ECOSPOR IV: An Open-Label Extension of Study SERES-012 and Open-Label Program for Evaluating SER-109 in Adult Subjects with Recurrent Clostridioides difficile Infection (RCDI)

Approximately 195 subjects with at least two episodes of CDI (including current episode) in the previous 12 months from Screening, a positive C. difficile toxin test result on a stool sample, and who have responded to standard-of-care (SOC) antibiotic treatment will be enrolled.

All enrolled subjects will have access to our Investigational Product, SER-109.

Subjects will receive an oral dose of SER-109 in 4 capsules once daily for 3 consecutive days.

SERES-013 Cohort 2 is a 24-week study, comprised of three study periods (Screening, Treatment, and Safety Follow Up), with two clinic visits and all other visits can be telephone visits.