Staten Island, New York, August 17, 2026
Acurx Pharmaceuticals, Inc., a late-stage biopharmaceutical company developing antibiotics for difficult-to-treat bacterial infections, announced that the U.S. Food and Drug Administration (FDA) has conditionally accepted the proposed proprietary name CIFBEZY for its lead antibiotic candidate ibezapolstat. The company also received a USPTO trademark allowance for CIFBEZY, establishing important regulatory and intellectual-property milestones as Acurx prepares to advance ibezapolstat toward an international Phase 3 clinical development program for Clostridioides difficile infection (CDI). The proposed brand name remains subject to final FDA review and approval when the company submits its New Drug Application (NDA).
FDA and USPTO Milestones Support Commercial Preparation
The conditional FDA acceptance of CIFBEZY represents an initial regulatory milestone focused on the potential proprietary name of ibezapolstat. According to Acurx, the name was developed through an extensive screening process involving external branding specialists, prescribers, pharmacists, and linguists, with evaluation by the FDA’s Division of Medication Error Prevention and Analysis. The regulatory review is intended to address patient safety and help prevent potential medication errors associated with proprietary drug names. Separately, the USPTO has allowed the trademark application, indicating that the proposed trademark has passed examination and the opposition period. Acurx said that securing both regulatory acceptance and trademark allowance provides a foundation for the commercial identity of ibezapolstat as the company advances the antibiotic toward later-stage development. However, CIFBEZY is not yet finally approved as a commercial brand name, as final FDA review will occur alongside the marketing application.
Ibezapolstat Targets C. difficile Infection
Ibezapolstat is Acurx’s lead antibiotic candidate and is being developed as an orally administered Gram-Positive Selective Spectrum (GPSS®) antibacterial for the treatment of CDI. The candidate represents a new class of DNA polymerase IIIC inhibitors designed to target the active site of the Gram-positive bacterial enzyme DNA polymerase IIIC, thereby inhibiting bacterial DNA replication. Acurx believes the selective activity of ibezapolstat may help preserve important components of the gut microbiome while targeting C. difficile. The company is preparing ibezapolstat for international Phase 3 clinical trials intended to support potential indications for both acute CDI treatment and reduction of recurrence. Ibezapolstat previously received FDA Qualified Infectious Disease Product (QIDP) designation in 2018 and Fast Track designation in 2019, reflecting its development as a potential therapy for a serious bacterial infection with significant unmet medical need.
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Phase 3 Program Could Address CDI Recurrence
Acurx reported that it has received FDA guidance regarding the planned Phase 3 development program for ibezapolstat. The company said the FDA is open to further discussion of the totality of evidence following completion of a single Phase 3 trial and other clinical studies conducted before a pre-NDA meeting. A successful outcome from the planned IBZ-ASPIRE Phase 3 trial, supported by the open-label IBZ-PATHFINDER Phase 2 trial in patients with multiply recurrent CDI, could support an NDA filing covering both acute treatment and reduction of recurrence, according to the company. Start-up activities for the IBZ-PATHFINDER study have begun, with patient enrollment expected in the coming months. Earlier Phase 2 development evaluated ibezapolstat’s clinical efficacy, pharmacokinetics, and effects on the gut microbiome, including changes in bacterial abundance and bile acid metabolism. In the Phase 2b study, Acurx reported that ibezapolstat-treated patients showed lower fecal primary bile acid concentrations and a higher secondary-to-primary bile acid ratio than patients treated with vancomycin.
Source: Acurx Pharmaceuticals press relese
