Vonoprazan is Efficacious for Treatment of Heartburn in Non-erosive Reflux Disease: A Randomized Trial.

BACKGROUND & AIMS: Potassium-competitive acid blockers have documented efficacy for erosive esophagitis. We performed a randomized trial in United States subjects diagnosed with non-erosive reflux disease of vonoprazan vs placebo for 4 weeks, followed by a 20-week active-treatment extension. METHODS: Adult subjects with heartburn ≥4 days/week during screening without erosive esophagitis on endoscopy were randomized to placebo, vonoprazan 10 mg, or vonoprazan 20 mg. After 4 weeks, subjects on placebo were re-randomized to vonoprazan 10 mg or 20 mg, and those already on vonoprazan continued at the same dose for 20 weeks. Electronic diaries were completed twice daily. The primary endpoint was percentage of days without daytime or nighttime heartburn (24-hour heartburn-free days). RESULTS: Among 772 randomized subjects, the percentage of 24-hour heartburn-free days was 27.7% for placebo vs 44.8% for vonoprazan 10 mg (least squares mean difference, 17.1%; P < .0001) and 44.4% for vonoprazan 20 mg (least squares mean difference, 16.7%; P < .0001). Differences in percentage of subjects with a 24-hour heartburn-free day for vonoprazan 10 mg vs placebo and vonoprazan 20 mg vs placebo were 8.3% and 11.6% on day 1 and 18.1% and 23.2% on day 2. The mean/median percentages of 24-hour heartburn-free days over the extension period were similar across the 4 study arms: 61%-63%/76%-79%. CONCLUSIONS: Vonoprazan reduced heartburn symptoms in subjects diagnosed with non-erosive reflux disease, with the benefit appearing to begin as early as the first day of therapy. Treatment effect persisted after the initial 4-week placebo-controlled period throughout the 20-week extension period. The 2 vonoprazan doses (10 mg and 20 mg) were similar in efficacy. (ClinicalTrials.gov: NCT05195528).

Heartburn Relief Is the Major Unmet Need for Drug Development in Gastroesophageal Reflux Disease: Threshold Value Analysis.

BACKGROUND AND AIMS: Heartburn symptoms contribute to healthcare-seeking among patients with gastroesophageal reflux disease (GERD). Despite clinical guidance, management is often dictated by insurance restrictions. Several potassium-competitive acid blockers (PCABs) are under development as a new class of therapy. We performed economic analyses to align GERD drug development with the needs of gastroenterologists, insurers and patients in a value-based environment. METHODS: A decision-analytic model was constructed to compare vonoprazan 20 mg daily (an example of a PCAB), common over-the-counter or prescription proton pump inhibitor regimens, and no treatment over a 1-year time horizon. Clinical responses were evaluated based on the proportions of heartburn-free days in a recent phase 3 multicenter trial. Healthcare utilization for persistent reflux symptoms was derived from national observational studies compared with healthy control subjects. Costs and quality-adjusted life years were reported. RESULTS: Without insurance coverage for appropriate therapy, patients spend $4443 and insurers spend $3784 on average per year for inadequately treated GERD symptoms. Our model estimates that PCABs could save at least $3000 in annual costs to patients and insurers, could generate quality-adjusted life year gains (+0.06 per year), and could be cost-saving to insurers as a covered option at a price up to $8.57 per pill, if these drugs are able to demonstrate similar effectiveness to proton pump inhibitors in future trials evaluating heartburn relief and erosive esophagitis healing to regulators. Threshold prices reflect pricing after all pharmacy benefits manager rebates and discounts. DISCUSSION: We demonstrate that aiming GERD-related drug development toward heartburn relief appears critical to align cost-effective incentives for industry and insurers with those of patients and gastroenterologists.

Association Between Vonoprazan and the Risk of Gastric Cancer After Helicobacter pylori Eradication.

