Two-dimension Tailor-made Therapy: A New Salvage Therapy After Multiple Eradication Failures for

Background and Aims: Vonoprazan-based eradication therapies have a higher eradication rate than usual proton pump inhibitor (PPI)-based therapies in treating Methods: Patients who failed twice or more PPI-based triple therapies were recruited. Patients underwent CYP2C19 genotype and antibiotic susceptibility tests (ASTs). PPI doses per day were decided as per the CYP2C19 genotype: twice for poor and 4 times for extensive metabolizers (dimension 1). Two antibiotics were selected as per the results of the AST in each patient (dimension 2). Regimens of 2dTMT included 2 susceptible antibiotics and a PPI. For those who could not have enough information with the AST, tailor-made PPI dosing was indicated with empirically selected 2 antibiotics (one-dimension tailor-made therapy [1dTMT]). Results: Of 51 candidates with multiple eradication failures, 37 patients underwent the genotype test and AST, and 24 succeeded to obtain sufficient information to select 2 susceptible antibiotics. Of them, 22 patients accepted to receive 14-day 2dTMT. Of the residual patients, 12 accepted to receive 14-day 1dTMT. The mean eradication rate of 2dTMT was 86.4% (95% confidence interval [CI]: 65.1%-98.8%) in intention-to-treat and 90.5% (95% CI: 69.6%-98.8%) in per-protocol analyses, whereas that of 1dTMT was 75.0% (95% CI: 42.8%-94.5%) in intention-to-treat and 90.0% (95% CI: 55.5%-99.7%) in per-protocol analyses. Conclusion: Without vonoprazan, 14-day 2dTMT could be one of the salvage therapies for patients with multiple eradication failures. In cases of insufficient information with the AST, 14-day 1dTMT could be an alternative therapy. Clinical Trials Registry number, UMIN000022154 (https://www.umin.ac.jp/icdr/index.html).