Clinical TrialJul 8, 2026, 07:02 AM
Seres Therapeutics SER-155 shows 80% response rate in irEC trial
AI Summary
Seres Therapeutics announced encouraging top-line results from an Investigator-Sponsored Trial (IST) evaluating SER-155 in patients with immune checkpoint inhibitor-related enterocolitis (irEC). The study showed that 80% of SER-155 recipients achieved an immunosuppressive-free clinical response at Day 15, with 33% achieving complete clinical remission. The drug was well-tolerated, with no drug-related serious adverse events, and pharmacology data supported its mechanism of action, suggesting potential for expansion into other inflammatory and immune diseases. Seres is now seeking partners for SER-155 in irEC and funding for its broader pipeline.
Key Highlights
- 80% of SER-155 recipients achieved immunosuppressive-free clinical response at Day 15 in irEC trial.
- 67% of responders showed >=2-grade improvement in diarrhea symptoms at Day 15.
- 33% of participants achieved immunosuppressive-free complete clinical remission at Day 15.
- SER-155 was well tolerated with no drug-related serious adverse events observed.
- Pharmacology data confirmed mucosal epithelial barrier repair and reduced gastrointestinal inflammation.
- Company is engaging potential partners for SER-155 development in irEC.
- Seeking funding to advance Phase 2 study of SER-155 in allo-HCT and broader pipeline.
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