Acurx Pharmaceuticals, Inc. announced positive comparative microbiology and microbiome data for ibezapolstat, its lead antibiotic candidate, from the Company's recently completed Phase 2b clinical trial in patients with CDI. Data showed that ibezapolstat outperformed vancomycin, a standard of care to treat patients with CDI, with eradication of fecal C. difficile at Day 3 of treatment in 15 of 16 patients (94%) versus vancomycin which had eradication of fecal C. difficile in 10 of 14 patients (71%). In addition, ibezapolstat, but not vancomycin, consistently preserved and allowed regrowth of key gut bacterial species believed to confer health benefits including to prevent CDI recurrence.

Further analyses will be forthcoming First Quarter 2024, as data become available, regarding other endpoints from the Phase 2b trial, including Extended Clinical Cure (ECC) data up to 94 days. Preparation is underway for meetings with FDA, European Medicines Agency and other global regulatory agencies and advancement to international Phase 3 clinical trials. The completed multicenter, open-label single-arm segment (Phase 2a) study was followed by a double-blind, randomized, active-controlled, non-inferiority, segment (Phase 2b) at 28 US clinical trial sites which together comprise the Phase 2 clinical trial.

This Phase 2 clinical trial was designed to evaluate the clinical efficacy of ibezapolstat in the treatment of CDI including pharmacokinetics and microbiome changes from baseline and continue to test for anti- recurrence microbiome properties seen in the Phase 2a trial, including the treatment- related changes in alpha diversity and bacterial abundance and effects on bile acid metabolism. The completed Phase 2a segment of this trial was an open label cohort of up to 20 subjects from study centers in the United States. In this cohort, 10 patients with diarrhea caused by C. difficile were treated with ibezapolstat 450 mg orally, twice daily for 10 days.

All patients were followed for recurrence for 28± 2 days. Per protocol, after 10 patients of the projected 20 Phase 2a patients completed treatment (100% cured infection at End of Treatment), the Trial Oversight Committee assessed the safety and tolerability and made its recommendation regarding early termination of the Phase 2a study and advancement to the Ph2b segment. The Company's Scientific Advisory Board concurred with this recommendation.

In the now completed Phase 2b trial segment, 32 patients with CDI 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, in each case, for 10 days and followed for 28 ± 2 days following the end of treatment for recurrence of CDI. The two treatments were identical in appearance, dosing times, and number of capsules administered to maintain the blind. 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 in the Modified Intent to Treat Population, plus 15 out of 16 (94%) patients in Phase 2b in the Per Protocol Population, who experienced Clinical Cure during treatment with ibezapolstat.

Ibezapolstat was well-tolerated, with three patients each experiencing one mild adverse event assessed by the blinded investigator to be drug-related. All three events were gastrointestinal in nature and resolved without treatment. There were no drug-related treatment withdrawals or no drug-related serious adverse events, or other safety findings of concern.

In the Phase 2b vancomycin control arm, 14 out of 14 patients experienced Clinical Cure. The Company is confident that based on the pooled Phase 2 ibezapolstat Clinical Cure rate of 96% and the historical vancomycin cure rate of approximately 81% (Vancocin® Prescribing Information, January 2021), we will demonstrate non-inferiority of ibezapolstat to vancomycin in Phase 3 trials in accordance with the applicable FDA Guidance for Industry (October, 2022). The Phase 2b clinical trial segment was discontinued due to success.

The Company made this decision in consultation with its medical and scientific advisors and statisticians based on observed aggregate blinded data and other factors, including the cost to maintain clinical trial sites and slow enrollment due to COVID-19 and its aftermath. The Company had determined that the trial performed as anticipated for both treatments, ibezapolstat and the control antibiotic vancomycin (a standard of care to treat patients with CDI), with high rates of clinical cure observed across the trial without any emerging safety concerns. Accordingly, an Independent Data Monitoring Committee was not required to perform an interim analysis of this Phase 2b trial data as originally planned.

The Company anticipated that this decision would allow the Company to advance this first-in-class, FDA QIDP/Fast Track-designated antibiotic product candidate to Phase 3 clinical trials more expeditiously. The Phase 2b trial was originally designed to be a non-inferiority (NI) trial and later amended to include an interim efficacy analysis with review by an Independent Data Monitoring Committee (IDMC). The decision to end the trial early based on blinded clinical observations obviated the need for an interim analysis, IDMC review, and NI assessment.

The Company determined, in consultation with its clinical and statistical experts, that presenting clinical cure rates for the primary efficacy endpoint is the most appropriate representation for the clinical activity of ibezapolstat in treating CDI. In the Phase 2 clinical trial, the Company will also evaluate pharmacokinetics (PK) and microbiome changes and test for anti-recurrence microbiome properties, including the change from baseline in alpha diversity and bacterial abundance, especially overgrowth of healthy gut microbiota Actinobacteria and Firmicute phylum species during and after therapy. Phase 2a data demonstrated complete eradication of colonic C. difficile by day three of treatment with ibezapolstat as well as the observed overgrowth of healthy gut microbiota, Actinobacteria and Firmicute phyla species, during and after therapy.

Very importantly, emerging data show an increased concentration of secondary bile acids during and following ibezapolstat therapy which is known to correlate with colonization resistance against C. difficile.