Gastro-esophageal reflux disease: the recent trend in Japan

Network Meta-analysis Comparing Vonoprazan and Proton Pump Inhibitors for Heartburn Symptoms in Erosive Esophagitis

GOALS

This systematic review and network meta-analysis aimed to assess the relative efficacy of vonoprazan and proton pump inhibitors (PPIs) on early heartburn symptom resolution in patients with erosive esophagitis.

BACKGROUND

Limited available data directly compare the efficacy of vonoprazan, a first-in-class potassium-competitive acid blocker, with PPIs in erosive esophagitis.

STUDY

We conducted a systematic literature review (in MEDLINE and CENTRAL) and subsequent network meta-analysis according to Cochrane and PRISMA guidelines. Double-blind, randomized controlled trials in adults with erosive esophagitis treated with vonoprazan or a PPI were included in the analysis. Primary outcomes were heartburn symptom resolution rate on Day 1 and Day 7. The study was performed with all available data, using a random effects model within a Bayesian framework.

RESULTS

Overall, 10 randomized controlled trials were included in the network meta-analysis. For heartburn resolution rate on Day 1 (9 of 10 trials), vonoprazan 20 mg once daily (QD) was superior to placebo (median odds ratio=16.75, 95% credible interval: 2.16-207.80). Point estimates numerically favored vonoprazan 20 mg QD over other comparators. For heartburn resolution rate on Day 7 (10 of 10 trials), vonoprazan 20 mg QD was superior to placebo and other comparators except rabeprazole 20 mg QD. Point estimates numerically favored vonoprazan 20 mg QD over rabeprazole 20 mg QD.

CONCLUSIONS

In this study, vonoprazan 20 mg QD was equally effective in heartburn resolution on Day 1, and equally or more effective on Day 7 versus PPIs in adults with erosive esophagitis.

Impaired Mucosal Integrity in Proximal Esophagus Is Involved in Development of Proton Pump Inhibitor-Refractory Nonerosive Reflux Disease

BACKGROUND AND OBJECTIVE

Weakly acidic reflux reaching to the proximal esophagus is closely related to the perception of gastroesophageal reflux in patients with nonerosive reflux disease despite treatment with a proton pump inhibitor (PPI). However, little is known about the involvement of the patients' mucosal integrity of the proximal esophagus.

METHODS

We recruited 15 symptomatic nonerosive gastroesophageal reflux disease (GERD) patients with a positive symptom index despite PPI treatment and 11 healthy asymptomatic volunteers as controls. The biopsy specimens obtained from the proximal and distal esophagus were applied to a mini-Ussing chamber system to measure transepithelial electrical resistance (TEER) against a pH 4 weak acid. The esophageal biopsy samples were subjected to quantitative real-time PCR and immunohistochemical analysis.

RESULTS

In the proximal esophagus, the weak acid exposure reduced the TEER in the PPI-refractory patients compared to that in the controls. The frequency of the reflux extending to the proximal esophagus had a significant correlation with the reduction in the proximal esophageal TEER in the patients. The reduced TEER in the proximal esophagus was accompanied by an increase in IL-8 and IL-1β mRNA and a decrease in occludin mRNA levels. The proximal esophageal mucosa in the patients presented infiltration of CD3-positive lymphocytes and an increased expression of solute carrier organic anion transporter family member 2A1 (SLCO2A1), a passage gate of reflux symptom-evoking molecules.

CONCLUSIONS

The reflux perception is related to an impairment of the proximal esophageal mucosal integrity in patients with nonerosive reflux disease despite PPI.

Efficacy of vonoprazan 10 mg compared with 20 mg for the initial treatment in patients with erosive esophagitis: a randomized pilot study

BACKGROUND

The study aimed to investigate the efficacy of vonoprazan 10 mg compared with 20 mg in patients with erosive esophagitis.

METHOD

Seventy-three patients with erosive esophagitis were randomly divided into two groups either vonoprazan 20 mg (n = 37) or 10 mg (n = 36). They were administered each dose for 4 weeks as the initial treatment followed by maintenance treatment with 10 mg for 8 weeks. The primary endpoints were mucosal healing rate and symptom relief at 4 weeks. The secondary endpoint was symptom relief at 12 weeks after the maintenance treatment. Mucosal healing was assessed endoscopically, and symptom relief was assessed using the FSSG score.

