Seres Therapeutics reported a third-quarter 2026 net loss of $16.3 million, compared to an $8.2 million profit in the prior-year period, driven by lower R&D and G&A expenses following cost reduction efforts and the absence of a $25 million gain on sale recognized in 2025. The company announced it is advancing plans for a next study evaluating SER-155 for the prevention of immune checkpoint inhibitor-related enterocolitis (irEC), with an expected FDA submission in Q1 2027, building on encouraging results from an investigator-sponsored trial where 80% of participants achieved an immunosuppressive-free clinical response. As of September 30, 2026, the company held $17.5 million in cash and expects its runway to extend through Q1 2027. Seres Therapeutics is a clinical-stage biotechnology company developing novel live biotherapeutics products in oncology and inflammatory diseases.
