Randomised trial of acid inhibition by vonoprazan 10/20 mg once daily vs rabeprazole 10/20 mg twice daily in healthy Japanese volunteers (SAMURAI pH study).

摘要: Background Vonoprazan (V), a potassium-competitive acid blocker, has more durable acid-inhibitory effect as compared with standard-dose proton pump inhibitors (PPIs) but not been 2-4 times higher daily PPI doses administered in two divided doses. Aims To evaluate the of V 10/20 mg once-daily (OD; V10/V20) vs rabeprazole (R) twice-daily (BID; R20/R40) healthy Japanese volunteers. Methods This multicentre, randomised, open-label, two-period, crossover study V10 or V20 R20, R40 using three cohorts 10 adults. Within each cohort, subjects were randomised to receive R for 7 days and, following washout period ≥7 days, other treatment days. On day 6 period, 24-hours multichannel gastric impedance-pH monitoring was performed. Percent pH ≥ 3, ≥4 and ≥5 (pH 4 5 holding time ratios [HTRs]) 24 hours evaluated primary pharmacodynamic endpoints. Results Acid-inhibitory (24-hours 3 HTR) greater than those R20 (91.0% 65.3%; P = .0049) (98.5% 85.9%; .0073). Similar results obtained HTRs. also achieved nocturnal (91.5% 73.2%; .0319) HTRs (78.8% 62.2%; .0325) R40. One subject (20%) developed diarrhoea while receiving which considered treatment-related. Conclusions Compared standard dose R, exerts potent effect. Trial identifier: UMIN000022198 (www.umin.ac.jp/ctr/index.htm).