Structural Modification and Biological Evaluation of 2,8-Disubstituted Adenine and Its Nucleosides as A2A Adenosine Receptor Antagonists: Exploring the Roles of Ribose at Adenosine Receptors.

Building on the preceding structural analysis and a structure-activity relationship (SAR) of 8-aryl-2-hexynyl nucleoside hA2AAR antagonist 2a, we strategically inverted C2/C8 substituents and eliminated the ribose moiety. These modifications aimed to mitigate potential steric interactions between ribose and adenosine receptors. The SAR findings indicated that such inversions significantly modulated hA3AR binding affinities depending on the type of ribose, whereas removal of ribose altered the functional efficacy via hA2AAR. Among the synthesized derivatives, 2-aryl-8-hexynyl adenine 4a demonstrated the highest selectivity for hA2AAR (Ki,hA2A = 5.0 ± 0.5 nM, Ki,hA3/Ki,hA2A = 86) and effectively blocked cAMP production and restored IL-2 secretion in PBMCs. Favorable pharmacokinetic properties and a notable enhancement of anticancer effects in combination with an mAb immune checkpoint blockade were observed upon oral administration of 4a. These findings establish 4a as a viable immune-oncology therapeutic candidate.

Evaluation of pharmacokinetic drug-drug interaction between tegoprazan and clarithromycin in healthy subjects.

Tegoprazan is a novel potassium-competitive acid blocker that treats gastric acid-related diseases. Clarithromycin was widely used as one of various regimens for eradicating Helicobacter pylori. This study compared the pharmacokinetic and safety profile of tegoprazan and clarithromycin between combination therapy and monotherapy to evaluate the potential drug-drug interaction. An open-label, randomized, 6-sequence, 3-period crossover study was conducted in 24 healthy subjects. According to the assigned sequence, the subject was administered the assigned treatment during 5 days in each period. PK parameters of tegoprazan and clarithromycin administered in combination were compared with those of the respective monotherapies. The co-administration of tegoprazan with clarithromycin increased maximum steady-state plasma concentration (Css,max) and area under the plasma concentration-time curve in dosing interval at steady-state (AUCss,tau) of tegoprazan (1.6-fold in Css,max and 2.5-fold in AUCss,tau) and M1 (2.0-fold in Css,max, 2.5-fold in AUCss,tau) than tegoprazan alone. The Css,max and AUCss,tau of 14-hydroxyclarithromycin increased 1.8- and 2.0-fold in co-administration, respectively. The AUCss.tau of clarithromycin was slightly increased in co-administration, but Css,max was not changed. Combination of tegoprazan and clarithromycin and those of the respective monotherapies were tolerated in 24 healthy subjects. There may exist drug interaction that lead to reciprocal increase in plasma drug concentrations when tegoprazan and clarithromycin were administrated in combination and no safety concerns were raised. It is suggested that an in-depth analysis of the concentration-response relationship is necessary to determine whether these concentration changes warrant clinical action. Trial Registration: ClinicalTrials.gov Identifier: NCT02052336.

Evaluation of the comparative pharmacokinetic properties of a new orally disintegrating tablet of tegoprazan in healthy Korean subjects.

PURPOSE: Tegoprazan is a differentiated gastric acid-pump blocker and belongs to a class of potassium-competitive acid secretion blockers. An orally disintegrating tablet (ODT) of tegoprazan was developed to improve patient compliance. The purpose of this study was to compare pharmacokinetics (PK) and safety profiles between the conventional tablet (as the reference drug) and the ODT (as the test drug) of 50 mg tegoprazan in healthy Korean subjects. MATERIALS AND METHODS: An open-label, randomized, single-dose, 6-sequence, 3-period crossover study was conducted in 48 healthy subjects. All subjects received a single oral dose of tegoprazan 50 mg tablet with water, tegoprazan 50 mg ODT with water, and tegoprazan 50 mg ODT without water. Serial blood samples were collected up to 48 hours after dosing. Plasma concentrations of tegoprazan and its metabolite M1 were measured by LC-MS/MS, and PK parameters were calculated with a non-compartmental method. Safety was evaluated by means of assessed adverse events, physical examinations, laboratory test results as well as measurements of vital signs and ECG throughout the study. RESULTS: A total of 47 subjects completed the study. The 90% confidence intervals of the geometric mean ratios for AUCt, Cmax, and AUCinf of tegoprazan were 0.8873 - 0.9729, 0.8865 - 1.0569, and 0.8835 - 0.9695 for the test drug with water to the reference drug and 0.9169 - 1.0127, 0.9569 - 1.1276, and 0.9166 - 1.0131 for the test drug without water to the reference drug, respectively. There were no serious adverse events, and all adverse events were mild. CONCLUSION: The PK profiles of tegoprazan were equivalent between the conventional tablet and ODT with or without water. There was no significant difference in the safety profiles. Therefore, the novel ODT of tegoprazan that can be taken without water may improve compliance among patients with acid-related diseases.