BACKGROUND & AIMS: Potassium-competitive acid blockers (PCABs) have been increasingly used to treat upper gastrointestinal disorders, replacing proton pump inhibitors (PPIs). Whereas PPIs are associated with an increased risk of gastric cancer (GC) after Helicobacter pylori (Hp) eradication, it is uncertain whether PCABs carry the same risk. METHODS: Using a population-based claims database in Japan, we identified patients who were prescribed a clarithromycin-based first regimen of Hp eradication between 2015 and 2018. Patients who failed this regimen and those diagnosed with GC before or within 1 year after Hp eradication were excluded. We compared GC incidence between PCAB users and histamine type-2 receptor antagonist (H2RA) users, matching them on the basis of propensity scores calculated with considerations for age, sex, smoking, alcohol consumption, comorbidities, and co-administered medications. PCABs included only vonoprazan in this study. RESULTS: Among 54,055 patients, 568 (1.05%) developed GC during the follow-up period (mean, 3.65 years). The cumulative incidence of GC was 1.64% at 3 years, 2.02% at 4 years, and 2.36% at 5 years in PCAB users and 0.71% at 3 years, 1.04% at 4 years, and 1.22% at 5 years in H2RA users. The use of PCABs was associated with a higher GC risk (matched hazard ratio, 1.92; 95% confidence interval, 1.13-3.25; P = .016). Longer PCAB use and high-dose PCAB use were significantly associated with higher incidence of GC. Sensitivity analyses showed the risk of GC incidence among PCAB users was comparable with that of PPI users. CONCLUSIONS: The use of PCABs was associated with an increased risk of GC among Hp-eradicated patients, with duration/dose response effects.

Analysis of Risk Factors for Febrile Neutropenia in Patients with Small-Cell Lung Cancer Receiving Carboplatin Plus Etoposide Therapy.

INTRODUCTION: Febrile neutropenia (FN) is an oncologic emergency requiring immediate empiric antibiotic therapy. Although carboplatin plus etoposide combination chemotherapy is associated with a relatively high frequency of FN, the risk factors are unclear. Hence, this retrospective study aimed to identify predictive markers of carboplatin/etoposide-induced FN. METHODS: We conducted a retrospective cohort analysis of patients with previously untreated small-cell lung cancer (SCLC) who received combination chemotherapy with carboplatin (area under the concentration curve: 5 mg/mL·min, day 1) and etoposide (80 or 100 mg/m2, days 1-3) between July 2007 and June 2022. FN was assessed during the 21 days after initiation of carboplatin and etoposide therapy according to the Japanese Society of Medical Oncology's definition. Fisher's exact test for categorical variables and Mann-Whitney U test for continuous variables were used to compare the two groups. Statistical significance was set at p values <0.05. Explanatory variables with p values <0.05 in the univariate analysis were included in the multivariate logistic regression analysis. RESULTS: Among the 176 eligible patients, the incidence of FN during the first cycle of chemotherapy was 25.0% (44/176). Multivariate analysis revealed that co-administration of proton pump inhibitors (PPIs) or potassium-competitive acid blockers (PCABs) and body mass index (BMI) were significantly associated with FN (p = 0.0035 and 0.0011, respectively). Patients with both co-administration of PPIs or PCABs and a BMI ≤22.509 kg/m2 presented with significantly higher frequencies of FN compared with the other patients (13/24 [54.2%] vs. 31/152 [20.4%] patients; odds ratio: 4.56, 95% confidence interval: 1.70-12.48; p = 0.00147). CONCLUSION: Patients who received carboplatin plus etoposide for SCLC with co-administration of PPIs or PCABs and a BMI ≤22.509 kg/m2 more frequently present with FN than those without the two factors.

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.

Vonoprazan is superior to lansoprazole for healing of severe but not mild erosive esophagitis: A systematic review with meta-analysis of randomized controlled trials.

