepared and characterized three novel cocrystals: VPZ–RES, VPZ–CAT, and VPZ–GAL. VPZ–RES had the highest solubility among the novel cocrystals studied here, and was even more soluble than the commercially available fumarate salt of VPZ in solution at pH 6.8. In addition, novel VPZ cocrystals had superior stability in aqueous media than VPZ fumarates, demonstrating their potential for improved pharmaceutical performance.

Combinations of antibiotics and vonoprazan for the treatment of Helicobacter pylori infections-Exploratory study

BACKGROUND

Vonoprazan fumarate is a novel potassium-competitive acid blocker more effective in suppressing acid production than proton pump inhibitors (PPIs) and when combined with antibiotics has been used to eradicate Helicobacter pylori (H. pylori) infection. However, it has not yet been examined in an Australian setting. This study aimed to report on the efficacy and safety of vonoprazan-containing antibiotic combination therapies in the eradication of H. pylori.

METHODS

A single-center, exploratory, clinical review of patients 18 years or over, positive for H. pylori on Urea Breath Test (UBT), and/or histopathology who underwent a 10-day treatment of combination antibiotics plus vonoprazan between January 2017 and September 2019 was conducted. Eleven different combinations of antibiotics that included 2-5 different antibiotics predominantly amoxicillin, rifabutin, levofloxacin, furazolidone, nitazoxanide, and tetracycline were included. The eradication success was based on negative UBT results and/or histopathology results after the treatment. Descriptive statistics were summarized.

RESULTS

One hundred and fifty-three patients (Female n = 74, 48%) with a positive for H. pylori were treated with vonoprazan-containing antibiotic combination therapy during the study period. Of the 153 patients, 48 (31%) had previously failed a PPI-based H. pylori treatment. Follow-up was available for 66/153 (43%) patients. In those who completed follow-up, overall eradication was achieved in 97% (64/66) of patients. In the subgroup of patients treated for the first time, eradication was achieved in 100% (44/44). In those who had failed prior, non-vonoprazan-containing treatment, eradication was achieved in 91% (20/22) of patients.

CONCLUSIONS

Vonoprazan-containing antibiotic therapy is an effective H. pylori eradication treatment. It is capable of achieving 100% efficacy in patients treated for the first time and even 91% efficacy in patients with previous eradication failure. Subsequent studies utilizing a factorial design will be needed to optimize each regimen as most regimens contained more than two antibiotics.

Helicobacter pylori infection and antibiotic resistance - from biology to clinical implications

Helicobacter pylori is a major human pathogen for which increasing antibiotic resistance constitutes a serious threat to human health. Molecular mechanisms underlying this resistance have been intensively studied and are discussed in this Review. Three profiles of resistance - single drug resistance, multidrug resistance and heteroresistance - seem to occur, probably with overlapping fundamental mechanisms and clinical implications. The mechanisms that have been most studied are related to mutational changes encoded chromosomally and disrupt the cellular activity of antibiotics through target-mediated mechanisms. Other biological attributes driving drug resistance in H. pylori have been less explored and this could imply more complex physiological changes (such as impaired regulation of drug uptake and/or efflux, or biofilm and coccoid formation) that remain largely elusive. Resistance-related attributes deployed by the pathogen cause treatment failures, diagnostic difficulties and ambiguity in clinical interpretation of therapeutic outcomes. Subsequent to the increasing antibiotic resistance, a substantial drop in H. pylori treatment efficacy has been noted globally. In the absence of an efficient vaccine, enhanced efforts are needed for setting new treatment strategies and for a better understanding of the emergence and spread of drug-resistant bacteria, as well as for improving diagnostic tools that can help optimize current antimicrobial regimens.

