Potassium-competitive acid blockade: a new therapeutic strategy in acid-related diseases

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.

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).

In Vitro Metabolism and Transport Characteristics of Zastaprazan

Zastaprazan (JP-1366), a novel potassium-competitive acid blocker, is a new drug for the treatment of erosive esophagitis. JP-1366 is highly metabolized in human, mouse, and dog hepatocytes but moderately metabolized in rat and monkey hepatocytes when estimated from the metabolic stability of this compound in hepatocyte suspension and when 18 phase I metabolites and 5 phase II metabolites [i.e., N-dearylation (M6), hydroxylation (M1, M19, M21), dihydroxylation (M7, M8, M14, M22), trihydroxylation (M13, M18), hydroxylation and reduction (M20), dihydroxylation and reduction (M9, M16), hydrolysis (M23), hydroxylation and glucuronidation (M11, M15), hydroxylation and sulfation (M17), dihydroxylation and sulfation (M10, M12), N-dearylation and hydroxylation (M3, M4), N-dearylation and dihydroxylation (M5), and N-dearylation and trihydroxylation (M2)] were identified from JP-1366 incubation with the hepatocytes from humans, mice, rats, dogs, and monkeys. Based on the cytochrome P450 (CYP) screening test and immune-inhibition analysis with CYP antibodies, CYP3A4 and CYP3A5 played major roles in the metabolism of JP-1366 to M1, M3, M4, M6, M8, M9, M13, M14, M16, M18, M19, M21, and M22. CYP1A2, 2C8, 2C9, 2C19, and 2D6 played minor roles in the metabolism of JP-1366. UDP-glucuronosyltransferase (UGT) 2B7 and UGT2B17 were responsible for the glucuronidation of M1 to M15. However, JP-1366 and active metabolite M1 were not substrates for drug transporters such as organic cation transporter (OCT) 1/2, organic anion transporter (OAT) 1/3, organic anion transporting polypeptide (OATP)1B1/1B3, multidrug and toxic compound extrusion (MATE)1/2K, P-glycoprotein (P-gp), and breast cancer-resistant protein (BCRP). Only M1 showed substrate specificity for P-gp. The findings indicated that drug-metabolizing enzymes, particularly CYP3A4/3A5, may have a significant role in determining the pharmacokinetics of zastaprazan while drug transporters may only have a small impact on the absorption, distribution, and excretion of this compound.

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.

Rebound Acid Hypersecretion after Withdrawal of Long-Term Proton Pump Inhibitor (PPI) Treatment-Are PPIs Addictive?

Proton pump inhibitors (PPIs) are widely used in the long-term treatment of gastroesophageal reflux disease (GERD) and other upper gastrointestinal disorders, such as the healing of peptic ulcers and/or prophylactic treatment of peptic ulcers. PPIs are also widely used as symptomatic treatment in patients with functional dyspepsia. One of the adverse effects of the long-term use of PPI is rebound acid hypersecretion (RAHS), which can occur after the withdrawal of PPI therapy due to a compensatory increase in gastric acid production. Mechanisms of the RAHS have been well established. Studies have shown that pentagastrin-stimulated acid secretion after the discontinuation of PPIs increased significantly compared to that before treatment. In healthy volunteers treated with PPIs, the latter induced gastrointestinal symptoms in 40-50% of subjects after the discontinuation of PPI therapy but after stopping the placebo. It is important for practicing physicians to be aware and understand the underlying mechanisms and inform patients about potential RAHS before discontinuing PPIs in order to avoid continuing unnecessary PPI therapy. This is important because RAHS may lead patients to reuptake PPIs as symptoms are incorrectly thought to originate from the recurrence of underlying conditions, such as GERD. Mechanisms of RAHS have been well established; however, clinical implications and the risk factors for RAHS are not fully understood. Further research is needed to facilitate appropriate management of RAHS in the future.

Case Report: The importance of early intervention for gastroesophageal reflex disease caused by hiatal hernia

Background

Gastroesophageal reflux (GER) disease (GERD) is a condition wherein GER causes troublesome symptoms that can affect daily functioning and/or clinical complications within the esophagus or other systems. To avoid this, patients with GERD often require treatment; hence, it is important to distinguish GER from GERD. Patients with GERD exhibiting alarm signs should be examined early to differentiate it from GER and treated accordingly. Herein, we present a case of GERD caused by a hiatal hernia that required surgical intervention for esophagial cicatrical stenosis despite oral treatment. We also discussed how to choose the appropriate acid suppressants for GERD.

Case presentation

A 1-year-old boy was referred to our hospital for repeated vomiting and poor weight gain. He received histamine 2 receptor antagonists (H2RAs) that contributed slightly to the decreased frequency of vomiting and aided weight gain; however, he soon stopped gaining weight and had bloody vomit. His upper gastrointestinal series revealed hiatal hernia, a 24 h impedance pH monitoring test indicated abnormal values for acid reflux, and esophagogastroduodenoscopy (EGD) revealed esophagitis. He was subsequently diagnosed with GERD associated with hiatal hernia. A proton pump inhibitor (PPI) was intravenously administered to him, following which his medication was changed to a potassium-competitive acid blocker (P-CAB). Thereafter, his vomiting episodes significantly decreased and his weight increased. However, 6 months after starting P-CAB, his vomiting episodes suddenly increased in frequency. EGD revealed the presence esophageal stricture due to scarring from GERD. He was then treated via laparoscopic fundoplication, gastrostomy, and esophageal balloon dilation. Thereafter, his vomiting episodes stopped and food intake improved, leading to weight gain.

Conclusion

It is essential to identify the cause of GERD early and take an appropriate treatment approach depending on the cause of GERD with alarm signs. Further, as a drug therapy for GERD as a clear acid mediated disease or in children with alarm signs, PPIs or P-CAB should be used from the beginning instead of H2RAs.

A case of cough syncope diagnosed by the Valsalva maneuver and cough induction test under invasive arterial pressure measurement

Following the loss of consciousness during the Valsalva maneuver and cough induction test, real-time arterial pressure measurement could clarify the significant blood pressure decrease in a patient with cough syncope.

Comparison of vonoprazan and proton pump inhibitors for the treatment of gastric endoscopic submucosal dissection-induced ulcer: an updated systematic review and meta-analysis

BACKGROUND

Both vonoprazan and proton pump inhibitors (PPIs) are currently used to treat artificial ulcers after gastric endoscopic submucosal dissection. However, evidence-based medicine proving the efficacy of vonoprazan is still lacking. Therefore, this meta-analysis aimed to compare the efficacy of vonoprazan and PPIs for the treatment of artificial ulcers after gastric endoscopic submucosal dissection.

METHODS

The PubMed, EMBASE and Cochrane Library databases were searched up to September 2023 for related randomized controlled trials (RCTs). RCTs that compared the efficacy of vonoprazan and PPIs in treating artificial gastric ulcers after gastric endoscopic submucosal dissection were included. Two independent reviewers screened the included studies, extracted the data and assessed the risk of bias. The following outcomes were extracted for comparison: ulcer healing rate, ulcer shrinkage rate, delayed postoperative bleeding rate, and ulcer perforation rate.

