Is It Time for Noncontinuous Therapy for Gastroesophageal Reflux Disease?

Gastroesophageal reflux disease (GERD) is a chronic disorder characterized by the reflux of gastric contents into the esophagus, leading to symptoms and potential long-term complications such as Barrett esophagus and esophageal adenocarcinoma. Currently, there are various medical, endoscopic, and surgical therapeutic strategies for GERD. However, proton pump inhibitors (PPIs), which effectively suppress acid secretion but require daily administration, remain the mainstay of treatment. Noncontinuous therapy for GERD includes on-demand and different variations of intermittent administration of antireflux medication. Attributes that make an antireflux medication a good candidate for noncontinuous therapy for GERD include potent acid suppression, rapid effect, durability of antisecretory effect, and flexibility of administration. Noncontinuous therapy for GERD is appealing to patients because it is convenient, reduces cost, and alleviates concerns about complications of long-term PPI use. Patients with nonerosive esophageal reflux disease or low-grade erosive esophagitis who have episodic heartburn are probably best suited for such treatment. Although PPIs have been shown to be efficacious as on-demand or intermittent therapy for GERD, their usefulness as on-demand treatment for episodic heartburn has been limited by their slow maximal effect on intragastric acid secretion. In contrast, potassium-competitive acid blockers (P-CABs) demonstrate the pharmacokinetic and pharmacodynamic characteristics that make this class of drugs a good candidate for noncontinuous treatment of GERD. Early studies using P-CABs for noncontinuous treatment of GERD have demonstrated promising results. Future studies are needed to further establish the value of P-CABs for such a therapeutic approach. This article reviews the current evidence on the use of PPIs and P-CABs in noncontinuous therapy for GERD.

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 the patients, especially those 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.

Safety of potassium-competitive acid blockers in the treatment of gastroesophageal reflux disease.

INTRODUCTION: Proton pump inhibitors (PPIs) are the first-line treatment for gastroesophageal reflux disease (GERD). However, due to their intrinsic limitations, there are still unmet clinical needs that have fostered the development of potassium-competitive acid blockers (P-CABs). Currently, four different drugs (vonoprazan, tegoprazan, fexuprazan, and keverprazan) are marketed in some Asian countries, whereas only vonoprazan and tegoprazan are available in Western countries (USA and Brazil or Mexico, respectively). AREAS COVERED: This review summarizes the current knowledge on P-CABs acute and long-term safety in GERD treatment compared to that of PPIs. Full-text articles and abstracts were searched in PubMed. EXPERT OPINION: P-CABs proved to address some of the unmet clinical needs in GERD, with a favorable risk-benefit ratio compared to conventional PPIs. Preclinical and clinical findings have highlighted P-CAB safety to be superimposable, to that of PPIs, in short-term treatments, although further studies are warranted to monitor their effects in long-term therapy. From an epidemiological point of view, the paucity of rigorous data for many variables (e.g. age, ethnicity, drug interactions, comorbidities, genetic polymorphisms, interindividual susceptibility, and gut dysbiosis) deserves a worldwide framework of continuous pre/post-marketing pharmacovigilance programs to reduce potential confounding factors and accurately link acute and chronic P-CAB therapy to adverse outcomes.

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).

