Vonoprazan Helicobacter pylori eradication therapy: ethical and interpretation issues

We read with interest the important study on vonoprazan in Helicobacter pylori eradication therapy.1 Vonoprazan likely represents a significant advance in antisecretory and H. pylori eradication therapy. Despite being technically well done, several issues related to study conduct and interpretation remain. Their sample size was based on 90% success with lansoprazole, which has not been achieved in Japan for several decades. When the cure rates proved to be lower, the sample size was increased to ‘maintain the statistical power of the study’. We question whether this was ethical. It is generally considered unethical to randomise against a regimen that provides unacceptably low cure rates; many journals reject papers that do this.2 , …