Potassium-competitive acid blockers: Advanced therapeutic option for acid-related diseases

Experimental drugs for erosive esophagitis: what is in the clinical development pipeline?

INTRODUCTION

Proton pump inhibitor (PPI) has revolutionized the treatment of erosive esophagitis (EE) in the past few decades. However, roughly 30-40% of patients, especially with severe EE (Los Angeles Grade C/D), remain poorly responsive to this medication. Novel drugs have been formulated and/or repurposed to address this problem.

AREAS COVERED

This review highlights novel drugs that have been investigated for use in EE, such as mucosal protectants, prokinetics, transient lower esophageal sphincter relaxation (TLESR) reducers, novel PPIs, and the new potassium-competitive acid blocker (PCAB). Studies have demonstrated that PCAB has promising results (efficacy and safety) compared to PPI for the healing of EE, especially in severe diseases.

EXPERT OPINION

PCAB has gained interest in recent years, with pharmacokinetics and pharmacodynamics properties surpassing PPI. Although recent data on PCABs, which comprised mainly of Vonoprazan, have shown promising results, more randomized controlled trials for other PCAB drugs are needed to elucidate and confirm the superiority of this drug class to PPI, the current first-line treatment of EE.

Potassium-competitive Acid Blockers: Current Clinical Use and Future Developments

PURPOSE OF THE REVIEW

Acid suppression with proton pump inhibitors (PPIs) represents the standard of care in the treatment of acid-related diseases. However, despite their effectiveness, PPIs display some intrinsic limitations, which underlie the unmet clinical needs that have been identified over the past decades. The aims of this review are to summarize the current status and future development of the new class of antisecretory drugs (potassium-competitive acid blockers, P-CABs) that have recently been introduced into medical practice.

RECENT FINDINGS

Over the past decades, clinical needs unmet by the current acid suppressants have been recognized, especially in the management of patients with GERD, Helicobacter pylori infection and NSAID-related peptic ulcer. The failure to address these needs is mainly due to their inability to achieve a consistent acid suppression in all patients and, particularly, to control nighttime acidity. It was then realized that an extended duration of acid suppression would exert additional benefits. The available data with P-CABs show that they are able to address these unmet clinical needs. Four different P-CABs (vonoprazan, tegoprazan, fexuprazan and keverprazan) are currently available. However, only two of them are approved outside Asia. Vonoprazan is available in North, Central and South America while tegoprazan is marketed only in Latin American countries. Two other compounds (namely linazapran glurate and zestaprazan) are presently under clinical development. While clinical trials on GERD have been performed with all P-CABs, only vonoprazan and tegoprazan have been investigated as components of Helicobacter pylori eradication regimens. The available data show that-in the above two clinical indications-P-CABs provide similar or better efficacy in comparison with PPIs. Their safety in the short-term overlaps that of PPIs, but data from long-term treatment are needed.

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.

Comparative Efficacy and Safety of Potassium-Competitive Acid Blockers vs. Proton Pump Inhibitors for Peptic Ulcer with or without Helicobacter pylori Infection: A Systematic Review and Network Meta-Analysis

Novel potassium-competitive acid blockers (P-CABs) have emerged as effective acid-suppressive drugs in recent years, replacing proton pump inhibitors (PPIs). We aim to compare the efficacy and safety of P-CABs versus PPIs in the treatment of peptic ulcers with or without Helicobacter pylori (H. pylori) infection. We searched in PubMed, Embase, WOS, Cochrane Library, ClinicalTrials.gov, CNKI, and Wanfang databases (all years up to January 2024). Efficacy and safety outcomes were evaluated using odds ratio (OR) and 95% confidence intervals (CI). The Surface Under the Cumulative Ranking (SUCRA) probabilities were used to rank each intervention. Among 14,056 studies screened, 56 studies involving 9792 participants were analyzed. Vonoprazan demonstrated the best efficacy in ulcer healing rate and H. pylori eradication rate (SUCRA = 86.4% and 90.7%, respectively). Keverprazan ranked second in ulcer healing rates (SUCRA = 76.0%) and was more effective in pain remission rates (SUCRA = 91.7%). The risk of adverse events was low for keverprazan (SUCRA = 11.8%) and tegoprazan (SUCRA = 12.9%), and moderate risk for vonoprazan (SUCRA = 44.3%) was demonstrated. Compared to lansoprazole, vonoprazan exhibited a higher risk of drug-related adverse events (OR: 2.15; 95% CI: 1.60-2.89) and serious adverse events (OR: 2.22; 95% CI: 1.11-4.42). Subgroup analysis on patients with H. pylori-positive peptic ulcers showed that vonoprazan was at the top of the SUCRA rankings, followed by keverprazan. Vonoprazan showed superior performance in peptic ulcers, especially for patients with H. pylori-positive peptic ulcers. However, the risk of adverse events associated with vonoprazan should be noted. Keverprazan has also shown good therapeutic outcomes and has performed better in terms of safety.

Absorption, distribution, metabolism and excretion of linaprazan glurate in rats

Linaprazan (AZD0865, TX07) is one of potassium-competitive acid blockers. However, linaprazan is rapidly excreted from the body, shortening its acid inhibition property. Linaprazan glurate (X842) is a prodrug of linaprazan with a prolonged inhibitory effect on gastric acid secretion. Linaprazan glurate has entered clinical trials, but few studies have reported its metabolism in non-clinical and clinical settings. In this study, we studied the pharmacokinetics, tissue distribution, mass balance, and metabolism of linaprazan glurate in rats after a single oral dose of 2.4 mg/kg (100 µCi/kg) [14C]linaprazan glurate. The results demonstrated that linaprazan glurate was mainly excreted via feces in rats with 70.48% of the dose over 168 h. The plasma AUC0-∞ of linaprazan glurate in female rats was 2 times higher than that in male rats. Drug-related substances were mainly concentrated in the stomach, eyes, liver, small intestine, and large intestine after administration. In blood, drug-related substances were mostly distributed into plasma instead of hemocytes. In total, 13 metabolites were detected in rat plasma, urine, feces, and bile. M150 (2,6-dimethylbenzoic acid) was the predominant metabolite in plasma, accounting for 80.65% and 67.65% of AUC0-24h in male and female rats, respectively. Based on the structures, linaprazan glurate was mainly hydrolyzed into linaprazan, followed by a series of oxidation, dehydrogenation, and glucuronidation in rats. Besides, CES2 is the main metabolic enzyme involved in the hydrolysis of linaprazan glurate to linaprazan.

Proton pump inhibitors stabilize the expression of PD-L1 on cell membrane depending on the phosphorylation of GSK3β

BACKGROUND

Preclinical and clinical evidence indicates that proton pump inhibitors (PPIs) may indirectly diminish the microbiome diversity, thereby reducing the effectiveness of immune checkpoint inhibitors (ICIs). Conversely, recent publications have shown that PPIs could potentially enhance the response to ICIs. The precise mechanism through which PPIs modulate the ICIs remains unclear. In this study, we discovered a novel molecular function of PPIs in regulating immune invasion, specifically through inducing PD-L1 translocation in various tumor cells.