A review and network meta-analysis of different medications for treating erosive esophagitis: potassium-competitive acid blockers and proton-pump inhibitors Why was the study done? Proton-pump inhibitors (PPIs) and potassium-competitive acid blockers (P-CABs) are commonly used to treat Erosive esophagitis (EE) due to their good safety and tolerance. This study aimed to compare the effectiveness of P-CABs and PPIs in healing EE patients. We wanted to determine the best treatment choice in terms of the duration of treatment (4 or 8 weeks) and the dosage (standard or double-dose). What did the researchers do? The researchers searched relevant databases for randomized controlled trials that studied the use of PPIs and P-CABs in treating EE up until May 31, 2023. They included studies that evaluated the healing effects of standard or double-dose PPIs or P-CABs over a period of 4 or 8 weeks. A network meta-analysis was performed to compare the effectiveness of these treatments. They also conducted sensitivity analysis and subgroup analysis to examine the effects on patients with different levels of EE. What did the researchers find? The results showed that the healing rate after 4 weeks of treatment was significantly lower than the healing rate after 8 weeks for most treatments. Additionally, the higher healing rate observed with double-dose treatment compared to standard-dose treatment was not seen in the initial treatment of most drugs. In the main analysis, which included studies with patients both with and without severe EE at the beginning, Keverprazan 20mg qd was ranked as the most effective treatment with a healing rate of 84.7, followed by Ilaprazole 10mg qd with a healing rate of 82.0 at 8 weeks. The results were robust in sensitivity analysis. Subgroup analysis showed that most P-CABs had higher healing rates than PPIs, especially for patients with severe EE. What do the findings mean? Treating EE patients for 8 weeks was more effective than treating them for 4 weeks. Keverprazan (20mg once a day) with the 8-week treatment is the optimal method.

Treatment of Helicobacter pylori with potassium competitive acid blockers: A systematic review and meta-analysis.

BACKGROUND: Helicobacter pylori (H. pylori) infects over half the global population, causing gastrointestinal diseases like dyspepsia, gastritis, duodenitis, peptic ulcers, G-MALT lymphoma, and gastric adenocarcinoma. Eradicating H. pylori is crucial for treating and preventing these conditions. While conventional proton pump inhibitor (PPI)-based triple therapy is effective, there's growing interest in longer acid suppression therapies. Potassium competitive acid blocker (P-CAB) triple and dual therapy are new regimens for H. pylori eradication. Initially used in Asian populations, vonoprazan (VPZ) has been recently Food and Drug Administration-approved for H. pylori eradication. AIM: To assess the efficacy of regimens containing P-CABs in eradicating H. pylori infection. METHODS: This study, following PRISMA 2020 guidelines, conducted a systematic review and meta-analysis by searching MEDLINE and Scopus libraries for randomized clinical trials (RCTs) or observational studies with the following command: [("Helicobacter pylori" OR "H pylori") AND ("Treatment" OR "Therapy" OR "Eradication") AND ("Vonaprazan" OR "Potassium-Competitive Acid Blocker" OR "P-CAB" OR "PCAB" OR "Revaprazan" OR "Linaprazan" OR "Soraprazan" OR "Tegoprazan")]. Studies comparing the efficacy of P-CABs-based treatment to classical PPIs in eradicating H. pylori were included. Exclusion criteria included case reports, case series, unpublished trials, or conference abstracts. Data variables encompassed age, diagnosis method, sample sizes, study duration, intervention and control, and H. pylori eradication method were gathered by two independent reviewers. Meta-analysis was performed in R software, and forest plots were generated. RESULTS: A total of 256 references were initially retrieved through the search command. Ultimately, fifteen studies (7 RCTs, 7 retrospective observational studies, and 1 comparative unique study) were included, comparing P-CAB triple therapy to PPI triple therapy. The intention-to-treat analysis involved 8049 patients, with 4471 in the P-CAB intervention group and 3578 in the PPI control group across these studies. The analysis revealed a significant difference in H. pylori eradication between VPZ triple therapy and PPI triple therapy in both RCTs and observational studies [risk ratio (RR) = 1.17, 95% confidence interval (CI): 1.11-1.22, P < 0.0001] and (RR = 1.13, 95%CI: 1.09-1.17, P < 0.0001], respectively. However, no significant difference was found between tegoprazan (TPZ) triple therapy and PPI triple therapy in both RCTs and observational studies (RR = 1.04, 95%CI: 0.93-1.16, P = 0.5) and (RR = 1.03, 95%CI: 0.97-1.10, P = 0.3), respectively. CONCLUSION: VPZ-based triple therapy outperformed conventional PPI-based triple therapy in eradicating H. pylori, positioning it as a highly effective first-line regimen. Additionally, TPZ-based triple therapy was non-inferior to classical PPI triple therapy.