RESULTS

Nine randomized controlled trials involving 926 patients were included. The pooled results showed that vonoprazan had a significantly lower rate of delayed postoperative bleeding than did PPIs (RR = 0.46; 95% CI = 0.23-0.91; P = 0.03). No significant differences were found in terms of ulcer healing, shrinkage rates, or ulcer perforation rates between vonoprazan and PPIs.

CONCLUSIONS

Compared with PPIs, vonoprazan is superior at reducing delayed postoperative bleeding after endoscopic submucosal dissection. However, further studies are needed to prove the efficacy of vonoprazan.

SYSTEMATIC REVIEW REGISTRATION

Identifier CRD42024509227.

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.

Anti-Inflammatory Effects of Tegoprazan in Lipopolysaccharide-Stimulated Bone-Marrow-Derived Macrophages

The purpose of this study was to investigate the anti-inflammatory effect of tegoprazan (TEGO) in lipopolysaccharide (LPS)-stimulated bone-marrow-derived macrophages (BMMs). To this end, compared to methylprednisolone (MP; positive control), we evaluated whether TEGO effectively differentiates LPS-stimulated BMMs into M2-phenotype macrophages. Moreover, the expression of pro- and anti-inflammatory cytokines genes influenced by TEGO was measured using quantitative real-time polymerase chain reaction (qRT-PCR) analysis. TEGO was found to reduce nitric oxide (NO) production in BMMs significantly. In addition, TEGO significantly decreased and increased the gene expression levels of pro-inflammatory and anti-inflammatory cytokines, respectively. In addition, we evaluated the phosphorylated values of the extracellular signal-regulatory kinase (ERK) and p38 in the mitogen-activated protein (MAP) kinase signaling pathway through Western blotting. TEGO significantly reduced the phosphorylated values of the ERK and p38. In other words, TEGO suppressed the various pro-inflammatory responses in LPS-induced BMMs. These results show that TEGO has the potential to be used as an anti-inflammatory agent.

Pharmacokinetic and pharmacodynamic exploration of various combinations of tegoprazan immediate and delayed-release formulations

AIMS

The new modified-release formulation of tegoprazan, a novel potassium-competitive acid blocker, is expected to improve the management of acid-related disease, including nocturnal acid breakthrough, by prolonging the duration of acid suppression. This study aimed to explore the pharmacokinetics (PK) and pharmacodynamics (PD) of various combinations of tegoprazan with immediate-release (IR) and delayed-release (DR) formulations.

METHODS

A three-cohort, open-label, randomized, single-dose, three-treatment, six-sequence, three-period crossover study was conducted. Various combinations of tegoprazan IR and DR formulations (50, 75 or 100 mg) were administered orally once per period. The 24-h intragastric pH was monitored before and after each administration. PK blood samples were collected for up to 48 h. PK and PD were compared among treatments.

RESULTS

Eighteen healthy Korean subjects completed the study. All treatment groups showed intragastric pH above 4 approximately 1 h following tegoprazan administration. Among the various combinations, the IR and DR combination at a 1:1 ratio induced greater gastric acid suppression (%Time pH ≥ 4) than IR alone in each dose group, both for 24 h (50 mg; 59% vs. 52%, P = .2188, 95% confidence interval [CI] -6.92-22.27, 100 mg; 85% vs. 70%, P < .05, 95% CI 8.92-22.19) and at night (50 mg; 27% vs. 16%, P = .1563, 95% CI -11.79-37.71, 100 mg; 77% vs. 49%, P < .05, 95% CI 16.14-42.98), with similar systemic exposure.

CONCLUSIONS

The combinatorial tegoprazan in the IR and DR 1:1 ratio formulation was found to induce stronger gastric acid suppression throughout the day and at night, compared to the conventional IR formulation.

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.

Randomised clinical trial: Safety, tolerability, pharmacodynamics and pharmacokinetics of zastaprazan (JP-1366), a novel potassium-competitive acid blocker, in healthy subjects

BACKGROUND

Zastaprazan (JP-1366) is a novel potassium-competitive acid blocker with favourable preclinical safety and efficacy profile being developed for the treatment of acid-related diseases.

AIMS

To investigate the safety, tolerability, pharmacodynamics and pharmacokinetics of zastaprazan.

METHODS

A randomised, open-label, placebo- and active-controlled, single and multiple ascending dose clinical trial was conducted in healthy Korean male subjects. Intragatric pH and serum gastrin were measured to assess the pharmacodynamics, while serial blood and urine samples were collected to assess the pharmacokinetics. Pharmacogenomic evaluation was conducted to explore genetic variants, which can affect the pharmacodynamics and pharmacokinetics. Safety and tolerability including hepatotoxicity were evaluated.

RESULTS

Suppression of gastric acid secretion increased as the dose of zastaprazan increased. The percentage of time that gastric pH was over 4 (%Time pH >4) with zastaprazan 20 mg (85.19%) and 40 mg (91.84%) were similar to or greater than that with esomeprazole 40 mg (72.06%). Zastaprazan was rapidly absorbed within 2 h and eliminated with a half-life of 6-10 h. Pharmacogenomic analysis found no genetic variant of drug metabolising enzymes including CYP2C19 or drug transporters associated with the exposure of zastaprazan. Zastaprazan was well tolerated with no clinically significant changes in safety and tolerability assessments.

CONCLUSIONS

Zastaprazan was safe and well tolerated after a single oral dose up to 60 mg and multiple oral doses up to 40 mg. It also showed rapid, potent suppression of gastric acid secretion. Pharmacodynamic and pharmacokinetic profile of zastaprazan was suitable for treatment of patients with acid-related diseases.

Efficacy and safety of vonoprazan-based regimen for Helicobacter pylori eradication therapy in Japanese adolescents: a prospective multicenter study

BACKGROUND

Vonoprazan (VPZ)-based regimen for Helicobacter pylori (H. pylori) is safe and more efficacious than the proton pump inhibitor-based regimen mainly in adults. This study aimed to evaluate the efficacy and safety of a VPZ-based regimen for H. pylori eradication therapy in adolescents.

METHODS

An H. pylori screening and treatment longitudinal project for third-year junior high school students in Saga Prefecture began in 2016. Students who tested positive for both urine and stool tests received a VPZ-based regimen. On the checklist, students were asked for diarrhea, fever, abdominal pain, nausea, vomiting, urticaria, dysgeusia, or bloody stool occurrence during the therapy.

RESULTS

The longitudinal project for H. pylori screening and treatment among third-grade students in Saga Prefecture targeted 41,115 students from 2017 to 2021 and 836 as positive. Of the 645 students, 542 (84.0% in per protocol [PP] analysis and 73.6% in intention-to-treat [ITT] analysis) were successful in primary eradication therapy. The secondary eradication therapy was successful in 79 (96.3% in PP analysis and 76.7% in ITT analysis) of 82 students. In the primary eradication therapy, abdominal pain occurred in 164 (27.9%), diarrhea in 217 (36.9%), nausea or vomiting in 7 (1.2%), and urticaria in 13 (2.2%) students. In the secondary eradication therapy, abdominal pain occurred in 12 (19.4%) and diarrhea in 17 (27.4%) students. The eradication therapy of 5 students was interrupted due to adverse events only by primary eradication therapy.