RESULTS

At 4 weeks, the endoscopic healing rates of the 20 mg and 10 mg groups were 94.6% and 94.4%, respectively. The FSSG scores of the 20 mg and 10 mg groups were significantly decreased in both treatment groups from 13 (4-39) to 4 (0-25) and 14 (4-40) to 3 (0-29), respectively. At 12 weeks, the scores further decreased to 2 (0-13) and 2 (0-26), respectively. The vonoprazan 10 mg group showed a similar therapeutic effect to the 20 mg group in mucosal healing at 4 weeks and in symptom relief throughout the study period. When stratified by esophagitis grading, these findings were still demonstrated in grade A/B patients but not in grade C/D patients.

CONCLUSION

Our findings suggest that initial treatment with vonoprazan 10 mg might be useful especially in patients with mild erosive esophagitis. Large controlled studies are warranted to confirm our investigation.

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).

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

BACKGROUND AND AIM

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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).

Systematic review with network meta-analysis: indirect comparison of the efficacy of vonoprazan and proton-pump inhibitors for maintenance treatment of gastroesophageal reflux disease

BACKGROUND

Long-term maintenance treatment of gastroesophageal reflux disease (GERD) is important to prevent relapse. Proton-pump inhibitors (PPIs) are used for both treatment and maintenance therapy of GERD. Recently, a potassium-competitive acid blocker vonoprazan was launched in Japan. We evaluated the comparative efficacy of vonoprazan and other PPIs for GERD maintenance.

METHODS

A systematic literature search was performed using MEDLINE and Cochrane Central Register of Controlled Trials. Double-blind randomized controlled trials (RCTs) of PPIs, vonoprazan, and placebo for GERD maintenance published in English or Japanese were selected. Among them, studies conducted at the recommended dose and for the recommended use, and containing information on maintenance rate based on endoscopic assessment, were included. The comparative efficacies of treatments were estimated by performing a Bayesian network meta-analysis, which assessed the consistency assumption. Outcomes were number or rate of patients who maintained remission.

RESULTS

Of 4001 articles identified, 22 RCTs were eligible for analysis. One study published as an abstract was hand-searched and added. The consistency hypothesis was not rejected for the analysis. The odds ratio of vonoprazan 10 mg to each PPI was 13.92 (95% credible interval [CI] 1.70-114.21) to esomeprazole 10 mg; 5.75 (95% CI 0.59-51.57) to rabeprazole 10 mg; 3.74 (95% CI 0.70-19.99) to lansoprazole 15 mg; and 9.23 (95% CI 1.17-68.72) to omeprazole 10 mg.

CONCLUSIONS

The efficacy of vonoprazan in GERD maintenance treatment may be higher than that of some PPIs. However, a direct comparison of vonoprazan and PPIs is required to confirm these effects.

Decline in perception of acid regurgitation symptoms from gastroesophageal reflux disease in diabetes mellitus patients

Objectives

To determine if a discrepancy exists between subjective symptoms and the grade of endoscopic gastroesophageal reflux disease (GERD) in diabetes mellitus (DM) patients.

Methods

All 2,884 patients who underwent esophagogastroduodenoscopy completed the modified Gastrointestinal Symptom Rating Scale (GSRS), an interview-based rating scale consisting of 16 items including a question on acid regurgitation. Patients were divided into DM and non-DM groups (1,135 and 1,749 patients, respectively). GERD was diagnosed endoscopically and graded according to the Los Angeles classification. Grade B or more severe GERD was defined as severe endoscopic GERD. The intergroup GSRS score was compared statistically.

Results

In severe endoscopic GERD patients, the prevalence of patients with a positive GSRS score in the acid regurgitation question was statistically lower in DM patients than non-DM patients. Of the 60 non-DM patients with severe endoscopic GERD, 40 patients (67%) had a positive GSRS score for acid regurgitation; however, of the 51 DM patients with severe endoscopic GERD, 23 patients (45%) had a positive GSRS score. Multivariate analysis showed that severe endoscopic GERD (OR: 2.01; 95% CI: 1.21–3.33; p = 0.0066), non-DM (OR: 0.74; 95% CI: 0.54–0.94; p = 0.0157), younger age (OR: 0.98; 95% CI: 0.97–0.99; p = 0.0125), and hiatal hernia (OR: 1.46; 95% CI: 1.12–1.90; p = 0.0042) were associated with acid regurgitation symptoms.

