A Novel Potassium-Competitive Acid Blocker Improves the Efficacy of Clarithromycin-containing 7-day Triple Therapy against Helicobacter pylori.

Background&Aims: In Japan, 7-day triple therapy for Helicobacter pylori including clarithromycin (CAM) was approved in 2000. However, antibiotic resistance subsequently reduced this rate to an unacceptable level (70%). Vonoprazan, an orally bioavailable potassium-competitive acid blocker (P-CAB), was approved in Japan in 2014. This could improve eradication rates by increasing the intragastric pH, thus increasing bacterial antibiotic susceptibility. This study compared the efficacy of 7-day triple therapies that included CAM and vonoprazan or proton pump inhibitor (PPI). Methods: We prospectively analyzed H. pylori eradication rates in 146 patients receiving 7-day triple therapy containing P-CAB (April 2015 to September 2015), and in a retrospective cohort of 1,305 patients who received 7-day triple therapy containing a PPI (April 2011 to September 2015). Results: H. pylori was eradicated in a significantly higher number of P-CAB-treated patients (89.7% [131/146]) than PPI-treated patients (73.9% [965/1305]; p < 0.05). The eradication rates in P-CAB-treated CAM-sensitive and CAM-resistant bacteria were 100% (44/44) and 87.5% (28/32), respectively, which were significantly higher than the corresponding rates in PPI-treated patients (88.0% [22/25] and 53.8% [7/13], p < 0.05). Conclusion: P-CAB improved the efficacy of CAM-containing 7-day triple therapy and would be a valuable first-line treatment for H. pylori infection.