METHODS

C57BL/6 mice subcutaneous transplantation model is used to verify the potential efficacy of PPIs and PD-L1 antibody. Western blotting analysis and phosphorylated chip are used to verify the alteration of PD-L1-related pathways after being treated with PPIs. The related gene expression is performed by qRT-PCR and luciferase reporter analysis. We also collected 60 clinical patients diagnosed with esophageal cancer or reflux esophagitis and then detected the expression of PD-L1 in the tissue samples by immunohistochemistry.

RESULTS

We observed that the IC50 of tumor cells in response to PPIs was significantly higher than that of normal epithelial cells. PPIs significantly increased the expression of PD-L1 on cell membrane at clinically relevant concentrations. Furthermore, pre-treatment with PPIs appeared to synergize the efficiency of anti-PD-L1 antibodies in mouse models. However, PPI administration did not alter the transcription or total protein level of PD-L1 in multiple tumor cells. Using a phosphorylated protein chip, we identified that PPIs enhanced the phosphorylation of GSK3β, then leading to PD-L1 protein translocation to the cell membranes. The capacity of PPIs to upregulate PD-L1 was negated following GSK3β knockout. Furthermore, our clinical data showed that the PPIs use resulted in increased PD-L1 expression in esophageal cancer patients.

CONCLUSION

We mainly address a significant and novel mechanism that the usage of PPIs could directly induce the expression of PD-L1 by inducing GSK3β phosphorylation and facilitate primary tumor progression and metastasis.

A cochleate formulation optimized by D-optimal mixture design enhances oral bioavailability of Revaprazan

A cochleate formulation was developed to enhance the oral bioavailability of revaprazan (RVP). Dimyristoyl phosphatidylcholine (DMPC) liposome containing dicetyl phosphate (DCP) successfully formed a cochleate after treatment with CaCl2, whereas that containing sodium deoxycholate did not. Cochleate was optimised using a D-optimal mixture design with three independent variables-DMPC (X1, 70.58 mol%), cholesterol (X2, 22.54 mol%), and DCP (X3, 6.88 mol%)-and three response variables: encapsulation efficiency (Y1, 76.92%), released amount of free fatty acid at 2 h (Y2, 39.82%), and released amount of RVP at 6 h (Y3, 73.72%). The desirability function was 0.616, showing an excellent agreement between the predicted and experimental values. The cylindrical morphology of the optimised cochleate was visualised, and laurdan spectroscopy confirmed the dehydrated membrane interface, showing an increased generalised polarisation value (approximately 0.5) over small unilamellar vesicle of RVP (RVP-SUV; approximately 0.1). The optimised cochleate showed greater resistance to pancreatic enzyme than RVP-SUV. RVP was released in a controlled manner, achieving approximately 94% release in 12 h. Following oral administration in rats, the optimised cochleate improved the relative bioavailability of RVP by approximately 274%, 255%, and 172% compared to RVP suspension, a physical mixture of RVP and the cochleate, and RVP-SUV, respectively. Thus, the optimised cochleate formulation might be a good candidate for the practical development of RVP.

Pantoprazole and Vonoprazan Performed Well in Preventing Peptic Ulcer Recurrence in Low-Dose Aspirin Users

BACKGROUND

Low-dose aspirin (LDA) administration is associated with an elevated risk of recurring peptic ulcer (PU) and gastrointestinal (GI) hemorrhage.

AIMS

This systematic review and Bayesian network meta-analysis aimed to comprehensively assess the effectiveness of diverse medications in preventing the recurrence of PU and GI hemorrhage in patients with a history of PU receiving long-term LDA therapy.

METHODS

This systematic review and network meta-analysis followed Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement and was registered on PROSPERO (CRD42023406550). We searched relevant studies in main databases from inception to March 2023. All statistical analyses were performed using R (version 4.1.3), with the "Gemtc" (version 1.0-1) package. The pooled risk ratio (RR), corresponding 95% credible interval (95% CrI), and the surface under the cumulative ranking curve (SUCRA) were calculated.

RESULTS

11 Randomized clinical trials (RCTs) were included. The analysis underscored pantoprazole was the most efficacious for reducing the risk of PU recurrence (RR [95% CrI] = 0.02 [0, 0.28]; SUCRA: 90.76%), followed by vonoprazan (RR [95% CrI] = 0.03 [0, 0.19]; SUCRA: 86.47%), comparing with the placebo group. Pantoprazole also performed well in preventing GI hemorrhage (RR [95% CrI] = 0.01[0, 0.42]; SUCRA: 87.12%) compared with Teprenone.

CONCLUSIONS

For patients with a history of PU receiving LDA, pantoprazole and vonoprazan might be the optimal choices to prevent PU recurrence and GI hemorrhage.

Good clinical practice recommendations for the diagnosis and treatment of gastroesophageal reflux disease. An expert review from the Asociación Mexicana de Gastroenterología

INTRODUCTION

Gastroesophageal reflux disease (GERD) is very prevalent in the general population, with a broad spectrum of clinical manifestations, requiring accurate diagnosis and treatment.

AIM

The aim of this expert review is to establish good clinical practice recommendations for the diagnosis and personalized treatment of GERD.

METHODS

The good clinical practice recommendations were produced by a group of experts in GERD, members of the Asociación Mexicana de Gastroenterología (AMG), after carrying out an extensive review of the published literature and discussing each recommendation at a face-to-face meeting. This document does not aim to be a clinical practice guideline with the methodology such a document requires.

RESULTS

Fifteen experts on GERD formulated 27 good clinical practice recommendations for recognizing the symptoms and complications of GERD, the rational use of diagnostic tests and medical treatment, the identification and management of refractory GERD, the overlap with functional disorders, endoscopic and surgical treatment, and GERD in the pregnant woman, older adult, and the obese patient.

CONCLUSIONS

An accurate diagnosis of GERD is currently possible, enabling the prescription of a personalized treatment in patients with this condition. The goal of the good clinical practice recommendations by the group of experts from the AMG presented in this document is to aid both the general practitioner and specialist in the process of accurate diagnosis and treatment, in the patient with GERD.

