H. pylori eradication therapy may reduce gastric cancer risk; rifabutin-based therapy effective in industry-sponsored trial

A meta-analysis suggested that, in addition to preventing progression, early Helicobacter pylori eradication therapy reduces gastric cancer risk, and a novel rifabutin-based therapy may offer physicians another option for initiating eradication treatment, an ACP Journal Club commentary on both studies said.

Two studies recently summarized in ACP Journal Club looked at Helicobacter pylori eradication.

The first, a meta-analysis of 10 randomized controlled trials (RCTs) of patients with H. pylori infection, including three (n=1,841) in patients with gastric neoplasia and seven (n=8,323) in patients without gastric neoplasia, assessed whether seven or more days of H. pylori eradication therapy reduces the risk for gastric cancer. Control groups received placebo or no treatment, and follow-up ranged from three to 22 years. Compared with placebo or no therapy, H. pylori eradication therapy reduced the risk for gastric cancer, irrespective of gastric neoplasia at the time of treatment. The study was published online on March 23 by Gut.

The second, an RCT, examined RHB-105, a novel, rifabutin-based therapy. The industry-funded, double-blinded phase 3 trial enrolled 455 treatment-naive adults with epigastric discomfort and confirmed H. pylori infection. Two hundred twenty-eight participants were randomly assigned to receive RHB-105 (amoxicillin, 3 g/d; omeprazole, 120 mg/d; and rifabutin, 150 mg/d), and 227 were randomly assigned to receive an active comparator (amoxicillin, 3 g/d, and omeprazole, 120 mg/d), given as four capsules every eight hours for 14 days. In the intention-to-treat population, the eradication rate was higher with RHB-105 than with the active comparator (83.8% vs. 57.7%; P<0.001) The study was published online on May 5 by Annals of Internal Medicine and was summarized in the May 22 ACP Gastroenterology Monthly.

The following commentary on both studies, by Jacob Mathew Jr., DO, FACP, appeared in the ACP Journal Club section of the Sept. 15 Annals of Internal Medicine.

H pylori infection, which affects more than half of the world population, is linked to atrophic gastritis, gastric and duodenal ulcers (10% to 20% lifetime risk), and gastric adenocarcinoma (1% to 2% lifetime risk). Early identification and treatment not only help to resolve presenting gastrointestinal symptoms but also promote regression of gastric mucosa−associated lymphoid tissue lymphoma. As a result, a test-and-treat approach for H pylori (assuming a local prevalence rate of >10%) has been used in patients aged <60 years who present with dyspepsia but without alarm features such as unintentional weight loss, anemia, gastrointestinal bleeding, dysphagia, recurrent emesis, palpable mass, or personal/family history of cancer. If any of these symptoms are present, or if the patient is >60 years, then routine esophagogastroduodenoscopy is done first.

The possibility of preventing gastric cancer with H pylori eradication in high-risk patients has been investigated. In a meta-analysis of 10 RCTs, Ford and colleagues investigated whether eradication therapy can reduce the risk for gastric cancer in patients with or without gastric neoplasia before H pylori therapy. They found that among high-risk individuals without gastric neoplasia at the time of H pylori therapy, gastric cancer developed in only 1.6% of people who were treated for H pylori infection vs. 3% of people who were not empirically treated, with a number needed to treat of 72. This suggests that in addition to preventing progression of gastric cancer, early treatment reduces the risk for developing it.

Given the benefits of H pylori therapy, RedHill Biopharma funded the ERADICATE Hp2 trial, which assessed the efficacy of a nonstandard formulation of amoxicillin, omeprazole, and rifabutin (RHB-105) for eradicating H pylori infection. The studied population notably excluded patients of Asian descent, those with multiple gastric or duodenal ulcers, and those who had used a proton-pump inhibitor in the preceding 2 weeks. The trial showed that RHB-105 eradicated infection, regardless of clarithromycin or metronidazole resistance, compared with amoxicillin plus omeprazole. Unfortunately, the control group did not receive either clarithromycin-based triple therapy or bismuth quadruple therapy, as recommended by the American College of Gastroenterology.

RHB-105 offers an option to primary care and specialty clinicians initiating treatment for H pylori infection, particularly given the increasing prevalence of macrolide resistance worldwide.