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

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

Comparison of Pharmacodynamics between Tegoprazan and Dexlansoprazole Regarding Nocturnal Acid Breakthrough: A Randomized Crossover Study.

Background/Aims: Tegoprazan, a novel potassium-competitive acid blocker, is expected to overcome the limitations of proton pump inhibitors and effectively control nocturnal acid breakthrough. To evaluate the pharmacodynamics of tegoprazan versus dexlansoprazole regarding nocturnal acid breakthrough in healthy subjects. Methods: In a randomized, open-label, single-dose, balanced incomplete block crossover study, 24 healthy male volunteers were enrolled and randomized to receive oral tegoprazan (50, 100, or 200 mg) or dexlansoprazole (60 mg) during each of two administration periods, separated by a 7- to 10-day washout period. Blood samples were collected for pharmacokinetic parameter analysis; gastric monitoring was performed for pharmacodynamic parameter evaluation. Results: All 24 subjects completed the study. Average maximum plasma concentration, area under the plasma concentration-time curve, and mean time with gastric pH >4 and pH >6 for tegoprazan demonstrated dose-dependent incremental increases. All the tegoprazan groups reached mean pH ≥4 within 2 hours, whereas the dexlansoprazole group required 7 hours after drug administration. Based on pharmacodynamic parameters up to 12 hours after evening dosing, 50, 100, and 200 mg of tegoprazan presented a stronger acid-suppressive effect than 60 mg of dexlansoprazole. Moreover, the dexlansoprazole group presented a comparable acid-suppressive effect with the tegoprazan groups 12 hours after dosing. Conclusions: All the tegoprazan groups demonstrated a significantly faster onset of gastric pH increase and longer holding times above pH >4 and pH >6 up to 12 hours after evening dosing than the dexlansoprazole group.

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 AUCτ (AUC profiles over the dosing interval) and Css,max (Cmax 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 AUCτ) was unchanged after concurrent administration of any 3 NSAIDs with tegoprazan, the increase in aceclofenac or celecoxib Css,max when administered with tegoprazan would not be clinically significant in practice. CLINICALTRIALS: gov Identifier: NCT04639804.

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

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

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.

Prediction of Drug-Drug Interaction Potential of Tegoprazan Using Physiologically Based Pharmacokinetic Modeling and Simulation.

This study aimed to develop a physiologically based pharmacokinetic (PBPK) model of tegoprazan and to predict the drug-drug interaction (DDI) potential between tegoprazan and cytochrome P450 (CYP) 3A4 perpetrators. The PBPK model of tegoprazan was developed using SimCYP Simulator® and verified by comparing the model-predicted pharmacokinetics (PKs) of tegoprazan with the observed data from phase 1 clinical studies, including DDI studies. DDIs between tegoprazan and three CYP3A4 perpetrators were predicted by simulating the difference in tegoprazan exposure with and without perpetrators, after multiple dosing for a clinically used dose range. The final PBPK model adequately predicted the biphasic distribution profiles of tegoprazan and DDI between tegoprazan and clarithromycin. All ratios of the predicted-to-observed PK parameters were between 0.5 and 2.0. In DDI simulation, systemic exposure to tegoprazan was expected to increase about threefold when co-administered with the maximum recommended dose of clarithromycin or ketoconazole. Meanwhile, tegoprazan exposure was expected to decrease to ~30% when rifampicin was co-administered. Based on the simulation by the PBPK model, it is suggested that the DDI potential be considered when tegoprazan is used with CYP3A4 perpetrator, as the acid suppression effect of tegoprazan is known to be associated with systemic exposure.

