Indirect comparison of randomised controlled trials: comparative efficacy of dexlansoprazole vs. esomeprazole in the treatment of gastro-oesophageal reflux disease

Comparison of exclusion, imputation and modelling of missing binary outcome data in frequentist network meta-analysis

Background

Missing participant outcome data (MOD) are ubiquitous in systematic reviews with network meta-analysis (NMA) as they invade from the inclusion of clinical trials with reported participant losses. There are available strategies to address aggregate MOD, and in particular binary MOD, while considering the missing at random (MAR) assumption as a starting point. Little is known about their performance though regarding the meta-analytic parameters of a random-effects model for aggregate binary outcome data as obtained from trial-reports (i.e. the number of events and number of MOD out of the total randomised per arm).

Methods

We used four strategies to handle binary MOD under MAR and we classified these strategies to those modelling versus excluding/imputing MOD and to those accounting for versus ignoring uncertainty about MAR. We investigated the performance of these strategies in terms of core NMA estimates by performing both an empirical and simulation study using random-effects NMA based on electrical network theory. We used Bland-Altman plots to illustrate the agreement between the compared strategies, and we considered the mean bias, coverage probability and width of the confidence interval to be the frequentist measures of performance.

Results

Modelling MOD under MAR agreed with exclusion and imputation under MAR in terms of estimated log odds ratios and inconsistency factor, whereas accountability or not of the uncertainty regarding MOD affected intervention hierarchy and precision around the NMA estimates: strategies that ignore uncertainty about MOD led to more precise NMA estimates, and increased between-trial variance. All strategies showed good performance for low MOD (<5%), consistent evidence and low between-trial variance, whereas performance was compromised for large informative MOD (> 20%), inconsistent evidence and substantial between-trial variance, especially for strategies that ignore uncertainty due to MOD.

Conclusions

The analysts should avoid applying strategies that manipulate MOD before analysis (i.e. exclusion and imputation) as they implicate the inferences negatively. Modelling MOD, on the other hand, via a pattern-mixture model to propagate the uncertainty about MAR assumption constitutes both conceptually and statistically proper strategy to address MOD in a systematic review.

HISTORICAL PERSPECTIVE OF GASTROESOPHAGEAL REFLUX DISEASE CLINICAL TREATMENT

BACKGROUND

Gastroesophageal reflux disease (GERD) is one of the most prevalent gastrointestinal diseases. GERD generates significant impairment in patients' quality of life and it is associated to relevant medical resources utilization. A better understanding of GERD pathophysiology in the past five decades has favored the evolution of therapeutic strategies from non-drug interventions and antacids to more efficacious and safer alternatives.

OBJECTIVE

To summarize data about the historical evolution of GERD management in Brazil, focusing on medical therapy and addressing evidence on efficacy and safety of drug classes currently recommended.

METHODS

A narrative review was conducted by systematizing information about discoveries on GERD pathophysiology. We also addressed efficacy and safety of medications currently used to reduce symptoms and improve endoscopic healing of esophageal lesions. A structured search on Pubmed was performed to identify systematic reviews and meta-analysis investigating GERD outcomes positively impacted by proton pump inhibitors (PPIs), the first choice of pharmacotherapy for the disease.

RESULTS

The chronological development of therapeutic measures for GERD in Brazil evolved from lifestyle interventions with relative poor effect on symptoms related to esophageal acid exposure, particularly heartburn, to effective and safe pharmacological interventions such as histamine H2-receptor antagonists and PPIs. In the present days, some drug classes play a minor role in disease management, namely prokinetics and antacids, due to their reduced efficacy and relevant safety concerns (particularly with prokinetics). The main challenge for prescribers and researchers seems to be finding long-acting acid suppressants strategies able to ameliorate patients' symptoms and quality of life, thereafter, reducing medical resource consumption. The dual delayed-release PPI dexlansoprazole seems to respond for some of the limitations other PPIs have.

CONCLUSION

Recognizing the historical evolution of GERD management can help care providers to better understand therapeutic options for their patients, as well as focus on unmet needs that deserve further attention. PPIs are still the first choice therapy, with good evidence in favor of their efficacy, despite some safety concerns. However, as with any medical intervention, it is recommended to prescribe PPIs for patients with clear indication, using adequate dosing and monitoring for adverse events.

