Randomised phase 3 trial: tegoprazan, a novel potassium-competitive acid blocker, vs. esomeprazole in patients with erosive oesophagitis

[Treatment of Acid-related Diseases Using Potassium-competitive Acid Blockers]

Proton pump inhibitors (PPIs) have several limitations to their efficacy including insufficient acid suppression, slow onset of action, and variable efficacy among patients due to CYP2C19 metabolism. Potassium-competitive acid blockers inhibit H⁺-K⁺-ATPase in a reversible and K⁺-competitive manner, are novel acid suppressive drugs with rapid onset of action, meal independence, and prolonged control of intragastric acidity compared to PPIs. Potassium-competitive acid blockers exhibited non-inferior therapeutic efficacies on reflux esophagitis, gastric ulcers, and Helicobacter pylori eradication. The review is focused on the unmet needs across the acid-related diseases and recent updates on clinical studies using vonoprazan and tegoprazan.

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.

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.

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

BACKGROUND

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

AIM

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

METHODS

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

RESULTS

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

CONCLUSION

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

Potassium-competitive acid blockers and gastroesophageal reflux disease

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

Pharmacokinetic Interactions Between Tegoprazan and Naproxen, Aceclofenac, and Celecoxib in Healthy Korean Male Subjects

PURPOSE

Tegoprazan is a potassium-competitive acid blocker used for gastric acid suppression and may be used with NSAIDs to reduce gastrointestinal adverse effects. The aim of this study was to evaluate the pharmacokinetic interaction between tegoprazan and commonly used NSAIDS, namely, naproxen, aceclofenac, and celecoxib.

METHODS

An open-label, 3-cohort, randomized, multiple-dose, 3-way crossover study was conducted in healthy male subjects. In cohort 1, tegoprazan (50-mg tablet, once daily) and naproxen (500-mg tablet, twice daily) were administered separately or concurrently for 7 days in each period. In cohort 2, tegoprazan and aceclofenac (100-mg tablet, twice daily) were administered separately or concurrently for 7 days in each period. In cohort 3, tegoprazan and celecoxib (200-mg capsule, twice daily) were administered separately or concurrently for 7 days in each period. Pharmacokinetic blood samples were collected up to 24 hours after the last dose.

FINDINGS

Seventeen subjects from cohort 1, sixteen subjects from cohort 2, and thirteen subjects from cohort 3 were included in the pharmacokinetic analysis. In cohort 1, the geometric least squares mean ratios (90% CIs) for AUC_τ (AUC profiles over the dosing interval) and C_ss,max (C_max at steady state) were 1.01 (0.91-1.12) and 0.99 (0.83-1.17) for tegoprazan, and 1.00 (0.97-1.03) and 1.04 (0.99-1.09) for naproxen, respectively. The values in cohort 2 were 1.03 (0.93-1.13) and 0.94 (0.86-1.04) for tegoprazan, and 1.06 (1.00-1.12) and 1.31 (1.08-1.60) for aceclofenac. The values in cohort 3 were 1.01 (0.86-1.18) and 1.02 (0.87-1.19) for tegoprazan, and 1.08 (0.96-1.22) and 1.18 (0.97-1.43) for celecoxib.

IMPLICATIONS

Changes in the maximum aceclofenac or celecoxib concentrations were detected after concurrent administration with tegoprazan, which were considered mainly due to the pharmacodynamic effect of tegoprazan. Because systemic drug exposure (shown as AUC_τ) was unchanged after concurrent administration of any 3 NSAIDs with tegoprazan, the increase in aceclofenac or celecoxib C_ss,max when administered with tegoprazan would not be clinically significant in practice.

CLINICALTRIALS

gov Identifier: NCT04639804.

