A comparative study on the modes of action of TAK-438, a novel potassium-competitive acid blocker, and lansoprazole in primary cultured rabbit gastric glands

Endoscopic findings and outcomes of gastric mucosal changes relating to potassium-competitive acid blocker and proton pump inhibitor therapy

Gastric mucosal changes associated with long-term potassium-competitive acid blocker and proton pump inhibitor (PPI) therapy may raise concern. In contrast to that for PPIs, the evidence concerning the safety of long-term potassium-competitive acid blocker use is scant. Vonoprazan (VPZ) is a representative potassium-competitive acid blocker released in Japan in 2015. In order to shed some comparative light regarding the outcomes of gastric mucosal lesions associated with a long-term acid blockade, we have reviewed six representative gastric mucosal lesions: fundic gland polyps, gastric hyperplastic polyps, multiple white and flat elevated lesions, cobblestone-like gastric mucosal changes, gastric black spots, and stardust gastric mucosal changes. For these mucosal lesions, we have evaluated the association with the type of acid blockade, patient gender, Helicobacter pylori infection status, the degree of gastric atrophy, and serum gastrin levels. There is no concrete evidence to support a significant relationship between VPZ/PPI use and the development of neuroendocrine tumors. Current data also shows that the risk of gastric mucosal changes is similar for long-term VPZ and PPI use. Serum hypergastrinemia is not correlated with the development of some gastric mucosal lesions. Therefore, serum gastrin level is unhelpful for risk estimation and for decision-making relating to the cessation of these drugs in routine clinical practice. Given the confounding potential neoplastic risk relating to H. pylori infection, this should be eradicated before VPZ/PPI therapy is commenced. The evidence to date does not support the cessation of clinically appropriate VPZ/PPI therapy solely because of the presence of these associated gastric mucosal lesions.

Insights into tumor-derived exosome inhibition in cancer therapy

Exosomes are critical mediators of cell-to-cell communication in physiological and pathological processes, due to their ability to deliver a variety of bioactive molecules. Tumor-derived exosomes (TDEs), in particular, carry carcinogenic molecules that contribute to tumor progression, metastasis, immune escape, and drug resistance. Thus, TDE inhibition has emerged as a promising strategy to combat cancer. In this review, we discuss the key mechanisms of TDE biogenesis and secretion, emphasizing their implications in tumorigenesis and cancer progression. Moreover, we provide an overview of small-molecule TDE inhibitors that target specific biogenesis and/or secretion pathways, highlighting their potential use in cancer treatment. Lastly, we present the existing obstacles and propose corresponding remedies for the future development of TDE inhibitors.

Emerging Long-Term Risks of the Use of Proton Pump Inhibitors and Potassium-Competitive Acid Blockers

Acid-related disorders represent a significant global health burden. Pharmacological treatment of these conditions has at times been challenged and limited by incomplete effectiveness, antibiotic resistance, adverse medication effects and/or interactions, and disease recurrence. Since the early 1990s, the mainstay of treatment has been proton pump inhibitors (PPIs). Recently, the US Food and Drug Administration issued a clearance for vonoprazan, a potassium-competitive acid blocker (PCAB). PCABs are a new class of acid-suppressing agents that may overcome some of these challenges. The aim of this review is to evaluate and compare the emerging long-term risks of PPI and PCAB therapies.

Efficacy and Safety of Potassium-competitive Acid Blockers Versus Proton Pump Inhibitors in Treating Erosive Esophagitis: A Meta-analysis Based on Randomized Controlled Trials

OBJECTIVE

This meta-analysis aimed to investigate the efficacy and safety of potassium-competitive acid blockers (P-CABs) and proton pump inhibitors (PPIs) in treating erosive esophagitis (EE).

METHODS

PubMed, Embase, Cochrane Library, and Web of Science were systematically searched using predefined search terms up to January 2024. Relevant randomized controlled trials were included. The outcoming were the EE healing rate and treatment-related adverse events incidence.

RESULTS

Nine randomized controlled trials involving 4012 patients were included. Patients receiving P-CAB exhibited a significantly better overall healing rate compared with PPI at week 2 [risk ratio (RR) = 1.06], but no statistical difference was observed at week 4 and week 8. Subgroup analysis revealed that P-CAB demonstrated a higher healing rate for patients with Los Angeles (LA) grade C/D, regardless of the assessment at week 2 (RR = 1.17), week 4 (RR = 1.10), or week 8 (RR = 1.08). However, no significant difference was found between PPI and P-CAB for patients with LA grade A/B at week 2, week 4, or week 8. Furthermore, patients treated with P-CAB had lower recurrence rates during maintenance therapy compared with PPI (RR = 0.79). In terms of safety, P-CAB was associated with a lower incidence of headache compared with PPI (RR = 0.32), with no statistical difference found in any treatment-related adverse events between the two groups.

CONCLUSIONS

P-CAB was found to be safe and effective for EE treatment compared with PPI, particularly in 2-week short-term treatment, severe EE (LA grade C/D) treatment, or maintenance therapy. Limitations such as potential heterogeneity among included trials should be considered in the interpretation of these findings.

Seven-Day Vonoprazan-Based Triple Therapy as First-Line Helicobacter pylori Treatment in Comparison With Extended Sequential Therapy: A Randomized Controlled Trial

BACKGROUND

Vonoprazan, a potassium-competitive acid blocker, has demonstrated greater potency and a longer duration of acid suppression when compared to the proton pump inhibitors. However, data regarding the comparison between vonoprazan-based triple therapy with standard treatment for first-line Helicobacter pylori treatment are limited. This study aimed to compare the efficacy between 7-day vonoprazan-based triple therapy with high-dose amoxicillin (VAC-7) and 14-day extended sequential therapy (S-14).

