A randomized, double-blind study to evaluate the acid-inhibitory effect of vonoprazan (20 mg and 40 mg) in patients with proton-pump inhibitor-resistant erosive esophagitis

Treatment Response With Potassium-competitive Acid Blockers Based on Clinical Phenotypes of Gastroesophageal Reflux Disease: A Systematic Literature Review and Meta-analysis

Background/Aims

Gastroesophageal reflux disease (GERD) is typically managed based on the clinical phenotype. We evaluated the efficacy and safety of potassium-competitive acid blockers (PCABs) in patients with various clinical GERD phenotypes.

Methods

Core databases were searched for studies comparing PCABs and proton pump inhibitors (PPIs) in clinical GERD phenotypes of erosive reflux disease (ERD), non-erosive reflux disease (NERD), PPI-resistant GERD and night-time heartburn. Additional analysis was performed based on disease severity and drug dosage, and pooled efficacy was calculated.

Results

In 9 randomized controlled trials (RCTs) evaluating the initial treatment of ERD, the risk ratio for healing with PCABs versus PPIs was 1.09 (95% CI, 1.04-1.13) at 2 weeks and 1.03 (95% CI, 1.00-1.07) at 8 weeks, respectively. PCABs exhibited a significant increase in both initial and sustained healing of ERD compared to PPIs in RCTs, driven particularly in severe ERD (Los Angeles grade C/D). In 3 NERD RCTs, PCAB was superior to placebo in proportion of days without heartburn. Observational studies on PPI-resistant symptomatic GERD reported symptom frequency improvement in 86.3% of patients, while 90.7% showed improvement in PPIresistant ERD across 5 observational studies. Two RCTs for night-time heartburn had different endpoints, limiting meta-analysis. Pronounced hypergastrinemia was observed in patients treated with PCABs.

Conclusions

Compared to PPIs, PCABs have superior efficacy and faster therapeutic effect in the initial and maintenance therapy of ERD, particularly severe ERD. While PCABs may be an alternative treatment option in NERD and PPI-resistant GERD, findings were inconclusive in patients with night-time heartburn.

Efficacy and safety of potassium-competitive acid inhibitors in the treatment of gastroesophageal reflux: a systematic review and meta-analysis

BACKGROUND

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, the potassium-competitive acid inhibitors have been increasingly in use in clinical practice. We aimed to evaluate the efficacy and safety of P-CABs in GERD.

METHODS

We searched PubMed, the Cochrane Library, EMBASE and Web Of Science for publications regarding randomized controlled trials comparing potassium-competitive acid inhibitors to PPI monotherapy or Placebo with respect to efficacy and safety in GERD (until April 2023). The primary outcome was an absence or global symptom improvement and the incidence of adverse events in GERD. The quality of the included literature was assessed using the bias assessment tool recommended in the Cochrane Systematic Assessor's Handbook 5.1.0. We use RevMan 5.3 software for Meta-analysis, sensitivity analysis and publication bias analysis.

RESULTS

Of the 991 screened studies, 14 studies including 4868 participants were analyzed. The ORs for the healing rates of GERD with P-CABs versus PPI/Placebo were 2.10 (95% confidence interval [CI] 1.53-2.88), additionally, 1.09 (95% CI 1.05-1.14), 1.03 (95% CI 1.00-1.06) and 1.03 (95% CI 0.99-1.06) in Weeks 2, 4, and 8, respectively. The effectiveness rate of the experimental group was significantly higher than that of the control group (RR 1.73; 95% CI 1.27-2.36). The overall OR of Incidence of adverse events with P-CABs versus PPI/Placebo was 1.08 (95% CI 0.88-1.12). Overall, the risk of bias was low to some concerns. Furthermore, sensitivity analyses confirmed the robustness of the study's conclusion.

CONCLUSIONS

Our findings suggest that potassium-competitive acid inhibitors is non-inferior to PPIs as therapy for patients with GERD. The safety outcomes for potassium-competitive acid inhibitors are similar to those for PPIs.