Pharmacologic Management of Eosinophilic Esophagitis.

Proton pump inhibitors (PPIs), swallowed topical corticosteroids (STSs), and dupilumab are highly effective therapies for the treatment of eosinophilic esophagitis. Shared decision-making informs the choice of therapy and factors such as ease of use, safety, cost, and efficacy should be addressed. PPIs are the most common medication utilized early in the disease course; however, for nonresponders, STSs are an excellent alternative. Dupilumab is unlikely to replace PPIs or STSs as first-line therapy, except in highly specific circumstances. Identification of novel biologic pathways and the development of small molecules may lead to a wider range of treatment options in the future.

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.

Potential drug interactions between pazopanib and proton pump inhibitors/potassium-competitive acid blockers in patients with soft tissue sarcoma.

Because absorption of the oral drug pazopanib depends on gastric pH, concomitant use of proton pump inhibitors (PPIs)/potassium-competitive acid blockers (P-CABs) may inhibit pazopanib absorption by elevating the gastric pH. This study investigated to what extent the concomitant use of PPIs/P-CABs affects treatment with pazopanib in patients with soft tissue sarcoma. We retrospectively reviewed the medical records of patients with soft tissue sarcoma who had received at least one dose of pazopanib at our institution, among which those who had received concomitant PPIs/P-CABs were included in this analysis. Using paired sample t tests, the frequency of dose reduction or interruption of pazopanib and the major adverse events (AEs) were compared in each patient between periods with and without PPIs/P-CABs. Between January 2018 and December 2022, eight patients were eligible. The median time to treatment failure (TTF) was 3.9 months (2.1-38.2 months). Two patients received concomitant PPIs/P-CABs throughout their treatment with pazopanib. Among the other six patients, dose reduction or interruption of pazopanib occurred less frequently (P = 0.021), and neutropenia tended to be milder (P = 0.155) with the concomitant use of PPIs/P-CABs. Although the concomitant use of PPIs/P-CABs had no apparent effect on TTF in patients undergoing pazopanib treatment, dose reduction or interruption of pazopanib occurred less frequently, and neutropenia was milder, suggesting that concomitant use of PPIs/P-CABs might decrease the pharmacological activity of pazopanib. Supplementary Information: The online version contains supplementary material available at 10.1007/s13691-023-00638-2.

Background factors of idiopathic peptic ulcers and optimal treatment methods: a multicenter retrospective Japanese study.

This study investigated the trends in idiopathic peptic ulcers, examined the characteristics of refractory idiopathic peptic ulcer, and identified the optimal treatment. The characteristics of 309 patients with idiopathic peptic ulcer were examined. We allocated idiopathic peptic ulcers that did not heal after 8 weeks' treatment (6 weeks for duodenal ulcers) to the refractory group and those that healed within this period to the healed group. The typical risk factors for idiopathic peptic ulcer (atherosclerosis-related underlying disease or liver cirrhosis complications) were absent in 46.6% of patients. Absence of gastric mucosal atrophy (refractory group: 51.4%, healed group: 28.4%; p = 0.016), and gastric fundic gland polyps (refractory group: 17.6%, healed group: 5.9%; p = 0.045) were significantly more common in the refractory group compared to the healed group. A history of H. pylori eradication (refractory group: 85.3%, healed group: 66.0%; p = 0.016), previous H. pylori infection (i.e., gastric mucosal atrophy or history of H. pylori eradication) (refractory group: 48.5%, healed group: 80.0%; p = 0.001), and potassium-competitive acid blocker treatment (refractory group: 28.6%, healed group, 64.1%; p = 0.001) were significantly more frequent in the healed group compared to the refractory group. Thus, acid hypersecretion may be a major factor underlying the refractoriness of idiopathic peptic ulcer.

Acid-suppressive drugs: A systematic review and network meta-analysis of their nocturnal acid-inhibitory effect.