MATERIALS AND METHODS

This was a single-center prospective randomized controlled trial following a noninferiority design. Subjects over 20 years old with confirmed H. pylori infection were enrolled prospectively from Fu Jen Catholic University Hospital. They were randomly assigned to the VAC-7 or S-14 group. The primary endpoint was the eradication rate in first-line treatment, evaluated by urea breath test, with noninferiority determined using the Farrington-Manning method. The secondary outcome included adverse effect rates and compliance, assessed through self-administered questionnaires.

RESULTS

Between December 2021 and June 2023, a total of 628 patients were recruited. The eradication rates by per-protocol analysis and intention-to-treat analysis were 88.6%/81.8% for VAC-7 and 90.3%/81.4% for S-14, respectively. The VAC-7 was non-inferior to S-14 in terms of ITT analysis. Subjects experienced fewer incidences of nausea, anorexia, dizziness, fatigue, and any severe adverse events in the VAC-7 group. Compliance was higher in the VAC-7 group, with 94% taking all the pills correctly.

CONCLUSIONS

Our findings supported the use of 7-day vonoprazan triple therapy with high-dose amoxicillin as the standard first-line treatment for H. pylori infection.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT05371249.

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).

Amelioration of obsessive-compulsive disorder by intracellular acidification of cortical neurons with a proton pump inhibitor

Obsessive-compulsive disorder (OCD) is a highly prevalent neuropsychiatric disorder poorly controlled with pharmacological treatment because of the wide variation in symptom patterns. We analysed real-world data on adverse self-reports and insurance claims to identify a novel therapeutic target for OCD. We found that dopamine D2 receptor (D2R) agonists increased the incidence of OCD-like symptoms, which were suppressed by the concomitant use of proton pump inhibitors (PPIs). Further, OCD-like repetitive and habitual behaviours were observed in mice repeatedly injected with a D2R agonist, quinpirole. However, these abnormalities were suppressed by short-term PPI treatment. In quinpirole-treated mice, PPI inhibited pyramidal neuron hyperactivity in the lateral orbitofrontal cortex, a region where the P-type proton pump gene Atp4a is abundantly expressed. In primary cultured cortical neurons, short-term PPI treatment lowered intracellular pH and decreased firing activity, which was mimicked by Atp4a knockdown. Our findings show that inhibition of P-type proton pumps may be a novel therapeutic strategy for OCD.

Network meta-analysis of multiple doses of vonoprazan for the treatment of erosive esophagitis

Aim: 20 mg of vonoprazan (VPZ20) is recommended in most countries to treat erosive esophagitis (EE). Whether other doses of vonoprazan, such as 5 mg (VPZ5), 10 mg (VPZ10), 20 mg (VPZ20), and 40 mg (VPZ40) are more effective is unknown. Materials & methods: Three databases were electronically searched to identify studies published before November 2021. Network meta-analysis was performed using STATA 14.0. Results: VPZ20 and VPZ40 were comparable to PPI, VPZ5 and VPZ10 in 4- and 8-week healing rates, and this was also detected in patients with refractory EE. All regimens resulted in similar treatment-emergent adverse events (TEAEs). However, VPZ40 ranked first for healing rate and TEAEs; however, VPZ20 ranked worst for TEAEs. Conclusion: Different doses of VPZ are comparable in efficacy and safety, but VPZ40 may be best in both effectiveness and safety.

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.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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

BACKGROUND

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

METHODS AND RESULTS

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

CONCLUSIONS

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

Seven-day vonoprazan-based triple therapy as first-lineHelicobacter pylori treatment in comparison with extended sequential therapy

Background and Aim

Vonoprazan as a new acid blocker has more potency and longer lasting acid suppression than proton pump inhibitors. Whether the efficacy of vonoprazan-based triple therapy is comparable with or even better than that of currently recommended first-line therapies is still unknown. Our study aims to compare the eradication rate and major adverse effects between 7-day vonoprazan-based triple therapy with high-dose amoxicillin and 14-day extended sequential therapy.

Methods

We performed a retrospective analysis from the database of ¹³C-urea breath test at Fu Jen Catholic University Hospital. All patients with a definite diagnosis of Helicobacter pylori infection by rapid urease test, urea breath test, stool antigen test, or pathology report were recruited. Patients receiving first-line regimens with vonoprazan-based triple therapy or extended sequential therapy were included. The respective eradication rate determined by ¹³C-urea breath test and major adverse effects were demonstrated.

Results

Totally, 106 patients were recruited in the vonoprazan-based triple therapy group and 357 in the extended sequential therapy group. There was no significant difference in eradication rate between vonoprazan-based triple therapy with high-dose amoxicillin and extended sequential therapy (83.0 vs 88.8%, P = 0.12). Major adverse effects occurred in 13 of the extended sequential therapy group but none in the other group (0% vs 3.6%, P = 0.046).

Conclusions

Seven-day vonoprazan-based triple therapy with high-dose amoxicillin is a potential first-line anti-Helicobacter pylori regimen alternative to current standard treatment, with the advantages of simplicity, short treatment duration, low pill burden, and fewer major adverse effects.