Drug-Drug Interaction between Tacrolimus and Vonoprazan in Kidney Transplant Recipients

Kidney transplant recipients with tacrolimus-based immunosuppressive therapy are often treated with proton-pump inhibitors (PPIs) to prevent gastric ulcer complications. Vonoprazan, a potassium-competitive acid blocker, is a novel PPI possessing different metabolic pathways from conventional PPIs (e.g., omeprazole, lansoprazole and rabeprazole). However, no data are available on the change in blood concentration of tacrolimus after switching rabeprazole, a conventional PPI, to vonoprazan coadministration in the initial period of post-transplantation. This is a retrospective study of 18 kidney transplant recipients. The blood concentration and the concentration to dose (C/D) ratio of tacrolimus were compared before and after switching from rabeprazole to vonoprazan. Impacts of CYP2C19 and CYP3A5 genetic polymorphisms on the drug-drug interaction were also examined. The median (range) trough concentration of tacrolimus was significantly increased from 5.2 (3.6-7.4) to 8.1 (6.1-11.7) ng/mL (p < 0.0005) after switching from rabeprazole to vonoprazan. The C/D ratio of tacrolimus was also significantly increased from 38.1 (16.5-138.1) to 48.9 (26.2-207.2) (p < 0.0005). The percent changes of tacrolimus concentrations and C/D were 65.8% and 41.8%, respectively. CYP2C19 and CYP3A5 genetic polymorphisms did not affect the change in concentration and C/D ratio of tacrolimus. The present study indicates that vonoprazan coadministration increases the tacrolimus concentration regardless of CYP2C19 or CYP3A5 genetic polymorphisms. Thus, frequent monitoring of blood tacrolimus concentration is required when vonoprazan is introduced as an intensive gastric acid blocker in the early phase of post-transplantation.

The Effect of Food on the Pharmacokinetics of the Potassium-Competitive Acid Blocker Vonoprazan

Herein, we report a food‐effect study of vonoprazan, an oral potassium‐competitive acid blocker. In a phase 1, randomized, open‐label, crossover study, healthy subjects received a single 20‐mg dose of vonoprazan either following an overnight fast or 30 minutes after a high‐fat breakfast. Plasma vonoprazan levels were determined at 0 hour and at 17 subsequent assessment points up to 48 hours after dosing. After a 5‐day washout, subjects received a second 20‐mg vonoprazan dose in the alternative fed/fasted state (identical process repeated). Twenty‐four subjects completed the study. Vonoprazan exposure was not meaningfully affected by food. Geometric mean ratios for maximum concentration, area under the concentration‐time curve from time 0 to 24 hours, and area under the plasma concentration–time curve extrapolated to infinity obtained under fed and fasting conditions were 1.05 (90% confidence interval, 0.98‐1.12), 1.13 (1.09‐1.18), and 1.15 (1.11‐1.19), respectively. Four subjects experienced 6 adverse events that were all mild and considered unrelated to the study drug. Vonoprazan can be administered without regard to food intake.

The status and progress of first-line treatment against Helicobacter pylori infection: a review

Helicobacter pylori (HP) is a major causative agent of chronic gastritis and peptic ulcer. HP is also engaged in the development of gastric cancer and gastric mucosa-associated lymphoid tissue lymphoma. It is an important pathogenic factor in various other systemic diseases, such as vitamin B12 deficiency, iron deficiency, and idiopathic thrombocytopenia. The current consensus is that unless there is a special reason, eradication therapy should be implemented whenever HP infection is found, and it is ideally successful the first time. International guidelines recommend that under certain conditions, treatment should be personalized based on drug susceptibility testing. However, drug susceptibility testing is often not available because it is expensive, time-consuming, and difficult to obtain living tissue. Each region has separately formulated guidelines or consensuses on empirical therapy. Owing to an increasing drug resistance rate in various places, the eradication rate of proton pump inhibitor (PPI) triple therapy and sequential therapy has been affected. These regimens are rarely used; the PPI triple especially has been abandoned in most areas. Currently, radical treatment regimens for HP involve bismuth-containing quadruple therapy and concomitant therapy. However, quadruple therapy has its own limitations, such as complex drug administration. To improve the effectiveness, safety, and compliance, many clinical studies have proposed useful modified regimens, which mainly include the modified bismuth-containing quadruple regimen, high-dose dual therapy, and vonoprazan-containing regimens. Studies have shown that these emerging regimens have acceptable eradication rates and safety, and are expected to become first-line treatments in empirical therapy. However, the problem of decline in the eradication rate caused by drug resistance has not been fundamentally solved. This review not only summarizes the effectiveness of mainstream regimens in the first-line treatment of HP infection with the currently increasing antibiotic resistance rates, but also summarizes the effectiveness and safety of various emerging treatment regimens.