In search of the grail: A race for acid suppression

Proton pump inhibitors are the reference standards for the treatment of acid-related diseases. Acid suppression in gastroesophageal reflux disease is associated with a high rate of mucosal cicatrization, but symptom response differs among endoscopic phenotypes. Extraesophageal manifestations have a good clinical response in patients that present with abnormal acid exposure (diagnostic test) in the esophagus. Proton pump inhibitors have shown their effectiveness for reducing symptom intensity in nighttime reflux and sleep disorders, improving quality of life and work productivity. That can sometimes be achieved through dose modifications by splitting or increasing the dose, or through galenic formulation. Proton pump inhibitors are not exempt from controversial aspects related to associated adverse events. Technological development is directed at improving proton pump inhibitor performance through increasing the half-life, maximum concentration, and area under the curve of the plasma concentrations through galenic formulation, as well as creating safer and more tolerable drugs. The present review is focused on the mechanisms of action, pharmacokinetic properties, and technological advances for increasing the pharmacologic performance of a proton pump inhibitor.

Clinical efficacy of 60-mg dexlansoprazole and 40-mg esomeprazole after 24 weeks for the on-demand treatment of gastroesophageal reflux disease grades A and B: a prospective randomized trial

Purpose: Research comparing the clinical efficacy of dexlansoprazole and esomeprazole has been limited. This study aims to compare the clinical efficacy of single doses of dexlansoprazole (modified-release 60 mg) and esomeprazole (40 mg) after 24-week follow-up in patients with mild erosive esophagitis. Methods: We enrolled 86 adult GERD subjects, randomized in a 1:1 ratio to two sequence groups defining the order in which they received single doses of dexlansoprazole (n=43) and esomeprazole (n=43) for 8 weeks as initial treatment. Patients displaying complete symptom resolution (CSR) by the end of initial treatment (8 weeks) were switched to on-demand therapy until the end of 24 weeks. Follow-up endoscopy was performed either at the end of 24 weeks or when severe reflux symptoms occurred. Five patients were lost to follow-up, leaving 81 patients (dexlansoprazole, n=41; esomeprazole, n=40) in the per-protocol analysis. Results: The GERDQ scores at 4-, 8-, 12-, 16-, 20-, and 24-week posttreatment were less than the baseline score. The CSR, rate of symptom relapse, days to symptom resolution, sustained healing rate of erosive esophagitis, treatment failure rate, and the number of tablets taken in 24 weeks were similar in both groups. The esomeprazole group had more days with reflux symptoms than the dexlansoprazole group (37.3±37.8 vs 53.9±54.2; P=0.008). In the dexlansoprazole group, patients exhibited persistent improvement in the GERDQ score during the on-demand period (week 8 vs week 24; P<0.001) but not in the esomeprazole group (week 8 vs week 24; P=0.846). Conclusions: This study suggests that the symptom relief effect for GERD after 24 weeks was similar for dexlansoprazole and esomeprazole. Dexlansoprazole exhibited fewer days with reflux symptoms in the 24-week study period, with better persistent improvement in the GERDQ score in the on-demand period. (ClinicalTrials. gov number: NCT03128736).

First-week clinical responses to dexlansoprazole 60 mg and esomeprazole 40 mg for the treatment of grades A and B gastroesophageal reflux disease

AIM

To compare the one-week clinical effects of single doses of dexlansoprazole and esomeprazole on grades A and B erosive esophagitis.

METHODS

We enrolled 175 adult patients with gastroesophageal reflux disease (GERD). The patients were randomized in a 1:1 ratio into two sequence groups to define the order in which they received single doses of dexlansoprazole (n = 88) and esomeprazole (n = 87) for an intention-to-treat analysis. The primary end-points were the complete symptom resolution (CSR) rates at days 1, 3, and 7 after drug administration.

RESULTS

Thirteen patients were lost to follow-up, resulting in 81 patients in each group for the per-protocol analysis. The CSRs for both groups were similar at days 1, 3 and 7. In the subgroup analysis, the female patients achieved higher CSRs in the dexlansoprazole group than in the esomeprazole group at day 3 (38.3% vs 18.4%, P = 0.046). An increasing trend toward a higher CSR was observed in the dexlansoprazole group at day 7 (55.3% vs 36.8%, P = 0.09). In the esomeprazole group, female sex was a negative predictive factor for CSR on post-administration day 1 [OR = -1.249 ± 0.543; 95%CI: 0.287 (0.099-0.832), P = 0.022] and day 3 [OR = -1.254 ± 0.519; 95%CI: 0.285 (0.103-0.789), P = 0.016]. Patients with spicy food eating habits achieved lower CSRs on day 1 [37.3% vs 21.4%, OR = -0.969 ± 0.438; 95%CI: 0.380 (0.161-0.896), P = 0.027].