A Phase III Head-to-Head Study to Compare the Efficacy and Safety of Fexuprazan and Esomeprazole in Treating Patients with Erosive Esophagitis

Background: Fexuprazan (Fexuclue®; Daewoong Pharmaceutical Co., Ltd., Seoul, Korea) is a novel potassium-competitive acid blocker (P-CAB). This multi-center, randomized, double-blind, active-controlled, parallel-group, therapeutic confirmatory, phase III study was conducted to assess its efficacy and safety compared with esomeprazole (Nexium®; AstraZeneca, Gothenburg, Mölndal, Sweden) in Korean patients with erosive esophagitis (EE). Methods: This study evaluated patients diagnosed with EE at a total of 25 institutions in Korea between 13 December 2018 and 7 August 2019. After voluntarily submitting a written informed consent form, the patients were evaluated using a screening test and then randomized to either of the two treatment arms. The proportion of the patients who achieved the complete recovery of mucosal breaks at 4 and 8 weeks, the proportion of those who achieved the complete recovery of heartburn at 3 and 7 days and 8 weeks, and changes in the GERD-Health-Related Quality of Life Questionnaire (GERD-HRQL) scores at 4 and 8 weeks from baseline served as efficacy outcome measures. The incidence of treatment-emergent adverse events (TEAEs) and adverse drug reactions (ADRs) and the serum gastrin levels served as safety outcome measures. Results: The study population comprised a total of 231 patients (n = 231) with EE, including 152 men (65.80%) and 79 women (34.20%); their mean age was 54.37 ± 12.66 years old. There were no significant differences in the efficacy and safety outcome measures between the two treatment arms (p > 0.05). Conclusions: It can be concluded that the efficacy and safety of Fexuclue® are not inferior to those of esomeprazole in Korean patients with EE.

A systematic review and meta-analysis of the efficacy of vonoprazan for proton pump inhibitor-resistant gastroesophageal reflux disease

BACKGROUND AND AIM

Up to 40% of gastroesophageal reflux disease (GERD) patients experience inadequate symptom relief with a proton pump inhibitor (PPI), termed PPI-resistant or refractory GERD. Vonoprazan, a potassium-competitive acid blocker, has better efficacy than PPI in suppressing gastric acid secretion. This meta-analysis summarizes the efficacy and safety of vonoprazan for treating PPI-resistant GERD (both erosive esophagitis [EE] and non-erosive reflux disease [NERD]).

METHODS

Four electronic databases (Medline, Embase, SCOPUS, and CENTRAL) were searched for studies indexed until August 1, 2023. Both observational studies and clinical trials assessing the efficacy and safety of vonoprazan in PPI-resistant GERD were included. Efficacy outcomes included healing and maintenance rates of EE and improvement of the Frequency Scale for Symptoms of GERD (FSSG) scores. Serious adverse events (SAEs) were considered a safety outcome. The modified Newcastle-Ottawa Scale (NOS) was used to assess study quality.

RESULTS

Twelve studies were included in this meta-analysis. Healing rates of PPI-resistant EE with vonoprazan 20 mg were 91.7% (95% CI 86.8-94.8%) and 88.5% (95% CI 69.7-96.2%) at weeks 4 and 8, respectively. For healed PPI-resistant EE, the overall maintenance rates with vonoprazan 10 mg were 82.6% (95% 61.2-95.0%) at week 8, 86.0% (95% CI 72.1-94.7%) at week 24, and 93.8% (95% CI 69.8-99.8%) at week 48. FSSG scores were improved in 74.6% (95% CI 65.8-81.7%) and 51.9% (95% CI 37.8-65.7%) of patients at weeks 4 and 8. Overall, no SAE was reported.

CONCLUSION

Vonoprazan demonstrated high efficacy in the healing and maintenance of PPI-resistant EE and moderate efficacy for the improvement of FSSG score. Vonoprazan was well tolerated in PPI-resistant GERD patients.

BRAZILIAN CLINICAL GUIDELINE FOR THE THERAPEUTIC MANAGEMENT OF GASTROESOPHAGEAL REFLUX DISEASE (BRAZILIAN FEDERATION OF GASTROENTEROLOGY, FBG)

BACKGROUND

Gastroesophageal Reflux Disease (GERD) is a prevalent condition in Brazil, affecting 12% to 20% of the urban population, with significant implications for patient quality of life and potential for complications.

OBJECTIVE

This paper focuses on the recent update of the Brazilian guidelines for GERD, a necessary revision due to advancements in knowledge and practice since the last publication over a decade ago. The update pays particular attention to the role and safety of proton pump inhibitors (PPIs), acknowledging the growing concerns about their long-term use, adverse events, and overprescription.

METHODS

The methodology of the guideline update involved an extensive literature review in multiple languages (English, French, Italian, Spanish, and Portuguese), drawing from major databases such as Medline, Embase, and SciELO-Lilacs.