BACKGROUND AND AIM: Healing rates of severe erosive esophagitis (EE; Los Angeles [LA] Grade C/D) in patients treated with a proton pump inhibitor (PPI) is suboptimal (~60-70%). Vonoprazan, a potassium-competitive acid blocker, is suggested to have better healing rates in patients with severe EE. This meta-analysis compares the efficacy and safety of vonoprazan 20 mg versus lansoprazole 30 mg daily in healing EE, specifically in those with LA Grade C/D. METHODS: We searched MEDLINE, Embase, and CENTRAL on May 24, 2023. Studies that randomized EE patients to vonoprazan 20 mg daily or lansoprazole 30 mg daily and compared healing rates were included. The risk of bias was assessed using Cochrane's Risk of Bias 2 tool. The fixed-effect model was used to obtain the pooled efficacy and safety outcomes. Subgroup analysis was done to compare healing rates in mild (LA Grade A/B) versus severe EE and based on study location. RESULTS: Four randomized controlled trials (RCTs) with low risks of bias comprising 2208 participants were included. Vonoprazan 20 mg was superior to lansoprazole 30 mg daily in healing severe EE at all weeks (Week 2 RR 1.294 [95% CI 1.169-1.433], Week 4 1.160 [1.059-1.270], and Week 8 1.175 [95% CI 1.107-1.247]), but was similar for mild EE at all weeks (P-interaction < 0.01). Vonoprazan 20 mg was more efficacious than lansoprazole 30 mg at Week 8 in Western versus Asian studies (P-interaction < 0.01). Any, serious, and drug-related treatment-emergent adverse events were comparable between groups. CONCLUSION: Vonoprazan 20 mg is superior to lansoprazole 30 mg for healing severe EE but not mild EE. Vonoprazan 20 mg daily has a similar safety profile to lansoprazole 30 mg daily.

Temporal trends in use of antisecretory agents among patients administered clopidogrel-based dual antiplatelet therapy after percutaneous coronary intervention.

BACKGROUND: Antisecretory drugs are commonly prescribed with clopidogrel-based dual antiplatelet therapy (DAPT) to prevent gastrointestinal bleeding in high-risk patients after percutaneous coronary intervention (PCI). However, omeprazole and esomeprazole (inhibiting proton pump inhibitors [PPIs]) may increase cardiovascular event rates on co-administration with clopidogrel. This study aimed to examine trends in the use of antisecretory agents in patients administered clopidogrel-based DAPT and the concomitant use of clopidogrel and inhibiting PPIs. METHODS: We used National Inpatient Sample data compiled by the Health Insurance Review & Assessment Service from 2009 to 2020. Further, we identified patients who were prescribed clopidogrel-based DAPT after PCI and investigated the concomitant use of antisecretory agents with clopidogrel. To verify the annual trend of drug utilization, we used the Cochran-Armitage trend test. RESULTS: From 2009 to 2020, the percentage of H2 receptor antagonist users decreased steadily (from 82.5% in 2009 to 25.3% in 2020); instead, the percentage of PPI users increased (from 23.7% in 2009 to 82.0% in 2020). The use of inhibiting PPI also increased (from 4.2% in 2009 to 30.7% in 2020). Potassium competitive acid blockers (P-CABs) were rarely used before 2019; however, in 2020, it accounted for 7.8% of the antisecretory users. CONCLUSIONS: Our study demonstrates that the use of inhibiting PPIs increased steadily in patients administered clopidogrel-based DAPT therapy. This is a major concern since the concomitant use of inhibiting PPIs with clopidogrel could increase the risk of cardiovascular events.

Clinical Impact of Proton Pump Inhibitor and Potassium-Competitive Acid Blocker for Predicting the Curability of Endoscopic Resection in Ulcerative Early Gastric Cancer.