CONCLUSION

The overall CSR for GERD patients was similar at days 1-7 for both the dexlansoprazole and esomeprazole groups, although a higher incidence of CSR was observed on day 3 in female patients who received a single dose of dexlansoprazole.

Recent Advances in the Pharmacological Management of Gastroesophageal Reflux Disease

The management of proton pump inhibitor-refractory GERD (rGERD) is a challenge in clinical practice. Since up to one-third of patients with typical GERD symptoms (heartburn and/or acid regurgitation) are not satisfied with proton pump inhibitor (PPI) therapy, new drug development targeting different pathophysiologies of GERD is imperative. At present, no other drugs serve as a more potent acid suppression agent than PPIs. As an add-on therapy, histamine type-2 receptor antagonists, alginates, prokinetics and transient lower esophageal sphincter relaxation inhibitors have some impact on the subgroups of rGERD, but greater effectiveness and fewer adverse effects for widespread use are required. Visceral hypersensitivity also contributes to the perception of GERD symptoms, and neuromodulators including antidepressants play a role in this category. Esophageal pH-impedance monitoring helps to distinguish functional heartburn from true GERD, and psychologic medication and cognitive behavior therapy are further therapy options instead of PPIs.

Comparative effectiveness and acceptability of the FDA-licensed proton pump inhibitors for erosive esophagitis: A PRISMA-compliant network meta-analysis

BACKGROUND

This study compared the effectiveness and acceptability of all Food and Drug Administration (FDA)-recommended dose proton pump inhibitors (PPIs) in erosive esophagitis (EE): Dexlansoprazole 60 mg, Esomeprazole 40 mg, Esomeprazole 20 mg, Pantoprazole 40 mg, Lansoprazole 30 mg, Rabeprazole 20 mg, Omeprazole 20 mg.

METHODS

A systematic literature search was performed using PubMed, Embase, and Cochrane Library. Totally, 25 randomized controlled trials (RCTs) met study selection criteria and were incorporated in this network meta-analysis (NMA) study.

RESULTS

For the NMA, eligible RCTs of adults with EE verified by endoscopic examination were randomly assigned to the licensed PPIs at least 4 weeks of continuous therapy. The primary efficacy outcome was the endoscopic healing rates at 4 and 8 weeks. Heartburn relief rates were a secondary efficacy outcome. The rates of withdrawal were analyzed as a safety outcome. In comparison to the common comparator omeprazole 20 mg, esomeprazole 40 mg provided significantly healing rates at 4 weeks [odds ratio (OR), 1.46 (95% confidence interval, 95% CI, 1.24-1.71)] and 8 weeks [1.58 (1.29-1.92)], and improved the heartburn relief rates [1.29 (1.07-1.56)]. In comparison to lansoprazole 30 mg, esomeprazole 40 mg provided significantly healing rates at 4 weeks [1.30 (1.10-1.53)] and 8 weeks [1.37 (1.13-1.67)], and improved the heartburn relief rates [1.29 (1.03-1.62)]. In terms of acceptability, only dexlansoprazole 60 mg had significantly more all-cause discontinuation than omeprazole 20 mg [1.54 (1.03-2.29)], pantoprazole 40 mg [1.68 (1.08-2.63)], and lansoprazole 30 mg [1.38 (1.02-1.88)].

CONCLUSION

The standard-dose esomeprazole 40 mg had more superiority in mucosal erosion healing and heartburn relief. Esomeprazole 40 mg, pantoprazole 40 mg, esomeprazole 20 mg, and lansoprazole 30 mg showed more benefits in effectiveness and acceptability than other interventions.

The role of dexlansoprazole modified-release in the management of gastroesophageal reflux disease

Dexlansoprazole modified-release (MR) is the R-enantiomer of lansoprazole and is currently the only proton-pump inhibitor (PPI) with a novel dual delayed release (DDR) formulation. Overall, dexlansoprazole MR demonstrates a similar safety and side-effect profile as lansoprazole. Dexlansoprazole MR has been shown to be highly efficacious in healing erosive esophagitis, maintaining healed esophageal mucosa in patients with erosive esophagitis and controlling symptoms of patients with nonerosive reflux disease (NERD). Recent studies have also demonstrated that dexlansoprazole MR is highly effective in improving nocturnal heartburn, gastroesophageal reflux disease (GERD) related sleep disturbances and bothersome regurgitation. Dexlansoprazole MR is well tolerated and can be taken without regard to food.

