For Physicians

Seres is now enrolling patients with first or subsequent recurrence of C. diff in the SERES-013 open-label study at sites across the U.S. and Canada ( NCT #03183141).

For information about referring patients to a site near you, or to inquire about participating as a principal investigator in the study, please fill out the form below.

What is SER-109?

SER-109 is an investigational, oral, biologically-derived microbiome therapeutic for the prevention of recurrent C. diff infection (CDI) in adults with recurrent CDI. SER-109 is a consortium of purified bacterial spores of multiple Firmicute species, manufactured by fractionating targeted bacteria from stool of healthy human donors with further steps to inactivate and remove potential pathogens. SER-109 is designed to break the cycle of recurrent CDI by simultaneously acting on multiple disease-relevant pathways to address key facets of the disease. The FDA has granted SER-109 both Breakthrough Therapy and Orphan Drug designations.

Click here to view the scientific literature supporting SER-109.

What is the clinical study protocol?

Patients enrolled in the study will receive SER-109 after standard of care antibiotic treatment. SER-109 will be administered orally for three consecutive days. Patients will undergo C. diff diagnostic testing at enrollment and whenever they are suspected to have a recurrence.

How has SER-109 performed in previous clinical studies?

In the Phase 3 ECOSPOR III blinded randomized controlled trial, SER-109 treatment resulted in a highly statistically significant absolute decrease of 27.4% in the proportion of patients who experienced a recurrence in CDI within eight weeks of administration versus placebo, the study’s primary endpoint. Patients administered SER-109 experienced a 12.4% rate of CDI recurrence versus 39.8% for placebo patients. The study results were equally compelling when characterized by the alternative metric of sustained clinical response, where 88.9% of patients in the SER-109 arm versus 58.7% of placebo patients achieved this objective.

SER-109 was well tolerated, with an adverse event (AE) profile similar to placebo. No treatment-related serious adverse events (SAEs) were observed on SER-109. The most commonly observed treatment-related AEs were flatulence, abdominal distention and abdominal pain, which were generally mild to moderate in nature, and these were observed at a similar rate in both the SER-109 and placebo arms.

How is SER-109 different from fecal microbiota transplantation (FMT)?

FMT and investigational FMT drug products are vulnerable to emerging infections because they utilize minimally processed stool. The FDA has issued several safety alerts related to pathogen transmission by FMT, including warnings related to multi-drug resistant organisms and SARS-CoV-2, the virus linked to COVID-19.

In Seres’ manufacturing process, solvent treatment and purification steps remove unwanted bacteria, fungi, parasites and viruses, reducing the risk of pathogen transmission to a level that cannot be achieved through donor screening alone. Seres’ microbiome therapeutics are manufactured in a controlled cGMP bioprocessing environment, with rigorous testing to ensure product purity.