INTRODUCTION: Endoscopic diagnosis is essential for predicting the curability of early gastric cancer (EGC; R0 resection) before treatment, but the relationship between ulcerative lesions and clinical outcomes remains unclear. We aimed to investigate the effect of proton pump inhibitor (PPI) or potassium-competitive acid blocker (P-CAB) on the morphological changes of ulcerative EGCs and its relevance to the clinical outcomes. METHODS: Altogether, 143 patients with differentiated ulcerative EGC that were resected by endoscopic submucosal dissection were retrospectively identified and divided into the following two cohorts depending on their PPI/P-CAB administration status: PPI/P-CAB (n = 76) and non-PPI/P-CAB (n = 67) cohorts. Furthermore, in each cohort, the patients were further divided into the improved and unimproved subgroups based on the ulcerative changes. RESULTS: In the PPI/P-CAB cohort, the deep submucosal invasion and lymphovascular invasion rates were significantly higher in the unimproved subgroup than in the improved subgroup, resulting in a significantly lower R0 resection rate. Contrarily, no significant differences were found between the two subgroups in the non-PPI/P-CAB cohort. The significance of PPI/P-CAB administration was observed only in the ulcerative EGCs with open-type atrophy (R0 resection rate; improved vs. unimproved, 90.9% vs. 48.0%, p = 0.001). When the finding of improved ulcer with PPI/P-CAB administration was used as the indication of endoscopic resection in ulcerative EGCs with open-type atrophy, high sensitivity (78.9%) and accuracy (76.3%) rates for the curability were observed, which were higher than those of conventional endoscopic diagnosis alone (p = 0.021). CONCLUSION: PPI or P-CAB administration might contribute to the potential selection of ulcerative EGCs, enabling endoscopic curative resection.

Self-controlled Case Series Study for Acute Kidney Injury after Starting Proton Pump Inhibitors or Potassium-Competitive Acid Blocker in Patients with Cancer Using a Large Claims Database.

To investigate the risk of acute kidney injury (AKI) in patients with cancer following the initiation of proton pump inhibitors (PPIs) and potassium-competitive acid blocker (PCAB), considering sex and anti-cancer drug use. We conducted a self-controlled case-series study using the Japan Medical Data Center claims data from 12422 patients with cancer who were prescribed PPIs or PCAB between January 2017 and December 2019. Considering the timing of PPI or PCAB, control period (days -120 to -1), risk period 1 (days 0 to +30), and risk period 2 (days +31 to +365) were defined. To assess the incidence rate ratio (IRR) and 95% confidence interval (CI) as the risk ratio, we adjusted for anti-cancer drugs to assess the risk of AKI. Additionally, we also examined sex differences to identify the risk of AKI. AKI was observed in risk period 1 [2.05 (1.12-3.72), p = 0.0192], but a slight reduction was noted in risk period 2 [0.60 (0.36-1.00), p = 0.0481]. A sex-specific increase in the risk of AKI was observed only in males during risk period 1 [2.18 (1.10-4.32), p = 0.0260], with a reduction in risk period 2 [0.48 (0.26-0.89), p = 0.0200]. We identified an increased risk of AKI in patients with cancer starting PPIs or PCAB particularly in males within 30 d after PPI or PCAB initiation, emphasizing the need for vigilant monitoring and management of AKI in this patient population.

Efficacy and safety of fexuprazan in patients with symptoms and signs of laryngopharyngeal reflux disease: a randomized clinical trial.

PURPOSE: Laryngopharyngeal reflux disease (LPRD) is mainly treated with proton pump inhibitors (PPI) such as esomeprazole, which have shortcomings like delayed absorption and increased osteoporosis. Fexuprazan is a novel potent potassium-competitive acid blocker that inhibits gastric acid secretion with rapid onset and long duration of action. To assess the efficacy and safety of fexuprazan compared to esomeprazole in patients with LPRD. METHODS: This prospective, randomized, double-blinded, multicenter, active-controlled trial was conducted in nine otolaryngologic clinics. Patients with reflux symptom index (RSI) ≥ 13 and reflux finding score (RFS) ≥ 7 were randomly assigned to the fexuprazan or esomeprazole groups, and received fexuprazan 40-mg or esomeprazole 40-mg once daily for 8 weeks. The outcomes were (1) mean change, change rate, and valid rate in RSI, RFS, and LPR-related questionnaires; and (2) adverse events. RESULTS: A total of 136 patients (fexuprazan n = 68, esomeprazole n = 68) were followed up for ≥ 1 month. Each parameter significantly improved after 4 and 8 weeks in each group, with no significant differences between the two groups. For those with severe symptoms (RSI ≥ 18), the fexuprazan group (n = 32) showed more improvement in the mean change and change rate in the RSI than esomeprazole group (n = 31) after 4 weeks (p = .036 and .045, respectively). This phenomenon was especially observed in hoarseness and troublesome cough. CONCLUSION: Fexuprazan improved symptoms and signs without no serious adverse events in patients with LPRD. In patients with severe symptoms, fexuprazan resulted in a faster symptom improvement than PPI. TRIAL REGISTRATION: KCT0007251, https://cris.nih.go.kr/cris/search/detailSearch.do?seq=22100 .