RESULTS

This comprehensive approach resulted in a carefully curated selection of studies, systematic reviews, and meta-analyses, specifically focusing on PPIs and other therapeutic strategies for GERD. The updated guidelines are presented in a user-friendly question-and-answer format, adhering to the PICO system (Population, Intervention, Comparison, Outcomes) for clarity and ease of interpretation. The recommendations are supported by robust scientific evidence and expert opinions, enhancing their practical applicability in clinical settings. To ensure the reliability and clarity of the recommendations, the GRADE system (Grading of Recommendations Assessment, Development, and Evaluation) was employed. This system categorizes the strength of recommendations as strong, weak, or conditional and classifies evidence quality as high, moderate, low, or very low. These classifications provide insight into the confidence level of each recommendation and the likelihood of future research impacting these guidelines.

CONCLUSION

The primary aim of these updated guidelines is to offer practical, evidence-based advice for the management of GERD in Brazil, ensuring that healthcare professionals are equipped with the latest knowledge and tools to deliver optimal patient care.

BACKGROUND

•Gastrointestinal specialists rely heavily on guidelines to manage digestive pathologies effectively. The Brazilian clinical guideline for therapeutic management of gastroesophageal reflux disease (GERD) is an invaluable tool for these specialists.

BACKGROUND

•It critically analyzes practical aspects of therapy through 12 questions covering a wide range of topics, from behavioral measures to surgical and endoscopic indications.

BACKGROUND

•The recommendations in this guideline are justified using the GRADE system (Grading of Recommendations Assessment, Development, and Evaluation), and experienced experts provide comments and suggestions at the end of each question.

Randomised clinical trial: Efficacy and safety of on-demand vonoprazan versus placebo for non-erosive reflux disease

BACKGROUND

Non-erosive reflux disease (NERD) symptoms are often episodic, making on-demand treatment an attractive treatment approach.

AIMS

We compared the efficacy and safety of on-demand vonoprazan versus placebo in patients with NERD.

METHODS

Patients with NERD, defined as heartburn for ≥6 months and for ≥4/7 consecutive days with normal endoscopy, received once-daily vonoprazan 20 mg during a 4-week run-in period. Patients without heartburn during the last 7 days and with ≥80% study drug and diary compliance were randomised 1:1:1:1 to vonoprazan 10, 20, 40 mg or placebo on-demand for 6 weeks. The primary endpoint was the percentage of evaluable heartburn episodes completely relieved within 3 h of on-demand dosing and sustained for 24 h.

RESULTS

Of 458 patients in the run-in period, 207 entered the on-demand period. In the vonoprazan 10 mg group, 56.0% (201/359) of evaluable heartburn episodes met the criteria for complete and sustained relief; 60.6% (198/327) in the 20 mg group; and 70.0% (226/323) in the 40 mg group, compared with 27.3% (101/370) in the placebo group (p < 0.0001 versus placebo for each vonoprazan group). By 1 h post-dose, vonoprazan was associated with complete relief of significantly more heartburn episodes compared with placebo. No serious treatment-emergent adverse events were reported.

CONCLUSION

On-demand vonoprazan may be a potential alternative to continued daily acid suppression therapy for the relief of episodic heartburn in patients with NERD.

CLINICALTRIALS

gov: NCT04799158.

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.

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).

Incidence and type of adverse events in patients taking vonoprazan: A systematic review and meta-analysis

Background

Vonoprazan, a novel acid-suppressive drug, is non-inferior to proton pump inhibitors (PPIs) for the management of gastric acid-related diseases. However, the safety of vonoprazan has not been systematically evaluated yet.

Objectives

To elucidate the incidence and type of adverse events (AEs) in patients taking vonoprazan.

Design

Systematic review and meta-analysis.

Data sources and methods

PubMed, EMBASE, and Cochrane Library databases were searched for all studies reporting the safety of vonoprazan. The incidences of any AEs, drug-related AEs, serious AEs, AEs leading to drug discontinuation, and common AEs were pooled. Odds ratios (ORs) were calculated to compare the incidence of AEs between patients taking vonoprazan and PPIs.

Results

Seventy-seven studies were included. The pooled incidences of any AEs, drug-related AEs, serious AEs, and AEs leading to drug discontinuation were 20, 7, 1, and 1%, respectively. The incidences of any AEs (OR = 0.96, p = 0.66), drug-related AEs (OR = 1.10, p = 0.44), serious AEs (OR = 1.14, p = 0.36), and AEs leading to drug discontinuation (OR = 1.09, p = 0.55) were not significantly different between patients taking vonoprazan and PPIs. In subgroup analyses, patients with peptic ulcer disease (PUD) had higher incidences of any AEs, serious AEs, and AEs leading to drug discontinuation than those with gastroesophageal reflux disease (GERD), Helicobacter pylori (H. pylori) infection, and artificial ulcer after gastric endoscopic submucosal dissection (ESD), but patients with H. pylori infection had a higher incidence of drug-related AEs than those with PUD, GERD, and artificial ulcer after gastric ESD. The incidence of AEs was higher in patients taking long-term use of vonoprazan than those taking short-term use of vonoprazan.