Acid Suppressive Drugs

Histamine H₂ receptor antagonists (H₂RAs) suppress gastric acid production by blocking H₂ receptors in parietal cells. Studies have shown that proton pump inhibitors (PPIs) are superior to H₂RAs as a treatment for acid-related disorders, such as peptic ulcer disease (PUD) and gastroesophageal reflux disease (GERD). PPIs reduce gastric acid production by irreversibly inhibiting the H⁺/K⁺ ATPase pump, and they also increase gastric emptying. Although PPIs have differing pharmacokinetic properties, each PPI is effective in managing GERD and PUDs. However, PPIs have some limitations, including short plasma half-lives, breakthrough symptoms (especially at night), meal-associated dosing, and concerns associated with long-term PPI use. Potassium-competitive acid blockers (P-CABs) provide more rapid and profound suppression of intragastric acidity than PPIs. P-CABs are non-inferior to lansoprazole in healing erosive esophagitis and peptic ulcers, and may also be effective in improving symptoms in patients with non-erosive reflux disease. Acid suppressive drugs are the most commonly used drugs in clinical practice, and it is necessary to understand the pharmacological properties and adverse effects of each drug.

The efficacy and safety of keverprazan, a novel potassium-competitive acid blocker, in treating erosive oesophagitis: a phase III, randomised, double-blind multicentre study

BACKGROUND

Keverprazan is a novel potassium-competitive acid blocker (P-CAB) with a strong acid-suppressive capacity that may provide clinical benefit in acid-related diseases.

AIMS

This study aimed to explore the non-inferior efficacy and safety of keverprazan to lansoprazole in treating erosive oesophagitis (EO).

METHODS

This was a phase III, randomised, double-blind multicentre study. Patients were randomised to receive keverprazan 20 mg once daily or lansoprazole 30 mg once daily for 4-8 weeks. EO healing rates and adverse events (AEs) were compared between the keverprazan group and the lansoprazole group.

RESULTS

A total of 238 patients comprised the full analysis set (FAS) while 221 patients comprised the per-protocol set (PPS). For FAS analysis, the EO healing rates at week 8 were 95.8% (114/119) and 89.9% (107/119) for keverprazan and lansoprazole respectively. For PPS analysis, the EO healing rates at week 8 were 99.1% (110/111) and 92.7% (102/110) for keverprazan and lansoprazole respectively. Non-inferiority of keverprazan compared with lansoprazole according to EO healing rates at 8 weeks was demonstrated in both FAS (difference: 5.8% [95% CI: -0.6% to 12.3%]; p = 0.081) and PPS (difference: 6.1% [95% CI: 1.1%-11.2%]; p = 0.018) analysis. Drug-related AEs were reported in 34.5% (41/119) patients of the keverprazan group and 25.2% (30/119) patients of the lansoprazole group with no significant difference (p = 0.156). No severe AE happened in the keverprazan group.

CONCLUSIONS

This study demonstrated the non-inferior efficacy of keverprazan to lansoprazole in treating EO. The incidences of drug-related AEs were comparable between keverprazan and lansoprazole.

Co-Administration of Vonoprazan, Not Tegoprazan, Affects the Pharmacokinetics of Atorvastatin in Healthy Male Subjects

Potassium-competitive acid blocker is a new class of drugs inhibiting gastric acid. It is controversial that vonoprazan showed the inhibitory activities of cytochrome P450 3A4. This study aimed to evaluate the pharmacokinetics (PK) of atorvastatin and safety when atorvastatin was administered alone and co-administered with vonoprazan or tegoprazan. An open-label, multiple-dose, 3-intervention, 4-sequence, 4-period, partial replicate crossover study was conducted, and three interventions were; one is orally administered atorvastatin 40 mg alone once daily for 7 days, another is atorvastatin co-administered with vonoprazan 20 mg, and the other is atorvastatin co-administered with tegoprazan 50 mg. PK blood samples were collected up to 24 h after the last dose, and PK parameters for atorvastatin, 2-hydroxyatorvastatin and atorvastatin lactone were estimated by a non-compartmental method. Safety was evaluated, including adverse events and clinical laboratory tests. A total of 28 subjects completed the study. When atorvastatin was co-administered with vonoprazan, the systemic exposures of atorvastatin and atorvastatin lactone significantly increased, and the metabolic ratio of 2-hydroxyatorvastatin significantly decreased. Hypergastrinemia only occurred when atorvastatin was co-administered with vonoprazan. However, the plasma concentration profiles of atorvastatin, 2-hydroxyatorvastatin and atorvastatin lactone were similar when atorvastatin was administered alone or co-administered with tegoprazan. In conclusion, after multiple doses of atorvastatin co-administered with vonoprazan in healthy subjects, the systemic exposure of atorvastatin and the incidence of hypergastrinemia increased. With tegoprazan, however, those interactions were not observed.