Effect of potassium-competitive acid blockers on human gut microbiota: a systematic review and meta-analysis

Background: Vonoprazan has been reported to exert more potent and long-lasting gastric acid inhibition than proton pump inhibitors, potentially leading to a greater impact on the gut microbiota. This study aimed to clarify changes in microbial diversity and bacterial composition after VPZ treatments. Methods: We searched from PubMed, Embase, WOS, Scopus, Cochrane Library, and ClinicalTrials.gov (all years up to May 2023). The primary outcomes were alpha and beta diversity, as well as differences in gut microbiota composition between before and after VPZ treatments. We performed a meta-analysis to uncover the potential changes in human gut microbiota among VPZ users by pooled mean difference (MD) with a 95% confidence interval (CI). The risk of bias was assessed using the ROBINS-I tool. Results: A total of 12 studies were included to compare differences before and after VPZ treatments. Compared with baseline, alpha diversity was significantly reduced after VPZ treatments and gradually returned to baseline with longer follow-up. At the phylum level, there was a decrease in the relative abundance of Firmicutes and Actinobacteria, while Bacteroidetes increased compared with baseline. At the genus level, we found a significant decrease in the relative abundance of Coprococcus and Bifidobacterium and a significant increase in the relative abundance of Bacteroides compared with those before treatment. In subgroup analyses according to country and participants, we found differences in microbial changes after VPZ treatments. Conclusion: Vonoprazan can affect the changes of gut microbiota, which may be potentially associated with its strong ability of acid inhibition. However, due to the large heterogeneity, further studies are required to validate these findings. Systematic Review Registration: https://www.crd.york.ac.uk/prospero/, identifier CRD42023412265.

Plants with potential anti-ulcerogenic activity and possible mechanism of actions based on their phyto-constitutional profile

Gastric ulcer, the most common disorder of the digestive tract is formed due to an imbalance between acid and mucus content of the stomach. However, the currently used western therapeutic regimens have many drawbacks like adverse effects, recurrence of gastric ulcers, are expensive, and also, may have interactions with other drugs. Hence, there is a need for effective alternative therapy. Medicinal herbs have been used since ancient times to treat several diseases and are also evidenced to be effective against gastric ulcers. It is also evident that medicinal herbs have been proved to be equally effective or superior as compared to the existing synthetic medicines. In this review, five herbs have been taken into consideration and assumed to be effective against gastric ulcers. Abrus mollis, Korean Thistle (Cirsium japonicum var. maackii), Astralagus complanatus Bunge, Bauhinia monandra, and Embelia ribes Burm f. are the herbs whose data is been collected and reviewed for their potential gastro-protective action. Although, their side effects and toxicity profile need to be further evaluated. Hence, the purpose of this review is to gather evidence of these five medicinal herbs and their probable mechanism of action against gastric ulcers based on their phyto-constitutional profile.

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.

Acid suppressants reduce the therapeutic effect of immune checkpoint inhibitors and increase the risk of acute kidney injury: a meta-analysis

BACKGROUND

Immune checkpoint inhibitors (ICIs) are used in cancer immunotherapy; however, they can lead to immune-related adverse events (irAEs) through immune function of patients. Therefore, this meta-analysis aimed to assess the concomitant effect of acid suppressants (ASs) on ICIs, including several subgroup analyses.

METHODS

We identified related studies and generated the forest plot. The primary endpoint was defined as the change in progression free survival (PFS) and overall survival (OS) with or without ASs administration. We also evaluated the effect of ASs on the incidence of irAEs.

RESULTS

The total hazard ratio (HR) of ASs on PFS with ICI treatment was 1.39 and the 95% confidence interval (95% CI) was 1.21-1.59 (Z: p < 0.00001). Moreover, the total HR of ASs on OS was 1.40 and the 95% CI was 1.21-1.61 (Z: p < 0.00001), suggesting that ASs reduced ICI's therapeutic effect. The total odds ratio (OR) for evaluating the effect of ASs on irAEs was 1.23 with a 95% CI of 0.81-1.88 (Z: p = 0.34). However, ASs significantly worsened acute kidney injury (AKI) (total OR 2.10; 95% CI 1.74-2.53 (Z, p < 0.00001)). Furthermore, although proton pump inhibitors (PPIs) reduced ICI's therapeutic effect, histamine H2-receptor antagonists (H2RAs) did not affect OS.

CONCLUSIONS

It was shown that ASs, especially PPIs, reduced ICI's therapeutic effect, while H2RAs had no effect, and ASs did not affect irAEs; however, it is a risk factor for ICIs-induced AKI.

A Modified 14-Day Dual Therapy with Vonoprazan and Amoxicillin Amplified the Advantages Over Conventional Therapies for Eradication of Helicobacter pylori: A Non-Inferiority Clinical Trial

Purpose

The emergence of resistant strains has greatly reduced the eradication rate of H. pylori (HP) in conventional bismuth-containing quadruple therapy. Meanwhile, the new 7-day dual therapy with vonoprazan (VPZ) and amoxicillin (AMO) failed to achieve the expected therapeutic effect in China.

Patients and Methods

A total of 256 untreated HP-infected patients are included in this non-inferiority clinical trial. The patients were randomly divided into three groups: 14-day dual therapy group (VPZ 20mg b.i.d + AMO 750mg t.i.d for 14 days, VA14), 14-day modified triple therapy group (VA14 + Jinghua Weikang Capsule 160mg t.i.d, VAC), and conventional bismuth-containing quadruple therapy group for 14 days (BCQ). Eradication rates, drug-related adverse events (AEs), patient compliance, and drug costs were compared among the three groups.

Results

The eradication rates in the BCQ, VA14, and VAC were 78.67, 77.33%, and 86.49% by intention-to-treat analysis, respectively, and 96.72%, 90.63%, and 92.75% by pre-protocol or modified intention-to-treat analysis, respectively. VA14 therapy indicated a non-inferiority eradication rate and advanced safety and economics to BCQ therapy. JWC further improved the eradication rate and reduced the incidence of AEs.

Conclusion

A modified 14-day dual therapy with VPZ and AMO provides satisfied efficacy as the first-line treatment for HP infection in China.

Vonoprazan-based triple and dual therapy versus bismuth-based quadruple therapy for Helicobacter pylori infection in China: a three-arm, randomised clinical trial protocol

BACKGROUND

Helicobacter pylori infection and associated diseases are a growing global public health issue. H. pylori infection is the major cause of gastric cancer, over 90% of duodenal ulcers, and over 70% of gastric ulcers. The infection rate of H. pylori is approximately 50%, and approximately 50% of new cases of gastric cancer worldwide occur in China. Bismuth (BI)-based quadruple therapy is recommended as the first-line treatment for H. pylori in China. Vonoprazan (VPZ), a new potassium-competitive acid blocker that can inhibit gastric acid secretion more effectively than proton pump inhibitors (PPIs), has been combined with antibiotics to effectively eradicate H. pylori. In this study, we compared the efficacy and safety of two VPZ-based therapies with that of BI-based therapy for H. pylori treatment.

