Houston Daily

A research team at the University of Houston has reported encouraging results from clinical trials of ibezapolstat, a new antibiotic aimed at combating Clostridioides difficile (C. diff), a bacterium that is the leading cause of death from gastroenteritis in the United States. C. diff causes an estimated 453,000 infections and 29,300 deaths each year.

Current standard treatments for C. diff include vancomycin and fidaxomicin, but their effectiveness is declining due to increasing antimicrobial resistance. Vancomycin provides a sustained clinical cure rate between 42% and 71%, while fidaxomicin achieves about 67%. Recurrence of infection remains a significant issue, contributing to higher mortality rates, reduced quality of life, and increased healthcare costs.

“Both vanco and fidaxo are associated with emerging antimicrobial resistance. C. difficile infection recurrence is associated with increased mortality, decreased quality of life and higher healthcare costs. New antibiotics are urgently needed,” said Kevin Garey, Robert L. Boblitt Endowed Professor of Drug Discovery at the University of Houston College of Pharmacy and senior author on recent clinical trial results with ibezapolstat published in Lancet Microbe.

C. diff infections often return when the natural gut microbiome is disrupted—beneficial bacteria decrease while harmful ones increase—weakening defenses against reinfection.

“Ibezapolstat’s mechanism of action helps restore the healthy microbiota that causes C. diff recurrence,” said study lead author Taryn A. Eubank, research assistant professor of Pharmacy Practice and Translational Research at UH.

Ibezapolstat targets C. difficile bacteria without harming beneficial gut bacteria that help prevent infection recurrences.

“A randomized, double-blind, active-controlled study showed high rates of initial clinical cure in participants treated with ibezapolstat, with no recurrence,” reports Garey.

“Ibezapolstat was found to be safe, well tolerated, and was associated with the preservation of key health-promoting bacteria responsible for bile acid homoeostasis, a key component in preventing recurrent C. difficile infection.”

Eubank added: “This helps confirm the important anti-C diff recurrence properties of Ibezapolstat.”

The drug is being developed by Acurx Pharmaceuticals as it advances toward phase III clinical trials. The recent study took place across 15 centers in the United States among adults aged 18–90 years diagnosed with mild or moderate C difficile infection.

“The findings of our study support further clinical development of ibezapolstat into phase III clinical trials and eventual use in our patients,” said Garey.