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

AIMS: The new modified-release formulation of tegoprazan, a novel potassium-competitive acid blocker, is expected to improve the management of acid-related disease, including nocturnal acid breakthrough, by prolonging the duration of acid suppression. This study aimed to explore the pharmacokinetics (PK) and pharmacodynamics (PD) of various combinations of tegoprazan with immediate-release (IR) and delayed-release (DR) formulations. METHODS: A three-cohort, open-label, randomized, single-dose, three-treatment, six-sequence, three-period crossover study was conducted. Various combinations of tegoprazan IR and DR formulations (50, 75 or 100 mg) were administered orally once per period. The 24-h intragastric pH was monitored before and after each administration. PK blood samples were collected for up to 48 h. PK and PD were compared among treatments. RESULTS: Eighteen healthy Korean subjects completed the study. All treatment groups showed intragastric pH above 4 approximately 1 h following tegoprazan administration. Among the various combinations, the IR and DR combination at a 1:1 ratio induced greater gastric acid suppression (%Time pH ≥ 4) than IR alone in each dose group, both for 24 h (50 mg; 59% vs. 52%, P = .2188, 95% confidence interval [CI] -6.92-22.27, 100 mg; 85% vs. 70%, P < .05, 95% CI 8.92-22.19) and at night (50 mg; 27% vs. 16%, P = .1563, 95% CI -11.79-37.71, 100 mg; 77% vs. 49%, P < .05, 95% CI 16.14-42.98), with similar systemic exposure. CONCLUSIONS: The combinatorial tegoprazan in the IR and DR 1:1 ratio formulation was found to induce stronger gastric acid suppression throughout the day and at night, compared to the conventional IR formulation.

Efficacy of tegoprazan-based bismuth quadruple therapy compared with bismuth quadruple therapy for Helicobacter pylori infection: A randomized, double-blind, active-controlled study.

BACKGROUND: Bismuth-based quadruple therapy (BQT) is recommended as the first-line empirical therapy for Helicobacter pylori eradication as it is not associated with resistance. However, few studies have investigated the use of potassium-competitive acid blockers for BQT. AIM: To investigate the efficacy and safety profiles of tegoprazan-based BQT (TBMT) versus lansoprazole-based BQT (LBMT) for H. pylori eradication. METHODS: We included patients older than 18 with an H. pylori infection without a history of H. pylori eradication who visited four university-affiliated hospitals between March 2020 and December 2021. H. pylori infection was diagnosed using a rapid urease test or Giemsa staining. Patients were randomly assigned to the TBMT or LBMT group. RESULTS: 217 subjects were randomly allocated to receive either TBMT (n = 108) or LBMT (n = 109) therapy. Intention-to-treat (ITT) eradication rates of TBMT and LBMT were 80.0% and 77.4% (95% confidence interval [CI]: -8.4 to 13.7, p = 0.0124), respectively. Corresponding modified ITT rates were 90.3% and 84.5% (95% CI: -3.6 to 15.2, p = 0.0005), respectively. Per-protocol (PP) eradication rates of TBMT and LBMT were 90.2% and 82.4% (95% CI: -2.5 to 18.2, p = 0.0003), respectively. There was no significant difference in the rate of adverse events between the TBMT and LBMT groups (39.1% vs. 43.4%, p = 0.5211). TBMT showed higher eradication rates than that of LBMT in ITT, m-ITT, and PP analysis. CONCLUSION: TBMT showed a noninferior eradication rate and similar adverse events to LBMT as a first-line eradication regimen. Our results suggest that tegoprazan might be substituted for proton pump inhibitors in H. pylori eradication regimens.