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

BACKGROUND

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

RESEARCH DESIGN AND METHODS

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

RESULTS

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

CONCLUSIONS

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

TRIAL REGISTRATION

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

The role of vonoprazan in patients with erosive esophagitis

Acid suppression is the primary therapy for erosive esophagitis (EE). Although proton pump inhibitors (PPIs) are considered as the first-line medication for EE, 10-20% of patients with Los Angeles C and D grade EE do not gain complete mucosal healing and symptom control despite 8-week double-dose PPI treatment. Vonoprazan is a novel potassium-competitive acid blocker (P-CAB), which blocks the H+, K+-adenosine triphosphatase enzymes in a K+-competitive and reversible manner. Vonoprazan exhibits different pharmacological and pharmacokinetic profiles from conventional PPIs, and has a rapid, potent and sustained acid inhibitory effect. In this review, we summarized and discussed current evidence regarding the role of vonoprazan in terms of mucosal healing, maintaining remission and symptom relief for the management of EE, including the initial and maintenance treatment of EE, as well as for PPI-resistant EE patients. Safety concerns and cost-effectiveness analysis of vonoprazan were also mentioned in the article. As a potent and well-tolerated acid blocker, vonoprazan has the potential to become a novel option for the management of EE.

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

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

Gastroprotective Effects of Spirulina platensis, Golden Kiwifruit Flesh, and Golden Kiwifruit Peel Extracts Individually or in Combination against Indomethacin-Induced Gastric Ulcer in Rats

This study was conducted to investigate the therapeutic effect of hydro-alcoholic extract of Spirulina platensis (SP), golden kiwifruit (Actinidia chinensis) flesh (KF), and golden kiwifruit peel (KP) individually or in combination (SFP) on indomethacin-induced gastric ulcer in rats. Negative control rats (GI) were orally administered distilled water in parallel with other treatments. The positive control rat group (GII) was administered 30 mg kg⁻¹ indomethacin to induce gastric ulcers. The KF and KF extracts were used individually or together with SP in treating indomethacin-induced gastric ulcerated rat groups. Gastric ulcerated rat’s groups GIII, GIV, GV, GVI, and GVII were orally administered at 30 mg kg⁻¹ rat body weight as total phenolic content (TPC) equivalent from SP, KF, KP, SPF extracts, and Lansoprazole (30 mg kg⁻¹, as reference drug) daily up to 14 days, respectively. The relevant biochemical parameters, antioxidant biomarkers, and histopathological examination were examined. Remarkably, treating rats with SP, KF, KP, and SFP extracts markedly reduced gastric juice and stomach volume expansion induced by indomethacin. The SP significantly retrieved the pH of gastric juice to a regular rate compared to GI. The ulcer index (UI) was significantly attenuated by SP, KF, KP, and SFP administration. The protection index percentage (PI %) was 80.79, 54.51, 66.08, 75.74, and 74.86% in GIII, GIV, GV, GVI, and GVII, respectively. The gastric mucin content was significantly better attenuated by 95.7 in GIII compared to its content in GI. Lansoprazole increased mucin content by 80.3%, which was considerably lower than SP and SFP. SP, KF, KP, SFP, and Lansoprazole improved the reform of gastric mucosal-increased secreted mucus by 95.6, 61.3, 64.8, 103.1, and 80.2% in GIII, GIV, GV, GVI, and GVII, respectively. Interestingly, SFP efficiently increased vit. B₁₂ level by 46.0% compared to other treatments. While Lansoprazole administrating did not significantly attenuate vit. B₁₂ level. The SP and SFP improved iron and Hemoglobin (HB) levels depending on treatment. SP, KF, KP, and SFP significantly decreased the malondialdehyde (MDA) and increased reduced glutathione (GSH) as well as superoxide dismutase (SOD) levels in blood and stomach tissues. The most potent effect was observed with SP, and SFP was even better than Lansoprazole. Histopathologically, treating rats with SP extract showed a marked reduction of gastric damage and severity changes induced by indomethacin. KP was much better than KF in lessening gastric histopathological damages caused by indomethacin. SFP significantly alleviates gastric histopathological alterations. The lansoprazole-treated group (GVII) greatly relieved the gastric histopathological changes and recorded mild focal necrosis and desquamation of the mucosa in addition to mild oedema in the serosal layer. In conclusion, the presented results proved the antiulcer potential of SP and A. chinensis extracts against an indomethacin-induced gastric ulcer in rats, which may be due to their antioxidant and anti-inflammation efficiency. Thus, these data suggested that SP, KF, KP, and SFP extracts as natural and safe alternatives have a gastroprotective potential against indomethacin-induced gastric ulceration. The antioxidative and anti-inflammatory properties are probable mechanisms.

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

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

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

Background

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

Methods

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

Results

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

Conclusions

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

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

High-dose dual therapy versus bismuth-containing quadruple therapy for the treatment of Helicobacter pylori infection – A review of the strengths, weaknesses, and proposed solutions

Helicobacter pylori is the principal cause of peptic ulcers, gastric cancer, and mucosa-associated lymphoid tissue lymphoma. The first treatment to H. pylori infection is dual therapy (a bismuth compound plus metronidazole). On the launch of omeprazole in 1988, dual therapy became omeprazole and amoxicillin (low dose). The poor H. pylori eradication rates by either bismuth-based or low-dose dual therapy drove more combinations of antibiotics were needed. Antibiotic resistance, especially clarithromycin and metronidazole, has made bismuth-containing quadruple therapy (BCQT) a savior for first-line and second-line treatments. However, its complicated dosing regimen commonly causes more adverse events and poor drug compliance. Thus, high-dose dual therapy (HDDT) has been re-arising. This article reviews the strengths and weaknesses of HDDT versus BCQT with proposed solutions.

