Seres Therapeutics Presents Phase III Results of SER-109 for Recurrent C. Difficile Infection at Digestive Disease Week (DDW) Annual Meeting

– In ECOSPOR lll, Seres’ lead therapeutic candidate integrated rapidly and durably into the microbiome to prevent recurrence of C. difficile infection –

– Within a week of treatment, SER-109 was observed to diversify the microbiome and support the production of fatty acids that inhibit the growth of C. difficile –

CAMBRIDGE, MA, USA I May 22, 2022 I Seres Therapeutics, Inc. (Nasdaq: MCRB), a leading microbiome company, today announced the presentation of data from its Phase 3 ECOSPOR III study that suggests that investigational microbiome-based therapeutic SER-109 warns them It’s hard (rCDI) by rapidly establishing a long-lasting colony of beneficial gut microbes, which can produce fatty acids that disrupt the It’s hard life cycle. These data were shared in oral and poster presentations at the 2022 Digestive Disease Week (DDW) Annual Meeting.

“These results suggest that our investigational microbiome therapeutic, SER-109, is a potentially fast-acting intervention that may provide lasting relief from recurrence. It’s hard infections when administered to vulnerable patients,” said Matthew Henn, Ph.D., Chief Scientific Officer at Seres. “Confirming the multiple mechanisms that SER-109 bacteria use to prevent this notoriously challenging infection at the cellular and molecular level not only increases our confidence in this particular therapeutic, but it has the potential to help guide the design of the next generation. of microbiome. therapies based on .

Seres expects to finalize a Biologics License Application (BLA) submission for SER-109 to the United States Food and Drug Administration (FDA) in mid-2022, positioning SER-109 to potentially become the first microbiome-based therapeutic treatment approved by the FDA for recurrent treatment It’s hard infections with a potential product launch in the first half of 2023.

SER-109 graft is durable for 24 weeks (Poster #3701110)

The Phase 3 ECOSPOR III study (NCT03183128), a multi-center, randomized, placebo-controlled clinical trial that enrolled 182 adults with rCRI, previously demonstrated that SER-109 prevented rCRI in 88% of recipients at primary endpoint of eight weeks, while only 60% of patients in the placebo group remained recurrence-free during the same period. The safety profile was similar in both groups.

A pre-planned exploratory analysis of the ECOSPOR III trial shows that approximately two-thirds of CDI recurrences occurred during the first two weeks following antibiotic treatment for CDI – the window of vulnerability – when the microbiome is further decimated and It’s hard the spores, unaffected by antibiotics, are free to germinate into toxin-producing vegetative bacteria.

“These results suggest that the first two weeks following antibiotic treatment are when microbiome therapeutics have the greatest potential benefit, restoring bacterial diversity and disrupting the cycle of recurrent infections. It’s hardsaid Lisa von Moltke, MD, chief medical officer at Seres.

SER-109 introduces a diverse consortium of bacterial species into the gut in the form of spores, which rapidly germinate and become incorporated into the microbiome, appearing in stool as vegetative bacteria. This process is called grafting.

Within a week of SER-109 treatment, the number of new bacterial species in the stool increased and remained significantly higher than the placebo group throughout the 24-week study period. Bacterial diversity rebounded more slowly and to a lesser extent in the placebo group.

The pattern of results was the same regardless of which antibiotic the participants received, vancomycin or fidaxomicin.

Impact of SER-109 on fatty acid production (Abstract # 3700066)

To better understand how SER-109 prevents rCDI at the molecular level in a post-hoc analysis, stool samples collected from ECOSPOR III participants were analyzed for changes in their microbial composition and fatty acid concentrations. during the eight weeks following treatment with SER-109. Long and medium carbon chain fatty acids such as butyrate, valerate and hexanoate have been shown to inhibit the growth of It’s hard.

For participants who received SER-109, butyrate, valerate, and hexanoate levels rose rapidly, beginning at the two-week window of vulnerability, and remained significantly higher than the placebo group over the period. eight-week data analysis.

Among the placebo group members who experienced a recurrence of CDI, valerate levels tended to be lower than those of the placebo group members who did not experience a recurrence, further suggesting that valerate plays a role protective against rCDI.

These data and data previously published in the New England Journal of Medicine suggest that a two-pronged approach to treating rCDI, with gold standard antibiotics to kill autonomic diseases It’s hard followed by the experimental agent SER-109 to repair the disrupted microbiome by grafting Firmicutes bacteria and modulating several metabolic pathways in the gut, may be effective.

Posters and presentations will be available for 90 days on the DDW conference website.

About SER-109
SER-109 is an oral microbiome therapeutic candidate composed of a consortium of highly purified Firmicutes spores, which normally live in a healthy microbiome. SER-109 is designed to prevent further recurrences of CDI by modulating the disrupted microbiome to a state that resists It’s hard colonization and growth. The manufacturing purification process of SER-109 is designed to remove unwanted microbes, thereby reducing the risk of transmitting pathogens beyond donor screening alone. The FDA has granted SER-109 Breakthrough Therapy Designation and Orphan Drug Designation for the treatment of rCDI.

About Seres Therapeutics
Seres Therapeutics, Inc. (Nasdaq: MCRB) is a leading microbiome therapeutics company developing a novel class of multifunctional bacterial consortia designed to functionally interact with host cells and tissues to treat disease. Seres’ SER-109 program achieved the first-ever positive pivotal clinical results for a microbiome-targeted drug candidate and was granted Breakthrough Therapy and Orphan Drug designations by the FDA. The SER-109 program is advanced to prevent the recurrence of It’s hard infection and has the potential to become a first-class FDA-approved microbiome treatment. Seres is evaluating SER-155 in a Phase 1b study in patients receiving allogeneic hematopoietic stem cell transplantation to reduce the incidence of gastrointestinal infections, bloodstream infections and graft-versus-host disease, as well as additional preclinical-stage programs targeting infection protection in medically compromised patients. The Company is also conducting research to inform the further development of microbiome therapies for ulcerative colitis.

For more information, please visit www.serestherapeutics.com.

THE SOURCE: Seres Therapeutic