Effect of Food on the Pharmacokinetics and Pharmacodynamics of a Single Oral Dose of Tegoprazan.

PURPOSE: Tegoprazan is a potassium-competitive acid blocker (P-CAB) that is designed to treat acid-related diseases through a fundamentally different mechanism than that of proton pump inhibitors (PPIs). Because PPIs inhibit only activated parietal cell H+/K+ adenosine triphosphatase, stimulation of parietal cells by a meal is necessary for optimal results. In contrast, P-CABs can inactivate proton pumps without acid activation and bind to both activated and inactivated adenosine triphosphatase. This study evaluates the effect of food consumption on the pharmacokinetic and pharmacodynamic properties of tegoprazan after a single oral dose in healthy men. METHODS: In this open-label, 2-period crossover study, 24 healthy men were randomized to 1 of 2 treatment sequence groups: administration of tegoprazan under the fasting condition and administration of tegoprazan under the fed condition. The dosing periods of both sequence groups were separated by a washout period of 7 days. At each dosing period, the participants received a single dose of 200 mg of tegoprazan followed by pharmacokinetic and pharmacodynamic analysis. FINDINGS: After the oral administration of 200 mg tegoprazan, the Cmax was decreased and delayed under the fed condition compared with that of the fasting condition. However, no significant differences were observed in the AUC and the time of gastric acid suppression (inhibition of integrated acidity) during 24 hours. IMPLICATIONS: The pharmacokinetic and pharmacodynamic properties of tegoprazan are independent of food effect; thus, tegoprazan could be administered regardless of the timing of food consumption in patients. ClinicalTrials.gov identifier: NCT01830309.

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 AUCτ and Cmax 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.

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 Css,max (2.2-fold) and AUCτ (2.7-fold) of tegoprazan and M1 (2.1- and 2.2-fold for Css,max and AUCτ , respectively) compared with administration of tegoprazan alone. The Css,max and AUCτ 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.

Effect of meal timing on pharmacokinetics and pharmacodynamics of tegoprazan in healthy male volunteers.

Tegoprazan, a novel potassium-competitive acid blocker, is used to treat acid-related diseases. However, there is no information on the pharmacokinetic (PK) and pharmacodynamic (PD) profiles of the marketed dosage of tegoprazan under various meal timings in a fed and fasted state. The study aimed to assess the effect of meal timing on PKs and PDs of tegoprazan 50 mg after a single administration in healthy male subjects. An open-label, single-dose, three-treatment, three-period crossover study was conducted. A total of 12 subjects were orally administered a single dose of tegoprazan 50 mg among various conditions: in a fasted state, at 30 min before or 30 min after a high-fat meal. PK parameters were estimated by the noncompartmental method. Continuous 24-h intragastric pH monitoring was done for PD analysis. The PKs and PDs of tegoprazan were compared among the various meal timings. Compared with the fasting condition, the PK profile of tegoprazan was similar when administered 30 min before a high-fat meal; however, delayed absorption with similar systemic exposure was observed when administered 30 min after a high-fat meal. The magnitude of acid suppression evaluated through the PD parameters increased when administered 30 min after a high-fat meal compared with fasting the condition and when administered 30 min before a high-fat meal. However, the increased difference in acid suppression was not clinically significant. Meal timing had no clinically significant effect on the PKs and PDs of tegoprazan 50 mg. Therefore, the marketed dosage of tegoprazan could be administered regardless of the meal timing. Study Highlights WHAT IS THE CURRENT KNOWLEDGE ON THE TOPIC? Tegoprazan, a novel potassium-competitive acid blocker, is used to treat acid-related diseases. WHAT QUESTION DID THIS STUDY ADDRESS? This study evaluated the effect of food on pharmacokinetics (PKs) and pharmacodynamics (PDs) of tegoprazan under various mealtime conditions. WHAT DOES THIS STUDY ADD TO OUR KNOWLEDGE? This study showed that delayed absorption of tegoprazan was observed at "after meal condition," however, the amount of systemic exposure of "after meal condition" was similar to "fasting condition" and "before meal condition." In addition, gastric acid suppression of tegoprazan was similar between fasting condition and before meal condition, whereas increased gastric acid suppression was observed at after meal condition. HOW MIGHT THIS CHANGE CLINICAL PHARMACOLOGY OR TRANSLATIONAL SCIENCE? In the actual clinical environment, patients take medicine under various fed conditions. This study evaluated the effect of food on PKs and PDs of tegoprazan in various clinical conditions, and provided the important information about meal timing when administering tegoprazan.