Dexlansoprazole: delayed-release orally disintegrating tablets for the treatment of heartburn associated with non-erosive gastroesophageal reflux disease and the maintenance of erosive esophagitis

Gastroesophageal reflux disease (GERD) is a common condition afflicting millions of patients, whose prevalence continues to rise owing to the aging population and increasing burden of comorbid conditions, such as obesity. Currently, the mainstay of therapy for GERD is treatment with proton pump inhibitors (PPIs), which have proven efficacy, safety, and tolerability. Despite this, a considerable number of patients have refractory symptoms to PPI therapy. Dexlansoprazole is a new addition to the class of PPIs, which has a unique dual delayed drug release system, which aims to address the current limitations of acid suppressive therapy by offering extended acid suppression and improved ease of administration. Areas covered: This manuscript covers the pharmacokinetics, pharmacodynamics, clinical efficacy, and regulatory approval of dexlansoprazole. Additionally, there is further discussion concerning the current market settings and the potential future impact of dexlansoprazole. Expert commentary: Overall, dexlansoprazole offers benefits in its ease of administration and proven efficacy in the healing, maintenance of erosive esophagitis, and symptomatic non-erosive GERD. Long-term, dexlansoprazole will likely find a niche market among patients who fail other acid suppressive therapy or who desire simplified administration for compliance concerns, but will likely come at a higher out of pocket expense than comparable generic PPIs.

The efficacy and safety of proton-pump inhibitors in treating patients with non-erosive reflux disease: a network meta-analysis

Proton-pump inhibitors (PPIs) have been proved as safe and effective ways to treat patients with non-erosive reflux disease (NERD). However, less is known about the comparisons among different PPIs and their best dosage. We aimed to synthesize the available evidence through network meta-analysis to investigate the efficacy and safety of different PPIs in treating patients with NERD. Fifteen studies with 6309 patients were included in the meta-analyses. For the rate of symptomatic relief, compared with control groups, all interventions except rabeprazole 5 mg significantly increased rate of symptomatic relief. Among the comparisons of different interventions, omeprazole 20 mg group was associated with a higher rate of symptomatic relief in contrast to omeprazole 10 mg group (odds ratio, OR: 1.89, 95% confidence interval, CI: 1.34, 2.67; p-value: 0.0005) or rabeprazole 5 mg group (OR: 2.51, 95%CI: 1.16, 5.42; p-value: 0.019); dexlansoprazole 30 mg therapy significantly improved the rate of symptomatic relief compared with rabeprazole 5 mg group (OR: 2.64, 95%CI: 1.08, 6.43; p-value: 0.03). For the rate of adverse events, there was no significant difference among all interventions.

Proton pump inhibitors for the treatment of patients with erosive esophagitis and gastroesophageal reflux disease: current evidence and safety of dexlansoprazole

Gastroesophageal reflux disease is the most common upper gastroenterology disorder in the US. It is associated with a variety of complications and significantly impacts quality of life. Proton pump inhibitors are the most effective treatment. Dexlansoprazole modified release (MR) is a proton pump inhibitor that employs a novel release formulation that prolongs its absorption and allows for more flexibility in dosing. Dexlansoprazole MR can be dosed without regard to food intake or time of day, and once-daily dosing may replace twice-daily dosing of other agents. Dexlansoprazole MR is effective for healing and maintenance of erosive esophagitis, and for the treatment of nonerosive disease, including nocturnal gastroesophageal reflux disease. Dexlansoprazole MR is safe and well tolerated, and can improve quality of life.

Dexlansoprazole - a new-generation proton pump inhibitor

Dexlansoprazole modified release (MR) is an R-enantiomer of lansoprazole and a new-generation proton pump inhibitor exhibiting high efficacy in the treatment of symptoms and lesions associated with erosive oesophagitis caused by gastroesophageal reflux disease (GERD). The dual release of the active ingredient - in the duodenum and the small intestine - makes it possible to achieve two peak concentrations at various times, within two and five hours of administration. Dexlansoprazole MR ensures the longest maintenance of drug concentration in the plasma of all known proton pump inhibitors, and the longest proton pump inhibitory effect. The basic indications for the drug include all forms of gastroesophageal reflux disease, especially with night-time heartburn and sleep disorders resulting from GERD. Dexlansoprazole can be taken regardless of meal times. It has a good safety profile and carries a low risk of adverse interactions with other drugs.