2020 Seoul Consensus on the Diagnosis and Management of Gastroesophageal Reflux Disease

Gastroesophageal reflux disease (GERD) is a condition in which gastric contents regurgitate into the esophagus or beyond, resulting in either troublesome symptoms or complications. GERD is heterogeneous in terms of varied manifestations, test findings, and treatment responsiveness. GERD diagnosis can be established with symptomatology, pathology, or physiology. Recently the Lyon consensus defined the "proven GERD" with concrete evidence for reflux, including advanced grade erosive esophagitis (Los Angeles classification grades C and or D esophagitis), long-segment Barrett's mucosa or peptic strictures on endoscopy or distal esophageal acid exposure time > 6% on 24-hour ambulatory pH-impedance monitoring. However, some Asian researchers have different opinions on whether the same standards should be applied to the Asian population. The prevalence of GERD is increasing in Asia. The present evidence-based guidelines were developed using a systematic review and meta-analysis approach. In GERD with typical symptoms, a proton pump inhibitor test can be recommended as a sensitive, cost-effective, and practical test for GERD diagnosis. Based on a meta-analysis of 19 estimated acid-exposure time values in Asians, the reference range upper limit for esophageal acid exposure time was 3.2% (95% confidence interval, 2.7-3.9%) in the Asian countries. Esophageal manometry and novel impedance measurements, including mucosal impedance and a post-reflux swallow-induced peristaltic wave, are promising in discrimination of GERD among different reflux phenotypes, thus increasing its diagnostic yield. We also propose a long-term strategy of evidence-based GERD treatment with proton pump inhibitors and other drugs.

Randomised clinical trial: comparison of tegoprazan and placebo in non-erosive reflux disease

BACKGROUND

Tegoprazan is a novel, fast- and long-acting potassium-competitive acid blocker that suppresses gastric acid secretion, which could benefit patients with non-erosive reflux disease (NERD), a type of gastroesophageal reflux disease.

AIM

To evaluate the efficacy and safety profiles of tegoprazan compared with those of a placebo in Korean patients with NERD.

METHODS

In this phase 3, double-blind, placebo-controlled, multicentre study, 324 Korean patients with NERD were randomised into three treatment groups: tegoprazan 50 mg, tegoprazan 100 mg and placebo. These drugs were provided once daily for 4 weeks. The primary endpoint was the proportion of patients with complete resolution of major symptoms (both heartburn and regurgitation) for the last 7 days of the 4-week treatment period. Other outcomes related to efficacy, safety and tolerability were also evaluated.

RESULTS

Among all, 42.5% (45/106), 48.5% (48/99) and 24.2% (24/99) of patients showed complete resolution of major symptoms at week 4 after receiving tegoprazan 50 mg, tegoprazan 100 mg, and placebo, respectively. Both doses of tegoprazan showed superior efficacy than the placebo (P = 0.0058 and P = 0.0004, respectively). The complete resolution rates of heartburn and proportions of heartburn-free days (as other efficacy outcomes) were significantly higher in both tegoprazan groups than in the placebo group (P < 0.05 for all). No significant difference in the incidence of treatment-emergent adverse events were noted.