Carcinogenicity assessment of tegoprazan in Sprague-Dawley (Crl:CD) rats and ICR (Crl:CD1) mice.

Tegoprazan is a novel potassium-competitive acid blocker (P-CAB) that reversibly inhibits the proton pump in gastric parietal cells and has been approved for the treatment of acid-related diseases in Korea. This study aimed to evaluate the carcinogenic potential of tegoprazan in Sprague-Dawley rats and CD-1 mice. Tegoprazan was administered daily by oral gavage to rats for up to 94 weeks and mice for up to 104 weeks. Evidence of carcinogenic potential of tegoprazan was identified in rats only and was limited to benign and/or malignant neuroendocrine cell tumors at exposures >7-fold of the recommended human dose. Glandular stomach findings were considered secondary to the expected pharmacology of tegoprazan, characterized by their location in the fundic and body regions of the stomach. Overall, tegoprazan induced gastric enterochromaffin-like (ECL) cell tumors in SD rats, but did not produce any treatment-related statistically significant increase in the incidence of neoplasms relevant to humans when administered to SD rats and CD-1 mice by gavage at doses up to 300 and 150 mg/kg/day, respectively. Gastric ECL cell tumors are thought to be induced by the exaggerated indirect pharmacological effect of tegoprazan, similar to that reported for proton pump inhibitors (PPIs) and other P-CABs.

Vonoprazan: A New Potassium-Competitive Acid Blocker.

Objective: To review the safety, efficacy, and tolerability of vonoprazan for the treatment of Helicobacter pylori infection in adults. Data Sources: A literature search was performed through PubMed using the following key terms: vonoprazan, Voquezna, TAK-438, potassium-competitive acid blocker, H pylori, and gastrointestinal. Study Selection and Data Extraction: Selected articles included those which described clinical studies of the pharmacology, pharmacokinetics, efficacy, safety, or tolerability of vonoprazan. Data Synthesis: Vonoprazan works by competing with potassium on the proton pump to inhibit gastric acid secretion. Phase 3 clinical trials have shown that vonoprazan is noninferior to proton pump inhibitors (PPIs) as a component of H pylori eradication regimens. Vonoprazan has also shown promise in duodenal ulcer-healing rates and in reducing symptoms of heartburn. Common adverse effects associated with vonoprazan include nasopharyngitis, diarrhea, constipation, flatulence, dyspepsia, headache, and abdominal pain. Conclusion: Clinical practice guidelines recommend PPIs as the antisecretory agent of choice in H pylori eradication regimens with histamine-2 receptor antagonists (H2RAs) as potential alternatives. However, the use of either class of medications may be limited by adverse effects, drug interactions, and tolerability. Potassium-competitive acid blockers (P-CABs), like vonoprazan, may be safe and effective alternative antisecretory agents for H pylori eradication regimens, as well as other gastrointestinal disorders.

Night-time gastric acid suppression by tegoprazan compared to vonoprazan or esomeprazole.

