Seres Therapeutics Inc. announced that new post hoc data from its SER-155 Phase 1b trial will be presented at IDWeek 2025, scheduled for October 19-22 in Atlanta, Georgia. The oral presentation will cover clinical and microbiological outcomes of bloodstream infections (BSI) in adults undergoing allogeneic hematopoietic stem cell transplant, based on results from a randomized, double-blind, placebo-controlled study. According to the company, SER-155 was associated with a 77% reduction in BSIs, as well as lowered systemic antibiotic use and rates of febrile neutropenia compared to placebo. The presentation, which will include data on BSI pathogens, clinical outcomes, prophylaxis, and antimicrobial resistance patterns, is set for October 20. Seres Therapeutics is finalizing plans for a Phase 2 study of SER-155 following feedback from the FDA.