Conclusions

There is a discrepancy between subjective symptoms and endoscopic GERD grade in DM patients. The ability of DM patients to feel acid regurgitation may be decreased.

Development and validation of a simple and multifaceted instrument, GERD-TEST, for the clinical evaluation of gastroesophageal reflux and dyspeptic symptoms

AIM

To evaluate the psychometric properties of a newly developed questionnaire, known as the gastroesophageal reflux and dyspepsia therapeutic efficacy and satisfaction test (GERD-TEST), in patients with GERD.

METHODS

Japanese patients with predominant GERD symptoms recruited according to the Montreal definition were treated for 4 wk using a standard dose of proton pump inhibitor (PPI). The GERD-TEST and the Medical Outcome Study Short Form-8 Health Survey (SF-8) were administered at baseline and after 4 wk of treatment. The GERD-TEST contains three domains: the severity of GERD and functional dyspepsia (FD) symptoms (5 items), the level of dissatisfaction with daily life (DS) (4 items), and the therapeutic efficacy as assessed by the patients and medication compliance (4 items).

RESULTS

A total of 290 patients were eligible at baseline; 198 of these patients completed 4 wk of PPI therapy. The internal consistency reliability as evaluated using the Cronbach's α values for the GERD, FD and DS subscales ranged from 0.75 to 0.82. The scores for the GERD, FD and DS items/subscales were significantly correlated with the physical and mental component summary scores of the SF-8. After 4 wk of PPI treatment, the scores for the GERD items/subscales were greatly reduced, ranging in value from 1.51 to 1.87 and with a large effect size (P < 0.0001, Cohen's d; 1.29-1.63). Statistically significant differences in the changes in the scores for the GERD items/subscales were observed between treatment responders and non-responders (P < 0.0001).

CONCLUSION

The GERD-TEST has a good reliability, a good convergent and concurrent validity, and is responsive to the effects of treatment. The GERD-TEST is a simple, easy to understand, and multifaceted PRO instrument applicable to both clinical trials and the primary care of GERD patients.

Medical cost, incidence rate, and treatment status of gastroesophageal reflux disease in Japan: analysis of claims data

OBJECTIVES

Published reports have shown the prevalence and incidence of gastroesophageal reflux disease (GERD) is increasing in Japan. The objective of this study is to examine change in GERD incidence, and to understand current patient demographics, medical costs, treatment status, and the suitability of current treatment based on analysis of an insurance claims database.

METHODS

An insurance claims database with data on ∼1.9 million company employees from January 2005 to May 2015 was used. Prevalence, demographics, and medical costs were analyzed by cross-sectional analysis, and incidence and treatment status were analyzed by longitudinal analysis among newly-diagnosed GERD patients.

RESULTS

GERD prevalence in 2014 was 3.3% among 20-59 year-olds, accounting for 40,134 people in the database, and GERD incidence increased from 0.63% in 2009 to 0.98% in 2014. In 2014, mean medical cost per patient per month for GERD patients aged 20-59 was JPY 31,900 (USD 266 as of January 2016), which was ∼2.4-times the mean national healthcare cost. The most frequently prescribed drugs for newly-diagnosed GERD patients were proton pump inhibitors (PPIs). Although PPIs were prescribed more often in patients with more doctor visit months, over 20% of patients that made frequent doctor visits (19 or more visits during a 24 calendar months period) were prescribed PPIs during only 1 calendar month or not at all.

LIMITATIONS

The database included only reimbursable claims data and, therefore, did not cover over-the-counter drugs. The database also consisted of employee-based claims data, so included little data on people aged 60 years and older.

CONCLUSIONS

Given the increasing incidence of GERD in Japan there is a need for up-to-date information on GERD incidence. This study suggests that some GERD patients may not be receiving appropriate treatment according to Japanese guidelines, which is needed to improve symptom control.