CONCLUSIONS

Tegoprazan 50 and 100 mg showed superior therapeutic efficacy compared with the placebo, as well as a favourable safety profile in patients with NERD. Registration number: ClinicalTrials.gov identifier NCT02556021.

Efficacy of Seven-Day Potassium-Competitive Acid Blocker-Based First-Line Helicobacter Pylori Eradication Therapy Administered with Bismuth

PURPOSE

To determine the efficacy of a potassium-competitive acid blocker (P-CAB)-based first-line eradication therapy with bismuth compared with that of proton pump inhibitor-based first-line therapy with bismuth.

MATERIALS AND METHODS

Eradication-naive H. pylori-infected patients were consecutively enrolled from January to November 2020. Before approval of the P-CAB-based eradication therapy, twice daily administration of a regimen containing lansoprazole 30 mg, amoxicillin 1 g, clarithromycin 500 mg, and bismuth potassium citrate 300 mg was prescribed for 7 days. After approval, lansoprazole was replaced with tegoprazan (50 mg). Clarithromycin resistance was examined in patients who underwent gastroscopic biopsy at our center. Efficacy was assessed via the ¹³C-urea breath test.

RESULTS

Of the 381 eradication-naive patients, eradication was successful in 88.3% (151/171) treated with tegoprazan and 82.8% (140/169) treated with lansoprazole in per-protocol analysis (p=0.151). In intention-to-treat analysis, eradication rates were 78.8% (152/193) in the tegoprazan and 74.5% (140/188) in the lansoprazole group (p=0.323). Clarithromycin resistance was observed in 30 (20.1%) of the 148 patients (74 from each group), and only four of the 16 clarithromycin-resistant patients in the tegoprazan group achieved successful eradication. Clarithromycin resistance [odds ratio (OR)=42.1, 95% confidence intervals (CIs)=12.6-141.0] and poor patient compliance (OR=17.1, 95% CIs=1.6-189.1) were independent risk factors for eradication failure.

CONCLUSION

In eradication-naive patients, eradication success rates for 7-day first-line triple therapy regimen exceeded 82% with bismuth administration. In clarithromycin-resistant patients, neither tegoprazan 50 mg nor lansoprazole 30 mg achieved acceptable eradication rates when administered twice daily for 7 days.

Is a Potassium-Competitive Acid Blocker Truly Superior to Proton Pump Inhibitors in Terms of Helicobacter pylori Eradication?

Vonoprazan (VPZ), a new potassium-competitive acid blocker, has been approved and used for Helicobacterpylori eradication in Japan. To date, many studies, as well as several systematic reviews and meta-analyses (MAs), have compared VPZ-based 7-day triple therapy with proton pump inhibitor (PPI)-based therapy. An MA of randomized controlled trials (RCTs) comparing first-line VPZ- with PPI-based triple therapy, the latter featuring amoxicillin (AMPC) and clarithromycin (CAM), found that approximately 30% of patients hosted CAM-resistant H. pylori; however, the reliability was poor because of high heterogeneity and a risk of selection bias. VPZ-based triple therapy is superior to PPI-based triple therapy for patients with CAM-resistant H. pylori, but not for those with CAM-susceptible H. pylori. An MA of non-RCTs found that second-line VPZ-based triple therapies were slightly (~2.6%) better than PPI-based triple therapies (with AMPC and metronidazole). However, the reliability of that MA was also low because of selection bias, confounding variables and a risk of publication bias; in addition, it is difficult to generalize the results because of a lack of data on antibiotic resistance. VPZ-based triple therapy (involving AMPC and sitafloxacin) was more effective than PPI-based triple therapy in a third-line setting, but a confirmatory RCT is needed. Non-RCT studies indicated that VPZ-based triple therapy involving CAM and metronidazole may be promising. Any further RCTs must explore the antibiotic-resistance status when evaluating the possible superiority of a potassium-competitive acid blocker.