Inhibition of gastric H+,K+-ATPase by new dihydropyrazole derivative KYY-008

The gastric proton pump (H⁺,K⁺-ATPase) responsible for the H⁺ secretion of gastric acid is an essential therapeutic target for acid-related diseases. H⁺,K⁺-ATPase belongs to a P₂-type ATPase family. Here, we examined the effects of a newly synthesized dihydropyrazole derivative KYY-008 on the H⁺,K⁺-ATPase. KYY-008 concentration-dependently inhibited the enzyme activity of the ATPase in the membrane fractions prepared from isolated hog gastric mucosa and from human kidney HEK293 cells in which gastric H⁺,K⁺-ATPase is exogenously expressed. The IC₅₀ values in these samples were 3.4 μM and 3.7 μM, respectively. In addition, KYY-008 significantly inhibited the H⁺,K⁺-ATPase-derived H⁺ uptake into the tightly sealed vesicles prepared from the hog gastric mucosa. In contrast, KYY-008 has no effect on the activities of other P₂-type ATPases such as Na⁺,K⁺-ATPase and Ca²⁺-ATPase. KYY-008 did not change the ionic currents of voltage-dependent Ca²⁺ channels, that were potential targets for some dihydropyrazole derivatives. Together, we discovered a new dihydropyrazole derivative which acts as a selective inhibitor of gastric H⁺,K⁺-ATPase.

Vonoprazan versus lansoprazole in the treatment of artificial gastric ulcers after endoscopic submucossal dissection: a randomized, open-label trial

Background

Vonoprazan is more potent and longer acting than traditional proton pump inhibitor. Although vonoprazan is expected to be superior to proton pump inhibitor, its efficacy in the treatment of gastric ulcers following endoscopic submucosal dissection (ESD) is not fully understood. The aim of this study was to evaluate the effectiveness of vonoprazan in artificial ulcer healing following ESD.

Methods

Patients with gastric tumors were randomly assigned to the vonoprazan group (group V) or lansoprazole group (group L) after ESD. Patients received intravenous lansoprazole (30 mg) twice on the day of ESD. Thereafter, patients were treated with vonoprazan (20 mg/day) in group V or lansoprazole (30 mg/day) in group L. Esophagogastroduodenoscopy was performed 4 and 8 weeks after the ESD.

Results

A total of 168 patients were analyzed. The 4-week healing rate for artificial ulcer was not significantly higher in group V versus group L (17/85, 20.0% vs. 14/83, 16.9%, respectively). In addition, there were no significant differences between the 4-week shrinkage rates between the two groups. Postoperative bleeding occurred in none of the patients in group V and three in group L. One patient in group V presented delayed perforation 2 days after ESD.

Conclusions

Vonoprazan might not be superior to lansoprazole in the healing of artificial gastric ulcer after ESD.

Trial registration: University hospital Medical Information Network (registration number: UMIN000016642), Registered 27 February 2015, https://www.umin.ac.jp/ctr/index-j.htm.

ESNM/ANMS consensus paper: Diagnosis and management of refractory gastro-esophageal reflux disease

Up to 40% of patients with symptoms suspicious of gastroesophageal reflux disease (GERD) do not respond completely to proton pump inhibitor (PPI) therapy. The term "refractory GERD" has been used loosely in the literature. A distinction should be made between refractory symptoms (ie, symptoms may or may not be GERD-related), refractory GERD symptoms (ie, persisting symptoms in patients with proven GERD, regardless of relationship to ongoing reflux), and refractory GERD (ie, objective evidence of GERD despite adequate medical management). The present ESNM/ANMS consensus paper proposes use the term "refractory GERD symptoms" only in patients with persisting symptoms and previously proven GERD by either endoscopy or esophageal pH monitoring. Even in this context, symptoms may or may not be reflux related. Objective evaluation, including endoscopy and esophageal physiologic testing, is requisite to provide insights into mechanisms of symptom generation and evidence of true refractory GERD. Some patients may have true ongoing refractory acid or weakly acidic reflux despite PPIs, while others have no evidence of ongoing reflux, and yet others have functional esophageal disorders (overlapping with proven GERD confirmed off therapy). In this context, attention should also be paid to supragastric belching and rumination syndrome, which may be important contributors to refractory symptoms.

