Among patients with Helicobacter pylori infection, higher vs lower body mass index (BMI) was found to correlate with the effectiveness of vonoprazan-based second-line therapy, according to the results of a study published in The Tohoku Journal of Experimental Medicine.
Investigators sought to determine factors that affect the success of second-line therapy using vonoprazan, a gastric acid secretion inhibitor that improves the success rate of H pylori eradication. First-line treatment in Japan involves a regimen in which vonoprazan is combined with amoxicillin and clarithromycin, and second-line treatment involves vonoprazan combined with amoxicillin and metronidazole.
The study authors measured metronidazole/amoxicillin minimal inhibitory concentrations (MICs) using H pylori isolated from each patient. They reviewed the records of 33 patients (aged 34-79 years; 22 men; BMI, 16.1-28.8 kg/m2) who had received vonoprazan-based second-line therapy after first-line therapy had failed.
The eradication success rate of the vonoprazan-based second-line therapy was 81.8% (95% CI, 64.5-93.0; 27/33). A receiver operating characteristic (ROC) analysis showed an area under the curve (AUC) and BMI cutoff value of 0.796 and 23.8 kg/m2, respectively.
The success rate of vonoprazan-based second-line therapy was greater in the high-BMI patient group (≥23.8 kg/m2) than in the low-BMI patient group (<23.8 kg/m2; P = .007). The investigators also found that the AUC value of the ROC curve for the metronidazole value against eradication success was 0.506, which indicated a failed correlation, and the AUC value of the ROC curve for the amoxicillin MIC value against eradication success was 0.497.
“Our findings indicated that, among the patient factors examined, only BMI was correlated with the success of vonoprazan-based second-line therapy,” the study authors commented. “In addition, metronidazole/amoxicillin MIC values were not correlated with the success of vonoprazan-based second-line therapy.”
The researchers noted that their findings are based on a retrospective subgroup analysis of a primary study and were based on a small sample. Also, all participants were Japanese, and there was potential selection bias for second-line eradication therapy regimens.
“We should be aware of the effect of obesity on H. pylori eradication success,” the investigators stated. “As there were no patients with severe obesity in the present study, the impact of higher BMI on H. pylori eradication success does not mean that obesity has a beneficial effect for vonoprazan-based second-line therapy.”
Disclosures: One of the study authors reported an affiliation with a pharmaceutical company. Please see the original reference for a full list of disclosures.
Kasai T, Suzuki S, Kusano C, et al. High body mass index is correlated with the success of vonoprazan-based second-line therapy for Helicobacter pylori infection. Tohoku J Exp Med. 2021;253(2):85-94. doi:10.1620/tjem.253.85