SER-109 (Seres Therapeutics), an investigational, oral, biologically-sourced microbiome therapeutic designed to reduce recurrence of C. difficile infection (CDI), demonstrated a 31.1% absolute reduction in the rate of CDI recurrence over 12 weeks compared to placebo, according to data from the ECOSPOR III trial. Further, the investigators found that the treatment’s efficacy was similar when stratified by age groups or prior antibiotic received. All data from the ECOSPOR III trial were presented at the Virtual American College of Gastroenterology Annual Scientific Meeting, October 23-28, 2020.
“These new SER-109 Phase 3 data extend the dramatic topline findings previously reported. The results demonstrate the remarkable efficacy levels are sustained over a twelve-week period, and similar treatment benefits are seen in both younger and older patients. In addition, the data show consistent patient benefits regardless of the baseline antibiotic treatment,” said Bret Lashner, MD, FACG, professor of medicine at the Cleveland Clinic, in a press release. “SER-109 has the potential to lead a paradigm shift in the clinical management of patients suffering from recurrent C. difficile infection.”
ECOSPOR III was a multicenter, randomized, placebo-controlled study that enrolled 182 patients with multiply recurrent CDI. Patients were randomized 1:1 to receive either SER-109 or placebo after standard of care antibiotic treatment. Previously reported data demonstrated that SER-109 met the study’s primary endpoint, with a 30.2% absolute reduction of recurrence of CDI compared to placebo 8 weeks post-treatment. New data show that at 12 weeks post treatment, the rate of recurrence in the SER-109 arm was 16.7% compared to 47.8% in the placebo arm.
SER-109 is a consortium of purified Firmicute bacteria in spore form, which are manufactured by fractionating targeted bacteria collected from the stool of healthy human donors with further steps to inactivate potential pathogens. According to Seres, SER-109 is distinct from fecal microbiota transplantation, as the company uses a unique manufacturing process designed to inactivate numerous potential pathogens, including species of non-spore bacteria, such as Escherichia coli, and viruses such as SARS-CoV-2.
Seres Therapeutics to present SER-109 phase 3 ECOSPOR III study results at American College Of Gastroenterology Annual Scientific Meeting [news release]. Seres Therapeutics; October 12, 2021. Accessed October 22, 2021. https://ir.serestherapeutics.com/news-releases/news-release-details/seres-therapeutics-present-ser-109-phase-3-ecospor-iii-study