Esophageal Epithelial-Derived IL-33 Is Upregulated in Patients with Heartburn

Background

Interleukin-33 (IL-33) is a tissue-derived cytokine that is constitutively expressed in epithelial cells of tissues exposed to the environment and plays a role in sensing damage caused by inflammatory diseases. IL-33 acts as both a traditional cytokine and as a chromatin-associated nuclear factor in both innate and adaptive immunity. We recently showed that IL-33 in esophageal mucosa is upregulated in reflux esophagitis. However, IL-33 expression in patients with heartburn without mucosal injury and its relationship with intercellular space (ICS) have never been examined. We therefore examined the expression of cytokines and ICS in patients with heartburn.

Methods

The expression of IL-33 in the middle and distal esophageal mucosa of patients with heartburn without mucosal break and control samples was examined using real-time RT-PCR and immunofluorescence. The mRNA expression of IL-6, IL-8, MCP-1, and RANTES, and ICS was also analyzed.

Results

IL-33 expression and the mean ICS were significantly increased in the mucosa of patients with heartburn compared to that of the control. IL-33 and ICS were not different between the patients who were taking a PPI and those who were not. The upregulated IL-33 expression in the heartburn group was located in the nuclei of the basal cell layer. Although IL-6, IL-8, MCP-1 and RANTES levels were not different between control and patients with heartburn samples, IL-33 mRNA levels were still significantly correlated with IL-6, IL-8, or MCP-1 mRNA levels.

Conclusion

Nuclear IL-33 is upregulated in patients with heartburn. Upregulated IL-33 in heartburn patients is related to the symptoms.

Histology of symptomatic gastroesophageal reflux disease: is it predictive of response to proton pump inhibitors?

BACKGROUND AND AIM

To examine the differences in esophageal histopathology between non-erosive reflux disease (NERD) and reflux esophagitis (RE), and to investigate whether baseline esophageal histopathology can predict the therapeutic response to proton pump inhibitors (PPIs).

METHOD

The subjects comprised 94 patients with NERD (n = 71) or mild RE (n = 23). Tissue was biopsied from 5 cm above the squamo-columnar junction (SCJ), and the degree or presence of nine histopathological markers was assessed. The patients were treated with rabeprazole (RPZ) 10 mg once daily for 4 weeks. If complete heartburn relief was not achieved, RPZ was increased to 10 mg twice daily for another 2 weeks, and then to 20 mg twice daily for another 2 weeks if heartburn remained.

RESULTS

Features of esophageal histopathology 5 cm above the SCJ differed between NERD and RE patients. The esophageal histopathology in patients unresponsive to RPZ was characterized by Protein Gene Product (PGP) 9.5 negativity in those with NERD, and intraepithelial bleeding in those with RE. In addition, the combination of dilated intercellular spaces (DIS) (+)/PGP 9.5 (-) was indicative of strong resistance to PPI therapy in NERD patients.

CONCLUSION

The therapeutic efficacy of PPI can be predicted from the features of biopsied esophageal tissue. Factors predictive of resistance to treatment with PPI are negativity for PGP 9.5 in NERD patients and intraepithelial bleeding in RE patients.

Maintenance therapy of gastroesophageal reflux disease

The aims of treatment of gastroesophageal reflux disease (GERD) are to cure mucosal breaks, control symptoms, and prevent complications (e.g. stricture, Barrett's esophagus, and esophageal adenocarcinoma). Proton pump inhibitors (PPIs) are known to be the best drugs to cure esophagitis; however, a highrecurrence rate of about 80% was described after the completion of initial therapy. Regretfully, not so many physicians perform maintenance therapy in clinical practice. Histamine H2 receptor antagonists have an insufficient effect in maintenance therapy compared with PPIs; therefore, they could be prescribed for mild reflux esophagitis. Several clinical trials have been conducted to investigate the efficacy of continuous PPI administration maintenance therapy for GERD. Among these trials, recent large-scale studies showed that esomeprazole was equal to or superior to other kinds of PPIs. On the other hand, on-demand PPI studies have been conducted, mainly in patients with nonerosive reflux disease or uninvestigated GERD;however, this strategy was less effective than continuous therapy in many studies. Because on-demand therapy is less expensive, it is worth confirming this strategy in further studies. Studies of maintenance therapy with investigations conducted for as long a period as 5 years have described that PPI maintenance therapy could be considered as effective, safe, and well tolerated.