AIMS: Nocturnal acid breakthrough has been considered an unmet need of proton-pump inhibitors. Tegoprazan, a novel potassium-competitive acid blocker, is expected to show improved properties for this unmet need. This study was aimed to compare night-time acid suppression by tegoprazan with that by vonoprazan or esomeprazole, and to explore the effect of CYP2C19 phenotypes on acid-suppressive effects. METHODS: A randomized, open-label, 3-period, 6-sequence crossover study was conducted. A single oral dose of tegoprazan 50 mg, vonoprazan 20 mg or esomeprazole 40 mg was administered at night in each period. Continuous intragastric pH was monitored at baseline and after each dosing. RESULTS: Sixteen healthy subjects (6 CYP2C19 extensive metabolizers, 5 intermediate metabolizers, 5 poor metabolizers) completed the study. After a single dose of tegoprazan, intragastric pH increased more rapidly to over 4 at approximately 1 hour compared to the other treatments, and elevated intragastric pH was maintained stably at night. Tegoprazan exhibited night-time acid suppression for slightly but not significantly longer than vonoprazan, and greater than esomeprazole; % time at pH ≥ 4 at night was 66.0%, 60.5% and 36.1% for tegoprazan, vonoprazan and esomeprazole, respectively. Night-time acid suppression by tegoprazan and vonoprazan was not dependent on CYP2C19 phenotypes, while that by esomeprazole tended to be influenced by CYP2C19 phenotypes. CONCLUSION: Tegoprazan produced more rapid, potent and well sustained night-time acid suppression vs. vonoprazan or esomeprazole when administered at night. Furthermore, tegoprazan showed no CYP2C19 phenotype dependency in acid suppression. It suggests the potential of tegoprazan, especially in preventing nocturnal acid breakthrough.

Efficacy and safety of low-dose rifabutin-based 7-day triple therapy as a third- or later-line Helicobacter pylori eradication regimen.

BACKGROUND: Rifabutin-based regimens are used as rescue therapy for refractory Helicobacter pylori infection; however, the duration for which treatment is required and side effects are concerning. This study assessed the efficacy and safety of 7-day rifabutin, amoxicillin, and vonoprazan triple therapy as third- or later-line treatment for H. pylori infection. MATERIALS AND METHODS: Patients who did not respond to second-line therapy were enrolled. After H. pylori infection was confirmed with the culture method, the patients received rifabutin-containing triple therapy (20 mg vonoprazan b.i.d., 500 mg amoxicillin q.i.d., and 150 mg rifabutin q.d.) for 7 days. Twelve weeks after the eradication therapy, successful eradication was confirmed using a 13 C urea breath test or the H. pylori stool antigen test. The results obtained from our previous study that reported a 10-day or 14-day esomeprazole based rifabutin-containing triple therapy as a third- or fourth-line rescue therapy treated patients were used as historical control. We determined the minimum inhibitory concentrations of amoxicillin and rifabutin. We also evaluated whether the patients were positive for the mutation of the rpoB gene. RESULTS: Intention-to-treat and per-protocol analyses showed that our regimen resulted in a high eradication rate (91.2%, 95% CI: 84%-99% and 92.7%, 95% CI: 86%-100%, respectively). Adverse events occurred in 31.6% of the patients, and two patients discontinued the therapy. CONCLUSIONS: This is the first study to evaluate the efficacy and safety of a 7-day low-dose rifabutin-based triple therapy with vonoprazan and amoxicillin. Our results suggest that our regimen was effective and safe as a third- or later-line H. pylori eradication regimen. To clarify what component in this regimen are critical, subsequent studies using a factorial design (comparing vonoprazan-amoxicillin dual therapy vs. vonoprazan-rifabutin triple therapy) will be needed.

Long-term changes in serum gastrin levels during standard dose vonoprazan therapy.

BACKGROUND: Long-term acid suppression during vonoprazan therapy causes hypergastrinemia which may induce gastric mucosal changes such as fundic gland and hyperplastic polyps. The aim of this study is to clarify the long-term changes in serum gastrin levels and risk factors for hypergastrinemia. METHODS: From July 2016 to April 2020, 48 patients receiving vonoprazan 10 mg once daily for more than one year were reviewed. Serum gastrin level was evaluated by radioimmunoassay in a fasting condition (reference range 37-172 pg/ml). RESULTS: The baseline median gastrin level was 100 (range, 54-415) pg/ml. The gastrin level over 4 years was 700-1200 pg/ml, which plateaued at 1.5 years. Multivariate analysis revealed factors associated with gastrin levels 12 months after starting vonoprazan and identified severe gastric atrophy as a significant positive risk factor (p = .046). The gastrin level over 4 years in patients with severe gastric atrophy and no atrophy was approximately 900-1500 and 500-1000 pg/ml, respectively. Female gender was also identified as a positive factor, although it was not statistically significant (p = .087). The gastrin level over 4 years in females was approximately 900-1300 pg/ml, greater than in males (500-900 pg/ml). CONCLUSION: A continued increase in gastrin levels was not found during long-term vonoprazan therapy. Severe gastric atrophy is a significant risk factor for hypergastrinemia.