CONCLUSIONS

VPZ-based regimen for H. pylori was efficacious and safe for adolescents, as in adults, for both primary and secondary eradication therapies.

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.

Distribution- and Metabolism-Based Drug Discovery: A Potassium-Competitive Acid Blocker as a Proof of Concept

Conventional methods of drug design require compromise in the form of side effects to achieve sufficient efficacy because targeting drugs to specific organs remains challenging. Thus, new strategies to design organ-specific drugs that induce little toxicity are needed. Based on characteristic tissue niche-mediated drug distribution (TNMDD) and patterns of drug metabolism into specific intermediates, we propose a strategy of distribution- and metabolism-based drug design (DMBDD); through a physicochemical property-driven distribution optimization cooperated with a well-designed metabolism pathway, SH-337, a candidate potassium-competitive acid blocker (P-CAB), was designed. SH-337 showed specific distribution in the stomach in the long term and was rapidly cleared from the systemic compartment. Therefore, SH-337 exerted a comparable pharmacological effect but a 3.3-fold higher no observed adverse effect level (NOAEL) compared with FDA-approved vonoprazan. This study contributes a proof-of-concept demonstration of DMBDD and provides a new perspective for the development of highly efficient, organ-specific drugs with low toxicity.

Integration of a Physiologically Based Pharmacokinetic and Pharmacodynamic Model for Tegoprazan and Its Metabolite: Application for Predicting Food Effect and Intragastric pH Alterations

A physiologically based pharmacokinetic/pharmacodynamic (PBPK/PD) model for tegoprazan and its major metabolite M1 was developed to predict PK and PD profiles under various scenarios. The PBPK model for tegoprazan and M1 was developed and predicted using the SimCYP^® simulator and verified using clinical study data obtained after a single administration of tegoprazan. The established PBPK/PD model was used to predict PK profiles after repeated administrations of tegoprazan, postprandial PK profiles, and intragastric pH changes. The predicted tegoprazan and M1 concentration-time profiles fit the observed profiles well. The arithmetic mean ratios (95% confidence intervals) of the predicted to observed values for the area under the curve (AUC_{0-24 h}), maximum plasma drug concentration (C_max), and clearance (CL) for tegoprazan and M1 were within a 30% interval. Delayed time of maximum concentration (T_max) and decreased C_max were predicted in the postprandial PK profiles compared with the fasted state. This PBPK/PD model may be used to predict PK profiles after repeated tegoprazan administrations and to predict differences in physiological factors in the gastrointestinal tract or changes in gastric acid pH after tegoprazan administration.

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.

Current advances in the diagnosis and management of gastroesophageal reflux disease

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

Prior oral proton-pump inhibitor use is associated with reduced severity of aspirin-related upper gastrointestinal bleeding in older people

Low-dose aspirin is commonly used for primary or secondary prophylaxis against cardiovascular disease in older people. However, the potential risk of upper gastrointestinal (UGI) ulceration and bleeding associated with low-dose aspirin use is often not appreciated by prescribers and older consumers. Among 133 serial patients with UGI bleeding, aspirin-users aged ≥70 years had a ninefold increased likelihood of overt UGI bleeding compared with non-users, reducing by 90% in regular proton-pump inhibitor users (adjusted odds ratio 0.10). We recommend risk-versus-benefit discussions when recommending aspirin to older people.

Comparison of the pharmacokinetics and pharmacodynamics of YH4808 in healthy subjects for defining an appropriate dosing regimen

YH4808 is a novel potassium-competitive acid blocker developed for gastric acid-related disorders. Previous studies indicate its potential to improve symptoms of gastric acid-related disorders. The current study was aimed to find the optimal regimen of YH4808 for night time pH control. This study was performed in two parts. Each was a randomized, open-label, active-controlled, multiple-doses, two-treatment, two-period crossover study conducted in 20 healthy Korean volunteers. Subjects were randomly assigned to one of the four groups. The three groups received different dosage regimens of YH4808 (100 mg twice a day, 200 mg once a day, or 200 mg twice a day), and the fourth group received esomeprazole 40 mg twice a day. The pharmacokinetic parameters demonstrated that the systemic exposure of YH4808 increased in a dose-proportional manner. The difference in the proportion of time above pH 4 over 24 h from the baseline was the greatest in the group receiving YH4808 200 mg twice a day. The values of the area under the effect curve at night time (12 A.M.–7 A.M.) were higher in all YH4808 groups than in the esomeprazole group. However, the differences among the YH4808 groups were not statistically significant (p > 0.05). YH4808 exhibited potential for better pH control during the night in comparison to esomeprazole. The optimal regimen for night time pH control among all the YH4808 regimens was 200 mg twice a day.

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.

In Esophageal Squamous Cells From Eosinophilic Esophagitis Patients, Th2 Cytokines Increase Eotaxin-3 Secretion Through Effects on Intracellular Calcium and a Non-Gastric Proton Pump

BACKGROUND & AIMS

In upper airway cells, T helper 2 cytokines that signal through interleukin-4 (IL-4) receptor-α have been shown to stimulate eotaxin-3 secretion via a nongastric proton pump (ngH⁺,K⁺ATPase). To seek novel targets for eosinophilic esophagitis (EoE) treatments, we evaluated ngH⁺,K⁺ATPase expression in EoE squamous cells, and explored molecular pathways involved in eotaxin-3 secretion by IL-4 receptor-α signaling.

METHODS

ngH⁺,K⁺ATPase expression in EoE cells was evaluated by quantitative real-time polymerase chain reaction and Western blotting. IL-4-stimulated eotaxin-3 secretion was measured by enzyme-linked immunosorbent assay after treatment with omeprazole, SCH 28080 (potassium-competitive acid blocker), ethylene glycol-bis(β-aminoethyl)-N,N,N',N'-tetraacetoxymethyl ester (calcium chelator), 2-aminoethoxydiphenyl borate (inhibitor of endoplasmic reticulum calcium release), verapamil, and diltiazem (L-type calcium channel inhibitors). Intracellular calcium transients were measured by Fluo-4 fluorescence. Key experiments were confirmed in EoE primary cells and in RNA sequencing datasets from mucosal biopsies of patients with EoE and controls.

RESULTS

EoE cells expressed ngH⁺,K⁺ATPase messenger RNA and protein. Omeprazole and SCH 28080 decreased IL-4-stimulated eotaxin-3 secretion. IL-4 increased intracellular calcium transients, and IL-4-stimulated eotaxin-3 secretion was blocked by ethylene glycol-bis(β-aminoethyl)-N,N,N',N'-tetraacetoxymethyl ester, 2-aminoethoxydiphenyl borate, verapamil, and diltiazem. The combination of omeprazole and verapamil suppressed IL-4-stimulated eotaxin-3 secretion more than either agent alone. EoE biopsies expressed higher ngH+,K+ATPase and exhibited more calcium signaling than controls.