METHODS

A three-armed randomised controlled trial (RCT) is being conducted in Shenzhen, with 327 participants recruited from the Gastroenterology Clinic of the University of Hong Kong-Shenzhen Hospital. Patients were diagnosed with H. pylori infection based on a positive ¹³C-urea breath test (UBT). Patients are kept naïve to their treatment and are randomly assigned in a 1:1:1 ratio to either VPZ-based triple, VPZ-based dual, or BI-based quadruple therapy for 14 days. All groups are subjected to follow-up evaluations of safety, adverse drug reactions, and clinical variables in the first, second, and fourth weeks after treatment. Successful eradication is confirmed by a negative ¹³C-UBT six weeks after treatment. If initial treatment fails, (1) those patients are turned to another regimen, or (2) a drug resistance test is conducted, after which an individualised treatment regimen shall be prescribed according to antimicrobial susceptibility testing. The resulting data will be evaluated using intention-treat and a per-protocol analysis.

DISCUSSION

This study is the a RCT aims to evaluate the efficacy and safety of 14-day VPZ-based triple and dual therapies in comparison with BI-based quadruple therapy. The outcomes of this study may allow treatment recommendations and update drug instructions in China.

TRIAL REGISTRATION

Chinese Clinical Trial Registry (No. ChiCTR2200056375). Registered on February 4, 2022, https://www.chictr.org.cn/showproj.aspx?proj=141314.

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.

Discovery of novel benzimidazole derivatives as potent potassium-competitive acid blockers for the treatment of acid-related diseases

H⁺, K⁺-ATPase, as the most critical enzyme in gastric acid secretion, has long been an attractive target for the treatment of acid-related diseases. In this study, a series of benzimidazole derivatives were designed and synthesized through conformational restriction and skeleton hopping strategies by using vonoprazan as the lead compound. Among them, compounds A12 (IC₅₀ = 9.32 μM) and A18 (IC₅₀ = 5.83 μM) showed better inhibition at the enzyme level. In addition, gastric acid secretion inhibition was assessed in vivo, and the results showed that A12 and A18 significantly inhibited basal gastric acid secretion, 2-deoxy-d-glucose (2DG) stimulated gastric acid secretion and histamine-stimulated gastric acid secretion. In further in vitro metabolic experiments, A12 and A18 demonstrated excellent stability and low toxicity. Pharmacokinetic studies showed that the p.o. and i.v. half-lives of A18 were 3.21 h and 8.67 ± 1.15 h, respectively. In summary, A18 might be a novel and effective potassium-competitive acid blocker, and this study provides strong support for it use in the treatment of acid-related diseases.

Parkinson's disease-associated ATP13A2/PARK9 functions as a lysosomal H+,K+-ATPase

Mutations in the human ATP13A2 (PARK9), a lysosomal ATPase, cause Kufor-Rakeb Syndrome, an early-onset form of Parkinson's disease (PD). Here, we demonstrate that ATP13A2 functions as a lysosomal H⁺,K⁺-ATPase. The K⁺-dependent ATPase activity and the lysosomal K⁺-transport activity of ATP13A2 are inhibited by an inhibitor of sarco/endoplasmic reticulum Ca²⁺-ATPase, thapsigargin, and K⁺-competitive inhibitors of gastric H⁺,K⁺-ATPase, such as vonoprazan and SCH28080. Interestingly, these H⁺,K⁺-ATPase inhibitors cause lysosomal alkalinization and α-synuclein accumulation, which are pathological hallmarks of PD. Furthermore, PD-associated mutants of ATP13A2 show abnormal expression and function. Our results suggest that the H⁺/K⁺-transporting function of ATP13A2 contributes to acidification and α-synuclein degradation in lysosomes.

Vonoprazan vs. Lansoprazole for the treatment of endoscopic submucosal dissection induced gastric ulcer: a systematic review and meta-analysis

BACKGROUND

Vonoprazan is a potassium competitive acid blocker (P-CAB) approved in Japan in 2014 to treat endoscopic submucosal dissection (ESD)-induced ulcers and bleeding or perforation. Therefore, this meta-analysis aimed to determine whether Vonoprazan is more effective than Lansoprazole in the treatment of ESD-induced ulcers which include ulcer healing and shrinking rate, among others.

METHODS

Randomized controlled trials (RCT) and retrospective studies were collected from the PubMed (Medline), Embase, Web of science and Cochrane Library databases. Meanwhile, studies were selected according to predetermined qualification criteria and data were extracted by two researchers. The quality of the methods for published papers was evaluated using the modified Jadad scale.

RESULTS

Five studies were included in this meta-analysis, the ulcer healing rate effect was not significantly higher in the intervention groups than in the control groups at 4 weeks, [OR：1.07 (0.51, 2.22), 95% CI, I2=2%, Z=0.18, P=0.86]. There was no significant difference in the ulcer shrinkage rate at 4 weeks [MD：0.20 (-1.51, 1.92), 95% CI, I2=0%, P=0.82] and 8 weeks [MD: -0.09 (-0.30, 0.12), 95% CI, I2=0%, P=0.39].

CONCLUSION

There was no significant difference between Vonoprazan and Lansoprazole in the ulcers induced by treatment after 4 weeks and 8 weeks of treatment with ESD.

Quadruple therapy with vonoprazan 20 mg daily as a first-line treatment for Helicobacter pylori infection: A single-center, open-label, noninferiority, randomized controlled trial

BACKGROUND

Although vonoprazan has been proven to be a highly potent drug for Helicobacter pylori eradication, there have been no randomized trials comparing the effectiveness of regimens containing vonoprazan 20 mg daily with alternative standard strategies. We aimed to assess the efficacy, tolerance, and cost-effectiveness of quadruple therapy with vonoprazan 20 mg daily as a first-line therapy for H. pylori eradication.

MATERIALS AND METHODS

We conducted a single-center, open-label, noninferiority, randomized controlled study in Zhejiang, China. Treatment-naive H. pylori-positive participants (n = 234) were randomly assigned to three groups in a 1:1:1 ratio: vonoprazan 20 mg daily with amoxicillin 1000 mg, furazolidone 100 mg and colloidal bismuth 200 mg each given twice a day for 10 days (V10) or 14 days (V14), or esomeprazole 20 mg with amoxicillin 1000 mg, furazolidone 100 mg and colloidal bismuth 200 mg each given twice a day for 14 days (E14). The primary endpoint was the eradication rates in each group. The secondary endpoints were the incidence of adverse events (AEs) and compliance.

RESULTS

The eradication rates in the V10, V14 and E14 groups were 96.2% (89.2-99.2%), 94.9% (87.4-98.6%), and 93.6% (85.7-97.9%) in the intention-to-treat analysis, and 98.6% (92.7-100.0%), 97.4% (90.8-99.7%), and 94.8% (87.2-98.6%) in the per-protocol analysis, respectively. Quadruple therapy with vonoprazan 20 mg daily was noninferior to the esomeprazole-based regimen (Farrington and Manning test: margin 10%, significance level 2.5%). The adverse event rates were 12.8% versus 3.8% versus 6.4% in the V10, V14, and E14 groups, respectively. All regimens were well tolerated without significant differences (p = 0.096). The cost-effectiveness ratio was 1.32, 1.88, and 3.06 for the V10, V14, and E14 groups in the intention-to-treat analysis, respectively. (NCT04907747).