BACKGROUND AND AIMS: Acid-suppressive drugs (ASDs) are widely used in many gastric acid-associated diseases. Nocturnal acid breakthrough has been a common problem of many ASDs, such as proton-pump inhibitors (PPIs) and H2 -receptor antagonists (H2RAs). Potassium-competitive acid blockers (P-CABs) are expected to solve this continuing conundrum. This article examined major ASDs and compared them with placebo in terms of nocturnal acid-inhibitory effects, using a network meta-analysis of randomized controlled trials (RCTs). METHODS: To compare the effectiveness of major ASDs, a Bayesian network meta-analysis (NMA) was applied to process data extracted from RCTs. The plausible ranking for each regimen and some subgroups were assessed by surface under the cumulative ranking curves (SUCRA). RESULTS: Fifty-five RCTs were conducted with 2015 participants. In terms of nocturnal acid-inhibitory effects, the overall results showed that tegoprazan (SUCRA 91.8%) and vonoprazan (SUCRA 91.0%) had the best performance, followed by new PPIs (including tenatoprazole and ilaprazole) (SUCRA 76.6%), additional H2RAs once at bedtime (AHB) (SUCRA 61.3%), isomer PPIs (including esomeprazole and dexlansoprazole) (SUCRA 38.6%), revaprazan (SUCRA 34.7%), traditional PPIs (including omeprazole, rabeprazole, pantoprazole, lansoprazole) (SUCRA 32.6%), H2RAs (SUCRA 23.1%), and placebo (SUCRA 0.3%). In some subgroups, the nocturnal acid-inhibitory effect of vonoprazan or tegoprazan was better than most of the other regimens, even new PPIs and AHB. CONCLUSIONS: This is the first study to compare the effect of ASDs on inhibiting nocturnal acid breakthrough. Overall, in terms of nocturnal acid-inhibitory effect, vonoprazan and tegoprazan had an advantage against other regimens including H2RAs, isomer PPIs, traditional PPIs, AHB, and new PPIs. Even in some subgroups, such as language classification (English), types of study design (crossover-RCT), age (≤40 years), BMI (18.5-24.9 kg/m2 ), continent (Asia and North America), disease status (health), the duration of therapy (2 weeks), and time of administration (at daytime or at night-time), the nocturnal acid-inhibitory effect of vonoprazan or tegoprazan were better than most regimens, even AHB and new PPIs.

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.

Efficacy comparison of 7- and 14-day P-CAB based bismuth-containing quadruple regimen with PPI based bismuth-containing quadruple regimen for Helicobacter pylori infection: rationale and design of an open-label, multicenter, randomized controlled trial.

BACKGROUND: Owing to its strong acid inhibition, potassium-competitive acid blocker (P-CAB) based regimens for Helicobacter pylori (H. pylori) eradication are expected to offer clinical advantages over proton pump inhibitor (PPI) based regimens. This study aims to compare the efficacy and adverse effects of a 7-day and a 14-day P-CAB-based bismuth-containing quadruple regimen (PC-BMT) with those of a 14-day PPI-based bismuth-containing quadruple regimen (P-BMT) in patients with high clarithromycin resistance. METHODS: This randomized multicenter controlled clinical trial will be performed at five teaching hospitals in Korea. Patients with H. pylori infection who are naive to treatment will be randomized into one of three regimens: 7-day or 14-day PC-BMT (tegoprazan 50 mg BID, bismuth subcitrate 300 mg QID, metronidazole 500 mg TID, and tetracycline 500 mg QID) or 14-day P-BMT. The eradication rate, treatment-related adverse events, and drug compliance will be evaluated and compared among the three groups. Antibiotic resistance testing by culture will be conducted during the trial, and these data will be used to interpret the results. A total of 366 patients will be randomized to receive 7-day PC-BMT (n = 122), 14-day PC-BMT (n = 122), or 14-day P-BMT (n = 122). The H. pylori eradication rates in the PC-BMT and P-BMT groups will be compared using intention-to-treat and per-protocol analyses. DISCUSSION: This study will demonstrate that the 7-day or 14-day PC-BMT is well tolerated and achieve similar eradication rates to those of 14-day P-BMT. Additionally, the 7-day PC-BMT will show fewer treatment-related adverse effects and higher drug compliance, owing to its reduced treatment duration. TRIAL REGISTRATION: Korean Clinical Research Information Service registry, KCT0007444. Registered on 28 June 2022, https://cris.nih.go.kr/cris/index/index.do .

