Rifabutin-Based Triple Therapy Eradicates Resistant H. Pylori

By Will Boggs MD

May 11, 2020

NEW YORK (Reuters Health) - Rifabutin-based triple therapy can eradicate Helicobacter pylori even in the face of resistance to clarithromycin or metronidazole, the ERADICATE Hp2 trial shows.

"In the U.S. clarithromycin, metronidazole, and levofloxacin resistance are high, so that none of these should be used as triple therapy unless one has evidence of susceptibility," Dr. David Y. Graham of Baylor College of Medicine, in Houston, Texas, told Reuters Health by email. "The two empiric regimens that one can use are the new rifabutin-containing therapy or bismuth quadruple therapy."

In their recent ERADICATE pilot study, Dr. Graham and colleagues found that a fixed-dose combination (RHB-105) containing a low dose of rifabutin (150 mg/day) plus amoxicillin (3,000 mg/day) and omeprazole (120 mg/day) provided an 89.4% cure rate in H. pylori-infected patients with dyspepsia.

In the phase-3 ERADICATE Hp2 study, they sought to confirm the efficacy of RedHill Biopharma's RHB-105 (versus amoxicillin-omeprazole treatment) in 455 treatment-naive patients with confirmed H. pylori infection and at least two weeks of dyspepsia.

At baseline, H. pylori strains were resistant to amoxicillin in 6.4% of patients, to clarithromycin in 17.4% and to metronidazole in 43.6%. None were resistant to rifabutin.

H. pylori eradication rates were higher with RHB-105 than with amoxicillin-omeprazole (83.8% vs. 57.7%, P<0.001), the team reports in Annals of Internal Medicine.

Eradication rates with RHB-105 were high regardless of the resistance or susceptibility of H. pylori strains causing the infection.

None of the patients, including 99 in whom treatment failed, had an H. pylori isolate that developed rifabutin resistance.

The most commonly reported adverse events were diarrhea, headache and nausea.

"We now have some choices for reliably more effective therapy," Dr. Graham said. "Using the principles of antimicrobial stewardship, all antimicrobial therapy should be basically susceptibility based, which can come from testing or from empiric evidence that the regimen is reliable."

RedHill Biopharma Ltd. (Tel Aviv, Israel) sponsored the trial and had financial relationships with three authors of the report, including Dr. Graham.

SOURCE: https://bit.ly/2zcyavM Annals of Internal Medicine, online May 5, 2020.