Pharmacodynamics of tegoprazan and revaprazan after single and multiple oral doses in healthy subjects.

BACKGROUND: Potassium-competitive acid blockers (P-CABs) are emerging as novel treatments for acid-related disorders including gastroesophageal reflux disease. Tegoprazan and revaprazan are approved P-CABs in South Korea, but the pharmacodynamics and safety/tolerability of the two drugs have never been compared. AIMS: To evaluate the pharmacodynamics and safety/tolerability of tegoprazan and revaprazan after single and multiple oral doses METHODS: A randomised, open-label, active-controlled study was conducted in Helicobacter pylori-negative healthy Korean male subjects. Tegoprazan 50 mg or revaprazan 200 mg was administered orally, once daily for 7 days; 24-h intragastric pH monitoring and serum gastrin were measured for pharmacodynamic evaluation. Safety parameters including serum microRNA-122 (miR-122) level were also collected. RESULTS: After a single dose, the %Time pH ≥4 for tegoprazan was greater than that for revaprazan (54.5% vs 25.1%). After multiple doses, the %Time pH ≥4 for tegoprazan was also greater than that for revaprazan (68.2% vs 25.3%). %Time pH ≥4 during 12 hours at nighttime for tegoprazan was greater than that for revaprazan (71.8% vs 31.9%). The changes in the serum gastrin were not clinically significant for either drug. Despite the slight increases of serum miR-122 for each drug, tegoprazan and revaprazan were well tolerated considering other safety parameters including AST and ALT levels. CONCLUSION: Tegoprazan 50 mg showed stronger gastric acid suppression than revaorazan 200 mg. Both drugs were well tolerated.

Randomised clinical trial: safety, tolerability, pharmacokinetics, and pharmacodynamics of single and multiple oral doses of tegoprazan (CJ-12420), a novel potassium-competitive acid blocker, in healthy male subjects.

BACKGROUND: Tegoprazan (CJ-12420) is a potassium-competitive acid blocker (P-CAB) with therapeutic potential for gastro-oesophageal reflux disease (GERD) by reversibly suppressing gastric H+ /K+ -ATPase. AIMS: To investigate the safety, tolerability, pharmacokinetics and pharmacodynamics of tegoprazan METHODS: A phase I, randomised, double-blind and placebo-controlled clinical trial was conducted in 56 healthy male subjects without Helicobacter pylori infection. In the single ascending dose study, 50, 100, 200 and 400 mg tegoprazan were administered to 32 subjects. In the multiple ascending dose study, 100 and 200 mg tegoprazan were administered every 24 hours to each of the eight subjects for 7 days. In the comparative pharmacodynamics study, 40 mg esomeprazole was administered to eight subjects every 24 hours for 7 days. The assessment included safety, tolerability, pharmacodynamics through monitoring of 24-hour gastric pH and pharmacokinetics of tegoprazan in plasma and urine. RESULTS: Tegoprazan was generally well tolerated. Most adverse events reported in the study were mild in intensity and resolved without any sequelae. Exposure to tegoprazan increased in a dose-proportional manner. Multiple dosing with tegoprazan showed no accumulation in plasma on day 7. The pharmacodynamic analysis revealed that tegoprazan showed rapid, dose-dependent gastric acid suppression. CONCLUSIONS: Tegoprazan was well tolerated and showed rapid and potent gastric acid suppression. This supports the further development of tegoprazan as a treatment for acid-related disorders.

Effects of Tegoprazan, a Novel Potassium-Competitive Acid Blocker, on Rat Models of Gastric Acid-Related Disease.