Direct Comparison of the Efficacy and Safety of Vonoprazan Versus Proton-Pump Inhibitors for Gastroesophageal Reflux Disease: A Systematic Review and Meta-Analysis

BACKGROUND

Gastroesophageal reflux disease (GERD) is a common disorder, and is typically treated with proton-pump inhibitors (PPIs) as the recommended first-line therapy. Recently, a new potassium-competitive acid blocker, vonoprazan, was launched in Japan. It is uncertain whether the standard dose of vonoprazan 20 mg is superior to that of PPIs for GERD, so a direct comparison of the therapeutic effects and adverse events between vonoprazan 20 mg and PPIs is needed.

METHODS

MEDLINE, the Cochrane Central Register of Controlled Trials, and Embase were chosen as the literature sources. Randomized controlled trials for vonoprazan 20 mg and PPIs published in English were searched. Data from studies meeting the eligibility criteria were extracted individually by two researchers and compared to maintain consistency.

RESULTS

Fifty-six articles were identified in the databases, and one study was manually searched and added to the analysis, ultimately yielding six eligible studies. For the main analysis, the risk ratios (RR) of efficacy and adverse events between vonoprazan and PPIs were 1.06 (0.99-1.13) and 1.08 (0.96-1.22), respectively. Subgroup analysis for patients with severe esophagitis at baseline showed significantly higher results for vonoprazan than lansoprazole, with an RR of 1.14 (1.06-1.22).

CONCLUSIONS

Our findings suggest that vonoprazan is non-inferior to PPIs as therapy for patients with GERD. Subgroup analysis indicates that vonoprazan is more effective than PPIs for patients with severe erosive esophagitis. The safety outcomes for vonoprazan are similar to those for PPIs.

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

Background

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

Materials and methods

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

Results

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

Conclusion

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

Randomised clinical trial: tegoprazan, a novel potassium-competitive acid blocker, or lansoprazole in the treatment of gastric ulcer

BACKGROUND

Tegoprazan is a novel potassium-competitive acid blocker for the treatment of acid-related disorders.

AIMS

To assess whether tegoprazan is non-inferior to lansoprazole in terms of efficacy and safety in patients with gastric ulcers.

METHODS

In this phase 3, double-blind, active control, multicentre study, 306 gastric ulcer patients were randomised to one of three treatment groups: tegoprazan 50 mg, tegoprazan 100 mg and lansoprazole 30 mg once daily for 4 or 8 weeks. The primary endpoint was the cumulative proportion of patients with healed ulcers confirmed by endoscopy up to 8 weeks from treatment initiation. Symptoms and safety were assessed.

RESULTS

In the full analysis set, the cumulative healing rates at week 8 were 94.8% (91/96) for the tegoprazan 50 mg, 95.0% (94/99) for the tegoprazan 100 mg and 95.7% (89/93) for the lansoprazole 30 mg groups. At week 4, the respective healing rates were 90.6% (87/96), 91.9% (91/99), and 89.2% (83/93). In per protocol analysis, 4-week healing rates were 95.4% (84/88), 94.6% (88/93) and 92.9% (79/85) for tegoprazan 50 mg, tegoprazan 100 mg and lansoprazole 30 mg, respectively. Both doses of tegoprazan were non-inferior to lansoprazole in ulcer healing at 4 and 8 weeks. The incidence of drug-related treatment-emergent adverse events did not differ among groups. The increase in serum gastrin concentration was not higher in tegoprazan-treated patients than in lansoprazole-treated patients.

CONCLUSIONS

Tegoprazan 50 or 100 mg were not inferior to lansoprazole 30 mg once daily in the treatment of gastric ulcers.

Upper gastrointestinal bleeding in Japanese patients with ischemic heart disease receiving vonoprazan or a proton pump inhibitor with multiple antithrombotic agents: A nationwide database study

BACKGROUND

Vonoprazan has been launched as an alternative to proton-pump inhibitors (PPIs). This was the first study to compare the occurrence of upper gastrointestinal bleeding (UGIB) with vonoprazan treatment to that with PPI treatment in patients with ischemic heart disease (IHD) taking ≥2 antithrombotic agents, including those receiving dual antiplatelet therapy (DAPT).

METHODS

Using Japanese Diagnosis Procedure Combination data from 2016 to 2017, we identified 16,415 patients with IHD who were prescribed ≥2 antithrombotic agents, including new antiplatelet medication with concurrent vonoprazan (n = 2226 or PPIs n = 14,189). UGIB occurrence was analyzed using an inverse probability-weighted Cox proportional hazards model. Non-inferiority of vonoprazan to PPI treatment for UGIB occurrence was assessed.

RESULTS

Six-month incidence of UGIB in patients treated with vonoprazan and PPIs was 3.14% 70/2226 and 4.17% (591/14,189), respectively. The adjusted hazard ratio (aHR) of 0.84 was significantly below the non-inferiority margin (HR 2.06) (p < 0.0001), and thus demonstrated that vonoprazan treatment was non-inferior to PPIs in terms of occurrence of UGIB events. The difference between the 2 treatments was also not statistically significant [aHR 0.84; 95% confidence interval (CI): 0.65-1.07; p = 0.154). In a subgroup analysis, UGIB occurrence with vonoprazan and other PPI treatment in patients receiving DAPT was 2.82% (22/779) and 3.96% (209/5276) respectively; a non-significant difference (aHR 0.74; 95% CI: 0.48-1.16; p = 0.189) that demonstrated non-inferiority (p < 0.0001).