Pharmacokinetic Interactions between Tegoprazan and Metronidazole/Tetracycline/Bismuth and Safety Assessment in Healthy Korean Male Subjects

PURPOSE

Tegoprazan is a potassium-competitive acid blocker used for gastric acid suppression, which may be used with Helicobacter pylori eradication therapies. The goal of this study was to evaluate the pharmacokinetic interaction between tegoprazan and triple-antibiotic therapy containing metronidazole, tetracycline, and bismuth.

METHODS

An open-label, 2-cohort, randomized, multiple-dose, crossover study was conducted in healthy subjects. In cohort 1, tegoprazan (100 mg/d) was administered orally with or without triple-antibiotic therapy (1500 mg/d metronidazole, 2000 mg/d tetracycline, and 1200 mg/d bismuth) for 7 days in each period. In cohort 2, triple-antibiotic therapy was administered orally with or without tegoprazan for 7 days in each period. Pharmacokinetic blood samples were collected within 24 h after the last dose. Safety assessments were performed.

FINDINGS

Eleven cohort 1 subjects and ten cohort 2 subjects were included in the pharmacokinetic analysis. The AUC_τ and C_max at steady state geometric mean ratios (90% CIs) were 0.78 (0.73-0.83) and 0.75 (0.68-0.82) for tegoprazan; 0.77 (0.68-0.88) and 0.84 (0.72-0.98) for tegoprazan metabolite M1; 1.03 (0.98-1.08) and 1.08 (0.99-1.18) for metronidazole; 0.63 (0.56-0.70) and 0.64 (0.56-0.74) for tetracycline; and 1.55 (0.99-2.44) and 1.38 (0.72-2.66) for bismuth, respectively. All reported adverse events were mild.

IMPLICATIONS

Changes in the tegoprazan, tetracycline, and bismuth pharmacokinetic parameters were detected after concurrent administration. These changes were considered mainly due to the pharmacodynamic effect of tegoprazan. The adverse events were predictable and reported as frequent adverse events during triple-antibiotic therapy. There were no significant differences in safety or tolerability between quadruple therapy, including tegoprazan and triple-antibiotic therapy. ClinicalTrials.gov identifier: NCT04066257.

Efficacy of Tegoprazan for Improving the Susceptibility of Antimicrobial Agents against Antibiotic-Resistant Helicobacter pylori

Background/Aims

Favorable outcomes of potassium-competitive acid blocker (PCAB)-containing eradication therapy have been reported. In fact, tegoprazan, a recently developed PCAB, was presumed to show good eradication efficacy even for resistant Helicobacter pylori. We aimed to investigate the anti-H. pylori efficacy of tegoprazan compared with that of vonoprazan.

Methods

A total of 220 resistant clinical H. pylori isolates were utilized. The anti-H. pylori efficacy of PCABs was determined by evaluating the minimum inhibitory concentrations (MICs) of clarithromycin, fluoroquinolone, metronidazole, and amoxicillin in combination with vonoprazan or tegoprazan by the agar dilution method. The impact of the mutations responsible for resistance development, such as 23S rRNA, gyrA, rdxA, frxA, and pbp1 mutations, was also analyzed.

Results

H. pylori growth was significantly inhibited in a medium containing 1 μg/mL clarithromycin with tegoprazan (128 μg/mL). The MICs of clarithromycin (46.3%), fluoroquinolone (46.7%), metronidazole (55.6%), and amoxicillin (34.5%) against resistant H. pylori isolates improved after tegoprazan administration. Tegoprazan demonstrated more frequent susceptibility acquisition with metronidazole than with vonoprazan (20.6% vs 4.7%, p=0.014). However, there were no significant differences depending on the mutational status of each antimicrobial agent.

Conclusions

Tegoprazan administration may improve the susceptibility of antimicrobial-resistant H. pylori, independent of acid suppression.