Predictors and timing for the development of symptomatic gastroesophageal reflux disease after successful Helicobactor pylori eradication therapy.

BACKGROUND: Helicobacter pylori (H. pylori) eradication success increases the incidence of erosive esophagitis by normalization of gastric acid secretion. The aim of this study is to clarify predictors and timing for the development of symptomatic gastroesophageal reflux disease (GERD) after successful H. pylori eradication based on long-term follow-up. METHODS: From April 2014 to October 2020, 330 patients with H. pylori infections treated with a standard triple-drug regimen were enrolled, and their records retrospectively reviewed. Development of symptomatic GERD was defined as requiring proton pump inhibitor or vonoprazan therapy to treat symptoms. RESULTS: The mean follow-up period was 2.8 years, and symptomatic GERD developed in 41 (12%) patients during the study period. Overall rates of GERD-symptom free patients at 6 months, 1, and 2 years after eradication were 97%, 93%, and 89%, respectively. We evaluated predictors for the development of symptomatic GERD using a Cox proportional hazards regression model. In multivariate analysis, being a current smoker, having functional dyspepsia, hiatal hernia, and severe gastric atrophy were identified as significant predictive factors. The GERD domain score in the Izumo scale was significantly decreased 1 month after vonoprazan therapy consistent with effective treatment of symptomatic GERD. CONCLUSIONS: The rate of development of symptomatic GERD after successful H. pylori eradication is low over long-term follow-up and is easily controlled by vonoprazan therapy. However, patients with smoking habits, functional dyspepsia, hiatal hernia, or severe gastric atrophy should be followed carefully after eradication.

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

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

A comparison of efficacy and safety of potassium-competitive acid blocker and proton pump inhibitor in gastric acid-related diseases: A systematic review and meta-analysis.

BACKGROUND AND AIM: Potassium-competitive acid blocker (PCAB) is a recent alternative to proton pump inhibitor (PPI) for potent acid suppression. The current systematic review and meta-analysis aimed to compare the efficacy and safety of PCAB versus PPI in treating gastric acid-related diseases. METHODS: We searched up to June 5, 2022, for randomized controlled trials of gastric acid-related diseases that included erosive esophagitis, symptomatic gastroesophageal reflux disease (GERD), peptic ulcers, and Helicobacter pylori infection. The pooled risk ratio (RR) was evaluated for the efficacy outcome and treatment-emergent adverse events (TEAEs) as the safety outcome. Sensitivity analyses were performed to test the robustness of the study findings. RESULTS: Of the 710 screened studies, 19 studies including 7023 participants were analyzed. The RRs for the healing of erosive esophagitis with Vonoprazan versus PPI were 1.09 (95% confidence interval [CI] 1.03-1.14), 1.03 (95% CI 1.00-1.07), and 1.02 (95% CI 1.00-1.05) in Weeks 2, 4, and 8, respectively. There were no differences in the improvement of GERD symptoms and healing of gastric and duodenal ulcers between PCAB and PPI. The pooled eradication rates of H. pylori were significantly higher in Vonoprazan versus PPI first-line treatment (RR 1.13; 95% CI 1.04-1.22). The overall RR of TEAEs with Vonoprazan versus PPI was 1.08 (95% CI 0.89-1.31). Overall, the risk of bias was low to some concerns. Furthermore, sensitivity analyses confirmed the robustness of the study's conclusion. CONCLUSION: Vonoprazan is superior to PPI in first-line H. pylori eradication and erosive esophagitis but non-inferior in other gastric acid-related diseases. Likewise, short-term safety is comparable in both treatment groups.