CONCLUSIONS

Vonoprazan was non-inferior to PPIs in terms of UGIB occurrence over 6 months in patients with IHD receiving ≥2 antithrombotic agents, including new antiplatelet medication.

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

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

Efficacy of vonoprazan for initial and maintenance therapy in reflux esophagitis, nonerosive esophagitis, and proton pump inhibitor-resistant gastroesophageal reflux disease

Proton pump inhibitors (PPIs) have been the first line treatment for gastroesophageal reflux disease (GERD). The aim of this study was to evaluate the efficacy of vonoprazan (VPZ), a potassium-competitive acid blocker for reflux esophagitis (RE), nonerosive reflux disease (NERD), and PPI-resistant GERD patients.An open-label, single-center, observational study in our hospital was performed from August 2016 to August 2017. All patients diagnosed with GERD were asked to self-report a questionnaire of frequency scale for the symptoms of GERD (FSSG) and rate their degree of satisfaction with the treatment of GERD during outpatient visit. A total of 200 (RE 47, NERD 49, PPI-resistant GERD 104) patients were included in the present study. The primary endpoint was the change of FSSG and the proportion of degree of satisfaction with the treatment at the end of the initial therapy. A percentage of improvement (improvement rate) and resolution (resolution rate) at the end of the initial therapy were evaluated. Secondary endpoint included the proportion of patients with symptomatic relapse in the 24-week maintenance phase.FSSG and the degree of satisfaction were significantly improved after the initial therapy in every group. Improvement and resolution rate after the initial therapy were 83.0% and 67.0% in RE, 66.7% and 60.4% in NERD, and 76.0% and 60.4% in PPI-resistant group. There was no significance between after the initial therapy and 24 weeks in improvement and resolution rate. Thirty-two of the total 48 patients did not take VPZ at 24 weeks. Total FSSG score in each group was 1.67 ± 1.97, 2.71 ± 4.91, and 4.0 ± 4.93. The nonrelapse rate at 24 weeks in each group was 66.7%, 60.0%, and 50.0%. The resolution rate at 24 weeks in each group was 38.9%, 45.0%, and 30.0%.The VPZ therapy is effective for initial and maintenance therapy and improves heartburn and patient's satisfaction significantly in all 3 groups. Among patients who stopped taking VPZ during the maintenance period, 42.0% of RE and NERD group and 30% of PPI-resistant group experience complete remission from GERD at 24 weeks by introduction of VPZ.

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.

Cost-utility analysis of a 'vonoprazan-first' strategy versus 'esomeprazole- or rabeprazole-first' strategy in GERD

BACKGROUND

Gastroesophageal reflux disease (GERD) can be treated using a vonoprazan-first strategy (first-line treatment with vonoprazan), or esomeprazole-first/rabeprazole-first strategies (first-line treatment with proton-pump inhibitors [PPIs], esomeprazole/rabeprazole, followed by a switch to vonoprazan). This cost-utility analysis used long-term simulation modeling to evaluate the cost-effectiveness of a vonoprazan-first strategy compared with the esomeprazole-first and rabeprazole-first strategies.

METHODS

A Markov simulation model was developed to evaluate the cost-effectiveness of vonoprazan-first, esomeprazole-first, and rabeprazole-first strategies, comprising healing and maintenance therapies, over 5 years (4-week cycles). Healing therapy began with the administration of a normal dose of drug per real-world practice. If patients were not healed endoscopically, either a longer duration of healing therapy was provided (vonoprazan), the dose was increased (rabeprazole), or patients were switched to vonoprazan (immediately for esomeprazole, and after dose-escalation for rabeprazole, respectively). Healed patients received maintenance (lower/same dose as healing therapy). Recurrence resulted in re-challenge with healing therapy. Transition probabilities were derived from the results of indirect comparisons (network meta-analysis) and costs calculated from the Japanese payer perspective. Outcomes were defined as quality-adjusted life years (QALYs), with utilities based on published values.

RESULTS

Expected costs of the vonoprazan-, esomeprazole-, and rabeprazole-first strategies were ¥36,194, ¥76,719, and ¥41,105, respectively, over 5 years. QALY gains for vonoprazan-first strategy versus the esomeprazole- and rabeprazole-first strategies were 0.014 and 0.003, respectively. Both estimated incremental cost-effectiveness ratios were dominant and robust to two sensitivity analyses.

CONCLUSIONS

Vonoprazan-first strategy increased QALYs and appeared to be cost-effective for GERD patients compared with the esomeprazole- or rabeprazole-first strategies.

Development of Helicobacter pylori treatment: How do we manage antimicrobial resistance?