Conclusion

Vonoprazan is well tolerated and shows similar safety compared to PPIs. The safety of vonoprazan may be primarily influenced by its indications and duration.

Registration

PROSPERO CRD42022314982.

Randomized controlled trial to evaluate the efficacy and safety of fexuprazan compared with esomeprazole in erosive esophagitis

BACKGROUND

Fexuprazan, a novel potassium-competitive acid blocker, reversibly suppresses the K⁺/H⁺-ATPase enzyme in proton pumps within gastric parietal cells. Fexuprazan’s suppression of gastric acid was maintained in healthy individuals for 24 h in a dose-dependent manner.

AIM

To compare fexuprazan to esomeprazole and establish its efficacy and safety in patients with erosive esophagitis (EE).

METHODS

Korean adult patients with endoscopically confirmed EE were randomized 1:1 to receive fexuprazan 40 mg or esomeprazole 40 mg once daily for eight weeks. The primary endpoint was the proportion of patients with healed EE confirmed by endoscopy at week 8. The secondary endpoints included the healing rate of EE at week 4, symptom response, and quality of life assessment. Safety profiles and serum gastrin levels were compared between the groups.

RESULTS

Of the 263 randomized, 218 completed the study per protocol (fexuprazan 40 mg, n = 107; esomeprazole 40 mg, n = 111). Fexuprazan was non-inferior to esomeprazole regarding the healing rate at week 8 [99.1% (106/107) vs 99.1% (110/111)]. There were no between-group differences in the EE healing rate at week 4 [90.3% (93/103) vs 88.5% (92/104)], symptom responses, and quality of life assessments. Additionally, serum gastrin levels at weeks 4 and 8 and drug-related side effects did not significantly differ between the groups.

CONCLUSION

Fexuprazan 40 mg is non-inferior to esomeprazole 40 mg in EE healing at week 8. We suggest that fexuprazan is an alternative promising treatment option to PPIs for patients with EE.

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.

Potassium-competitive acid blockers and gastroesophageal reflux disease

Proton pump inhibitors (PPIs), the most commonly used antisecretory medi-cations in the management of reflux illness, virtually eliminate elective surgery for ulcer disease, and relegate anti-reflux surgery to patients with gastroesophageal reflux disease (GERD) who are inadequately managed by medical therapy. However, PPI medications still leave some therapeutic demands of GERD unmet. Furthermore, up to 40%-55% of daily PPI users have chronic symptoms, due to PPI refractoriness. Potassium-competitive acid blockers (P-CABs) transcend many of the problems and limits of PPIs, delivering quick, powerful, and extended acid suppression and allowing for treatment of numerous unmet needs. Recently, it has become clear that compromised mucosal integrity plays a role in the etiology of GERD. As a result, esophageal mucosal protection has emerged as a novel and potential treatment approach. An increasing body of research demonstrates that when P-CABs are used as primary drugs or add-on drugs (to regular treatment), they provide a considerable extra benefit, particularly in alleviating symptoms that do not respond to PPI therapy.

A study for every second day administration of vonoprazan for maintenance treatment of erosive GERD (ESD von GERD): a multicenter randomized cross-over study

BACKGROUND

Vonoprazan is a potassium competitive acid blocker used to treat erosive gastroesophageal reflux disease (GERD) with stronger, more stable acid-suppressing effects than proton pump inhibitors (PPIs). This study clarified the usefulness and superiority of vonoprazan administered every second day over PPIs in the maintenance therapy of erosive GERD.

METHODS

This is a prospective, multicenter, open-label, two-period randomized cross-over study. Patients were randomized to either the vonoprazan-lansoprazole (VP-LZ) group, who were given vonoprazan 10 mg for the first 4 weeks and then lansoprazole 15 mg for the next 4 weeks both administered once every second day, or the lansoprazole-vonoprazan (LZ-VP) group, who were treated in reverse. GERD symptoms were compared using symptom diaries, the frequency scale for symptoms of GERD (FSSG), and the gastrointestinal symptom rating scale (GSRS).

RESULTS

We enrolled 122 patients between December 2017 and May 2019. Symptoms were well controlled in vonoprazan administration and lansoprazole administration were 93.6% and 82.1%, respectively, with a significant difference on McNemar's test (P = 0.003). During the second 4 weeks, 94.4% and 76.7% of patients in the VP-LZ and LZ-VP groups, respectively, were well controlled following for ≥ 6 consecutive days a week (P = 0.009). During the first 4 weeks, 96.7% and 80.0% of patients were well controlled with < 1 weekly in the VP-LZ and LZ-VP groups, respectively, during the first 4 weeks (P = 0.007). GERD symptoms, assessed via FSSG and GSRS, significantly decreased with vonoprazan administration once every second day.