Tegoprazan, a novel potassium-competitive acid blocker (P-CAB), is a next-generation therapeutics developed for the treatment of acid-related gastrointestinal diseases such as gastroesophageal reflux disease (GERD) and peptic ulcers. In the present study, the in vitro and in vivo pharmacological properties of tegoprazan were compared with those of esomeprazole, a representative proton pump inhibitor. In vitro enzyme assays were performed using ion-leaky vesicles containing gastric H+/K+-ATPases isolated from pigs. The in vivo efficacies of tegoprazan were evaluated in rat models of GERD and peptic ulcer. Tegoprazan inhibited the activity of porcine H+/K+-ATPase with an IC50 value of 0.53 µM in a reversible manner, whereas esomeprazole showed weak and irreversible inhibition with an IC50 value of 42.52 µM. In a GERD model, tegoprazan showed dose-dependent efficacy in inhibiting esophageal injury and gastric acid secretion with an ED50 of 2.0 mg/kg, which was 15-fold more potent than that of esomeprazole. In peptic ulcer models, tegoprazan exhibited superior antiulcer activity compared with esomeprazole. The ED50 of tegoprazan in the naproxen-, ethanol-, and water-immersion restraint stress-induced peptic ulcer models were 0.1, 1.4, and 0.1 mg/kg, respectively. In the acetic acid-induced peptic ulcer model, the curative ratio of tegoprazan at 10 mg/kg was higher than that of esomeprazole at 30 mg/kg (44.2% vs. 32.7%, respectively), after 5 days of repeated oral administration. Thus, tegoprazan is a novel P-CAB that shows potent and reversible inhibition of gastric H+/K+-ATPase and may provide stronger efficacy compared with previous proton pump inhibitors.

Expression of myeloperoxidase in swine influenza virus (SIV)-infected neutrophils in lungs from pigs experimentally infected with SIV subtype H1N2.

The expression of myeloperoxidase (MPO) was examined in the swine influenza virus (SIV)-infected neutrophils in the lungs of pigs experimentally infected with swine influenza virus (SIV) subtype H1N2 by immunohistochemistry. Five pigs each from the infected and non-infected group were euthanized 1, 3, 5, 7, and 10 days post-inoculation (dpi). Immunohistochemical reactivity was mainly seen in neutrophils. The score for pulmonary histopathological lesions correlated with the score for MPO immunohistochemical reactivity (r ( s ) = 0.962, P < 0.01). In addition, the score for in situ hybridization of SIV nucleic acid correlated with the score for MPO immunohistochemical reactivity (r ( s ) = 0.976, P < 0.01). These results suggest neutrophils are one of the primary effector cells in the early phase of SIV infection in pigs.

Development of in situ hybridization for the detection of Mycoplasma hyorhinis in formalin-fixed paraffin-embedded tissues from naturally infected pigs with polyserositis.

The aim of this study was to develop in situ hybridization for detection of Mycoplasma hyorhinis in formalin-fixed, paraffin-wax-embedded tissues from pigs with polyserositis. M. hyorhinis was isolated from the spleen (2 pigs) and pericardium (1 pig). M. hyorhinis DNA was detected 16 out of 20 pigs with polyserositis. In situ hybridization produced a distinct positive signal for the M. hyorhinis p37 gene in inflammatory cells in the polyserositis. In situ hybridization developed in the present study present diagnostic tools capable of detection of M. hyorhinis in formalin-fixed, paraffin-wax-embedded tissues from the naturally infected pigs.

Association of tumor necrosis factor-alpha with fever and pulmonary lesion score in pigs experimentally infected with swine influenza virus subtype H1N2.

The relationship between tumor necrosis factor (TNF)-alpha level, body temperature, and pulmonary lesion score was determined in 3-week-old pigs inoculated intranasally with swine influenza virus (SIV) subtype H1N2. The expression of TNF-alpha was measured in bronchoalveolar lavage (BAL) fluids by enzyme-linked immunosorbent assay and lung tissues by immunohistochemistry. In BAL fluid, TNF-alpha concentration was maximal at 1 days post-inoculation (dpi), declined markedly by 3 dpi (P<0.05) and steady thereafter. Mean rectal temperatures were above 40 degrees C for the infected groups at 1 dpi and declined markedly by 3 dpi. The body temperatures were correlated with the levels of TNF-alpha in BAL fluids from pigs experimentally infected with SIV (r(s)=0.9754, P<0.05). The pulmonary lesion scores were correlated with the means of positive cells by immunohistochemistry for TNF- alpha (r(s)=0.9949, P<0.001). The results suggest that the expression of TNF-alpha protein plays an important role in induction of pulmonary lesion and clinical sign such as fever in SIV infection.