Potassium competitive acid blockers go toe-to-toe with PPI in gastric acid diseases

Vonoprazan, a potassium competitive acid blocker (PCAB), is better than proton pump inhibitors (PPI) for the treatment of Helicobacter pylori and erosive oesophagitis, according to a new meta-analysis.

Nineteen eligible studies were included in the quantitative synthesis, corresponding to a total of 7,023 participants. All were randomized controlled trials (RCT) of gastric acid-related diseases, such as H. pylori infection, erosive oesophagitis, gastroesophageal reflux disease (GERD), and peptic ulcers. The databases of Cochrane, Scopus, Embase, and Medline were searched for this meta-analysis.

The most common comparison was between 20-mg vonoprazan and 30-mg lansoprazole, which was assessed in 42.1 percent of studies. In terms of quality, the researchers reported an overall low risk of bias (52.6 percent of studies), though some included papers had minor causes for concern. Majority (60.8 percent) of patients were treated with PCAB, while only 39.2 percent received PPI therapy. [J Gastroenterol Hepatol 2022;doi:10.1111/jgh.16017]

Erosive oesophagitis was assessed in six studies that compared PCAB with PPI directly. Pooled analysis revealed that vonoprazan treatment induced a higher healing rate than in PPI comparators at weeks 2 (84.81 percent vs 77.36 percent), 4 (91.48 percent vs 88.95 percent), and 8 (95.74 percent vs 93.76 percent).

Vonoprazan was only significantly better than PPI during week 2 (risk ratio [RR], 1.09, 95 percent confidence interval [CI], 1.03–1.14).

For the analysis of H. pylori infection, the present meta-analysis included nine studies in which 869 patients received PCAB treatments while 846 were given PPIs. Pooled data revealed that H. pylori eradication was 91.89 percent following first-line PCAB treatment, as opposed to only 79.95 percent in PPI comparators. This reflected significant superiority of PCAB (RR,1.13, 95 percent CI, 1.04–1.22).

However, no such effect was reported for PCAB when given as a second- (RR, 0.89, 95 percent CI, 0.66–1.22) or third-line (RR, 1.42, 95 percent CI, 0.97–2.09) intervention.

Of note, vonoprazan treatment was not significantly better than PPI in treating GERD or gastric and duodenal ulcers.

In terms of safety, pooled analysis of 15 studies (n=4,519) revealed that treatment-emergent adverse events (TEAE) were only slightly more common in vonoprazan-treated participants than in PPI comparators, with corresponding rates of 35.7 percent and 32.9 percent. This did not correspond to a statistically significant difference in TEAE incidence (RR, 1.08, 95 percent CI, 0.89–1.31).

In turn, vonoprazan did yield a statistically significant increase in safety risk in patients with erosive oesophagitis (RR, 1.05, 95 percent CI, 0.90–1.22) or H. pylori infection (RR, 0.84, 95 percent CI, 0.69–1.02). The same was true for those with symptomatic GERD (RR, 0.20, 95 percent CI, 0.01–4.15), gastric ulcers (RR, 1.47, 95 percent CI, 0.43–5.05), or duodenal ulcers (RR, 1.37, 95 percent CI, 1.19–1.59).

“Vonoprazan is not inferior to PPI in healing erosive esophagitis and gastric and duodenal ulcers and improving GERD symptoms,” the researchers said, pointing out that the PCAB drug also demonstrated significant superiority as a first-line treatment for H. pylori.

Nevertheless, the present study only looked at short-term effects.

“Further RCTs with larger samples, in different populations, and more variable use of PCABs (other than vonoprazan) are needed to confirm findings of PCAB being the more potent and quicker acid suppressant and the alternative to PPIs in PPI-refractory conditions,” the researchers said. “Likewise, long-term safety data of PCABs is greatly needed.”