CONCLUSIONS

EoE cells express a nongastric proton pump that mediates T helper 2 cytokine-stimulated eotaxin-3 secretion. IL-4 induces calcium release from the endoplasmic reticulum and calcium entry via L-type calcium channels, increasing intracellular calcium that contributes to eotaxin-3 secretion by EoE cells. L-type calcium channel inhibitors block T helper 2 cytokine-stimulated eotaxin-3 secretion, suggesting a potential role for these agents in EoE treatment.

Vonoprazan vs lansoprazole for the treatment of artificial gastric ulcer after endoscopic submucosal dissection: a prospective randomized comparative study

Vonoprazan is a potent inhibitor of gastric acid secretion and may have better response than proton pump inhibitors (PPIs) in the treatment of endoscopic submucosal dissection induced artificial ulcers. However, reported outcomes remain controversial. In this study, we conducted a prospective, randomized comparative trial to evaluate healing effects of vonoprazan and lansoprazole on endoscopic submucosal dissection (ESD)-induced ulcers. We enrolled 216 patients who underwent endoscopic submucosal dissection for early gastric neoplasms. They were randomly divided into vonoprazan (20 mg/day) and lansoprazole (30 mg/day) groups. The primary endpoint was the reduction rate of ulcer and complete healing (scar) ratio of ESD-induced ulcers at 4 and 8 weeks. Finally, 101 patients of the vonoprazan group and 95 patients of the lansoprazole group were included in the analysis. There were no significant differences in the reduction rate between the vonoprazan and lansoprazole groups at either timepoint (4 weeks, 94.0 vs 93.4%; 8 weeks, 99.8 vs 99.9%, respectively). The complete healing ratio at 4 and 8 weeks did not differ significantly between the vonoprazan and lansoprazole groups (4 weeks, 11.9 vs 12.6%; 8 weeks, 87.1 vs 86.3%, respectively). In the anti-H. pylori-antibody negative or positive patients, there were no significant differences in the reduction rate and complete healing ratio between the vonoprazan and lansoprazole groups. Regardless of treatment choice, the overall complete healing ratio at 8 weeks was significantly higher in the anti-H. pylori-antibody negative patients than the positive patients (p = 0.006). The healing effects of vonoprazan on ESD-induced ulcers were comparative to those of lansoprazole.

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

PURPOSE

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

METHODS

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

FINDINGS

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

IMPLICATIONS

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

Daily Usage of Proton Pump Inhibitors May Reduce the Severity of Critical Upper Gastrointestinal Bleeding in Elderly Patients

Introduction

We retrospectively examined the relationship between daily proton pump inhibitor (PPI) use and severity of upper gastrointestinal bleeding (UGIB), mainly in the elderly.

Methods

We included 97 patients with nonvariceal UGIB diagnosed at our hospital from January 2012 to October 2017. Bleeding severity was assessed using the shock index (SI) and estimated bleeding volume; 49 patients met the criterion for the mild group and 48 for the moderate/severe group. The effect of PPI use on bleeding severity was compared between the groups. The relationships of PPI use and dose with the clinical symptoms of UGIB were also analyzed.

Results

Among the 97 patients, 17 (17.5%) habitually used PPIs. The rate of habitual PPI use was significantly higher in the mild group, indicating as an independent factor contributing to a reduction in the severity of UGIB in a multiple logistic regression analysis (30.6% vs. 4.2%; OR 10.147; 95% CI 2.174–47.358, P < 0.01). When analyzing data for a subgroup of patients older than 75 years, we found the protective PPI effect to be even higher in the mild UGIB group than in the moderate/severe group (37.0% vs. 5.6%; OR 10.000; 95% CI 1.150–86.951, P < 0.05). Conversely, we found no association between PPI prescription and UGIB symptoms in patients younger than 75 years. The mean estimated bleeding volume and SI in the 17 habitual PPI users were both significantly less than those among the 80 nonhabitual users, respectively (P < 0.05). The proportion of patients with mild UGIB was similar between the low- and high-dose PPI users.

Conclusions

Particularly in elderly patients with nonvariceal UGIB, habitual PPI use can alleviate the clinical symptoms of UGIB by suppressing the volume of bleeding, regardless of the adapted dose of PPIs.

Proton pump inhibitors for chronic obstructive pulmonary disease

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is a common and progressive disease characterised by chronic cough, airflow limitation and recurrent exacerbations. Since COPD exacerbations are linked to rising mortality and reduced quality of life, the condition poses a substantial burden on individuals, society and the healthcare system. Effective management of COPD exacerbations that includes treatment of related conditions in people with COPD is thus recognised as a relevant clinical question and an important research topic. Gastroesophageal reflux disease (GERD) is a known comorbidity of COPD, and pulmonary microaspiration of gastric acid is thought to be a possible cause of COPD exacerbations. Therefore, reducing gastric acid secretion may lead to a reduction in COPD exacerbations. Proton pump inhibitors (PPIs) are one of the most commonly prescribed medications and are recommended as first-line therapy for people with GERD because of their inhibitory effects on gastric acid secretion. Treatment with PPIs may present a viable treatment option for people with COPD.

OBJECTIVES

To evaluate the efficacy and safety of PPI administration for people with COPD, focusing on COPD-specific outcomes.

SEARCH METHODS

We searched the Cochrane Airways Register of Trials and conventional clinical trial registers from inception to 22 May 2020. We also screened bibliographies of relevant studies.

SELECTION CRITERIA

Parallel-group and cluster-randomised controlled trials (RCTs) that compared oral PPIs versus placebo, usual care or low-dose PPIs in adults with COPD were eligible for inclusion. We excluded cross-over RCTs, as well as studies with a duration of less than two months.

DATA COLLECTION AND ANALYSIS

Two independent review authors screened search results, selected studies for inclusion, extracted study characteristics and outcome data, and assessed risk of bias according to standard Cochrane methodology. We resolved discrepancies by involving a third review author. Primary outcomes of interest were COPD exacerbations, pneumonia and other serious adverse events. Secondary outcomes were quality of life, lung function test indices, acute respiratory infections and disease-specific adverse events. We extracted data on these outcome measures and entered into them into Review Manager software for analysis.

MAIN RESULTS

The search identified 99 records, and we included one multicentre RCT that randomised 103 adults with COPD. The 12-month RCT compared an oral PPI (lansoprazole) and usual care versus usual care alone. It was conducted at one tertiary care hospital and three secondary care hospitals in Japan. This study recruited participants with a mean age of 75 years, and excluded people with symptoms or history of GERD. No placebo was used in the usual care arm. Among the primary and secondary outcomes of this review, the study only reported data on COPD exacerbations and acute respiratory infections (the common cold). As we only included one study, we could not conduct a meta-analysis. The included study reported that 12 of the 50 people on lansoprazole had at least one exacerbation over a year, compared to 26 out of 50 on usual care (risk ratio 0.46, 95% CI 0.26 to 0.81). The frequency of COPD exacerbations per person in a year was also lower in the PPI plus usual care group than in the usual care alone group（0.34 ± 0.72 vs 1.18 ± 1.40; P < 0.001). The number of people with at least one cold over the year was similar in both groups: 26 people on lansoprazole and 27 people in the usual care group. We judged the evidence to be of low to very low certainty, according to GRADE criteria. The study reported no data on pneumonia and other serious adverse events, quality of life, lung function test indices or disease-specific adverse events. The risk of bias was largely low or unclear for the majority of domains, though the performance bias was a high risk, as the study was not blinded.

