Seres says Phase 1b trial shows SER-155 shifts gut microbiome in allo-HCT patients

• Seres Therapeutics highlighted Phase 1b biomarker and clinical pharmacology findings for SER-155 at ESCMID Global 2026.
• Results were already presented in a poster tied to a randomized, placebo-controlled trial in adults undergoing allogeneic hematopoietic cell transplantation.
• Data showed SER-155 produced a durable shift in gut microbiome composition versus placebo.
• Findings also indicated improved gut barrier integrity, supporting prior clinical observations of fewer bloodstream infections in SER-155-treated patients following transplant.
• Additional microbiome-focused work will be presented at the meeting on April 20-21, including an in vitro IBD model collaboration intended to inform clinical development and patient stratification strategies.

Disclaimer: This news brief was created by Public Technologies (PUBT) using generative artificial intelligence. While PUBT strives to provide accurate and timely information, this AI-generated content is for informational purposes only and should not be interpreted as financial, investment, or legal advice. Seres Therapeutics Inc. published the original content used to generate this news brief via GlobeNewswire (Ref. ID: 202604200700PRIMZONEFULLFEED9692817) on April 20, 2026, and is solely responsible for the information contained therein.