Randomised clinical trial: safety, tolerability, pharmacokinetics and pharmacodynamics of repeated doses of TAK‐438 (vonoprazan), a novel potassium‐competitive acid blocker, in healthy male subjects

• Published in: Alimentary pharmacology & therapeutics Vol. 41; no. 7; pp. 636 - 648
• Main Authors: Jenkins, H., Sakurai, Y., Nishimura, A., Okamoto, H., Hibberd, M., Jenkins, R., Yoneyama, T., Ashida, K., Ogama, Y., Warrington, S.
• Format: Journal Article
• Language: English
• Published: England Blackwell Publishing Ltd 01-04-2015
• Subjects: Adult; Asian Continental Ancestry Group; Dose-Response Relationship, Drug; Double-Blind Method; European Continental Ancestry Group; Gastric Acid; Gastrointestinal Agents - adverse effects; Gastrointestinal Agents - pharmacokinetics; Gastrointestinal Agents - pharmacology; Half-Life; Humans; Japan; Male; Metabolic Clearance Rate; Middle Aged; Nervous System Diseases; Potassium - pharmacology; Pyrroles - adverse effects; Pyrroles - pharmacokinetics; Pyrroles - pharmacology; Randomised Clinical Trials; Sulfonamides - adverse effects; Sulfonamides - pharmacokinetics; Sulfonamides - pharmacology; United Kingdom; Young Adult
• ISSN: 0269-2813; 1365-2036
• DOI: 10.1111/apt.13121

Summary
Background
TAK‐438 (vonoprazan) is a potassium‐competitive acid blocker that reversibly inhibits gastric H+, K+‐ATPase.
Aim
To evaluate the safety, tolerability, pharmacokinetics and pharmacodynamics of TAK‐438 in healthy Japanese and non‐Japanese men.
Methods
In two Phase I, randomised, double‐blind, placebo‐controlled studies, healthy men (Japan N = 60; UK N = 48) received TAK‐438 10–40 mg once daily at a fixed dose level for 7 consecutive days. Assessments included safety, tolerability, pharmacokinetics and pharmacodynamics (intragastric pH).
Results
Plasma concentration–time profiles of TAK‐438 at all dose levels showed rapid absorption (median Tmax ≤2 h). Mean elimination half‐life was up to 9 h. Exposure was slightly greater than dose proportional, with no apparent time‐dependent inhibition of metabolism. There was no important difference between the two studies in AUC0‐tau on Day 7. TAK‐438 caused dose‐dependent acid suppression. On Day 7, mean 24‐h intragastric pH>4 holding time ratio (HTR) with 40 mg TAK‐438 was 100% (Japan) and 93.2% (UK), and mean night‐time pH>4 HTR was 100% (Japan) and 90.4% (UK). TAK‐438 was well tolerated. The frequency of adverse events was similar at all dose levels and there were no serious adverse events. There were no important increases in serum alanine transaminase activity. Serum gastrin and pepsinogen I and II concentrations increased with TAK‐438 dose.
Conclusions
TAK‐438 in multiple rising oral dose levels of 10–40 mg once daily for 7 days was safe and well tolerated in healthy men and caused rapid, profound and sustained suppression of gastric acid secretion throughout each 24‐h dosing interval. Clinicaltrials.gov identifiers: NCT02123953 and NCT02141711.