Investigational Antibiotic Comparable to Vancomycin in Curing C diff

The investigational antibiotic, ibezapolstat, was shown to have a similar cure rate vs vancomycin when treating patients with CDI.

"This randomized, active-controlled study showed ibezapolstat was comparable to vancomycin in achieving clinical cure in patients with mild-to-moderate CDI,” said Kevin Garey, PharmD, chair of the Department of Clinical Sciences and Administration and professor of Pharmacy Practice at the University of Houston College of Pharmacy. “Notably, no patients whose CDI was cured by ibezapolstat experienced recurrence of their disease within the 28-day follow-up period.”

Specifically, in a phase 2b vancomycin control arm, 14 out of 14 patients experienced clinical cure, and 15 out of 16 (94%) patients in a phase 2b ibezapolstat arm experienced a clinical cure. The findings were presented at the recent ESCMID conference.

Ibezapolstat is manufactured by Staten Island, NY-based Acurx Pharmaceuticals, and the antibiotic is a novel, orally administered antibiotic being developed as a gram-positive selective spectrum antibacterial. It is the first of a new class of DNA polymerase IIIC inhibitors under development by Acurx to treat bacterial infections.

See more: An interview with Garey discussing ibezapolstat.

Study Specifics and Safety Profile
The investigators have completed the phase 2b trial segment. Thirty-two patients with C diff were enrolled and randomized in a 1:1 ratio to either ibezapolstat 450 mg every 12 hours or vancomycin 125 mg orally every 6 hours for 10 days and followed for 28 ± 2 days following the end of treatment for recurrence of CDI. The 2 treatments were identical in appearance, dosing times, and number of capsules administered to maintain the blind.

In terms of safety profile, ibezapolstat was well-tolerated, with 3 patients experiencing 1 mild adverse event assessed by the blinded investigator to be drug- related. All 3 events were gastrointestinal in nature and resolved without treatment. There were no drug-related treatment withdrawals or no drug-related serious adverse events associated with ibezapolstat.

Acurx had previously reported that the overall observed clinical cure rate in the combined phase 2 trials in patients with CDI was 96% (25 out of 26 patients), based on 10 out of 10 patients (100%) in phase 2a study in the modified intent to treat population, plus 15 out of 16 (94%) patients in phase 2b in the per protocol population.

In a news statement, Acurx said they were confident that based on the pooled phase 2 ibezapolstat clinical cure rate and the historical vancomycin cure rate of approximately 81%—according to its prescribing information—they will demonstrate non-inferiority of ibezapolstat to vancomycin in phase 3 trials.

“These data reinforce earlier findings related to the anti-recurrence properties of ibezapolstat and warrant further development in phase 3 trials with further microbiome studies planned to confirm the mechanisms behind these clinical findings,” Garey concluded.

Reference
Acurx Pharmaceuticals Announces Presentation of Ibezapolstat Phase 2 Clinical Trial Results at ESCMID Global 2024 Scientific Conference. Acurx media statement. May 2, 2024. Accessed May 7, 2024.