Helicobacter pylori (H. pylori) antimicrobial resistance is an urgent, global issue. In 2017, the World Health Organization designated clarithromycin-resistant H. pylori as a high priority bacterium for antibiotic research and development. In addition to clarithromycin, resistance to metronidazole and fluoroquinolones has also increased worldwide. Recent international guidelines for management of H. pylori infection recommend bismuth or non-bismuth quadruple therapy for 14 d as a first-line treatment for H. pylori in areas of high clarithromycin and/or metronidazole resistance. Although these treatment regimens provide acceptable H. pylori eradication rates, the regimens used should not contribute to future resistance of H. pylori to antimicrobials. Moreover, these regimens can promote resistance, due to prolonged therapy with multiple antibiotics. A new strategy that can eradicate H. pylori as well as reduce the antibiotics used is required to prevent future antimicrobial resistance in H. pylori. Dual-therapy with vonoprazan and amoxicillin could be a breakthrough for H. pylori eradication in an era of growing antimicrobial resistance. This regimen may provide a satisfactory eradication rate of H. pylori and also minimize antimicrobial resistance due to single antibiotic use and the strong inhibitory effect of vonoprazan on gastric acid secretion.

A prospective randomized trial of a potassium competitive acid blocker vs proton pump inhibitors on the effect of ulcer healing after endoscopic submucosal dissection of gastric neoplasia

Background/Aims

Vonoprazan is a new a potassium-competitive acid blocker (P-CAB) that was recently developed in Japan. However, vonoprazan’s efficacy in healing gastric ulcers after endoscopic submucosal dissection (ESD) remains controversial. This study aimed to compare the efficacy of P-CABs and proton pump inhibitors (PPIs) in healing post-ESD ulcers.

Materials and Methods

This prospective randomized controlled trial (UMIN000017386) enrolled 40 patients with gastric neoplasia, who underwent ESD at our hospital from April 2015 to January 2016. Before ESD, patients were randomly divided into the following two groups: group V, vonoprazan 20 mg/day; or group R, rabeprazole 10 mg/day. Medications were taken 1 day before to 4 weeks after ESD. The ESD-induced artificial ulcer size was measured just after ESD and 4 weeks after ESD to calculate the reduction rate as follows: (ulcer area 4 weeks after ESD)/(ulcer area just after ESD) × 100.

Results

Eighteen patients in group V and 15 patients in group R were analyzed. The mean reduction rate was significantly different in groups V and R (93.3% vs 96.6%, respectively). Post-ESD bleeding was observed in two patients in group R and drug-induced hepatic injury in one patient in group R.

Conclusion

Rabeprazole facilitated the healing process post-ESD.

Comparison of the Use of Vonoprazan and Proton Pump Inhibitors for the Treatment of Peptic Ulcers Resulting from Endoscopic Submucosal Dissection: A Systematic Review and Meta-Analysis

BACKGROUND Currently, proton pump inhibitors (PPIs) are the first-line treatment for ulcers resulting from endoscopic submucosal dissection (ESD). Vonoprazan is a new oral potassium-competitive acid blocker (P-CAB). The aim of this systematic review and meta-analysis was to compare the efficacy, safety, and tolerance of vonoprazan with PPIs in the treatment of peptic ulcers resulting from ESD. MATERIAL AND METHODS Published results of randomized clinical trials (RCTs) comparing vonoprazan with PPIs in the treatment of ulcers resulting from ESD were identified up to March 2018. The main clinical endpoints evaluated were healing rate and adverse events. The meta-analysis included quality assessment of the studies, statistical analysis of endpoints, and sensitivity analysis using Revman version 5.3 meta-analysis software. RESULTS Systematic literature review identified seven published studies that included 548 patients. Five studies were published as full-text manuscripts, and two studies were published as abstracts. Meta-analysis of the vonoprazan treatment, compared with PPI treatment, for ESD showed that the pooled relative risk (RR) of healing rate was 0.64 (95% CI, 0.33-1.22) for the 4-week study group and 0.98 (95% CI, 0.84-1.15) for the 8-week study group. The RR for adverse events was 0.65 (95% CI, 0.31-1.38) (P>0.05). No statistical evidence of publication bias was found. CONCLUSIONS The findings of the systematic review and meta-analysis showed that the efficacy of vonoprazan was comparable with PPIs for the treatment of peptic ulcers following ESD. Further studies are required to support the safety and efficacy of vonoprazan compared with different types of PPIs.

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.

Vonoprazan is Superior to Rabeprazole for Healing Endoscopic Submucosal Dissection: Induced Ulcers

BACKGROUND AND AIMS

Endoscopic submucosal dissection (ESD) is a well-established minimally invasive treatment for early gastric cancer. To heal ESD-induced ulcers, we commonly prescribe proton pump inhibitors (PPIs). Vonoprazan is our new choice, which is reported to have a stronger and longer acid inhibitory effect than existing PPIs. Here, we aimed to evaluate the efficacy of vonoprazan for healing ESD-induced ulcers compared with rabeprazole.

METHODS

We reviewed 190 patients who underwent ESD before and after we switched the acid secretion inhibitor from rabeprazole to vonoprazan. We evaluated scarring and reduction rates at 4 weeks after ESD.

RESULTS

Scarring rates were not different between vonoprazan and rabeprazole (31.7 vs. 18.9%; p = 0.07). However, for ulcers ≤35 mm, vonoprazan was superior to rabeprazole (42.2 vs. 19.2%; p < 0.05). Reduction rates were superior for vonoprazan compared with rabeprazole (93.0 vs. 90.4%; p < 0.05). In multivariate analysis, vonoprazan was superior to rabeprazole for ulcer scarring (OR 2.21; p < 0.05), and ulcer location in the lower-third of the stomach had higher risk of incomplete scarring (OR 0.37; p < 0.05).

CONCLUSION

Vonoprazan was superior to rabeprazole for healing ESD-induced ulcers.

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.