CONCLUSIONS

Vonoprazan (20 mg daily) was as effective as esomeprazole (20 mg twice a day) in quadruple therapies for the eradication of H. pylori, was more economical, and was well tolerated. In addition, the 10-day regimen of vonoprazan (20 mg daily) was comparable to the 14-day regimen.

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.

[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.

A population PK–PD model of YH4808 , a novel P‐CAB , and intragastric pH that incorporated negative feedback by increased intragastric pH onto the systemic exposure to YH4808

YH4808 is a novel potassium‐competitive acid blocker that is under clinical development to treat patients with gastroesophageal reflux disease and peptic ulcer diseases. In this study, the pharmacokinetic (PK) and pharmacodynamic (PD) profiles of YH4808 were modeled in healthy male volunteers who received a single oral dose of YH4808 at 30, 50, 100, 200, 400, 600, and 800 mg or matching placebo and multiple once‐daily oral doses of YH4808 at 100, 200, and 400 mg or matching placebo for 7 days. A population PK–PD model adequately described the time–concentration‐effect profiles of YH4808. The maximum increasing effect of YH4808 on intragastric pH was 4.38, which was higher than the observed maximum increase in intragastric pH after omeprazole at 40 mg (2.2 in pH). The maximum inhibitory effect by the increased intragastric pH on the exposure to repeated YH4808 was 58% from baseline. Monte–Carlo simulation experiments based on the final model showed that YH4808 at 200 mg will produce a higher percentage of time at pH > 4 over 24 h on day 1 than observed value of esomeprazole at 40 mg once‐daily, an active comparator (84.7% time vs. 58.3% time, respectively). Because YH4808 at ≥200 mg resulted in a higher percentage of time at intragastric pH > 4 than seen after once‐daily esomeprazole at 40 mg and YH4808 showed acceptable tolerability at a single‐dose of 30–800 mg, we suggest to test the 200 mg once daily dosage regimen in further clinical trials of YH4808.

Novel Potassium-Competitive Acid Blocker, Tegoprazan, Protects Against Colitis by Improving Gut Barrier Function

Inflammatory bowel disease (IBD) is a chronic immune-mediated disorder characterized by prolonged inflammation of the gastrointestinal tract. IBD can result from gut barrier dysfunction, altered gut microbiota, and abnormal intestinal immunity induced by environmental factors in genetically susceptible individuals. Proton pump inhibitors (PPIs) such as rabeprazole are frequently employed for gastric acid inhibition. However, long-term PPI administration can alter the intestinal microbiome composition, possibly worsening IBD severity. The present study revealed that tegoprazan, a potassium-competitive acid blocker, significantly improved colitis in mice and enhanced the intestinal epithelial barrier function. Tegoprazan alleviated gut microbiota dysbiosis and enhanced the growth of Bacteroides vulgatus. In turn, B. vulgatus alleviated intestinal inflammation by inhibiting epithelial adhesion of pathogenic bacteria. Unlike rabeprazole, tegoprazan did not induce gut dysbiosis. Our findings provide novel insights into the potential role of tegoprazan as an intestinal protectant for IBD and as a therapeutic agent for gastric acid-related diseases.

Design, synthesis and biological evaluation of novel 5-methyl-2,4,5,6-tetrahydropyrrolo[3,4-c]pyrazole derivatives as potent potassium-competitive acid blockers

With the aim to discover a novel potent potassium-competitive acid blocker (P-CAB) agent, a series of 5-methyl-2,4,5,6-tetrahydropyrrolo[3,4-c]pyrazole derivatives were synthesized, and their H⁺/K⁺-ATPase inhibitory activities and inhibitory action on histamine-stimulated gastric acid secretion in rats were evaluated. Among the compounds synthesized, compound 3'-((3-(2-fluorophenyl)-5-methyl-5,6-dihydropyrrolo[3,4-c]pyrazol-2(4H)-yl)methyl)-[1,1'-biphenyl]-3-carboxamide not only exhibited potent H⁺/K⁺-ATPase inhibitory activity but olso showed potent inhibitory action in vivo on histamine-stimulated gastric acid secretion. In addition, the lead compound displayed favourable oral pharmacokinetic properties in rats, which was worthy of further study as a novel P-CAB agent.

Structural Basis for Binding of Potassium-Competitive Acid Blockers to the Gastric Proton Pump

As specific inhibitors of the gastric proton pump, responsible for gastric acidification, K⁺-competitive acid blockers (P-CABs) have recently been utilized in the clinical treatment of gastric acid-related diseases in Asia. However, as these compounds have been developed based on phenotypic screening, their detailed binding poses are unknown. We show crystal and cryo-EM structures of the gastric proton pump in complex with four different P-CABs, tegoprazan, soraprazan, PF-03716556 and revaprazan, at resolutions reaching 2.8 Å. The structures describe molecular details of their interactions and are supported by functional analyses of mutations and molecular dynamics simulations. We reveal that revaprazan has a novel binding mode in which its tetrahydroisoquinoline moiety binds deep in the cation transport conduit. The mechanism of action of these P-CABs can now be evaluated at the molecular level, which will facilitate the rational development and improvement of currently available P-CABs to provide better treatment of acid-related gastrointestinal diseases.

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.

Enhanced dissolution and bioavailability of revaprazan using self-nanoemulsifying drug delivery system

A self-nanoemulsifying drug delivery system (SNEDDS) was developed to enhance the dissolution and oral bioavailability (BA) of revaprazan (RVP). Various SNEDDSs containing 200 mg of RVP were formulated using Capmul MCM, Tween 80, and Brij L4, and they were characterized according to their size, polydispersity index, and dissolution behavior. Dissolution rates of all SNEDDS formulations significantly (p <0.05) improved with the formation of nanoemulsion with monodispersity. Formulation D resulted in RVP dissolution exceeding 70% at 2 h. Compared to raw RVP, SNEDDS exhibited a 4.8- to 7.4-fold improved effective permeability coefficient (P_eff) throughout the intestine in the in situ single pass intestinal permeability study and a 5.1-fold increased oral BA in the in vivo oral absorption assessment in rats. To evaluate the degree of lymphatic uptake, cycloheximide (CYC), a chylomicron flowing blocker, was pretreated prior to the experiment. This pretreatment barely affected the absorption of raw RVP; however, it greatly influenced the absorption of SNEDDS, resulting in an approximately 40% reduction in both the P_eff value and oral BA representing lymphatic transport. Thus, we suggest that the SNEDDS formulation is a good candidate for improving oral absorption of RVP through enhanced lymphatic uptake.

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.