CONCLUSIONS

Vonoprazan administered once every second day could be an effective alternative to PPIs in the maintenance treatment of erosive GERD (UMIN000030393).

Serum Gastrin and Pepsinogen Levels after Administration of Acid Secretion Inhibitors for Ulcers due to Endoscopic Submucosal Dissection in Patients with Early Gastric Cancer

Acid secretion inhibitors, such as proton pump inhibitors (PPIs) and potassium competitive acid blockers (PCABs), are used to treat ulcers after endoscopic submucosal dissection (ESD) for early gastric cancer. These drugs can influence serum gastrin and pepsinogen (PG) levels; however, their definite effects remain unclear. This open-label, randomized study investigated the effect of acid secretion inhibitors on the serum gastrin and pepsinogen levels. In total, 76 patients were enrolled in the study. They underwent gastric ESD and received a PPI (n = 21) or PCAB (n = 55). Changes in the serum gastrin and PG levels before and 4 weeks after administration were examined. Patient factors associated with the alteration of serum PG or gastrin levels were identified. The median serum levels of gastrin, PGI, and PGII before the administration of the acid secretion inhibitors were 110.5 pg/mL, 36.4 ng/mL, and 8.9 ng/mL, respectively; after administration, the levels increased to 300 pg/mL, 64.7 ng/mL, and 15.8 ng/mL, respectively (P < 0.01). Univariate analysis revealed that PCABs led to a more significant increase in the serum gastrin and PG levels as compared to PPIs. Furthermore, the PG levels were significantly increased in patients with previous Helicobacter pylori infections than in those with current infections. In conclusion, the serum gastrin and PG levels increased after the use of acid secretion inhibitors. This elevation was affected by the type of drug used, whereas the elevation in PGs was affected by the patient's background as well.

Strategies for discontinuation of proton pump inhibitors (PPIs) in patients with long-term PPI administration: a randomized controlled trial

BACKGROUND

Proton pump inhibitors (PPIs), including potassium ion-competitive acid blocker, are widely used worldwide and are often used for long periods of time. However, in recent years, potential side effects associated with long-term PPI use have been reported. Many patients take PPI for a long period of time, even though it is unnecessary, and it is necessary to discontinue PPI administration in such patients. However, sudden discontinuation may cause symptoms to recur and discontinuation may be unsuccessful. A strategy for safe and secure PPI discontinuation has not yet been established. The purpose of this study is to determine whether PPI can be safely discontinued by tapering the PPI dose or by abrupt discontinuation of PPI, and to establish a strategy for safe and secure PPI discontinuation.

METHODS

The evaluation will be conducted as a multicenter, randomized, parallel-group clinical trial with five assessment points at the start of the study and 2 weeks, 4 weeks, 6 months, and 12 months after the start of the study. One intervention group is the group in which PPI administration is abruptly discontinued (Group A), and the second group is the group in which the PPI dose is gradually tapered and then PPI administration is discontinued (Group B). The primary outcome and secondary outcome are the proportion of patients who successfully discontinued the PPI at 6 months and at 12 months after the start of the study in groups A and B, respectively.

DISCUSSION

We predict that the proportion of patients who successfully discontinue PPI will be higher in the group in which PPI administration was gradually tapered than in the group in which PPI administration was abruptly discontinued. On the other hand, we expect that many participants will succeed in discontinuing PPI regardless of the discontinuation strategy due to the explanation that discontinuation is necessary.

TRIAL REGISTRATION

Japan Registry of Clinical Trials, jRCT1031180383. Registered 20 March 2019, https://jrct.niph.go.jp/latest-detail/jRCT1031180383 .