Pharmacokinetic Interactions between Tegoprazan and Metronidazole/Tetracycline/Bismuth and Safety Assessment in Healthy Korean Male Subjects

PURPOSE

Tegoprazan is a potassium-competitive acid blocker used for gastric acid suppression, which may be used with Helicobacter pylori eradication therapies. The goal of this study was to evaluate the pharmacokinetic interaction between tegoprazan and triple-antibiotic therapy containing metronidazole, tetracycline, and bismuth.

METHODS

An open-label, 2-cohort, randomized, multiple-dose, crossover study was conducted in healthy subjects. In cohort 1, tegoprazan (100 mg/d) was administered orally with or without triple-antibiotic therapy (1500 mg/d metronidazole, 2000 mg/d tetracycline, and 1200 mg/d bismuth) for 7 days in each period. In cohort 2, triple-antibiotic therapy was administered orally with or without tegoprazan for 7 days in each period. Pharmacokinetic blood samples were collected within 24 h after the last dose. Safety assessments were performed.

FINDINGS

Eleven cohort 1 subjects and ten cohort 2 subjects were included in the pharmacokinetic analysis. The AUC_τ and C_max at steady state geometric mean ratios (90% CIs) were 0.78 (0.73-0.83) and 0.75 (0.68-0.82) for tegoprazan; 0.77 (0.68-0.88) and 0.84 (0.72-0.98) for tegoprazan metabolite M1; 1.03 (0.98-1.08) and 1.08 (0.99-1.18) for metronidazole; 0.63 (0.56-0.70) and 0.64 (0.56-0.74) for tetracycline; and 1.55 (0.99-2.44) and 1.38 (0.72-2.66) for bismuth, respectively. All reported adverse events were mild.

IMPLICATIONS

Changes in the tegoprazan, tetracycline, and bismuth pharmacokinetic parameters were detected after concurrent administration. These changes were considered mainly due to the pharmacodynamic effect of tegoprazan. The adverse events were predictable and reported as frequent adverse events during triple-antibiotic therapy. There were no significant differences in safety or tolerability between quadruple therapy, including tegoprazan and triple-antibiotic therapy. ClinicalTrials.gov identifier: NCT04066257.

Measurement of the Intestinal pH in Mice under Various Conditions Reveals Alkalization Induced by Antibiotics

The intestinal pH can greatly influence the stability and absorption of oral drugs. Therefore, knowledge of intestinal pH is necessary to understand the conditions for drug delivery. This has previously been measured in humans and rats. However, information on intestinal pH in mice is insufficient despite these animals being used often in preclinical testing. In this study, 72 female ICR mice housed in SPF (specific pathogen-free) conditions were separated into nine groups to determine the intestinal pH under conditions that might cause pH fluctuations, including high-protein diet, ageing, proton pump inhibitor (PPI) treatment, several antibiotic treatment regimens and germ-free mice. pH was measured in samples collected from the ileum, cecum and colon, and compared to control animals. An electrode, 3 mm in diameter, enabled accurate pH measurements with a small amount of gastrointestinal content. Consequently, the pH values in the cecum and colon were increased by high-protein diet, and the pH in the ileum was decreased by PPI. Drastic alkalization was induced by antibiotics, especially in the cecum and colon. The alkalized pH values in germ-free mice suggested that the reduction in the intestinal bacteria caused by antibiotics led to alkalization. Alkalization of the intestinal pH caused by antibiotic treatment was verified in mice. We need further investigations in clinical settings to check whether the same phenomena occur in patients.

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.

Randomized controlled study on the effects of triple therapy including vonoprazan or rabeprazole for the second-line treatment of Helicobacter pylori infection

BACKGROUND AND AIM

Inhibition of gastric acid secretion is important for eradicating Helicobacter pylori. Vonoprazan (VPZ) is a strong, long-lasting inhibitor of gastric acid secretion. Studies that examined the effectiveness of VPZ-based triple therapy in second-line treatment have been performed. However, there have been no randomized controlled studies to compare the effect between VPZ-based triple therapy and proton pump inhibitor (PPI)-based triple therapy in second-line treatment, and it is not known which is more effective between VPZ-based and PPI-based therapies. This study aimed to compare the effectiveness of second-line triple therapies including VPZ or rabeprazole (RPZ) as the PPI.