Efficacy of vonoprazan against bleeding from endoscopic submucosal dissection-induced gastric ulcers under antithrombotic medication: A cross-design synthesis of randomized and observational studies

Vonoprazan, a potassium-competitive acid blocker, is expected to be superior to proton pump inhibitors (PPIs) in preventing post-endoscopic submucosal dissection (ESD)-induced gastric bleeding. However, the results of randomized controlled trials (RCTs) and observational studies on the efficacy of vonoprazan have been inconsistent. This study aimed to evaluate the effectiveness of vonoprazan in antithrombotic drug users, a population that has been excluded from RCTs. Treatment effects were assessed using cross-design synthesis, which can be adjusted for differences in study design and patient characteristics. We used data from an RCT in Japan (70 patients in the vonoprazan group and 69 in the PPI group) and an observational study (408 patients in the vonoprazan group and 870 in the PPI group). After matching, among the antithrombotic drug users in the observational study, post-ESD bleeding was noted in 8 out of 86 patients in the vonoprazan group and 18 out of 86 patients in the PPI group. After pooling the data from the RCT and observational study, the risk difference for antithrombotic drug users was -14.6% (95% CI: -22.0 to -7.2). CDS analysis suggested that vonoprazan is more effective than PPIs in preventing post-ESD bleeding among patients administered antithrombotic medications.

Co-Administration of Vonoprazan, Not Tegoprazan, Affects the Pharmacokinetics of Atorvastatin in Healthy Male Subjects

Potassium-competitive acid blocker is a new class of drugs inhibiting gastric acid. It is controversial that vonoprazan showed the inhibitory activities of cytochrome P450 3A4. This study aimed to evaluate the pharmacokinetics (PK) of atorvastatin and safety when atorvastatin was administered alone and co-administered with vonoprazan or tegoprazan. An open-label, multiple-dose, 3-intervention, 4-sequence, 4-period, partial replicate crossover study was conducted, and three interventions were; one is orally administered atorvastatin 40 mg alone once daily for 7 days, another is atorvastatin co-administered with vonoprazan 20 mg, and the other is atorvastatin co-administered with tegoprazan 50 mg. PK blood samples were collected up to 24 h after the last dose, and PK parameters for atorvastatin, 2-hydroxyatorvastatin and atorvastatin lactone were estimated by a non-compartmental method. Safety was evaluated, including adverse events and clinical laboratory tests. A total of 28 subjects completed the study. When atorvastatin was co-administered with vonoprazan, the systemic exposures of atorvastatin and atorvastatin lactone significantly increased, and the metabolic ratio of 2-hydroxyatorvastatin significantly decreased. Hypergastrinemia only occurred when atorvastatin was co-administered with vonoprazan. However, the plasma concentration profiles of atorvastatin, 2-hydroxyatorvastatin and atorvastatin lactone were similar when atorvastatin was administered alone or co-administered with tegoprazan. In conclusion, after multiple doses of atorvastatin co-administered with vonoprazan in healthy subjects, the systemic exposure of atorvastatin and the incidence of hypergastrinemia increased. With tegoprazan, however, those interactions were not observed.

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.

Clinical significance of P-class pumps in cancer

P-class pumps are specific ion transporters involved in maintaining intracellular/extracellular ion homeostasis, gene transcription, and cell proliferation and migration in all eukaryotic cells. The present review aimed to evaluate the role of P-type pumps [Na⁺/K⁺ ATPase (NKA), H⁺/K⁺ ATPase (HKA) and Ca2⁺-ATPase] in cancer cells across three fronts, namely structure, function and genetic expression. It has been shown that administration of specific P-class pumps inhibitors can have different effects by: i) Altering pump function; ii) inhibiting cell proliferation; iii) inducing apoptosis; iv) modifying metabolic pathways; and v) induce sensitivity to chemotherapy and lead to antitumor effects. For example, the NKA β2 subunit can be downregulated by gemcitabine, resulting in increased apoptosis of cancer cells. The sarcoendoplasmic reticulum calcium ATPase can be inhibited by thapsigargin resulting in decreased prostate tumor volume, whereas the HKA α subunit can be affected by proton pump inhibitors in gastric cancer cell lines, inducing apoptosis. In conclusion, the present review highlighted the central role of P-class pumps and their possible use and role as anticancer cellular targets for novel therapeutic chemical agents.

Development of a Solid Supersaturable Micelle of Revaprazan for Improved Dissolution and Oral Bioavailability Using Box-Behnken Design

PURPOSE

To enhance the oral bioavailability of revaprazan (RVP), a novel solid, supersaturable micelle (SSuM) was developed.

METHODS

Surfactants and solid carriers were screened based on a solubility and a flowability test, respectively. Supersaturating agents, including Poloxamer 407 (P407), were screened. The SSuM was optimized using a Box-Behnken design with three independent variables, including Gelucire 44/14:Brij L4 (G44/BL4; X1) and the amounts of Florite PS-10 (FLO; X2) and Vivapur 105 (VP105; X3), and three response variables, ie, dissolution efficiency at 30 min (Y1), dissolution enhancing capacity (Y2), and Carr's index (Y3). The solid state property was evaluated, and a dissolution test was conducted. RVP, Revanex®, solid micelle (P407-free from the composition of SSuM), and SSuM were orally administrated to rats (RVP 20 mg equivalent/kg) for in vivo pharmacokinetic study.

RESULTS

G44 and BL4 showed great solubility, with a critical micelle concentration range of 119.2-333.0 μg/mL. P407 had an excellent supersaturating effect. FLO and VP105 were selected as solid carriers, with a critical solidifying ratio (g/mL) of 0.30 and 0.91, respectively. With optimized values of X1 (-0.41), X2 (0.31), and X3 (-0.78), RVP (200 mg)-containing SSuM consisting of G44 (253.8 mg), BL4 (106.2 mg), FLO (99.3 mg), VP105 (199.8 mg), and P407 (40 mg) was developed, resulting in Y1 (40.3%), Y2 (0.008), and Y3 (12.3%). RVP existed in an amorphous state in the optimized SSuM, and the SSuM formed a nanosized dispersion in the aqueous phase, with approximately 71.7% dissolution at 2 h. The optimized SSuM improved the relative bioavailability of RVP in rats by approximately 478%, 276%, and 161% compared to raw RVP, Revanex®, and solid micelle, respectively.

CONCLUSION

The optimized SSuM has great potential for the development of solidified formulations of poorly water-soluble drugs with improved oral absorption.

