title: 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.
abstract: BACKGROUND
  TAK-438 (vonoprazan) is a potassium-competitive acid blocker that reversibly inhibits gastric H(+) , K(+) -ATPase.
  
  
  OBJECTIVE
  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.
authors.affiliation: Takeda Development Centre Europe Ltd, London, UK.
authors.forename: H
authors.initials: H
authors.lastname: Jenkins
authors.forename: Y
authors.initials: Y
authors.lastname: Sakurai
authors.forename: A
authors.initials: A
authors.lastname: Nishimura
authors.forename: H
authors.initials: H
authors.lastname: Okamoto
authors.forename: M
authors.initials: M
authors.lastname: Hibberd
authors.forename: R
authors.initials: R
authors.lastname: Jenkins
authors.forename: T
authors.initials: T
authors.lastname: Yoneyama
authors.forename: K
authors.initials: K
authors.lastname: Ashida
authors.forename: Y
authors.initials: Y
authors.lastname: Ogama
authors.forename: S
authors.initials: S
authors.lastname: Warrington
mesh_terms: D000328:Adult; D044466:Asian People; D004305:Dose-Response Relationship, Drug; D004311:Double-Blind Method; D005744:Gastric Acid; D005765:Gastrointestinal Agents / Q000009:adverse effects / Q000493:pharmacokinetics / Q000494:pharmacology*; D006207:Half-Life; D006801:Humans; D007564:Japan; D008297:Male; D008657:Metabolic Clearance Rate; D008875:Middle Aged; D009422:Nervous System Diseases; D011188:Potassium / Q000494:pharmacology*; D011758:Pyrroles / Q000009:adverse effects / Q000493:pharmacokinetics / Q000494:pharmacology*; D013449:Sulfonamides / Q000009:adverse effects / Q000493:pharmacokinetics / Q000494:pharmacology*; D006113:United Kingdom; D044465:White People; D055815:Young Adult
chemical_list: C552956:1-(5-(2-fluorophenyl)-1-(pyridin-3-ylsulfonyl)-1H-pyrrol-3-yl)-N-methylmethanamine; D005765:Gastrointestinal Agents; D011758:Pyrroles; D013449:Sulfonamides; D011188:Potassium