AUTHORS' CONCLUSIONS

Evidence identified by this review is insufficient to determine whether treatment with PPIs is a potential option for COPD. The sample size of the included trial is small, and the evidence is low to very low-certainty. The efficacy and safety profile of PPIs for people with COPD remains uncertain. Future large-scale, high-quality studies are warranted, which investigate major clinical outcomes such as COPD exacerbation rate, serious adverse events and quality of life.

Pazopanib-associated interstitial lung disease in a patient with renal cell carcinoma

Pazopanib is a multi-targeted tyrosine kinase inhibitor, which is indicated for use in patients with advanced renal cell carcinoma or advanced soft-tissue sarcomas. Although rare, interstitial lung disease has been reported as among the adverse sequelae of pazopanib therapy. We report the case of a 75-year-old man who developed interstitial lung disease during treatment with pazopanib for renal cell carcinoma with multiple lung metastases. The patient presented with dry cough and new-onset fatigue 3 months after initiation of pazopanib. He had mild hypoxia with bilateral ground-glass opacities on chest CT. He was treated with antibiotics for presumptive pneumonia, but his respiratory status rapidly deteriorated, and he required non-invasive positive pressure ventilation. He recovered on discontinuation of pazopanib and systemic steroids. Clinicians should recognise that interstitial lung disease can occur in patients who are undergoing treatment with pazopanib.

Evaluation of pharmacokinetic interactions between amoxicillin, clarithromycin, and the potassium-competitive acid blocker YH4808 in healthy subjects

YH4808 is a novel potassium-competitive acid blocker that was developed as a therapeutic agent for gastric acid-related diseases; it may replace proton pump inhibitors, which are widely used in combination with amoxicillin and clarithromycin for Helicobacter pylori eradication. We compared the pharmacokinetic (PK) profiles and safety of amoxicillin, clarithromycin, and YH4808 used as monotherapies or in combination for evaluating potential drug interactions. An open-label, randomized, single-dose, Latin-square (4 × 4) crossover study was conducted in 32 healthy Korean volunteers. Subjects were randomly assigned to one of the 4 treatment sequences that consisted of 4 periods separated by 21-day washout intervals. PK parameters of YH4808, amoxicillin and clarithromycin administered in combination were compared with those of the respective monotherapies. The geometric mean ratios of the maximum concentration (C_max) and the area under the time-concentration curve from time zero to time of the last quantifiable concentration (AUC_last) of YH4808 increased during the triple therapy by 48.6% and 29.1%, respectively. Similarly, the C_max and AUC_last of M3 (active metabolite of YH4808) increased by 23.3% and 16.0%, respectively. The C_max and AUC_last of clarithromycin increased by 27.4% and 30.5%, and those of 14-hydroxyclarithromycin were increased by 23.1% and 32.4%, respectively. The corresponding amoxicillin values decreased during the triple therapy by 21.5% and 15.6%, respectively. There was no clinically significant change in safety assessment related to either monotherapies or triple therapy. In conclusion, amoxicillin, clarithromycin and YH4808 administered as triple therapy did not exhibit significant PK interactions and were not associated with safety issues.

The Physiology of the Gastric Parietal Cell

Parietal cells are responsible for gastric acid secretion, which aids in the digestion of food, absorption of minerals, and control of harmful bacteria. However, a fine balance of activators and inhibitors of parietal cell-mediated acid secretion is required to ensure proper digestion of food, while preventing damage to the gastric and duodenal mucosa. As a result, parietal cell secretion is highly regulated through numerous mechanisms including the vagus nerve, gastrin, histamine, ghrelin, somatostatin, glucagon-like peptide 1, and other agonists and antagonists. The tight regulation of parietal cells ensures the proper secretion of HCl. The H+-K+-ATPase enzyme expressed in parietal cells regulates the exchange of cytoplasmic H+ for extracellular K+. The H+ secreted into the gastric lumen by the H+-K+-ATPase combines with luminal Cl- to form gastric acid, HCl. Inhibition of the H+-K+-ATPase is the most efficacious method of preventing harmful gastric acid secretion. Proton pump inhibitors and potassium competitive acid blockers are widely used therapeutically to inhibit acid secretion. Stimulated delivery of the H+-K+-ATPase to the parietal cell apical surface requires the fusion of intracellular tubulovesicles with the overlying secretory canaliculus, a process that represents the most prominent example of apical membrane recycling. In addition to their unique ability to secrete gastric acid, parietal cells also play an important role in gastric mucosal homeostasis through the secretion of multiple growth factor molecules. The gastric parietal cell therefore plays multiple roles in gastric secretion and protection as well as coordination of physiological repair.

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.

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.

Vonoprazan versus proton-pump inhibitors for healing gastroesophageal reflux disease: A systematic review

BACKGROUND AND AIM

Gastroesophageal reflux disease (GERD) is a common disease caused by reflux of gastric contents to the esophagus. Proton-pump inhibitors (PPIs) are recommended as a first-line therapy to treat GERD. Recently, a new potassium-competitive acid blocker, vonoprazan, was launched in Japan. We aimed to evaluate the comparative efficacy of vonoprazan and other PPIs in healing GERD.

METHODS

We used MEDLINE and the Cochrane Central Register of Controlled Trials to search the literature. Double-blind randomized controlled trials for PPIs and/or vonoprazan that were published in English or Japanese and assessed healing effects in adult GERD patients were included. To estimate the comparative efficacy of treatments, we performed a Bayesian network meta-analysis to assess the consistency assumption.

RESULTS

Of 4001 articles identified in the database, 42 studies were eligible. One study was hand-searched and added to the analysis. For the main analysis of healing effects at 8 weeks, odds ratios (ORs) of vonoprazan (20 mg daily) to esomeprazole (20 mg), rabeprazole (20 mg), lansoprazole (30 mg), and omeprazole (20 mg) were 2.29 (95% credible interval, 0.79-7.06), 3.94 (1.15-14.03), 2.40 (0.90-6.77), and 2.71 (0.98-7.90), respectively. Subgroup analysis for patients with severe esophagitis at baseline showed significantly higher ORs for vonoprazan versus most of the comparator PPIs.

CONCLUSIONS

This analysis shows that the GERD healing effect of vonoprazan is higher than that of rabeprazole (20 mg) but not higher than other PPIs. Subgroup analysis indicated that vonoprazan is more effective than most PPIs for patients with severe erosive esophagitis.