The Potential Benefits of Vonoprazan as Helicobacter pylori Infection Therapy

Helicobacter pylori infection is a severe global health problem that is closely associated with acid-related diseases and gastric malignancies. Eradicating H. pylori is strongly recommended for lowering peptic ulcer recurrence and preventing gastric cancer. The current approved H. pylori eradication regimen combines a proton pump inhibitor (PPI) with two antibiotics. Unfortunately, this regimen failed to meet expectations mostly due to antibiotic resistance and insufficient gastric acid suppression. Vonoprazan, a novel potassium-competitive acid blocker, showed promising results as a PPI replacement. Vonoprazan inhibits gastric acid secretion by acting as a reversible competitive inhibitor against potassium ions and forming disulfide bonds with the cysteine molecule of H⁺/K⁺-ATPase. Vonoprazan has superior pharmacological characteristics over PPI, such as no requirement for acid activation, stability in acidic conditions, shorter optimum acid suppression period, and resistance to cytochrome P (CYP)2C19 polymorphism. Several comparative randomized controlled trials and meta-analyses revealed the superiority of vonoprazan in eradicating H. pylori, notably the resistant strains. The adverse effect caused by vonoprazan is long-term acid suppression that may induce elevated gastrin serum, hypochlorhydria, and malabsorption. All vonoprazan studies have only been conducted in Japan. Further studies outside Japan are necessary for universally conclusive results.

Pharmacologic treatment of GERD: Where we are now, and where are we going?

The introduction of acid inhibition in clinical practice has revolutionized the management of acid-related diseases, leading to the virtual abolition of elective surgery for ulcer disease and relegating antireflux surgery to patients with gastroesophageal reflux disease (GERD) not adequately managed by medical therapy. Proton pump inhibitors (PPIs) are the antisecretory drugs of choice for the treatment of reflux disease. However, these drugs still leave some unmet clinical needs in GERD. PPI-refractoriness is common, and persistent symptoms are observed in up to 40-55% of daily PPI users. Potassium-competitive acid blockers (P-CABs) clearly overcome many of the drawbacks and limitations of PPIs, achieving rapid, potent, and prolonged acid suppression, offering the opportunity to address many of the unmet needs. In recent years, it has been increasingly recognized that impaired mucosal integrity is involved in the pathogenesis of GERD. As a consequence, esophageal mucosal protection has emerged as a new, promising therapeutic avenue. When P-CABS are used as add-on medications to standard treatment, a growing body of evidence suggests a significant additional benefit, especially in the relief of symptoms not responding to PPI therapy. On the contrary, reflux inhibitors are considered a promise unfulfilled, and prokinetic agents should only be used on a case-by-case basis.

Review - Treatment of Helicobacter pylori infection 2020

This review summarizes important studies regarding Helicobacter pylori therapy published from April 2019 to April 2020. The main themes that emerge involve studies assessing antibiotic resistance, and there is also growing momentum behind the utility of vonoprazan as an alternative to proton pump inhibitor (PPI) therapy and also bismuth-based regimens as a first-line regimen. Antibiotic resistance is rising wherever it is being assessed, and clarithromycin resistance in particular has reached a point where it may no longer be a viable therapy without previous testing in many regions of the world. The evidence for the efficacy of a bismuth-based quadruple therapy as a first-line therapy is now very clearly established, and there is substantial evidence that it is the best performing first-line therapy. The utility of vonoprazan as an alternative to PPI therapy, especially in resistant and difficult-to-treat groups, has also been considered in great detail this year, and it may offer an opportunity in the near future to reduce the problem of antibiotic resistance.

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.

Randomised trial of acid inhibition by vonoprazan 10/20 mg once daily vs rabeprazole 10/20 mg twice daily in healthy Japanese volunteers (SAMURAI pH study)

BACKGROUND

Vonoprazan (V), a potassium-competitive acid blocker, has a more durable acid-inhibitory effect as compared with standard-dose proton pump inhibitors (PPIs) but has not been compared with 2-4 times higher daily PPI doses administered in two divided doses.

AIMS

To evaluate the acid-inhibitory effect of V 10/20 mg once-daily (OD; V10/V20) vs rabeprazole (R) 10/20 mg twice-daily (BID; R20/R40) in healthy Japanese volunteers.

METHODS

This multicentre, randomised, open-label, two-period, crossover study compared V10 or V20 vs R20, or V20 vs R40 using three cohorts of 10 healthy Japanese adults. Within each cohort, subjects were randomised to receive V or R for 7 days and, following a washout period ≥7 days, the other treatment for 7 days. On day 6 of each period, 24-hours multichannel gastric impedance-pH monitoring was performed. Percent times pH ≥ 3, ≥4 and ≥5 (pH 3, 4 and 5 holding time ratios [HTRs]) in 24 hours were evaluated as primary pharmacodynamic endpoints.

RESULTS

Acid-inhibitory effect (24-hours pH 3 HTR) of V20 was greater than those of R20 (91.0% vs 65.3%; P = .0049) and R40 (98.5% vs 85.9%; P = .0073). Similar results were obtained for 24-hours pH 4 and 5 HTRs. V20 also achieved greater nocturnal pH 4 (91.5% vs 73.2%; P = .0319) and 5 HTRs (78.8% vs 62.2%; P = .0325) as compared with R40. One subject (20%) developed diarrhoea while receiving R40 which was considered treatment-related.

CONCLUSIONS

Compared with 2-4 times the standard daily dose of R, V20 exerts a more potent and durable acid-inhibitory effect. Trial identifier: UMIN000022198 (www.umin.ac.jp/ctr/index.htm).

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

OBJECTIVE

To establish the non-inferior efficacy of vonoprazan versus lansoprazole in the treatment of Asian patients with erosive oesophagitis (EO).

DESIGN

In this phase III, double-blind, multicentre study, patients with endoscopically confirmed EO were randomised 1:1 to receive vonoprazan 20 mg or lansoprazole 30 mg, once daily for up to 8 weeks. The primary endpoint was EO healing rate at 8 weeks. The secondary endpoints were EO healing rates at 2 and 4 weeks. Safety endpoints included treatment-emergent adverse events (TEAEs).

RESULTS

In the vonoprazan (n=238) and lansoprazole (n=230) arms, 8-week EO healing rates were 92.4% and 91.3%, respectively (difference 1.1% (95% CI -3.822% to 6.087%)). The respective 2-week EO healing rates were 75.0% and 67.8% (difference 7.2% (95% CI -1.054% to 15.371%)), and the respective 4-week EO healing rates were 85.3% and 83.5% (difference 1.8% (95% CI -4.763% to 8.395%)). In patients with baseline Los Angeles classification grade C/D, 2-week, 4-week and 8-week EO healing rates were higher with vonoprazan versus lansoprazole (2 weeks: 62.2% vs 51.5%, difference 10.6% (95% CI -5.708% to 27.002%); 4 weeks: 73.3% vs 67.2%, difference 6.2% (95% CI -8.884 to 21.223); and 8 weeks: 84.0% vs 80.6%, difference 3.4% (95% CI -9.187% to 15.993%)). Overall, EO healing rates appeared higher with vonoprazan versus lansoprazole. TEAE rates were 38.1% and 36.6% in the vonoprazan and lansoprazole group, respectively.

CONCLUSION

Our findings demonstrate the non-inferior efficacy of vonoprazan versus lansoprazole in terms of EO healing rate at 8 weeks in this population. Safety outcomes were similar in the two treatment arms.