METHODS

Eligible patients with H. pylori infection who failed first-line triple therapy were assigned randomly to the VPZ [VPZ40 mg/day, amoxicillin (AMPC) 1500 mg/day, metronidazole (MNZ) 500 mg/day] or RPZ (RPZ20 mg/day, AMPC1500 mg/day, MNZ500 mg/day) group. A ¹³C-urea breath test result of less than 2.5% was considered as successful eradication.

RESULTS

In total, 46 and 41 patients were analyzed as intention to treat (ITT) and per protocol (PP), respectively. Eradication rates in the VPZ and RPZ groups were 73.9% [95% confidence interval (CI) 51.6-89.8%] and 82.6% (95% CI 61.2-95.0%) based on ITT analysis, respectively (p = 0.72). Based on PP analysis, the eradication rates in the VPZ and RPZ groups were 89.5% (95% CI 66.9-98.7%) and 86.4% (95% CI 65.1-97.1%), respectively (p = 1.00). Two patients in the VPZ group and one in the RPZ group discontinued treatment due to side effects (p = 1.00).

CONCLUSION

There were no significant differences in efficacy and safety between second-line therapies including VPZ or RPZ.

Vonoprazan-based triple therapy is effective for Helicobacter pylori eradication irrespective of clarithromycin susceptibility

BACKGROUND

Helicobacter pylori causes peptic ulcers and accounts for over 90% of gastric cancers; however, eradication rates have been declining due to antimicrobial resistance. Vonoprazan (VPZ), a potassium-competitive acid blocker, produces rapid and profound gastric acid suppression and has shown promising effects in the improvement of H. pylori eradication rates. The efficacy and safety of VPZ-based triple therapy as a first-line regimen for H. pylori eradication and its relationship with clarithromycin (CAM) susceptibility were evaluated.

METHODS

From May 2015 to September 2017, H. pylori-infected patients who underwent esophagogastroduodenoscopy with CAM susceptibility testing were prospectively enrolled. Patients received a 7-day triple therapy regimen (VAC) of VPZ (20 mg), amoxicillin (750 mg), and CAM (200 mg) twice daily. Eradication rates, demographics, CAM susceptibility, and safety profiles were assessed.

RESULTS

VAC was administered to 146 patients (median age: 63, range: 22-85 years) (60% of whom were females) who underwent CAM susceptibility testing, and 131 patients underwent ¹³C-urea breath testing to evaluate eradication success. The prevalence of CAM resistance was 34.2%. The overall eradication rates of VAC in per protocol (PP) and "intention to treat" (ITT) analyses were 90.8% (n = 131) and 81.5% (n = 146), respectively. In PP analysis for CAM susceptibility, the eradication rates of VAC were comparable between CAM-sensitive (91.6%, n = 83) and CAM-resistant (89.4%, n = 47) strains. The corresponding rates from the ITT analysis were 80.0% (n = 95) and 84.0% (n = 50), respectively. No adverse events requiring discontinuation of VAC were observed.

CONCLUSIONS

CAM-resistant H. pylori was prevalent in one-third of patients in the Tokyo metropolitan area. VPZ-based triple therapy was highly effective and well-tolerated irrespective of CAM susceptibility. Therefore, it could be a valuable first-line treatment regimen for H. pylori infection.

Effects of vonoprazan on gastric PH and clinical course after gastric ESD: A retrospective and prospective study

Background

Vonoprazan has been more widely used for artificial ulcers after endoscopic submucosal dissection (ESD) for early gastric cancer; however, no reports have examined intragastric pH during ESD. The present study aimed to measure gastric pH at the time of ESD and the clinical course afterwards for patients treated with vonoprazan the night before undergoing ESD.

Materials and methods

We examined medication status regarding gastric acid secretion and antithrombotic drugs, post-ESD bleeding as a perioperative complication, and the timing of upper gastrointestinal endoscopy after ESD and ulcer healing in 156 patients who underwent gastric ESD at our hospital from January 2014 to December 2019. The gastric pH was measured at the time of ESD after administration of 20 mg vonoprazan on the night before gastric ESD.

Results

There were 14 cases of post-ESD bleeding in patients treated with proton-pump inhibitors (PPIs), including oozing during second-look endoscopy compared to only 1 case of bleeding with vonoprazan administration (p < 0.05). Vonoprazan was also associated with better post-ESD ulcer healing than PPIs. Gastric pH during ESD after vonoprazan administration on the night before gastric ESD was ≥6.96 in all 11 patients.

