VE303 is an orally administered, rationally-defined bacterial consortium candidate being developed for high-risk Clostridioides difficile (CDI) infection. VE303 consists of 8 types of clonal human commensal bacteria strains selected for their ability to provide colonization resistance to C. difficile and manufactured under cGMP conditions. It is produced under cGMP conditions from pure, clonal bacterial cell banks, which yield a standardized drug product in powdered form and bypasses the need to rely on direct sourcing of fecal donor material of inconsistent composition. 

In a Phase 2 trial of patients at high risk of recurrence, VE303 met its primary endpoint of preventing C. difficile infection recurrence at eight weeks. This is the most advanced clinical trial of an investigational drug based on a rationally defined bacterial consortium, with a Phase 3 trial of VE303 planned to initiate in 2022.