A physiologically-based pharmacokinetic model adequately predicted the human pharmacokinetic profiles of YH4808, a novel K+-competitive acid blocker

A physiologically-based pharmacokinetic (PBPK) model was developed for YH4808, a novel potassium-competitive acid blocker, using the SimCYP® Simulator based on the physicochemical, in vitro preclinical and clinical data of YH4808. The PBPK model was optimized using YH4808 concentrations obtained from the single-dose phase I clinical trial. Overall, the PBPK model adequately predicted the observed pharmacokinetic profiles of YH4808 in humans. The pharmacokinetic profiles of YH4808 after multiple oral administrations were predicted using a refined PBPK model. The ratios of model-predicted to observed C_max, AUC_inf and AUC_τ values on Day 1 and Day 7 at 100 mg were 0.7-1.0. However, the model failed to predict a decreased exposure after multiple oral administration particularly at higher doses of 200 and 400 mg. The reduced solubility of YH4808 at higher pH was hypothesized as the main cause of the reduction in exposure such that absorption was decreased as pH was increased. This hypothesis was confirmed by PBPK modeling and simulation, where intragastric pH was increased by YH4808.

Efficacy of vonoprazan in prevention of bleeding from endoscopic submucosal dissection-induced gastric ulcers: a prospective randomized phase II study

BACKGROUND

Vonoprazan, potassium-competitive acid blocker, is expected to reduce incidence of delayed bleeding after gastric endoscopic submucosal dissection (ESD); however, preliminary data to design a large-scale comparative study are lacking. This study aimed to assess the efficacy of vonoprazan in preventing delayed bleeding after gastric ESD.

METHODS

In this single-center randomized phase II trial, a modified screened selection design was used with a threshold non-bleeding rate of 89% and an expected rate of 97%. In this design, Simon's optimal two-stage design was first applied for each parallel group, and efficacy was evaluated in comparison with the threshold rate using binomial testing. Patients were randomly assigned in a 1:1 ratio to receive either vonoprazan 20 mg (VPZ group) or lansoprazole 30 mg (PPI group) for 8 weeks from the day before gastric ESD. The primary endpoint was the incidence of delayed bleeding, defined as endoscopically confirmed bleeding accompanied by hematemesis, melena, or a decrease in hemoglobin of ≥ 2 g/dl.

RESULTS

Delayed bleeding occurred in three of 69 patients (4.3%, 95% CI 0.9-12.2%, p = 0.047) in the VPZ group, and four of 70 (5.7%, 95% CI 1.6-14.0%, p = 0.104) in the PPI group. As only vonoprazan showed significant reduction in delayed bleeding compared with the threshold rate, it was determined to be efficacious treatment.

CONCLUSIONS

Vonoprazan efficaciously reduced the delayed bleeding rate in patients with an ESD-induced gastric ulcer. A large-scale, randomized, phase III study is warranted to definitively test the effectiveness of vonoprazan compared with proton pump inhibitors.

Short-Term Symptomatic Relief in Gastroesophageal Reflux Disease: A Comparative Study of Esomeprazole and Vonoprazan

BACKGROUND AND AIM

Proton pump inhibitors and vonoprazan (a potassium-competitive acid blocker) are recommended as first-line treatments for gastroesophageal reflux disease (GERD). However, few reports have investigated the onset of action of these agents for GERD symptom relief. The present study compared the symptom relief of esomeprazole with that of vonoprazan via monitoring self-reported GERD symptoms after treatment initiation.

METHODS

This was a prospective, multicenter, randomized, open-label, parallel group, comparative clinical study between esomeprazole (20 mg/day) and vonoprazan (20 mg/day) administered for 4 weeks to patients with GERD symptoms. Patients who had scores ≥ 8 on the Gastroesophageal Reflux Disease Questionnaire (GerdQ) were defined as having GERD and enrolled in this study. Sixty patients were randomly assigned to either the esomeprazole group (n = 30) or the vonoprazan group (n = 30). Treatment response rates in each drug group were evaluated according to the GerdQ. The Frequency Scale for the Symptoms of GERD (FSSG) scores from the 1st day after treatment initiation and the Global Overall Symptom (GOS) scale scores during treatment were also evaluated.

RESULTS

At 4 weeks, the treatment response rates for symptom relief according to the GerdQ were 88.0% in the esomeprazole group and 81.8% in the vonoprazan group. The GOS scales, which reflect the impact of GERD symptoms, were similar for both groups. The FSSG scores decreased from the 1st to the 14th day in both groups.

CONCLUSIONS

There were no substantial differences in the symptom relief between the two groups at any time point in this short-term study.

Randomised clinical trial: vonoprazan versus lansoprazole for the initial relief of heartburn in patients with erosive oesophagitis

BACKGROUND

Proton pump inhibitors (PPIs) are widely used to treat gastro-oesophageal reflux disease (GORD). However, the onset of action is considered slow and PPIs cannot completely block acid secretion at night. A new potassium-competitive acid blocker (P-CAB) can rapidly block acid secretion. However, whether this P-CAB can relieve GORD symptoms quickly and adequately soon after starting treatment is unknown.

AIM

To determine how rapidly vonoprazan and lansoprazole provide heartburn relief.

METHODS

Patients (n = 32) with endoscopically confirmed erosive oesophagitis who experienced heartburn at least once a week were randomised in a double-blind manner to receive either daily vonoprazan (20 mg) or lansoprazole (30 mg) before breakfast for 14 days. Day time and night time heartburn were assessed daily throughout the study using a five-point Likert scale. The primary endpoint was the first day of complete day and night heartburn relief for at least seven consecutive days. The ethics committees of the participating institutions approved the study protocol.

RESULTS

Heartburn was relieved sooner with vonoprazan than with lansoprazole (P < 0.05, log-rank test). Heartburn was completely relieved in 31.3% and 12.5% of patients on day 1 with vonoprazan and lansoprazole, respectively. Significantly more patients achieved complete nocturnal heartburn relief with vonoprazan than lansoprazole (P < 0.01). Both regimens were well tolerated.

CONCLUSIONS

Complete sustained heartburn relief was achieved sooner with vonoprazan than with lansoprazole during the first week of therapy. (UMIN000018776).

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

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

[Pharmacological characteristics and clinical efficacies of a novel potassium-competitive acid blocker, vonoprazan fumarate]

Proton pump inhibitors (PPIs) inhibit H⁺, K⁺-ATPase, an enzyme which is the final step of gastric acid secretion and is selectively located in the gastric parietal cells. PPIs block the enzyme in a covalent and irreversible binding manner, thus providing better efficacy than previous pharmacological agents such as antacids and histamine H₂ receptor antagonists. Although PPIs have been the first-line therapeutic option for acid related diseases (ARDs), there are several limitations to their efficacy, i.e. short half-life in blood, insufficient acid suppression especially at night, necessity of repeated dosages for full action, and large variation in efficacy among patients due to CYP2C19 polymorphism. To overcome these shortcomings, we performed a high-throughput random screening using in-house chemical libraries and further lead optimization to look for the most relevant clinical candidate compounds. As the results of these researches, we discovered vonoprazan fumarate, a novel gastric acid antisecretory agent which inhibits H⁺, K⁺-ATPase in a reversible and K⁺-competitive manner. Vonoprazan exerted a more potent and longer lasting inhibitory effect than lansoprazole on gastric acid secretion in preclinical studies, presumably by its high accumulation profile in the gastric parietal cells. It also exhibited a rapid onset of action and prolonged inhibition of intragastric acidity in humans and showed remarkable effects on multiple ARDs including erosive esophagitis and Helicobacter pylori eradication. Vonoprazan fumarate was approved in 2014 for clinical use in Japan. Vonoprazan is a new therapeutic option which can potentially improve outcomes compared with conventional PPI-based treatments for ARDs.

