Spotlight on H. pylori

Several recent studies analyzed Helicobacter pylori therapies.

The first study, published by Gut on June 21, looked at treatment for H. pylori infection in patients with penicillin allergy. The open-label trial, conducted in China, included 300 treatment-naïve adults with H. pylori infection and penicillin allergy who were randomized to either dual therapy with vonoprazan, 20 mg two times per day, plus tetracycline, 500 mg three times a day, (the VT group) or bismuth quadruple therapy (BQT; lansoprazole, 30 mg two times per day, plus colloidal bismuth, 150 mg three times a day, plus tetracycline, 500 mg three times a day, plus metronidazole, 400 mg three times a day) for 14 days.

Eradication rates in the VT and BQT groups were similar at 92.0% and 89.3%, respectively, in an intention-to-treat analysis. Adverse events were significantly lower in the VT group (14.0% vs 48.0%), as was the rate of related treatment discontinuation (2.0% vs. 8.7%). "Antibiotic resistance is a significant factor contributing to the failure of H. pylori eradication," said the study authors, noting that both tetracycline and amoxicillin have emerged as candidates for treating these infections, with tetracycline offering the advantage of not requiring allergy testing. They cautioned that past studies have found differences in antibiotic resistance between Asia and the U.S. and called for additional research.

Another study, published by the United European Gastroenterology Journal on June 17, compared tailored versus empirical therapy for H. pylori. This open-label, multicenter Korean trial included a total of 312 treatment-naïve patients with H. pylori-positive culture tests randomized 3:1 to either culture-based susceptibility-guided tailored therapy (clarithromycin-based or metronidazole-based triple therapy for susceptible strains or BQT for dual-resistant strains, n=234) or empirical concomitant therapy (n=78) for 10 days.

Eradication rates were similar in the tailored and concomitant groups (84.2% vs. 83.3% by intention-to-treat analysis and 92.9% and 91.5% by per-protocol analysis, respectively). However, among the 8% of patients with dual resistance to both clarithromycin and metronidazole, eradication rates were significantly higher with tailored therapy. Adverse events were also significantly lower in the tailored group. The study authors concluded that tailored therapy failed to show superiority over the empirical therapy, but that "treatment choice in clinical practice would depend on the background rate of antimicrobial resistance, availability of resources and costs associated with culture and susceptibility testing."

Finally, a third study, published by JAMA Network Open on May 29, focused on the effects of H. pylori treatment in Chinese patients with an elevated genetic risk of gastric cancer. The cohort trial looked at 2,816 participants of one trial and 100,228 participants in another, with 147 and 825 cases of gastric cancer, respectively. Researchers developed a score to assess genetic risk for gastric cancer and categorized patients accordingly. Treatment of H. pylori was associated with significantly reduced gastric cancer risk only in the patients at high genetic risk (hazard ratio [HR] for patients in top 25% of risk, 0.45; 95% CI, 0.25 to 0.82). Those with low genetic risk showed no significant effect of H. pylori treatment on gastric cancer risk (HR, 0.81; 95% CI, 0.50 to 1.34). The results suggest "that chemoprevention strategies should be tailored to genetic risk for effective [gastric cancer] prevention," the study authors said.