ECOSPOR IV: An Open-Label Extension of Study SERES-012 and Open-Label Program for Evaluating SER-109 in Subjects With Recurrent Clostridioides Difficile Infection (RCDI) (ECOSPORIV)
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ClinicalTrials.gov Identifier: NCT03183141 |
Recruitment Status :
Recruiting
First Posted : June 9, 2017
Last Update Posted : August 21, 2020
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Cohort 1: Subjects who had a CDI recurrence in study SERES-012 within 8 weeks of receipt of study drug will be eligible. The purpose of this cohort is to assess safety and efficacy of SER-109 in reducing recurrence of Clostridioides difficile infection (CDI) in adults who had a CDI recurrence within 8 weeks after receipt of SER-109 or Placebo in study SERES-012.
Cohort 2: Cohort 2 is an open-label program for subjects who were not part of SERES-012. The purpose of this cohort is to describe safety and tolerability of SER-109 in subjects 18 years of age or older with at least a first recurrence of CDI within the past 12 months.
Condition or disease | Intervention/treatment | Phase |
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Clostridioides Difficile Infection | Drug: SER-109 | Phase 3 |
Cohort 1 is an open-label extension of study SERES-012. Subjects who had a CDI recurrence in study SERES-012 within 8 weeks of receipt of study drug, have responded to a course of standard of care (SOC) antibiotic treatment, and who have completed their SERES-012 Week 8 visit will receive an oral dose of SER-109. A treatment regimen of SER-109 is defined as an oral dose of SER-109 (4 capsules once daily) for 3 consecutive days.
Approximately 30 eligible subjects with recurrent CDI disease from study SERES-012 are expected to enroll. Screening for this study will begin at the Week 8 Visit of study SERES-012.
Cohort 2 is an open-label program for subjects who were not part of SERES-012. Subjects 18 years of age or older who had one or more CDI recurrence within 12 months and have responded to a course of SOC antibiotic treatment will receive an oral dose of SER-109. The CDI recurrence must be confirmed by a positive C. difficile stool toxin assay. A treatment regimen of SER-109 is defined as an oral dose of SER-109 (4 capsules once daily) for 3 consecutive days.
Approximately 195 eligible subjects with recurrent CDI disease are expected to enroll.
Study Type : | Interventional (Clinical Trial) |
Estimated Enrollment : | 225 participants |
Allocation: | N/A |
Intervention Model: | Single Group Assignment |
Masking: | None (Open Label) |
Primary Purpose: | Treatment |
Official Title: | ECOSPOR IV: An Open-Label Extension of Study SERES-012 and Open-Label Program for Evaluating SER-109 in Subjects With Recurrent Clostridioides Difficile Infection (RCDI) |
Actual Study Start Date : | October 23, 2017 |
Estimated Primary Completion Date : | December 2021 |
Estimated Study Completion Date : | April 2022 |
Arm | Intervention/treatment |
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Experimental: SER-109
SER -109 is an ecology of bacteria in spore form, enriched from stool donations obtained from healthy, screened donors
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Drug: SER-109
SER -109 is an ecology of bacteria in spore form, enriched from stool donations obtained from healthy, screened donors
Other Name: Eubacterial Spores, Purified Suspension, Encapsulated |
- Cohort 1: Recurrence of CDI up to 8 Weeks after treatment [ Time Frame: Up to Week 8 ]Recurrence of CDI
- Cohort 1: Safety and tolerability of SER-109 assessed by incidence of AEs, lab results, vital signs, ECG, and physical examination findings [ Time Frame: Up to Week 24 ]Safety & Tolerability
- Cohort 2: Recurrence of CDI and sustained clinical response up to 8 and 12 weeks after treatment [ Time Frame: Up to Weeks 8 and 12 ]Recurrence of CDI and sustained clinical response
- Cohort 2: Safety and tolerability of SER-109 assessed by incidence of AEs, lab results, vital signs, and physical examination findings [ Time Frame: Up to Week 24 ]Safety & Tolerability
- Cohort 1: Time to recurrence of CDI [ Time Frame: Up to Week 24 ]Time to recurrence of CDI
- Cohort 1: Recurrence of CDI up to 4, 12 and 24 Weeks after treatment [ Time Frame: Up to 4, 12 and 24 Weeks ]Recurrence of CDI

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Ages Eligible for Study: | 18 Years and older (Adult, Older Adult) |
Sexes Eligible for Study: | All |
Accepts Healthy Volunteers: | No |
Cohort 1 Inclusion Criteria:
- Previously enrolled in Study SERES-012, had CDI recurrence within 8 weeks after receipt of study drug, and have completed their SERES-012 Week 8 visit.
