Seres Therapeutics(US:MCRB) Globenewswire·2026-01-06 12:00Core Insights - Seres Therapeutics has published new findings on the mechanisms of action and clinical impact of its live biotherapeutic product VOWST, reinforcing the company's approach to developing next-generation live biotherapeutics [1][3][4] Group 1: VOWST Development and Approval - VOWST is the first FDA-approved oral microbiome biotherapeutic, designed to prevent recurrent Clostridioides difficile infection (rCDI), with its approval granted in April 2023 [2] - The product was sold to Nestlé Health Science in September 2024, marking a significant milestone for the company [2][7] Group 2: Clinical Findings and Mechanisms - A study published in Nature Medicine confirmed that higher doses of VOWST lead to enhanced pharmacokinetics, resulting in faster and more robust engraftment of therapeutic species in the gut [3] - Treatment with VOWST significantly altered the intestinal microbiome composition and increased beneficial metabolites, which inhibit C. difficile growth [3] - A complementary analysis in the Journal of Infectious Diseases showed that VOWST demonstrated similar efficacy across patients with first and multiply recurrent CDI, indicating consistent pharmacological effects [4] Group 3: Future Pipeline and SER-155 - The company is advancing its lead candidate SER-155, which has shown a 77% reduction in bacterial bloodstream infections in a Phase 1b study for patients undergoing allogeneic hematopoietic stem cell transplant (allo-HSCT) [5][7] - SER-155 has received Breakthrough Therapy designation for reducing bloodstream infections and Fast Track designation for preventing infections and graft-versus-host disease in allo-HSCT patients [7] - The company aims to explore SER-155 in various medically vulnerable populations, including cancer patients and those in intensive care [7]