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

Vonoprazan: A Review in Helicobacter pylori Infection

Treatment for the eradication of Helicobacter pylori infection, a leading cause of peptic ulcer disease and an important risk factor for gastric cancer and mucosa-associated lymphoid tissue lymphoma, is indicated whenever infection is identified. However, treatment success rates with current guideline-recommended proton-pump inhibitor (PPI)-based regimens remain suboptimal, with one potential factor associated with treatment failure being inadequate acid suppression. Vonoprazan (Voquezna®) is a first-in-class potassium-competitive acid blocker with the potential to provide potent and sustained acid suppression. Following clinical trials conducted mainly in Asia (supported by post-marketing experience from Asia) and the phase III PHALCON-HP trial conducted in the USA and Europe, vonoprazan is now approved in the USA for use in combination with amoxicillin (dual therapy) or amoxicillin and clarithromycin (triple therapy) for the treatment of H. pylori infection in adults. The vonoprazan-based dual and triple therapy regimens were generally well tolerated in PHALCON-HP. In addition, vonoprazan has advantages including a rapid onset of action and no food effect, making vonoprazan-based dual and triple therapy regimens valuable alternatives to standard PPI-based triple therapy in the treatment of H. pylori infection.

Why the Vonoprazan Helicobacter pylori Therapies in the US-European Trial Produced Unacceptable Cure Rates

INTRODUCTION

Helicobacter pylori infects a large percentage of the world's population and is etiologically related to gastric cancer. The U.S. Food and Drug Administration recently approved two 14-day vonoprazan-containing regimens (vonoprazan-amoxicillin with or without clarithromycin) for H. pylori infections in the United States/Europe.

METHODS

We critically reviewed the trial methods to discover why the results were unacceptable low [i.e., no regimen achieved clinically acceptable (≥ 90%) or even conditionally acceptable cure rates (≥ 85%)]. Cure rates with antibiotic susceptible strains were 84.7 for vonoprazan triple therapy, 78.5 for vonoprazan-amoxicillin, and 78.7 for lansoprazole triple therapy, respectively. As was previously shown in Japan, the benefit from adding clarithromycin to vonoprazan-amoxicillin was minimal and the majority of the clarithromycin administered was unnecessary.

RESULTS

The possible reasons for failure to achieve high cure rates discussed include (a) reduced intragastric antibiotic concentrations, (b) an increase in heteroresistance, and (c) failure to achieve an intragastric pH conducive for amoxicillin to eradicate the infection. In addition, there was no pilot study or other attempt to optimize any regimen.

CONCLUSION

The most likely reason for failure was failure to achieve high intragastric concentrations of antibiotics or to achieve an intragastric pH conducive for amoxicillin to be active. Importantly, vonoprazan triple therapy resulted in > 10 tons of unneeded clarithromycin/million courses of vonoprazan triple therapy. Antibiotic misuse combined with low cure rates suggest that vonoprazan-clarithromycin triple therapies should not be prescribed for H. pylori infection. Dual vonoprazan-amoxicillin therapy has proven effective elsewhere and after optimization may eventually prove useful in the U.S./Europe.

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.

Potassium-Competitive Acid Blockers: Present and Potential Utility in the Armamentarium for Acid Peptic Disorders

Potassium-competitive acid blockers (PCABs) such as vonoprazan represent a novel class of acid suppressants that show tremendous promise to enhance care of acid peptic disorders. PCAB characteristics distinct from those of proton pump inhibitors-such as acid stability with dosing independent of food consumption, rapid onset of action, less variability with CYP2C19 polymorphisms, and extended half-lives-may add value in clinical practice. With recently reported data beyond Asian populations and expanding regulatory approval of PCABs, clinicians should be aware of these medications and their potential roles in the management of acid peptic disorders. This article provides an up-to-date summary of the evidence around PCABs for the treatment of gastroesophageal reflux disease (especially erosive esophagitis healing and maintenance), eosinophilic esophagitis, Helicobacter pylori infection, and peptic ulcer healing and secondary prophylaxis.

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.

A population PK–PD model of YH4808 , a novel P‐CAB , and intragastric pH that incorporated negative feedback by increased intragastric pH onto the systemic exposure to YH4808

YH4808 is a novel potassium‐competitive acid blocker that is under clinical development to treat patients with gastroesophageal reflux disease and peptic ulcer diseases. In this study, the pharmacokinetic (PK) and pharmacodynamic (PD) profiles of YH4808 were modeled in healthy male volunteers who received a single oral dose of YH4808 at 30, 50, 100, 200, 400, 600, and 800 mg or matching placebo and multiple once‐daily oral doses of YH4808 at 100, 200, and 400 mg or matching placebo for 7 days. A population PK–PD model adequately described the time–concentration‐effect profiles of YH4808. The maximum increasing effect of YH4808 on intragastric pH was 4.38, which was higher than the observed maximum increase in intragastric pH after omeprazole at 40 mg (2.2 in pH). The maximum inhibitory effect by the increased intragastric pH on the exposure to repeated YH4808 was 58% from baseline. Monte–Carlo simulation experiments based on the final model showed that YH4808 at 200 mg will produce a higher percentage of time at pH > 4 over 24 h on day 1 than observed value of esomeprazole at 40 mg once‐daily, an active comparator (84.7% time vs. 58.3% time, respectively). Because YH4808 at ≥200 mg resulted in a higher percentage of time at intragastric pH > 4 than seen after once‐daily esomeprazole at 40 mg and YH4808 showed acceptable tolerability at a single‐dose of 30–800 mg, we suggest to test the 200 mg once daily dosage regimen in further clinical trials of YH4808.

Scope and Limitations of Current Antibiotic Therapies against Helicobacter pylori: Reviewing Amoxicillin Gastroretentive Formulations

Even though general improvement of quality of life has happened around the globe, statistics show that gastric cancer is still a very serious medical concern in some regions of the world. A big portion of malignant neoplasms that develop inside the stomach are linked to an infection of Helicobacter pylori; in fact, this pathogen has already been categorized as a group 1 carcinogen by the World Health Organization (WHO). Still, the efficacy of current anti-H. pylori therapeutic approaches is insufficient and follows a worrying decreasing trend, mainly due to an exponential increase in resistance to key antibiotics. This work analyzes the clinical and biological characteristics of this pathogen, especially its link to gastric cancer, and provides a comprehensive review of current formulation trends for H. pylori eradication. Research effort has focused both on the discovery of new combinations of chemicals that function as optimized antibiotic regimens, and on the preparation of gastroretentive drug delivery systems (GRDDSs) to improve overall pharmacokinetics. Regarding the last topic, this review aims to summarize the latest trend in amoxicillin-loaded GRDDS, since this is the antibiotic that has shown the least bacterial resistance worldwide. It is expected that the current work could provide some insight into the importance of innovative options to combat this microorganism. Therefore, this review can inspire new research strategies in the development of efficient formulations for the treatment of this infection and the consequent prevention of gastric cancer.