Pharmacokinetics and Pharmacodynamics of Tegoprazan Coadministered With Amoxicillin and Clarithromycin in Healthy Subjects

This clinical trial was conducted to evaluate the pharmacokinetics and pharmacodynamics of tegoprazan when coadministered with amoxicillin/clarithromycin in healthy subjects. Cohort 1 was an open-label, randomized multiple-dose study to evaluate the mutual interaction of tegoprazan and amoxicillin/clarithromycin on the disposition of 3 tested drugs including tegoprazan M1 metabolite and 14-hydroxyclarithromycin (14-OH-clarithromycin). Cohort 2 was an open-label, randomized, active-controlled, parallel multiple-dose study to compare the intragastric pH profile after multiple oral doses of 50 or 100 mg tegoprazan coadministered with amoxicillin/clarithromycin 1000/500 mg for 7 days and pantoprazole-based triple therapy as the comparator arm. The coadministration of tegoprazan with amoxicillin/clarithromycin increased C_ss,max (2.2-fold) and AUC_τ (2.7-fold) of tegoprazan and M1 (2.1- and 2.2-fold for C_ss,max and AUC_τ , respectively) compared with administration of tegoprazan alone. The C_ss,max and AUC_τ of 14-OH-clarithromycin increased by 1.7- and 1.8-fold, respectively; the disposition of amoxicillin and clarithromycin were not significantly changed. On days 1 and 7 of treatment, tegoprazan-based therapies (both 50- and 100-mg therapies) maintained pH above 6 for more than 88% of the 24-hour period, which was significantly longer compared with pantoprazole-based therapy. Tegoprazan either alone or in combination with amoxicillin/clarithromycin was well tolerated in healthy subjects. In conclusion, the exposure of tegoprazan was increased after coadministration of amoxicillin/clarithromycin, which led to increase pharmacodynamic response measured by intragastric pH compared with tegoprazan alone. Therefore, tegoprazan-based triple therapy would be effective therapeutic regimen to manage intragastric pH in terms of gastric or duodenal ulcers healing, treatment of gastroesophageal reflux disease, and Helicobacter pylori eradication.

The Natural Course of Gastroesophageal Reflux Disease: A Critical Appraisal of the Literature

Interpreting natural course studies have been very difficult due to their retrospective design, lack of standardization, reliability of reported mucosal findings, liberal use of antireflux medications and accuracy of chart documentation. Studies provided a wide range of progression rates of patients from nonerosive reflux disease (NERD) to erosive esophagitis (EE). However, direct progression from NERD to Barrett's esophagus appears to be an uncommon phenomenon. Importantly, progression of NERD patients was commonly reported to low grades of EE, which are currently considered inconclusive of gastroesophageal reflux disease. Reports of progression rates from low grades to high grades EE also vary considerably. Progression of patients with EE, without metaplastic epithelium underneath the inflammation, to Barrett's esophagus is relatively uncommon. Recently, it was also recognized that regression from high grades to low grades EE and from EE to NERD is a common phenomenon affecting up to 25% of the patients from each group.

Safety, Tolerability and Pharmacokinetics of Single Ascending and Multiple Oral Doses of Tegoprazan in Healthy Chinese Subjects

BACKGROUND AND OBJECTIVES

Tegoprazan is one of the potassium-competitive acid blockers (P-CABs). It exhibits its anti-secretory effects by competitively and reversibly blocking the availability of K⁺ of the H⁺, K⁺-ATPase. This study was designed to investigate the safety and pharmacokinetics of tegoprazan in healthy Chinese subjects.

METHODS

Thirty-eight healthy Chinese subjects were recruited in this randomized, single-center, double-blind, placebo-controlled study, with a single ascending dose of 50, 100, 200 mg and a multiple dose of 100 mg for 10 days. The plasma concentration of tegoprazan was determined by a validated liquid chromatography tandem mass spectrometry (LC-MS/MS) method. Pharmacokinetics were evaluated via non-compartmental and compartmental model analysis. Safety was assessed by physical examinations, vital signs, clinical laboratory tests, and electrocardiograms.

