Seres Therapeutics to Present SER-428 Data at IDWeek

The company will unveil preclinical findings for a new liquid biotherapeutic at the IDWeek 2026 conference.

Updated on Oct. 15, 2026 in Life Sciences

Seres Therapeutics to Present SER-428 Data at IDWeek

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Seres Therapeutics is set to present preclinical data on its investigational drug SER-428 at the upcoming IDWeek 2026 conference in Washington, D.C., taking place October 21-24, 2026. The drug is a liquid formulation of a live biotherapeutic designed for delivery via feeding tubes.

Why it matters

This development addresses a critical need for critically ill patients in intensive care units who are unable to swallow traditional oral capsules. By preventing pathogen colonization, the treatment aims to reduce the risk of secondary infections in vulnerable hospital populations.

In preclinical models, the drug successfully reduced the abundance of specific pathogens by up to 1,000-fold. The study also verified the stability of the liquid formulation during simulated feeding tube delivery.

The players

Seres Therapeutics

A Cambridge-based biotechnology company focused on the development of microbiome-based therapeutic products.

CARB-X

A global non-profit partnership that provides funding for research and development to address drug-resistant bacteria.

The details

SER-428 functions within the gastrointestinal tract to inhibit the overgrowth of pathogens and enhance mucosal epithelial barrier integrity. The drug's development, which builds on previous research where SER-155 showed a 77% relative risk reduction in bloodstream infections, received grant support from CARB-X.

October 21 to October 24, 2026: The IDWeek 2026 conference occurs in Washington, D.C.
October 22, 2026: Presentation of SER-428 poster P-22.

The Big Picture

This research follows the standard development trajectory for innovations backed by the CARB-X research funding program. It shifts the focus of microbiome therapy from oral capsules to hospital-integrated liquid systems to address infection in ICU environments.

This drug could eventually offer a new way for hospitals to prevent severe infections in patients who cannot take oral medications. If successful in trials, the technology could reduce the reliance on traditional antibiotics for critically ill patients.

The takeaway

Advancements in liquid biotherapeutics offer potential new pathways for treating patients who cannot use standard oral delivery methods. Such innovations may eventually provide new methods for clinicians to manage infection risks in hospital settings.

What happens next

Seres Therapeutics is currently designing a Phase 1b open-label clinical trial to test the drug in intensive care unit patients, though further progress depends on future grant or private funding.