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Seres Therapeutics to Highlight VOWST™ Data at IDWeek

Oct 12, 2023 at 7:00 AM EDT

CAMBRIDGE, Mass.--(BUSINESS WIRE)--Oct. 12, 2023-- Seres Therapeutics, Inc. (Nasdaq: MCRB) today announced multiple abstracts to be presented at IDWeek 2023 in Boston, Massachusetts (October 11-15, 2023), including two posters of post-hoc analyses from the ECOSPOR III and ECOSPOR IV Phase 3 trials, which supported the recent approval by the US Food and Drug Administration (FDA) of VOWST as the first orally-administered microbiota-based therapeutic for the prevention of recurrent C. difficile infection (rCDI) in adults following antibacterial treatment for rCDI. VOWST is commercialized in collaboration with Nestlé Health Science.

“The data we are presenting this year at IDWeek build upon our earlier findings that the gastrointestinal microbiome is similarly disrupted in patients with first or multiple rCDI. The introduction of VOWST has provided a means to alleviate suffering and health risks associated with recurrent instances of this serious disease," said Matthew Henn, Ph.D., Chief Scientific Officer at Seres.

Details for illustrative Seres-sponsored oral presentation and posters are below:

  • Poster Title: Analysis of Microbiome Diversity and Secondary Bile Acid Synthesis Following SER-109 or Placebo in Patients with First Recurrent or Multiply Recurrent Clostridioides difficile Infection
    • Poster/Abstract Number: 655
    • Date/Time: Thursday, October 12 at 12:15 – 1:30 p.m. ET
  • Poster Title: Rapid Change in Microbiome Profiles Regardless of Diagnostic Method in a Post Hoc Comparative Analysis of Phase 3 Trials of Fecal Microbiota Spores, Live-brpk (formerly SER-109) for the Prevention of Recurrent Clostridioides difficile Infection (rCDI)
    • Poster/Abstract Number: 653
    • Date/Time: Thursday, October 12 at 12:15 – 1:30 p.m. ET



VOWST is indicated to prevent the recurrence of Clostridioides difficile infection (CDI) in individuals 18 years of age and older following antibacterial treatment for recurrent CDI (rCDI).

Limitation of Use: VOWST is not indicated for treatment of CDI.



Transmissible infectious agents: Because VOWST is manufactured from human fecal matter, it may carry a risk of transmitting infectious agents. Report any infection that is suspected to have been transmitted by VOWST to Aimmune Therapeutics, Inc. at 1-833-246-2566.

Potential presence of food allergens: VOWST may contain food allergens. The potential to cause adverse reactions due to food allergens is unknown.


The most common adverse reactions (reported in ≥5% of participants) were abdominal distension (31.1%), fatigue (22.2%), constipation (14.4%), chills (11.1%), and diarrhea (10.0%).

To report SUSPECTED ADVERSE REACTIONS, contact Aimmune Therapeutics at 1-833-AIM-2KNO (1-833-246-2566), or the FDA at 1-800-FDA-1088, or visit


Do not administer antibacterials concurrently with VOWST.

Please see Full Prescribing Information and Patient Information

About Recurrent C. difficile Infection (rCDI)

Recurrent C. difficile infection is a gastrointestinal infection caused by C. difficile bacteria. rCDI is linked to dysbiosis of the gastrointestinal microbiome and is associated with increased morbidity and mortality. CDI has been characterized as an Urgent Health Threat by the Centers for Disease Control and Prevention (CDC). rCDI results in a substantial burden on the healthcare system1 with the average rCDI-related annual costs per patient at approximately $43K.2

About Seres Therapeutics

Seres Therapeutics, Inc. (Nasdaq: MCRB) is a commercial-stage company developing novel microbiome therapeutics for serious diseases. Seres’ lead program, VOWST™, obtained U.S. FDA approval in April 2023 as the first orally administered microbiota-based therapeutic to prevent recurrence of C. difficile infection (CDI) in adults following antibacterial treatment for recurrent CDI and is being commercialized in collaboration with Nestlé Health Science. Seres is evaluating SER-155 in a Phase 1b study in patients receiving allogeneic hematopoietic stem cell transplantation. The Company is also conducting research to inform further development of microbiome therapeutics for ulcerative colitis. For more information, please visit

Forward-Looking Statements

This press release contains forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995. All statements contained in this press release that do not relate to matters of historical fact should be considered forward-looking statements, including the ability for microbiome therapeutics to treat and prevent infections, and other statements which are not historical fact.

These forward-looking statements are based on management’s current expectations. These statements are neither promises nor guarantees, but involve known and unknown risks, uncertainties and other important factors that may cause our actual results, performance or achievements to be materially different from any future results, performance or achievements expressed or implied by the forward-looking statements, including, but not limited to, the following: we have incurred significant losses, are not currently profitable and may never become profitable; our need for additional funding; our limited operating history; the impact of the COVID-19 pandemic; our unproven approach to therapeutic intervention; our reliance on third parties and collaborators to conduct our clinical trials, manufacture our product candidates and develop and commercialize our product candidates, if approved; the unknown degree and competing factors of market acceptance for VOWST; the competition we will face; our ability to protect our intellectual property; and our ability to retain key personnel and to manage our growth. These and other important factors discussed under the caption “Risk Factors” in our Quarterly Report on Form 10-Q filed with the Securities and Exchange Commission (SEC), on August 8, 2023, and our other reports filed with the SEC could cause actual results to differ materially from those indicated by the forward-looking statements made in this press release. Any such forward-looking statements represent management’s estimates as of the date of this press release. While we may elect to update such forward-looking statements at some point in the future, we disclaim any obligation to do so, even if subsequent events cause our views to change. These forward-looking statements should not be relied upon as representing our views as of any date subsequent to the date of this press release.


  1. U.S. Bureau of Labor Statistics. CPI Inflation Calculator. U.S. Bureau of Labor Statistics. Published 2022. CPI inflation adjusted to March 2023.
  2. Rodrigues R, Barber GE, Ananthakrishnan AN. A Comprehensive Study of Costs Associated With Recurrent Clostridium difficile Infection. Infect Control Hosp Epidemiol. 2016;38:196-202. DOI: 10.1017/ice.2016.246


Seres IR and PR Contact:
Kevin Mannix

Source: Seres Therapeutics, Inc.

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