RESULTS

No serious adverse event was observed in this study. After single-dose administration (50, 100 and 200 mg), tegoprazan was rapidly absorbed with a median maximum measure plasma concentration (T_max) at 0.5 h and declined with a terminal (elimination) half-life (t_1/2) of 3.87-4.57 h. The maximum measured plasma concentration (C_max) for tegoprazan was 813.80, 1494.60 and 2829.00 ng/mL. Meanwhile, the corresponding area under the concentration-time curve (AUC) from time zero to infinity (AUC_0-inf) was 2761.00, 5980.05 and 11,044.72 ng∙h/mL in 50, 100, 200 mg group, respectively. Dose-dependent increase was observed in the value of C_max and AUC after administration of tegoprazan 50 to 200 mg. The two-compartment model well described the pharmacokinetic profile of tegoprazan. In the steady state, no accumulation was found after repeated administration at the 100-mg dose level. No experimental differences were found based on gender.

CONCLUSIONS

Tegoprazan was well tolerated in the dose range of 50-200 mg in single- and 100 mg in multiple-dose studies. Tegoprazan shows dose linearity with oral administration after a single dose of 50 to 200 mg and less drug accumulation after 10 days of continuous administration in 100 mg.

The Potential Benefits of Vonoprazan as Helicobacter pylori Infection Therapy

Helicobacter pylori infection is a severe global health problem that is closely associated with acid-related diseases and gastric malignancies. Eradicating H. pylori is strongly recommended for lowering peptic ulcer recurrence and preventing gastric cancer. The current approved H. pylori eradication regimen combines a proton pump inhibitor (PPI) with two antibiotics. Unfortunately, this regimen failed to meet expectations mostly due to antibiotic resistance and insufficient gastric acid suppression. Vonoprazan, a novel potassium-competitive acid blocker, showed promising results as a PPI replacement. Vonoprazan inhibits gastric acid secretion by acting as a reversible competitive inhibitor against potassium ions and forming disulfide bonds with the cysteine molecule of H⁺/K⁺-ATPase. Vonoprazan has superior pharmacological characteristics over PPI, such as no requirement for acid activation, stability in acidic conditions, shorter optimum acid suppression period, and resistance to cytochrome P (CYP)2C19 polymorphism. Several comparative randomized controlled trials and meta-analyses revealed the superiority of vonoprazan in eradicating H. pylori, notably the resistant strains. The adverse effect caused by vonoprazan is long-term acid suppression that may induce elevated gastrin serum, hypochlorhydria, and malabsorption. All vonoprazan studies have only been conducted in Japan. Further studies outside Japan are necessary for universally conclusive results.

Randomised clinical trial: tegoprazan, a novel potassium-competitive acid blocker, or lansoprazole in the treatment of gastric ulcer

BACKGROUND

Tegoprazan is a novel potassium-competitive acid blocker for the treatment of acid-related disorders.

AIMS

To assess whether tegoprazan is non-inferior to lansoprazole in terms of efficacy and safety in patients with gastric ulcers.

METHODS

In this phase 3, double-blind, active control, multicentre study, 306 gastric ulcer patients were randomised to one of three treatment groups: tegoprazan 50 mg, tegoprazan 100 mg and lansoprazole 30 mg once daily for 4 or 8 weeks. The primary endpoint was the cumulative proportion of patients with healed ulcers confirmed by endoscopy up to 8 weeks from treatment initiation. Symptoms and safety were assessed.