A Population Pharmacokinetic Model of Vonoprazan: Evaluating the Effects of Race, Disease Status, and Other Covariates on Exposure

Vonoprazan, a potassium‐competitive acid blocker, is under investigation in the United States and Europe for the treatment of erosive esophagitis and Helicobacter pylori infection. Population pharmacokinetic (popPK) analysis allows the identification of factors that could affect drug exposure in population subgroups. Here, we report a popPK model based on pooled data sets of available pharmacokinetic (PK) studies in healthy volunteers and patients with gastroesophageal reflux disease, including erosive esophagitis, from Asia and Europe. This model was used to evaluate the impact of different covariates, including race and disease status, on vonoprazan exposure. We analyzed PK data from 746 patients and 410 healthy volunteers from 15 clinical trials using a nonlinear mixed‐effects approach to develop the popPK model. Model development focused on characterizing and quantifying the effects of clinical covariates of race (Asian vs non‐Asian) and disease status (gastroesophageal reflux disease vs healthy volunteers) on vonoprazan exposure. Identified clinical covariates included fed/fasting status, race, sex, disease status, weight, serum creatinine, and age. The impact of variations in these clinical covariates on exposure to vonoprazan was smaller than the effect of halving or doubling the dose. PK parameters were similar in Asian and non‐Asian populations. Variations in weight, age, and race are not predicted to have a clinically relevant impact on vonoprazan exposure or safety and require no changes in vonoprazan dosing. The limited impact of race on exposure suggests that efficacy and safety data for vonoprazan in Asian populations are translatable to non‐Asian populations.

Vonoprazan for treatment of gastroesophageal reflux disease: Research advances

Gastroesophageal reflux disease is a common gastrointestinal disease that can be effectively treated by drugs alone. Proton pump inhibitors are the currently mainstay drugs for the treatment of gastroesophageal reflux disease, but are insufficiently effective. Vonoprazan, which is a new type of drug that inhibits gastric acid secretion, has been employed for the management of gastroesophageal reflux disease. In this article, we comprehensively review the current evidence regarding clinical efficacy and safety of vonoprazan for the treatment of gastroesophageal reflux disease to guide the clinical decision.

The early therapeutic response at 2 weeks is a crucial predictor of proton pump inhibitor-refractory gastroesophageal reflux disease

BACKGROUND

In recent years, the prevalence of proton pump inhibitor (PPI)-refractory gastroesophageal reflux disease (GERD) has been increasing, posing a clinical obstacle to improving the management of GERD patients. The ability of known predictive factors to explain therapeutic response to PPI remains insufficient. Therefore, we examined whether the addition of early therapeutic response to PPI as an explanatory variable may increase the predictive power for PPI-refractory GERD.

METHODS

The severity and therapeutic response of GERD symptoms to PPI were evaluated using the GastroEsophageal Reflux and Dyspepsia Therapeutic Efficacy and Satisfaction Test (GERD-TEST) questionnaire at baseline and at 2 and 4 weeks after treatment. The relevance of the therapeutic effect of PPI at 2 weeks compared to that at 4 weeks was examined in 301 patients with GERD. Independent predictive factors for refractory GERD at 4 weeks of PPI therapy were examined in 182 patients. The effect of various clinical factors, including the early response to PPI, was assessed using multiple regression analysis.

RESULTS

The number of PPI-therapy responders increased significantly with the duration of treatment (p < 0.0001). The response to PPI therapy at 2 weeks was significantly correlated with that at 4 weeks (p < 0.0001). Multiple regression analysis revealed that the therapeutic response to PPI at 2 weeks was by far the strongest predictor of the therapeutic effect at 4 weeks among all clinical factors.

CONCLUSIONS

Medication change for PPI-refractory GERD at 2 weeks may be an efficacious therapeutic strategy to improve patients' quality of life.

Long-term vonoprazan therapy is effective for controlling symptomatic proton pump inhibitor-resistant gastroesophageal reflux disease

Vonoprazan, a novel potassium-competitive acid blocker, results in greater inhibition of gastric acid secretion than proton pump inhibitors (PPI). The aim of this study was to assess the long-term outcomes of patients with PPI-resistant gastroesophageal reflux disease (GERD) treated with vonoprazan. The medical records of patients with symptomatic GERD treated with vonoprazan for 1 year were retrospectively reviewed. Changes in abdominal symptoms were assessed using the Izumo scale, a self-reported questionnaire which is useful in evaluating the symptoms of GERD, epigastric pain, postprandial distress, constipation and diarrhea, and is commonly used in routine clinical practice. A total of 30 patients were included and stratified into a non-erosive (n=22) and erosive group (n=8). At baseline, postprandial distress symptoms were significantly greater in the non-erosive group compared with the erosive group (P=0.013). Even with vonoprazan therapy, symptoms of GERD in the non-erosive group were refractory compared with the erosive group, and required additional treatment in a larger proportion of patients (45 vs. 13%). GERD symptoms in the non-erosive group significantly improved from baseline and remained better after 1 year of vonoprazan therapy, similar to the erosive group. In addition, vonoprazan improved epigastric pain and postprandial distress symptoms in the non-erosive group, and 1 year of vonoprazan therapy did not aggravate constipation or diarrhea. In conclusion, 1 year of vonoprazan therapy improves GERD symptoms in patients with PPI-resistant GERD.