Gastric development of pancreatic acinar cell metaplasia after Vonoprazan therapy in rats.

BACKGROUND: Vonoprazan is a new acid-suppressing drug that received FDA approval in 2022. It reversibly inhibits gastric acid secretion by competing with the potassium ions on the luminal surface of the parietal cells (potassium-competitive acid blockers or P-CABs). Vonoprazan has been on the market for a short time and there are many clinical trials to support its clinical application. However, medical experience and comprehensive clinical data is still limited, especially on how and if, gastric histology is altered due to therapy. METHODS: A 12-week experiment trial with 30 Wistar rats was to assess the presence of gastrointestinal morphologic abnormalities upon administration of omeprazole and vonoprazan. At six weeks of age, rats were randomly assigned to one of 5 groups: (1) saline as negative control group, (2) oral omeprazole (40 mg/kg), as positive control group, (3) oral omeprazole (40 mg/kg) for 4 weeks, proceeded by 8 weeks off omeprazole, (4) oral vonoprazan (4 mg/kg), as positive control group, and (5) oral vonoprazan (4 mg/kg) for 4 weeks, proceeded by 8 weeks off vonoprazan. RESULTS: We identified non-inflammatory alterations characterized by parietal (oxyntic) cell loss and chief (zymogen) cell hyperplasia and replacement by pancreatic acinar cell metaplasia (PACM). No significant abnormalities were identified in any other tissues in the hepatobiliary and gastrointestinal tracts. CONCLUSION: PACM has been reported in gastric mucosa, at the esophagogastric junction, at the distal esophagus, and in Barrett esophagus. However, the pathogenesis of this entity is still unclear. Whereas some authors have suggested that PACM is an acquired process others have raised the possibility of PACM being congenital in nature. Our results suggest that the duration of vonoprazan administration at a dose of 4 mg/kg plays an important role in the development of PACM.

Review of the clinical development of fexuprazan for gastroesophageal reflux-related disease.

Proton pump inhibitors (PPIs) are a mainstay treatment for acid peptic disorders such as gastroesophageal reflux disease (GERD). Although PPIs are considered first-line medications for acid suppression, they have notable limitations such as requiring acid-mediated activation, short half-life and duration of action, and metabolic variability. Fexuprazan is a newly developed potassium-competitive acid blocker (P-CAB), which inhibits acid generation and secretion in a competitive and reversible manner. Fexuprazan, like other P-CABs, has significantly different pharmacodynamic and pharmacokinetic properties than PPIs with potential advantages including rapid, robust, and durable acid suppression, lack of CYP2C19 metabolism, independence from food intake, and no requirement for activation into an active form. Completed clinical trials of fexuprazan have demonstrated comparable efficacy to PPIs for the healing of erosive esophagitis and relief of GERD-related esophageal symptoms without concerning safety signals. Ongoing clinical trials are evaluating fexuprazan for the prevention of NSAID-induced peptic ulcer disease, non-erosive GERD, and acute and chronic gastritis, as well as healing efficacy and maintenance of erosive esophagitis (EE). Fexuprazan is approved in South Korea for the treatment of EE and at the time of this writing is being considered for regulatory approval in several other countries. In this article, we summarize and discuss the pharmacology, efficacy, and safety of fexuprazan.

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.

Newer, Older, and Alternative Agents for the Eradication of Helicobacter pylori Infection: A Narrative Review.