- Signed informed consent prior to initiation of any study-specific procedure or treatment. The subject must be able to provide written informed consent and understand the potential risks and benefits from study enrollment and treatment.
- The CDI recurrence in Study SERES-012 must have met the protocol definition of ≥ 3 unformed stools per day over 2 consecutive days, a positive C. difficile stool test, and assessment by the investigator that the clinical condition of the subject warranted treatment.
Cohort 1 Exclusion Criteria:
- Female subjects who are pregnant, breastfeeding, lactating, or planning to become pregnant during the study.
- Known or suspected toxic megacolon and/or known small bowel ileus.
- Admitted to or expected to be admitted to an intensive care unit for medical reasons (not just boarding). Note: nursing homes, rehabilitation, assisted living centers and acute care hospitals are acceptable.
- Absolute neutrophil count of <500 cells/ml3.
- Major gastrointestinal surgery (e.g. significant bowel resection or diversion) within 3 months before enrollment (this does not include appendectomy or cholecystectomy), or any history of total colectomy or bariatric surgery (bariatric surgery which does not disrupt the gastrointestinal lumen, i.e., restrictive procedures such as banding, are permitted).
- History of active inflammatory bowel disease (ulcerative colitis, Crohn's disease, microscopic colitis) with diarrhea believed to be caused by active inflammatory bowel disease in the past 3 months.
- Concurrent intensive induction chemotherapy, radiotherapy, or biologic treatment for active malignancy (subjects on maintenance chemotherapy may only be enrolled after consultation with the study medical monitor).
- Any history of fecal microbiota transplantation (FMT).
Cohort 2 Inclusion Criteria:
- Subjects 18 years of age or older who had one or more CDI recurrence (as confirmed by a C. difficile stool toxin test) within 12 months and have responded to a course of standard of care antibiotic treatment.
- Signed informed consent prior to initiation of any study-specific procedure or treatment. The subject must be able to provide written informed consent and understand the potential risks and benefits from study enrollment and treatment.
Cohort 2 Exclusion Criteria:
(all Cohort 1 exclusion criteria [#1-8 above] plus the below addition criterion) 9. Previously enrolled in a Seres Therapeutics clinical study.

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.
Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT03183141
Contact: Elaine Wang, MD | 617-945-9626 | ewang@serestherapeutics.com | |
Contact: Lisa von Moltke, MD | 617-945-9626 | lvonmoltke@serestherapeutics.com |
United States, Massachusetts | |
University of Massachusetts Memorial Medical Center | Recruiting |
Worcester, Massachusetts, United States, 01655 | |
Contact: JeanMarie Houghton, MD 508-856-6441 | |
United States, Montana | |
Mercury Street Medical | Recruiting |
Butte, Montana, United States, 59701 | |
Contact: John Pullman, MD 406-723-1300 |
Study Director: | Elaine Wang, MD | Seres Therapeutics, Inc. |
Responsible Party: | Seres Therapeutics, Inc. |
ClinicalTrials.gov Identifier: | NCT03183141 |
Other Study ID Numbers: |
SERES-013 |
First Posted: | June 9, 2017 Key Record Dates |
Last Update Posted: | August 21, 2020 |
Last Verified: | August 2020 |
Individual Participant Data (IPD) Sharing Statement: | |
Plan to Share IPD: | No |
Studies a U.S. FDA-regulated Drug Product: | Yes |
Studies a U.S. FDA-regulated Device Product: | No |
Infection Communicable Diseases Clostridium Infections Gram-Positive Bacterial Infections Bacterial Infections |