Use of vonoprazan for management of systemic sclerosis-related gastroesophageal reflux disease

Gastroesophageal reflux disease (GERD) in systemic sclerosis (SSc) can significantly reduce a patient's quality of life. GERD in SSc is occasionally resistant to conventional anti-acid treatment. Vonoprazan is an H⁺/K⁺-ATPase blocker that is approved in Japan for treatment of GERD. The aim of the present study was to evaluate the efficacy of vonoprazan in SSc-related GERD. The frequency scale for symptoms of GERD (FSSG) scores were collected before and after vonoprazan treatment in 15 SSc patients with GERD. Additionally, endoscopic esophagogastroduodenoscopy was performed in select patients. Conventional proton pump inhibitors or histamine-2 receptor antagonists had been previously administered in 93% (14/15) of the patients. Although the baseline esophagogastroduodenoscopy examination did not show severe erosion in the majority of patients, the mean total FSSG score before vonoprazan treatment was notably high (25.2±10.7) compared to a normal score of <8. After vonoprazan treatment, the FSSG score decreased to 9.6±7.0. The mean improvement rate of the total FSSG, acid reflux and dysmotility scores were 60.8±21.2% (P=0.0004), 67.3±24.8% (P<0.0001) and 55.4±26.0% (P=0.0022), respectively. These results suggest that vonoprazan may be a potentially effective treatment for GERD in patients with SSc.

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.

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.

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

BACKGROUND

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

AIMS

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Role of Acid Suppression in Acid-related Diseases: Proton Pump Inhibitor and Potassium-competitive Acid Blocker

Proton pump inhibitors are commonly utilized for the treatment of gastric acid-related diseases, such as gastroesophageal reflux disease, peptic ulcer disease, and Helicobacter pylori infection, and for the prevention of low-dose aspirin or nonsteroidal anti-inflammatory drug-induced peptic ulcers. Vonoprazan is a first-in-class potassium-competitive acid blocker, which has distinct advantages compared to other conventional proton pump inhibitors in terms of the efficacy for acid suppression. Due to its strong gastric acid suppression capabilities, vonoprazan serves as an effective drug for the treatment of gastroesophageal reflux disease and H. pylori infection.

Vonoprazan versus proton-pump inhibitors for gastric endoscopic submucosal dissection-induced ulcers: a systematic review and meta-analysis

Acid secretion inhibitors are usually prescribed to promote the healing of artificial ulcers caused by endoscopic submucosal dissection (ESD) to reduce the risk of gastric perforation and delayed bleeding. Vonoprazan is a newer agent that has been shown to be more potent than a proton-pump inhibitor (PPI). However, it remains unclear whether vonoprazan is more effective than PPI in promoting healing of ulcers caused by ESD. Medline and Embase databases were searched through January 2018 for studies that compared the rate of complete healing of ulcers caused by ESD and post-ESD delayed bleeding in patients who received vonoprazan versus those who received PPI after ESD. Pooled odds ratio (OR) and 95% confidence interval (CI) were calculated using a random-effect model, generic inverse variance method. The between-study heterogeneity was quantified using the Q-statistic and I. A total of six studies consisting of 461 patients were identified. The likelihood that ulcers caused by ESD were completely healed at 4-8 weeks after the procedure was significantly higher among patients who received vonoprazan compared with those who received PPI, with a pooled OR of 2.27 (95% CI=1.38-3.73; I=0%). The risk of developing post-ESD delayed bleeding was also numerically lower among those who received vonoprazan, with a pooled OR of 0.79, although the result did not reach statistical significance (95% CI=0.18-3.49; I=29%). This study found that patients who received vonoprazan after ESD had a significantly higher rate of completely healed ulcers compared with those who received PPI.

Vonoprazan versus proton pump inhibitors for the management of gastroesophageal reflux disease: A protocol for a systematic review with meta-analysis

BACKGROUND AND AIM

Vonoprazan, a novel potassium-competitive acid blocking agent, is used in the management of gastroesophageal reflux disease (GERD). We aim to perform a systematic review and meta-analysis for the comparison of the effects of vonoprazan and proton pump inhibitors (PPIs) in GERD in randomized controlled trials (RCTs).