Conclusion

Post-ESD bleeding was reduced, and ulcer healing was improved in patients treated with vonoprazan the night before their procedure. Our results suggest high gastric pH during ESD due to vonoprazan administration may be beneficial for hemostasis and ulcer healing following ESD.

Effect of Antibiotic Susceptibility and CYP3A4/5 and CYP2C19 Genotype on the Outcome of Vonoprazan-Containing Helicobacter pylori Eradication Therapy

Background: Helicobacter pylori eradication containing the potassium-competitive acid blocker, vonoprazan, achieves a higher eradication rate than therapy with proton pump inhibitors (PPIs). Because vonoprazan is mainly metabolized by CYP3A4/5, CYP genotype may affect the eradication rate. We investigated the influence of antibiotic susceptibility and CYP3A4/5 and CYP2C19 genotypes on the eradication rates. Methods: A total of 307 Japanese who were genotyped for CYP3A4 *1/*22, CYP3A5 *1/*3 and CYP2C19 *1/*2/*3/*17, and investigated for susceptibility to antimicrobial agents, received vonoprazan-containing regimens: (1) With amoxicillin and clarithromycin as the first-line treatment; (2) with amoxicillin and metronidazole as the second-line treatment; or (3) with amoxicillin and sitafloxacin as the third-line treatment. Results: The eradication rate was 84.5% (95% confidence interval [CI]: 78.9–89.1%) using first-line, 92.6% (95% CI: 82.1–97.9%) using second-line and 87.5% (95% CI: 73.1–95.8%) using third-line treatment. Infection with clarithromycin-resistant strains was a predictive factor for failed eradication (odds ratio: 5.788, 95% CI: 1.916–17.485, p = 0.002) in multivariate analysis. No significant differences were observed in the eradication rate of regimens among CYP3A4, CYP3A5 and CYP2C19 genotypes. Conclusions: Genotyping for CYP3A4 *1/*22, CYP3A5 *1/*3 and CYP2C19 *1/*2/*3/*17 before vonoprazan-containing eradication treatment may not be useful for predicting clinical outcomes.

Physiologically based pharmacokinetic-pharmacodynamic modeling for prediction of vonoprazan pharmacokinetics and its inhibition on gastric acid secretion following intravenous/oral administration to rats, dogs and humans

Vonoprazan is characterized as having a long-lasting antisecretory effect on gastric acid. In this study we developed a physiologically based pharmacokinetic (PBPK)-pharmacodynamic (PD) model linking to stomach to simultaneously predict vonoprazan pharmacokinetics and its antisecretory effects following administration to rats, dogs, and humans based on in vitro parameters. The vonoprazan disposition in the stomach was illustrated using a limited-membrane model. In vitro metabolic and transport parameters were derived from hepatic microsomes and Caco-2 cells, respectively. We found the most predicted plasma concentrations and pharmacokinetic parameters of vonoprazan in rats, dogs and humans were within twofold errors of the observed data. Free vonoprazan concentrations (f_u × C₂) in the stomach were simulated and linked to the antisecretory effects of the drug (I) (increases in pH or acid output) using the fomula dI/dt = k × f_u × C₂ × (I_max − I) − k_d × I. The vonoprazan dissociation rate constant k_d (0.00246 min⁻¹) and inhibition index K_I (35 nM) for H⁺/K⁺-ATPase were obtained from literatures. The vonoprazan-H⁺/K⁺-ATPase binding rate constant k was 0.07028 min⁻¹· μM⁻¹ using ratio of k_d to K_I. The predicted antisecretory effects were consistent with the observations following intravenous administration to rats (0.7 and 1.0 mg/kg), oral administration to dogs (0.3 and 1.0 mg/kg) and oral single dose or multidose to humans (20, 30, and 40 mg). Simulations showed that vonoprazan concentrations in stomach were 1000-fold higher than those in the plasma at 24 h following administration to human. Vonoprazan pharmacokinetics and its antisecretory effects may be predicted from in vitro data using the PBPK-PD model of the stomach. These findings may highlight 24-h antisecretory effects of vonoprazan in humans following single-dose or the sustained inhibition throughout each 24-h dosing interval during multidose administration.