Seres Therapeutics Appoints Co-CEOs as Company Seeks Partnerships for SER-155 Development
核心洞察
Seres Therapeutics has appointed Thomas DesRosier and Marella Thorell as co-CEOs following Eric Shaff's departure after a decade leading the company.
The company is actively engaging with multiple parties for business development partnerships to secure additional capital for advancing SER-155, which showed a 77% relative risk reduction in bloodstream infections (搜索).
SER-155 has received FDA Breakthrough Therapy designation for reducing bloodstream infections (搜索) in adults undergoing allogeneic hematopoietic stem cell transplant.
Seres Therapeutics announced a leadership transition that positions the live biotherapeutics company to advance its promising SER-155 program through strategic partnerships. Thomas DesRosier and Marella Thorell have been appointed as co-Chief Executive Officers, effective July 31, 2025, following the departure of Eric Shaff after a decade with the company.
The leadership change comes as Seres actively engages with multiple parties regarding various deal structures, including potential business development and partnerships, aimed at securing additional capital and resources to enable clinical advancement of SER-155 and other live biotherapeutic product candidates.
SER-155 Shows Strong Clinical Promise
SER-155, the company's lead investigational therapy, has demonstrated significant clinical potential in reducing bloodstream infections (搜索). Previously disclosed Phase 1b placebo-controlled study results showed a 77% relative risk reduction in bloodstream infections in adults undergoing allogeneic hematopoietic stem cell transplant (allo-HSCT), a high-risk patient population.
The therapy has received FDA Breakthrough Therapy designation for the reduction of bloodstream infections (搜索) in adults undergoing allo-HSCT, as well as Fast Track designation for reducing the risk of infection and graft-versus-host disease (搜索) in the same patient population.
"SER-155, which was granted Breakthrough Therapy designation for the reduction of BSIs in adults undergoing allo-HSCT, and Seres' broader portfolio of live biotherapeutics represent substantial therapeutic and commercial opportunities," said DesRosier and Thorell in a joint statement.
Expanding Treatment Horizons
Beyond allo-HSCT patients, Seres intends to evaluate SER-155 and other cultivated live biotherapeutic candidates across multiple medically vulnerable patient populations. These include autologous-HSCT patients, cancer patients with neutropenia, CAR-T recipients, individuals with chronic liver disease, solid organ transplant recipients, as well as patients in intensive care units and long-term acute care facilities.
The company's pipeline also includes additional assets targeting inflammatory and immune diseases, including ulcerative colitis (搜索) and Crohn's disease (搜索), supported by clinical and biomarker data from the live biotherapeutics platform.
Leadership Expertise and Company Foundation
DesRosier, who joined Seres in May 2016 as Chief Legal Officer, brings extensive pharmaceutical industry experience from previous roles at ARIAD Pharmaceuticals (搜索), Cubist Pharmaceuticals, Sanofi, and Wyeth Pharmaceuticals. He led the negotiation of Cubist's acquisition by Merck (搜索) and holds a chemistry degree from the University of Vermont and a law degree from Wake Forest University.
Thorell joined Seres in March 2024 as Chief Financial Officer, bringing over 25 years of finance and operations experience. Her background includes CFO roles at Evelo Biosciences, Palladio Biosciences, and Realm Therapeutics, along with experience in IPO preparation and execution.
Seres has established itself as a pioneer in the live biotherapeutics field, having successfully developed and gained FDA approval for VOWST, the first FDA-approved orally administered microbiome therapeutic, which was sold to Nestlé Health Science (搜索) in September 2024.
"During his tenure, Seres has dramatically advanced the field and successfully delivered the first-ever FDA-approved oral microbiome therapy to patients," said Stephen Berenson, Chairman of Seres' Board of Directors, regarding outgoing CEO Shaff's contributions.
Strategic Focus on Partnerships
The new co-CEOs emphasized their focus on securing partnerships to advance the clinical development of SER-155. "Engagements with several parties are underway regarding various deal structures, including potential business development and partnership opportunities, aimed at securing additional capital and support for continued advancement of our pipeline," they stated.
SER-155 and the company's other pipeline programs are manufactured from standard clonal cell banks via cultivation, representing a different approach from the donor-sourced production process used for VOWST. This manufacturing approach is designed to target multiple disease-relevant pathways across various patient populations at high risk of serious infections.