Second-line triple therapy in failures with vonoprazan-based triple therapy for eradication of Helicobacter pylori

Gastric acid inhibition during treatment is important for the eradication of Helicobacter pylori (H. pylori) infection. A novel potassium-competitive acid blocker, vonoprazan (VPZ), has been demonstrated to achieve high eradication rates; however, the efficacy of second-line treatment in failures of VPZ-based triple therapy has not been well studied. The aim of the current study was to determine the efficacy of VPZ in a first-line regimen for H. pylori eradication, and the efficacy of a second-line regimen using metronidazole (MTZ) in failures with the first-line regimen. Of 580 subjects enrolled in the study, 524 patients completed first-line treatment (275 patients who received VPZ and 249 patients who received LPZ). First-line regimens consisted of a combination of clarithromycin (CAM) 200 or 400 mg twice a day, amoxicillin (AMPC) 750 mg twice a day, and either LPZ 30 mg or VPZ 20 mg twice a day, administered orally for 7 days. CAM and VPZ/LPZ were replaced with metronidazole (MTZ) 250 mg and rabeprazole 10 mg in the second-line regimens. The eradication of H. pylori was assessed by the H. pylori stool antigen test. The overall first-line eradication rate with VPZ was significantly higher than that with LPZ [91.0% (250/275) vs. 84.7% (211/249), respectively, P=0.030]. The dose of CAM (400 vs. 800 mg) did not affect the eradication rate in either the VPZ or LPZ regimens. The overall eradication rates of the second-line regimens with MTZ did not differ significantly between the VPZ-failure and LPZ-failure groups [87.0% (20/23) vs. 87.9% (29/33), respectively, P=0.700]. Therefore, VPZ was significantly more effective than LPZ for first-line treatment. In patients with failure of first-line eradication therapy, successful results of second-line eradication therapy did not differ between the VPZ- and LPZ-failure groups. In conclusion, VPZ-based triple therapy should be recommended for eradication of H. pylori.

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.

The Effects of Switching to Vonoprazan, a Novel Potassium-Competitive Acid Blocker, on Gastric Acidity and Reflux Patterns in Patients with Erosive Esophagitis Refractory to Proton Pump Inhibitors

BACKGROUND/AIM

The effects of vonoprazan and proton pump inhibitors (PPIs) in patients with reflux esophagitis (RE) have not yet been compared using multichannel intraluminal impedance-pH (MII-pH).

METHODS

A total of 8 patients with persistent gastric mucosal injury, despite completing an 8-week standard PPI therapy, were enrolled in the study. While they were on standard PPI therapy, the baseline values of reflux parameters, holding time ratio (HTR) of gastric pH >4, and esophageal pH <4 were obtained by using 24 h MII-pH monitoring. They were re-evaluated after discontinuation of the therapy and 4 weeks of subsequent treatment with vonoprazan 20 mg/day.

RESULTS

The patients were found to be CYP2C19 extensive metabolizers and negative for Helicobacter pylori infection. In 7 patients (87.5%), the mucosal lesions had healed completely after vonoprazan therapy. A significant increase in gastric pH >4 HTR was observed, from 26.5 to 78.0% (p = 0.029). A reduction in esophageal pH <4 HTR was also observed but it was not statistically significant. Furthermore, acid clearance time and the total number of reflux events, including acid and proximal reflux events, were significantly reduced.

CONCLUSION

Vonoprazan may be a better therapy for the treatment of patients with PPI-refractory RE.

Maintenance for healed erosive esophagitis: Phase III comparison of vonoprazan with lansoprazole

AIM

To compare vonoprazan 10 and 20 mg vs lansoprazole 15 mg as maintenance therapy in healed erosive esophagitis (EE).

METHODS

A total of 607 patients aged ≥ 20 years, with endoscopically-confirmed healed EE following 8 wk of treatment with vonoprazan 20 mg once daily, were randomized 1:1:1 to receive lansoprazole 15 mg (n = 201), vonoprazan 10 mg (n = 202), or vonoprazan 20 mg (n = 204), once daily. The primary endpoint of the study was the rate of endoscopically-confirmed EE recurrence during a 24-wk maintenance period. The secondary endpoint was the EE recurrence rate at Week 12 during maintenance treatment. Additional efficacy endpoints included the incidence of heartburn and acid reflux, and the EE healing rate 4 wk after the initiation of maintenance treatment. Safety endpoints comprised adverse events (AEs), vital signs, electrocardiogram findings, clinical laboratory results, serum gastrin and pepsinogen I/II levels, and gastric mucosa histopathology results.

RESULTS

Rates of EE recurrence during the 24-wk maintenance period were 16.8%, 5.1%, and 2.0% with lansoprazole 15 mg, vonoprazan 10 mg, and vonoprazan 20 mg, respectively. Vonoprazan was shown to be non-inferior to lansoprazole 15 mg (P < 0.0001 for both doses). In a post-hoc analysis, EE recurrence at Week 24 was significantly reduced with vonoprazan at both the 10 mg and the 20 mg dose vs lansoprazole 15 mg (5.1% vs 16.8%, P = 0.0002, and 2.0% vs 16.8%, P < 0.0001, respectively); by contrast, the EE recurrence rate did not differ significantly between the two doses of vonoprazan (P = 0.1090). The safety profiles of vonoprazan 10 and 20 mg were similar to that of lansoprazole 15 mg in patients with healed EE. Treatment-related AEs were reported in 11.4%, 10.4%, and 10.3% of patients in the lansoprazole 15 mg, vonoprazan 10 mg, and vonoprazan 20 mg arms, respectively.