Although discovered 40 years ago, Helicobacter pylori infection is still raising diagnostic and therapeutic problems today. The infection is currently managed based on statements in several guidelines, but implementing them in practice is a long process. Increasing antibiotic resistance and weak compliance of the patients limit the efficacy of eradication regimens, leaving much room for improvement. Third-generation proton pump inhibitors have added little to the results of the first two generations. Potassium-competitive acid blockers have a stronger and longer inhibitory action of acid secretion, increasing the intragastric pH. They obtained superior results in eradication when compared to proton pump inhibitors. Instead of innovative antibiotics, derivatives of existing antimicrobials were developed; some new fluoroquinolones and nitazoxanide seem promising in practice, but they are not recommended by the guidelines. Carbonic anhydrase inhibitors have both anti-secretory and bactericidal effects, and some researchers are expecting their revival in the treatment of infection. Capsules containing components of the eradication regimens have obtained excellent results, but are of limited availability. Probiotics, if containing bacteria with anti-Helicobacter pylori activity, may be useful, increasing the rates of eradication and lowering the prevalence and severity of the side effects.

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.

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.

Efficacy and Tolerability of 14-Day Tegoprazan- versus Rabeprazole-Based Triple Therapy for Eradication of Helicobacter pylori: A Real-World Evidence Study.

Background/Aims: Tegoprazan, a new, fast, and strong potassium-competitive acid blocker, has been approved for the treatment of gastric acid-related diseases in Korea. However, real-world clinical data regarding this drug are scarce. We aimed to compare the Helicobacter pylori eradication rates of tegoprazan- and rabeprazole-based triple therapy. Methods: We retrospectively reviewed data from patients who received first-line treatment for H. pylori infection using tegoprazan- or rabeprazole-based triple therapy for 2 weeks (50 mg tegoprazan or 20 mg rabeprazole+1,000 mg amoxicillin+500 mg clarithromycin twice daily). The primary endpoint was the eradication rate as determined by intention-to-treat analysis. Results: Of the 677 patients included in our study, 344 and 333 received tegoprazan-based and rabeprazole-based triple therapy, respectively. The eradication rate from intention-to-treat analysis was 76.7% (95% confidence interval [CI], 72.1% to 81.0%) for tegoprazan-based triple therapy and 75.4% (95% CI, 70.5% to 79.8%) for rabeprazole-based triple therapy. There was no significant difference in the eradication rates between the two groups (p>0.999). Per-protocol analysis also revealed no significant difference between the eradication rates of the two groups (tegoprazan 83.4% [95% CI, 79.0% to 87.2%] vs rabeprazole 83.5% [79.0% to 87.4%], p>0.999). Furthermore, there was no significant difference in adverse event rates between the two groups (tegoprazan, 27.6%; rabeprazole, 25.8%; p=0.604). Conclusions: The eradication rate of tegoprazan-based triple therapy was similar to that of rabeprazole-based triple therapy. Further studies on the dose-escalation effect of tegoprazan for H. pylori eradication and the efficacy of tegoprazan in regimens other than conventional triple therapy are needed.

Hypercontractile esophagus responsive to potassium-competitive acid blockers: a case report.

BACKGROUND: Hypercontractile esophagus is a rare hypercontractile esophageal motility disorder. The etiology of hypercontractile esophagus is unknown but an association between acid reflux and hypercontractile esophagus has been suggested. We present the first report on the use of potassium-competitive acid blockers in the treatment of hypercontractile esophagus. CASE PRESENTATION: A 43-year-old man presented with dysphagia, chest pain and regurgitation for a period of 1 year. Initial workup showed a twisted lumen with abnormal contractions in the distal esophagus during upper gastrointestinal endoscopy and abnormal acid exposure under 24-h esophageal pH monitoring. The use of standard-dose proton pump inhibitors didn't relieve his symptoms. Subsequent high-resolution esophageal manometry made a diagnosis of hypercontractile esophagus. Treatment with vonoprazan resulted in symptomatic resolution and abnormal contractions were no longer detected on follow-up high-resolution manometry. CONCLUSIONS: Potassium-competitive acid blockers like vonoprazan offer an alternative therapeutic method for patients with hypercontractile esophagus who are refractory to proton pump inhibitor therapy. The use of potassium-competitive acid blockers in hypercontractile esophagus warrants further research and may provide evidence for an acid-related etiology of hypercontractile esophagus.