Potent Potassium-competitive Acid Blockers: A New Era for the Treatment of Acid-related Diseases

Conventional proton pump inhibitors (PPIs) are used as a first-line therapy to treat acid-related diseases worldwide. However, they have a number of limitations including slow onset of action, influence by cytochrome P450 polymorphisms, unsatisfactory effects at night, and instability in acidic conditions. Alternative formulations of conventional PPIs have been developed to overcome these problems; however, these drugs have only introduced small advantages for controlling acid secretion compared to conventional PPIs. Potassium-competitive acid blockers (P-CABs) were developed and have beneficial effects including rapid, long-lasting, and reversible inhibition of the gastric hydrogen potassium ATPase, the proton pump of the stomach. Vonoprazan was recently innovated as a novel, orally active P-CAB. It is currently indicated for the treatment of gastric and duodenal ulcers, reflux esophagitis, and prevention of low-dose aspirin- or nonsteroidal anti-inflammatory drug-related gastric and duodenal ulcer recurrence in Japan. Vonoprazan does not require enteric coating as it is acid-stable, and it can be taken without food because it is quickly absorbed. Vonoprazan accumulates in parietal cells under both acidic and neutral conditions. It does not require an acidic environment for activation, has long-term stability at the site of action, and has satisfactory safety and tolerability. Thus, vonoprazan may address the unmet medical need for the treatment of acid-related diseases.

Modulations in extracellular calcium lead to H+-ATPase-dependent acid secretion: a clarification of PPI failure

The H⁺,K⁺-ATPase was identified as the primary proton secretory pathway in the gastric parietal cell and is the pharmacological target of agents suppressing acid secretion. Recently, we identified a second acid secretory protein expressed in the parietal cell, the vacuolar H⁺-ATPase (V-type ATPase). The aim of the present study was to further characterize H⁺-ATPase activation by modulations in extracellular calcium via the calcium sensing receptor (CaSR). Isolated gastric glands were loaded with the pH indicator dye BCECF-AM [2',7'-bis-(2-carboxyethyl)-5-(and-6)-carboxyfluorescein acetoxymethyl ester] to measure intracellular pH. Experiments were conducted in the absence of sodium and potassium to monitor H⁺-ATPase-specific transport activity. CaSR was activated with the calcimimetic R568 (400 nM) and/or by modulations in extracellular Ca²⁺. Elevation in calcium concentrations increased proton extrusion from the gastric parietal cell. Allosteric modification of the CaSR via R568 and calcium increased vacuolar H⁺-ATPase activity significantly (ΔpH/min_lowCa²⁺_(0.1mM) = 0.001 ± 0.001, ΔpH/min_normalCa²⁺_(1.0mM) = 0.033 ± 0.004, ΔpH/min_highCa²⁺_(5.0mM) = 0.051 ± 0.005). Carbachol significantly suppressed calcium-induced gastric acid secretion via the H⁺-ATPase under sodium- and potassium-free conditions. We conclude that the V-type H⁺-ATPase is tightly linked to CaSR activation. We observed that proton pump inhibitor (PPI) exposure does not modulate H⁺-ATPase activity. This elevated blood calcium activation of the H⁺-ATPase could provide an explanation for recurrent reflux symptoms while taking a PPI therapy. NEW & NOTEWORTHY This study emphasizes the role of the H⁺-ATPase in acid secretion. We further demonstrate the modification of this proton excretion pathway by extracellular calcium and the activation of the calcium sensing receptor CaSR. The novelty of this paper is based on the modulation of the H⁺-ATPase via both extracellular Ca (activation) and the classical secretagogues histamine and carbachol (inactivation). Both activation and inactivation of this proton pump are independent of PPI modulation.

Safety, tolerability, pharmacodynamics and pharmacokinetics of DWP14012, a novel potassium-competitive acid blocker, in healthy male subjects

BACKGROUND

A novel potassium-competitive acid blocker, DWP14012, is in clinical development as a potential alternative to proton pump inhibitors for the treatment of acid-related diseases.

AIMS

To evaluate the safety, tolerability, pharmacodynamics and pharmacokinetics of DWP14012 in humans.

METHODS

A randomised, double-blind, double-dummy, placebo- and active-controlled, single- and multiple-ascending dose (SAD and MAD, respectively) study was conducted in healthy male subjects without Helicobacter pylori infection. Subjects randomly received a single oral dose of 10-320 mg DWP14012, esomeprazole (active comparator) or placebo in the SAD study (n = 72) and once daily doses of 20-160 mg DWP14012, esomeprazole or placebo for 7 days in the MAD study (n = 48; 8:2:2). Tolerability was evaluated using a microRNA-122 assay. Pharmacodynamics were evaluated through 24-hour gastric pH monitoring, and pharmacokinetics were evaluated plasma and urine DWP14012 concentrations.

RESULTS

DWP14012 was generally well tolerated. The liver toxicity of DWP14012 was not higher than that of placebo after multiple oral administrations. DWP14012 showed rapid and sustained suppression of gastric acid secretion for 24 hours after dosing. Clear dose-response and exposure-response relationships were observed. Plasma concentrations of DWP14012 increased in a dose-proportional manner in the MAD study, whereas in the SAD study, DWP14012 did not significantly accumulate in the plasma.

CONCLUSIONS

DWP14012 was well tolerated, and showed a rapid and long-lasting gastric acid suppression effect in healthy subjects. These results justify further investigation of DWP14012 in patients with acid-related disorders.

Effect of food on the pharmacokinetics of YH4808, a potassium-competitive acid blocker, after single- and multiple-oral dosing in healthy subjects

PURPOSE

YH4808 is a potassium-competitive acid blocker, developed for the treatment of acid-related disorders. Two clinical studies in healthy male subjects were conducted to evaluate the effect of food on the pharmacokinetics of YH4808.

METHODS

The first study, a randomized, three-treatment, three-period, crossover study, compared pharmacokinetics of YH4808 (300 mg) after a single dose at fed state with a standard or a high-fat meal to those at fasted state. The second study, a randomized, two-treatment, two-period, crossover study, investigated pharmacokinetics at fasted or fed state with a standard meal after twice daily dose of YH4808 (100 mg) for 7 days. Bloods for pharmacokinetic evaluation were sampled up to 48 h post-dose and 24 h post-dose at steady state, respectively. The pharmacokinetic parameters were estimated by non-compartmental method.

