Seres Therapeutics to Present Preclinical Data for SER-428, an Investigational Live Biotherapeutic Designed to Reduce Risk of Bloodstream Infections in Critically Ill Patients, at IDWeek 2026

Seres Therapeutics announced preclinical data for SER-428, an investigational live biotherapeutic designed to reduce bloodstream infections in critically ill patients. The novel oral liquid formulation showed up to 1,000-fold reduction of pathogenic bacteria in preclinical models and builds on positive results from SER-155. The company is designing a Phase 1b trial in collaboration with Columbia University, with further development pending funding.