RESULTS

In the full analysis set, the cumulative healing rates at week 8 were 94.8% (91/96) for the tegoprazan 50 mg, 95.0% (94/99) for the tegoprazan 100 mg and 95.7% (89/93) for the lansoprazole 30 mg groups. At week 4, the respective healing rates were 90.6% (87/96), 91.9% (91/99), and 89.2% (83/93). In per protocol analysis, 4-week healing rates were 95.4% (84/88), 94.6% (88/93) and 92.9% (79/85) for tegoprazan 50 mg, tegoprazan 100 mg and lansoprazole 30 mg, respectively. Both doses of tegoprazan were non-inferior to lansoprazole in ulcer healing at 4 and 8 weeks. The incidence of drug-related treatment-emergent adverse events did not differ among groups. The increase in serum gastrin concentration was not higher in tegoprazan-treated patients than in lansoprazole-treated patients.

CONCLUSIONS

Tegoprazan 50 or 100 mg were not inferior to lansoprazole 30 mg once daily in the treatment of gastric ulcers.

The first case of tegoprazan-induced urticaria

WHAT IS KNOWN AND OBJECTIVE

Tegoprazan induces adverse drug reactions during clinical trials; however, tegoprazan-induced urticaria has not been reported. Here, we describe the first case of this.

CASE DESCRIPTION

A 55-year-old woman presented with acute urticaria with pruritus after taking the gastro-oesophageal reflux disease medication, tegoprazan. Urticaria disappeared after tegoprazan discontinuation. In an oral provocation test, after taking 10% of tegoprazan, she developed pruritus, and after taking 30%, she developed urticaria on her back.

WHAT IS NEW AND CONCLUSION

This is the first case of urticaria induced by tegoprazan. Physicians should understand the possibility of a tegoprazan-induced hypersensitivity reactions.

Novel Therapies for Gastroesophageal Reflux Disease: Beyond Proton Pump Inhibitors

PURPOSE OF REVIEW

Despite the many areas of unmet needs in gastroesophageal reflux disease (GERD), proton pump inhibitors (PPIs) remain the cornerstone of medical therapy. However, since their introduction, the therapeutic limitations of PPIs in GERD management have been increasingly recognized.

RECENT FINDINGS

In this review we discuss the new medical, endoscopic, and surgical therapeutic modalities that have been developed over the last decade. They include the potassium-competitive acid blockers (P-CABs) which provide a rapid onset, prolonged, and profound acid suppression, mucosal protectants which promote the physiological protective barrier of the esophageal mucosa, new prokinetics and neuromodulators. There are growing numbers of novel therapeutic endoscopic techniques that are under investigation or were recently introduced into the market, further expanding our therapeutic armamentarium for GERD. The development of diverse therapeutic modalities for GERD, despite the availability of PPIs, suggests that there are many areas of unmet need in GERD that will continue and drive future exploration for novel therapies.

The potential role of potassium-competitive acid blockers in the treatment of gastroesophageal reflux disease

PURPOSE OF REVIEW

Gastroesophageal reflux disease (GERD) is primarily a motor disorder, but its pathogenesis is multifactorial. Although gastric acid secretion is usually normal in GERD patients, treatment with proton pump inhibitors (PPIs) has become the standard of care, despite increasing awareness of their shortcomings. In this article, a new class of antisecretory drugs (namely potassium-competitive acid blockers, P-CABs), developed to overcome these limitations, is discussed.

RECENT FINDINGS

P-CABs block the K exchange channel of the proton pump, resulting in rapid, competitive, reversible inhibition of acid secretion. These drugs offer a more rapid elevation of intragastric pH than PPIs, while maintaining similar antisecretory effect, the duration of which is dependent on half-life and can be prolonged with extended release formulations. Thus, P-CABs offer advances in the treatment of GERD including rapid heartburn relief, faster and more reliable healing of severe grades of erosive esophagitis, as a consequence of better control of nighttime acid secretion than PPIs.

SUMMARY

P-CABs overcome many of the drawbacks of PPIs. The unique antisecretory effects of vonoprazan might be especially useful in the long-term treatment of patients with Barrett's esophagus.