RESULTS

After single dosing, the geometric means of maximum plasma concentration increased by 1.2 and 2.1 times in the fed states with a standard meal and a high-fat meal, respectively, of that in fasted state. Corresponding values of area under the plasma concentration-time curve (AUC) from time 0 to the last measurable time point increased by 1.8 and 2.8 times, respectively. After multiple dosing, the geometric mean for 24-h AUC at steady state slightly increased in fed state by 1.1 times of that in fasted state.

CONCLUSIONS

As fat content of the food increased, the systemic exposure of YH4808 after single dosing increased. However, systemic exposures at steady state after multiple dosing between fasted and fed states were similar.

TRIAL REGISTRATION

ClinicalTrials.gov registry no.: NCT01520012.

Vonoprazan prevents low-dose aspirin-associated ulcer recurrence: randomised phase 3 study

OBJECTIVE

Compare efficacy and safety of vonoprazan and lansoprazole for secondary prevention of low-dose aspirin (LDA)-associated peptic ulcers in a 24-week study and long-term extension therapy in separate study.

DESIGN

Double-blind, randomised, non-inferiority study; single-blind extension study at 104 Japanese sites, including 621 patients (439 in extension) with a history of peptic ulcers who required long-term LDA therapy. Randomised (1:1:1, computer generated) patients received lansoprazole 15 mg (n=217), vonoprazan 10 mg (n=202) or vonoprazan 20 mg (n=202) once daily for 24 weeks (double blind) and ≤2 years (extension). The following measurements were made: 24-week (primary outcome; double blind) and 12-week peptic ulcer recurrence rate, 24-week GI bleeding rate, cumulative incidences of peptic ulcer recurrence and GI bleeding, treatment-emergent adverse events, laboratory results, serum gastrin and pepsinogen I/II concentrations.

RESULTS

The 24-week peptic ulcer recurrence rate was 2.8%, 0.5% and 1.5% in the lansoprazole 15 mg, vonoprazan 10 mg and vonoprazan 20 mg groups, respectively. Vonoprazan was non-inferior (Farrington and Manning test: margin 8.7%, significance level 2.5%) to lansoprazole. In the post hoc analyses of the extension study, peptic ulcer recurrence rates were significantly lower with vonoprazan 10 mg (log-rank test, P=0.039), but not vonoprazan 20 mg (P=0.260), compared with lansoprazole 15 mg. GI bleeding rates were higher with lansoprazole compared with two doses of vonoprazan in both 24-week study and extension study.

CONCLUSION

Vonoprazan (10 and 20 mg) was as effective as lansoprazole (15 mg) in preventing peptic ulcer recurrence during LDA therapy, had a similar long-term safety profile and was well tolerated.

TRIAL REGISTRATION NUMBERS

NCT01452763; NCT01456247.

Safety of first-line triple therapy with a potassium-competitive acid blocker for Helicobacter pylori eradication in children

BACKGROUND

Helicobacter pylori infection is a risk factor for gastric cancer, and it has been reported that eradication of H. pylori is effective for preventing such cancer. Recently, H. pylori eradication has been performed in children as first-line therapy against gastric cancer. Here, we report use of triple therapy with a potassium-competitive acid blocker (P-CAB) for H. pylori eradication in children.

METHODS

H. pylori infection testing and eradication therapy began in fiscal year 2015 in junior high school students located in Yurihonjo city and Nikaho city, Akita prefecture, Japan. Urine-based immunochromatography, stool antigen enzyme-linked immunosorbent assay tests, and serum antibody tests were performed as the initial screening examination. Those who tested positive on one of the three examinations then underwent a urea breath test (¹³C-UBT). Those who tested positive on ¹³C-UBT and expressed the desire to undergo H. pylori eradication then received eradication therapy comprising 20 mg P-CAB, 750 mg amoxicillin, and 200 mg clarithromycin twice a day for 7 days. At least 8 weeks after treatment, eradication success was evaluated using ¹³C-UBT.

RESULTS

A total of 118 students received eradication therapy. Eradication rates were 81.3% (95% confidence interval: 74.3-88.4, 96/118) in ITT analysis and 85.7% (95% confidence interval: 79.1-92.9 96/112) in PP analysis. Adverse effects associated with eradication therapy were observed in 25 of 118 subjects (21.1%), seven of whom required hospital treatment (rash in five, vomiting in two). All seven subjects either discontinued therapy or were administered anti-allergy drugs, which resulted in swift alleviation of symptoms.

CONCLUSIONS

First-line triple therapy with a P-CAB for H. pylori eradication in children was found to be safe.

Severity of gastric mucosal atrophy affects the healing speed of post-endoscopic submucosal dissection ulcers

AIM

To investigate factors associated with the healing of endoscopic submucosal dissection (ESD)-induced ulcers.

METHODS

We enrolled 132 patients with gastric tumors scheduled for ESD. Following ESD, patients were treated with daily lansoprazole 30 mg or vonoprazan 20 mg. Ulcer size was endoscopically measured on the day after ESD and at 4 and 8 wk. The gastric mucosa was endoscopically graded according to the Kyoto gastritis scoring system. We assessed the number of patients with and without a 90% reduction in ulcer area at 4 wk post-ESD and scar formation at 8 wk, and looked for risk factors for slower healing.

RESULTS

The mean size of gastric tumors and post-ESD ulcers was 17.4 ± 12.1 mm and 32.9 ± 13.0 mm. The mean reduction rates in ulcer area were 90.4% ± 0.8% at 4 wk and 99.8% ± 0.1% at 8 wk. The reduction rate was associated with the Kyoto grade of gastric atrophy at 4 wk (A0: 97.9% ± 0.6%, A1: 93.4% ± 4.1%, and A2: 89.7% ± 1.0%, respectively). In multivariate analysis, the factor predicting 90% reduction at 4 wk was gastric atrophy (Odds ratio: 5.678, 95%CI: 1.190-27.085, P = 0.029).

CONCLUSION

The healing speed of post-ESD ulcers was associated with the degree of gastric mucosal atrophy, and Helicobacter pylori eradication therapy is required to perform at younger age.

Comparison of the early effects of vonoprazan, lansoprazole and famotidine on intragastric pH: a three-way crossover study

To promote symptom relief from acid-related diseases, a medicine with a rapid-onset effect is ideal. The aim of this study was to investigate the early inhibitory effect on gastric acid secretion after a single oral administration of vonoprazan, which represents a new class of proton pump inhibitors, and to compare this effect with those of lansoprazole and famotidine. Ten Helicobacter pylori (HP)-negative male subjects participated in this randomized, three-way crossover study. A single oral administration of vonoprazan (20 mg), lansoprazole (30 mg) or famotidine (20 mg) was performed, and the intragastric pH was continuously monitored for 6 h. Each drug was administered at least seven days apart. The average intragastric pH during the 6-h period after the administration of famotidine was higher than that after the administration of lansoprazole (median: 4.45 vs 2.65; p = 0.0284). A similar result was observed for vonoprazan and lansoprazole (median: 4.30 vs 2.65; p = 0.0322). In conclusions, oral administration of vonoprazan and famotidine in HP-negative healthy male subjects caused the intragastric pH to rise more quickly than did lansoprazole. (Trial Registration: UMIN000020989)