Seres Therapeutics — Third Quarter 2026 Earnings Summary

Seres Therapeutics reported a net loss of $16.3 million for the third quarter of 2026, driven by a $5.7 million non-cash impairment charge related to lease termination and reduced research and development expenses. The company announced plans to advance SER-155 into a new study for the prevention of immune checkpoint inhibitor-related enterocolitis, with a study design submission to the FDA expected in the first quarter of 2027. This development strategy builds on positive results from an investigator-sponsored trial where 80% of participants with moderate-to-severe enterocolitis achieved an immunosuppressive-free clinical response. As of September 30, 2026, Seres held $17.5 million in cash and cash equivalents, with an expected runway extending through the first quarter of 2027.