CONCLUSION

Our findings confirm the non-inferiority of vonoprazan 10 and 20 mg to lansoprazole 15 mg as maintenance therapy for patients with healed EE.

Comparison of the Effects of Vonoprazan and Lansoprazole for Treating Endoscopic Submucosal Dissection-Induced Artificial Ulcers

BACKGROUND

Vonoprazan exhibits a more potent, rapid, and longer-lasting inhibitory effect on gastric acid secretion than proton pump inhibitors; however, whether it is more effective than PPI for treating endoscopic submucosal dissection (ESD)-induced artificial ulcers remains controversial.

AIM

This study aimed to assess and compare the effects of vonoprazan and lansoprazole for treating ESD-induced artificial ulcers.

METHODS

This prospective, randomized controlled trial enrolled 149 patients who underwent ESD for the treatment of early gastric neoplasms from April 2015 to May 2017. They were randomly treated with either 20 mg/day vonoprazan (V group) or 30 mg/day lansoprazole (L group) orally. The primary end points were the area and shrinkage ratio of the ulcers at 4 and 8 weeks post-ESD.

RESULTS

Data from 127 patients were analyzed, which showed that the 4- and 8-week healing ratios were not significantly different between the V and L groups (4 weeks, 16.3 vs. 25.8%; 8 weeks, 86.9 vs. 90.9%, respectively). Similarly, the shrinkage ratio, categorized as less than 90%, 90% or more but less than 100%, or 100% at 4 weeks and as less than 100% or 100% at 8 weeks were not statistically different between the V and L groups (4 weeks: 12, 41, 8 vs. 13, 41, 12, p = 0.7246; 8 weeks: 9, 52 vs. 9, 57, p = 0.8568). Delayed bleeding was also not significantly different between both the groups (5.4 vs. 5.3%; p = 0.9844).

CONCLUSIONS

Vonoprazan is as effective as lansoprazole in treating ESD-induced ulcers.

Rationale and design of the VISION study: a randomized, open-label study to evaluate the long-term safety of vonoprazan as maintenance treatment in patients with erosive esophagitis

Erosive esophagitis (EE) occurs when the epithelial mucosa is damaged due to gastric acid reflux, and the incidence of this disease is increasing in Japan due to changes in diet and lifestyle. The condition can be treated using proton pump inhibitors (PPIs) that act by irreversibly blocking the H+,K+-ATPase responsible for acid secretion. Vonoprazan is a K+ competitive channel inhibitor, which reversibly and potently inhibits gastric acid secretion. However, long-term data on vonoprazan use are limited. The aim of the VISION trial is to investigate the long-term efficacy and safety of vonoprazan in comparison with the PPI lansoprazole. This randomized, multicenter, 5-year, open-label study has a planned recruitment of 195 participants (2:1 allocation vonoprazan:lansoprazole) from 33 sites in Japan. The study comprises an 8-week "healing" phase (vonoprazan 20 mg or lansoprazole 30 mg p.o.) and a 260-week "maintenance" phase (vonoprazan 10 mg or lansoprazole 15 mg). Safety populations in both phases are defined as participants who receive at least one dose of the study or control drug in the healing and maintenance phases, respectively. The full analysis set in both phases is defined as participants who are randomized and receive at least one dose of the study or control drug in the healing and maintenance phases, respectively. The primary endpoint of the study is the histopathological evaluation of gastric mucosa for the presence of neoplastic alteration of gastric mucosal epithelial cells. Secondary efficacy endpoints include endoscopic EE recurrence rate and EE healing rate, and secondary safety endpoints include incidence of adverse events (coded using MedDRA terminology) and endoscopic evaluation of malignant changes in the gastric mucosa. Patient recruitment started in March 2016 and is now complete. The estimated study completion date is February 2022.

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

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

A review of medical therapy for proton pump inhibitor nonresponsive gastroesophageal reflux disease

Up to 40% of patients report persistent gastroesophageal reflux disease (GERD) symptoms despite proton pump inhibitor (PPI) therapy. This review outlines the evidence for medical therapy for PPI nonresponsive GERD. A literature search for GERD therapies from 2005 to 2015 in PubMed, EMBASE, Cochrane Central Register of Controlled Trials, and the Cochrane Database of Systematic Reviews identified 2928 unique citations. Of those, 40 unique articles specific to the impact of PPI metabolizer genotype on PPI response and the use adjunctive medical therapies were identified. Thirteen articles reported impacts on CYP genotypes on PPI metabolism demonstrating lower endoscopic healing rates in extensive metabolizers; however, outcomes across genotypes were more uniform with more CYP independent PPIs rabeprazole and esomeprazole. Twenty-seven publications on 11 adjunctive medications showed mixed results for adjunctive therapies including nocturnal histamine-2 receptor antagonists, promotility agents, transient lower esophageal sphincter relaxation inhibitors, and mucosal protective agents. Utilizing PPI metabolizer genotype or switching to a CYP2C19 independent PPI is a simple and conservative measure that may be useful in the setting of incomplete acid suppression. The use of adjunctive medications can be considered particularly when the physiologic mechanism for PPI nonresponse is suspected. Future studies using adjunctive medications with improved study design and patient enrollment are needed to better delineate medical management options before proceeding to antireflux interventions.

Vonoprazan fumarate for the management of acid-related diseases

INTRODUCTION

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