TRIAL REGISTRATION NUMBER

NCT02388724.

Proton Pump Inhibitors and Radiofrequency Ablation for Treatment of Barrett's Esophagus

Gastroesophageal Reflux Disease (GERD) is characterized by acid and bile reflux in the distal oesophagus, and this may cause the development of reflux esophagitis and Barrett's oesophagus (BE). The natural histological course of untreated BE is non-dysplastic or benign BE (ND), then lowgrade (LGD) and High-Grade Dysplastic (HGD) BE, with the expected increase in malignancy transfer to oesophagal adenocarcinoma (EAC). The gold standard for BE diagnostics involves high-resolution white-light endoscopy, followed by uniform endoscopy findings description (Prague classification) with biopsy performance according to Seattle protocol. The medical treatment of GERD and BE includes the use of proton pump inhibitors (PPIs) regarding symptoms control. It is noteworthy that long-term use of PPIs increases gastrin level, which can contribute to transfer from BE to EAC, as a result of its effects on the proliferation of BE epithelium. Endoscopy treatment includes a wide range of resection and ablative techniques, such as radio-frequency ablation (RFA), often concomitantly used in everyday endoscopy practice (multimodal therapy). RFA promotes mucosal necrosis of treated oesophagal region via high-frequency energy. Laparoscopic surgery, partial or total fundoplication, is reserved for PPIs and endoscopy indolent patients or in those with progressive disease. This review aims to explain distinct effects of PPIs and RFA modalities, illuminate certain aspects of molecular mechanisms involved, as well as the effects of their concomitant use regarding the treatment of BE and prevention of its transfer to EAC.

The efficacy of vonoprazan for management of post-endoscopic submucosal dissection ulcers compared with proton pump inhibitors: A meta-analysis

OBJECTIVE

Artificial ulcers after endoscopic submucosal dissection (ESD) are usually treated by proton pump inhibitors (PPIs) in clinical setting. Vonoprazan, a newly developed potassium-competitive acid blocker, has recently been used to treat post-ESD ulcers. We aimed to evaluate the efficacy and safety of vonoprazan on the healing of post-ESD artificial ulcers compared with those of proton pump inhibitors (PPIs) using a meta-analysis.

METHODS

EMBASE, MEDLINE, Scopus and Cochrane Library databases were searched for all studies comparing the efficacy and safety of vonoprazan with those of PPIs in the treatment of post-ESD ulcers.

RESULTS

Fourteen articles with 1328 patients were included in this meta-analysis. When comparing ulcer shrinkage rate, vonoprazan showed a better efficacy than PPIs (mean difference 0.56, 95% confidence interval [CI] 0.18-0.93). Vonoprazan also led to a higher scar formation rate (odds ratio [OR] 1.58, 95% CI 1.00-2.47) and showed a potential superiority on reducing the risk of post-ESD bleeding compared with PPIs, with a pooled OR of 0.69, although there was no statistically significant difference.

CONCLUSIONS

Compared with PPIs, vonoprazan showed a better efficacy in ulcer shrinkage rate and achieved more complete healing in the treatment of post-ESD ulcers. Vonoprazan did not induce any incremental risk of post-ESD bleeding as well. It may be an appropriate choice in the management of artificial ulcers after ESD.

HISTORICAL PERSPECTIVE OF GASTROESOPHAGEAL REFLUX DISEASE CLINICAL TREATMENT

BACKGROUND

Gastroesophageal reflux disease (GERD) is one of the most prevalent gastrointestinal diseases. GERD generates significant impairment in patients' quality of life and it is associated to relevant medical resources utilization. A better understanding of GERD pathophysiology in the past five decades has favored the evolution of therapeutic strategies from non-drug interventions and antacids to more efficacious and safer alternatives.

OBJECTIVE

To summarize data about the historical evolution of GERD management in Brazil, focusing on medical therapy and addressing evidence on efficacy and safety of drug classes currently recommended.

METHODS

A narrative review was conducted by systematizing information about discoveries on GERD pathophysiology. We also addressed efficacy and safety of medications currently used to reduce symptoms and improve endoscopic healing of esophageal lesions. A structured search on Pubmed was performed to identify systematic reviews and meta-analysis investigating GERD outcomes positively impacted by proton pump inhibitors (PPIs), the first choice of pharmacotherapy for the disease.

RESULTS

The chronological development of therapeutic measures for GERD in Brazil evolved from lifestyle interventions with relative poor effect on symptoms related to esophageal acid exposure, particularly heartburn, to effective and safe pharmacological interventions such as histamine H2-receptor antagonists and PPIs. In the present days, some drug classes play a minor role in disease management, namely prokinetics and antacids, due to their reduced efficacy and relevant safety concerns (particularly with prokinetics). The main challenge for prescribers and researchers seems to be finding long-acting acid suppressants strategies able to ameliorate patients' symptoms and quality of life, thereafter, reducing medical resource consumption. The dual delayed-release PPI dexlansoprazole seems to respond for some of the limitations other PPIs have.

CONCLUSION

Recognizing the historical evolution of GERD management can help care providers to better understand therapeutic options for their patients, as well as focus on unmet needs that deserve further attention. PPIs are still the first choice therapy, with good evidence in favor of their efficacy, despite some safety concerns. However, as with any medical intervention, it is recommended to prescribe PPIs for patients with clear indication, using adequate dosing and monitoring for adverse events.

Simultaneous quantification of tegoprazan and its major metabolite M1 in dog plasma using liquid chromatography-tandem mass spectrometry

Tegoprazan is a novel potassium-competitive acid blocker (P-CAB) recently approved in Korea as a next-generation therapeutics for gastric acid-related diseases. In the present study, we demonstrate a simple bioanalytical liquid chromatography/tandem mass spectrometry (LC-MS/MS) method for the simultaneous quantification of tegoprazan and its major metabolite (M1) in dog plasma. The developed method is based on protein precipitation and LC-MS/MS, validated according to the regulatory guidance for bioanalytical method validation. The calibration curves were linear in the concentration range of 50 ng/mL-50 μg/mL and 5 ng/mL-5 μg/mL for tegoprazan and M1, respectively. The inter- and intra-day precisions were evaluated with a coefficient of variation of <15%, and the mean accuracy ranged 92.6%-105%. The method exhibited good sensitivity and specificity. The stability of bench-top (for 8 h), freeze-thaw (3 cycles), and processed-samples (for 24 h at 4 °C) was acceptable. Tegoprazan was stable in dog plasma for 6 weeks at -70 °C. In conclusion, we successfully established a method for the simultaneous quantification of tegoprazan and M1 in dog plasma, and the method was validated for specificity, sensitivity, linearity, matrix effects, recovery, accuracy, precision, and stability. Finally, we show that the method was successfully applied to a pharmacokinetic study in dogs.