METHODS

A systematic and comprehensive search will be performed using MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials (CENTRAL), Google Scholar, and clinical trial registries, for studies published up to September 2018. Only randomized clinical trials will be included. Primary outcomes of symptoms and esophageal erosion improvement in the intention-to-treat analysis, and secondary outcomes of symptoms and esophageal erosion improvement rate in the per protocol analysis, the comparative efficacy in terms of healing rate of esophageal erosion on endoscopy, the comparative efficacy in terms of improvement of esophageal impedance-pH study, adverse events, long-term safety, and the comparative efficacy in terms of CYP2C19 metabolite levels will be studied. The quality of included studies will be assessed using the modified risk of bias tool. Heterogeneity of estimates across studies as well as publication bias will be assessed. This systematic review and meta-analysis will be performed according to the protocol recommended by the Cochrane Collaboration and reported according to the preferred reporting items for systematic reviews and meta-analysis (PRISMA) guidelines. All statistical analyses will be conducted using Stata SE version 15.0.

RESULTS

The results of this systematic review and meta-analysis will be published in a peer-reviewed journal.

CONCLUSION

To our knowledge, this systematic review and meta-analysis will be the first to evaluate existing research comparing Vonoprazan and PPIs in GERD. Our study will provide information about the effect of vonoprazan and PPIs in GERD in RCTs. The review will benefit patients, healthcare providers, and policymakers.

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.

Medical Therapy of Gastroesophageal Reflux Disease Beyond Proton Pump Inhibitors: Where Are We Heading?

Proton pump inhibitors (PPI) have greatly improved the treatment of gastroesophageal reflux disease. However, recent investigations have revealed that reflux symptoms persist in a substantial number of patients. Therefore, treatment strategies beyond PPI are urgently required. One such strategy may involve more reliable acid suppression, e.g., with new acid inhibitory drugs. Furthermore, the rapid appearance of an acidic compartment in the proximal stomach after a meal, which is largely responsible for postprandial heartburn, requires a specific kind of therapy in addition to PPI which still needs to be established. Pharmacological augmentation of the lower esophageal sphincter may represent another approach to diminish reflux, but the clinical efficacy of compounds tested so far is limited. Altered e-sophageal perception represents a major component involved in the generation of reflux symptoms, particularly in non-erosive reflux disease, but effective pharmacological intervention is largely lacking. Presumed reflux-induced respiratory symptoms (cough, laryngitis, etc.) in the absence of typical esophageal symptoms (e.g., heartburn) remain a hot topic, but recent research points towards a hypersensitivity syndrome and only a minor role of gastroesophageal reflux. Treatment options for this condition are still pending.

Efficacy of vonoprazan for 24-week maintenance therapy of patients with healed reflux esophagitis refractory to proton pump inhibitors

The aim of the present study was to evaluate the efficacy of a potassium-competitive acid blocker (P-CAB), vonoprazan, for the maintenance therapy of healed reflux esophagitis (RE). A total of 60 patients were enrolled in this open-label, single-center, prospective study. All patients were diagnosed with RE with a frequency scale for the symptoms of gastroesophageal reflux disease (FSSG) total score ≥8 following treatment with standard proton pump inhibitors (PPIs) for a minimum of 8 weeks. Standard PPI treatment was switched to vonoprazan 20 mg once daily for 4 weeks. A total of 52 patients, who had no endoscopic evidence of erosive esophagitis following vonoprazan treatment, received maintenance therapy with vonoprazan 10 mg once daily for 24 weeks. Symptoms were evaluated using the FSSG and Gastrointestinal Symptom Rating Scale (GSRS). Upper gastrointestinal endoscopies were performed following 24 weeks of maintenance therapy. The primary endpoint was to determine the proportion of patients who exhibited maintenance of healed RE refractory to PPIs following 24 weeks of maintenance therapy with vonoprazan 10 mg once daily. Secondary endpoints included evaluation of the proportion of patients with symptomatic non-relapse at 24 weeks. Maintenance therapy with vonoprazan 10 mg once daily prevented relapse of esophageal mucosal breaks in 37/43 (86.0%) patients at 24 weeks. However, the number of patients with symptomatic relapse was 1 (1.9%) and 4 (7.7%) at 4 and 8 weeks, respectively. A total of 4 patients were withdrawn due to loss to follow-up. At the end of the 24-week maintenance period, the symptomatic non-relapse rate for acid reflux-associated and dysmotility symptom FSSG scores were 86.5 and 80.8%, respectively. Furthermore, the symptomatic non-relapse rate for reflux, abdominal pain, indigestion, diarrhea, and constipation GSRS scores at 24 weeks were 86.5, 80.8, 75.0, 71.2 and 76.9%, respectively. No serious adverse events were reported during the study. The mean gastrin level was 1,059 pg/ml. In conclusion, the results of the present study indicate that vonoprazan 10 mg once daily is effective for 24-week maintenance therapy of healed RE refractory to PPIs.

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.