Managing gastroesophageal reflux disease - comparative efficacy and outcomes of dexlansoprazole MR

The management of gastroesophageal reflux disease (GERD) has been revolutionized with the development of proton pump inhibitors (PPIs). Unfortunately, due to the inherent pharmacokinetic and pharmacodynamic profiles of conventional PPIs, many patients continue to suffer from symptoms related to GERD despite appropriate use of PPIs. Dexlansoprazole MR is a PPI with a unique dual delayed-release delivery system that has been designed to address the unmet needs in GERD management. Specifically, dexlansoprazole MR addresses limitations with short plasma half-life and need for meal-associated dosing, characteristic of conventional PPIs. In addition, dexlansoprazole MR has been shown to be effective in several specific clinical situations. These include coadministration with clopidogrel, healing of all grades of erosive esophagitis, improvement in reflux-related quality of life, step down to once-per-day dosing, and treatment of Helicobacter pylori infections. Furthermore, dexlansoprazole MR has been found to induce symptom improvement in patients with nonerosive esophageal reflux disease, nocturnal heartburn and GERD-related sleep disturbance, and regurgitation. Overall, dexlansoprazole MR is a unique and useful tool in the management of GERD.

H+/K+-ATPase inhibitors and acid-related disorders

H⁺/K⁺-ATPase inhibitors, which inhibit gastric acid secretion, are a known class of pharmaceutical agents generally used for the treatment of gastric acid-related diseases including peptic ulcer disease, functional dyspepsia and gastroesophageal reflux disease. This paper reviews the recent progress in research of H⁺/K⁺-ATPase inhibitors and their applications in gastric acid-related diseases.

Identifying the proton transfer reaction mechanism via a proton-bound dimeric intermediate for esomeprazoles by a kinetic method combined with density functional theory calculations

RATIONALE

Esomeprazole analogs are a class of important proton pump inhibitors for the treatment of gastro-esophageal reflux diseases. Understanding the fragmentation reaction mechanism of the protonated esomeprazole analogs will facilitate the characterization of their complex metabolic fate in humans. In this paper, the kinetic method and theoretical calculations were applied to evaluate the fragmentation of protonated esomeprazole analogs.

METHODS

All collision-induced dissociation (CID) mass spectrometry experiments were carried out using electrospray ionization (ESI) ion trap mass spectrometry in positive ion mode. Also the accurate masses of fragments were measured on by ESI quadrupole time-of-flight (QTOF) MS in positive ion mode. Theoretical calculations were carried out by the density functional theory (DFT) method with the 6-31G(d) basis set in the Gaussian 03 program.

RESULTS

In the fragmentation of the protonated esomeprazole analogs, C-S bond breakage is observed, which gives rise to protonated 2-(sulfinylmethylene)pyridines and protonated benzimidazoles. DFT calculations demonstrate that the nitrogen atom of the pyridine part is the thermodynamically most favorable protonation site, and the C-S bond cleavage is triggered by the transfer of this ionizing proton from the nitrogen atom of the pyridine part to the carbon atom of the benzimidazole part to which the sulfinyl is attached. Moreover, with the kinetic plot, the intensity ratios of two protonated product ions yield a linear relationship with the differences in proton affinities of the corresponding neutral molecules, which provides strong experimental evidence that the reaction proceeds via proton-bound 2-(sulfinylmethylene)pyridine/benzimidazole complex intermediates.

CONCLUSIONS

The kinetic method combined with theoretical calculations was successfully applied to probe the proton transfer reaction by proton-bound 2-(sulfinylmethylene)pyridine/benzimidazole complexes in the fragmentation of protonated esomeprazole analogs by ESI CID MS, which is a strong evidence that the kinetic method can be applied in identifying a proton-bound dimeric intermediate in the fragmentation of protonated ions.

Complications of gastro-oesophageal reflux disease

Gastro-oesophageal reflux disease (GORD) is on the rise with more than 20% of the western population reporting symptoms and is the most common gastrointestinal disorder in the United States. This increase in GORD is not exactly clear but has been attributed to the increasing prevalence of obesity, changing diet, and perhaps the decreasing prevalence of H. pylori infection. Complications of GORD could be either benign or malignant. Benign complications include erosive oesophagitis, bleeding and peptic strictures. Premalignant and malignant lesions include Barrett's metaplasia, and oesophageal cancer. Management of both the benign and malignant complications can be challenging. With the use of proton-pump inhibitors, peptic strictures (i.e., strictures related to reflux) have significantly declined. Several aspects of Barrett's management remain controversial including the stage in the disease process which needs to be intervened, type of the intervention and surveillance of these lesions to prevent development of high grade dysplasia and oesophageal adenocarcinoma.