Benzinga | Oct 26, 2021 07:59AM EDT

Seres Therapeutics Highlights Presentation Of Late-Breaking Phase 3 Data On Its SER-109 In Recurrent C. Difficile Infection At American College Of Gastroenterology Meeting Oct. 26 At 6:25 p.m. EDT

-- Study shows that SER-109 reduced the risk of recurrent C. difficile infection in patients with risk factors for recurrence, including acid-reducing medications --

CAMBRIDGE, Mass.--(BUSINESS WIRE)-- Seres Therapeutics, Inc. (NASDAQ:MCRB), a leading microbiome therapeutics company, today announced late-breaking data from its Phase 3 ECOSPOR III study evaluating SER-109, an investigational oral microbiome therapeutic for recurrent C. difficile infection (rCDI). New data from an exploratory analysis demonstrate SER-109 reduced the risk of rCDI compared to placebo in patients with risk factors for recurrence, including those taking acid-reducing medications such as proton pump inhibitors (PPIs) and H2 blockers (40.7% of patients). These data, presented by Louis Korman, M.D. on October 26 from 3:25-3:35 PM PT at the American College of Gastroenterology 2021 Annual Scientific Meeting in Las Vegas, may assist healthcare providers in their clinical decision-making on the use of PPIs and H2 blockers in patients at risk for recurrent CDI.

"Those living with gastrointestinal issues are faced with limited treatment options to help address some of the debilitating symptoms they face each day. While many turn to acid-reducing medicines, previous studies have shown that this can result in a higher risk of recurrent C. difficile infection," said Lisa von Moltke, M.D., Chief Medical Officer at Seres. "We were pleased to see that with the administration of SER-109, subjects in the study experienced a lower CDI recurrence rate regardless of their risk factors, including the use of acid-reducing medications--a highly prevalent characteristic in this study population."

The SER-109 ECOSPOR III Phase 3 study (ClinicalTrials.gov identifier: NCT03183128) was a multicenter, randomized, placebo-controlled study. Previously reported topline data demonstrated that the study achieved its primary endpoint where SER-109 was superior to placebo in reducing CDI recurrence at eight weeks reflecting a sustained clinical response rate of approximately 88% at eight weeks post-treatment. SER-109 resulted in a 27% absolute reduction of recurrence of CDI compared to placebo at eight weeks post-treatment, which is a relative risk reduction of 68%. In May 2021, Seres presented 24-week clinical data from the study that demonstrated significantly reduced recurrence rates compared to placebo over 24 weeks (21% vs. 47%, respectively). SER-109 was observed to be well tolerated in the study, with no treatment-related serious adverse events observed in the active arm and an adverse event profile comparable to placebo.

"As a clinician treating people living with recurrent C. difficile infection, I recognize the serious and often debilitating impact it has on their lives. I'm further encouraged by these new findings as they show that SER-109 has the potential to be broadly effective, including in patients known to be at higher risk of experiencing a recurrence of C. difficile infection," said Louis Korman, M.D., Director, Chevy Chase Clinical Research, Principal Investigator of the SER-109 Phase 3 trial and presenting author.

Seres expects both the completed Phase 3 study results and the pending open-label study database to enable a Biologics License Application (BLA) filing in mid-2022.