The Food and Drug Administration (FDA) has granted Breakthrough Therapy designation for ribaxamase (SYN-004; Synthetic Biologics) for the prevention of Clostridium difficile infection (CDI).

The designation was supported by data from the Phase 2b proof-of-concept trial of ribaxamase, which evaluated its efficacy to prevent the onset of primary CDI, antibiotic-associated diarrhea (AAD) and the emergence of antimicrobial resistance (AMR) in hospitalized patients with lower respiratory infection receiving IV ceftriaxone. The study met its primary endpoint of significantly reducing CDI, with ribaxamase achieving a 71.4% relative risk reduction (P=0.045) in CDI rates vs. placebo. Treatment with ribaxamase also showed a significant reduction in new colonization by vancomycin-resistant enterococci (VRE) compared to placebo (P=0.0002). Additional data analysis, such as the ability of ribaxamase to prevent the emergence and proliferation of AMR in the gut microbiome, is ongoing. 

Related Articles

Ribaxamase (SYN-004) is a first-in-class oral enzyme designed to degrade certain IV beta-lactam antibiotics within the GI tract and maintain the natural balance of the gut microbiome.

For more information visit