DiarrheaPhase 1NCT06801067
A Study of SER-155 to Treat Diarrhea in People on Immunotherapy
A Phase 1 study testing SER-155 in people with Diarrhea and Enterocolitis, run by Memorial Sloan Kettering Cancer Center at 7 sites in United States.
Trial summary
The purpose of this study is to find out whether SER-155 may be a safe first treatment that causes few or mild side effects for people due to irEC. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Diarrhea, Enterocolitis
- What is being tested?
- SER-155
- Type of treatment
- Pill or oral medicine
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 15 participants
- Where
- 7 sitesUnited States
- Study dates
- 24 Jan 2025to 24 Jan 2027
- Phase
- Phase 1
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Age > 18 years
- Receipt of ICI (single-agent or combination) within the 180 days preceding screening.
- Concurrent treatment with cytotoxic chemotherapy or other tumor-directed agents is permitted.
- Grade 2 - 3 diarrhea (i.e., increase of at least 4 bowel movements a day above baseline during the screening window), deemed by the treating provider as likely related to ICI therapy, with or without concomitant symptoms of grade 1 - 2 colitis (e.g.
- abdominal pain, bloody or mucoid stools)
- Able to swallow oral medication
- Individuals of childbearing potential willing to use a highly effective method of contraception (failure rate of <1% per year when used consistently and correctly) for 30 days after the last dose of SER-155.
- Willing to provide written informed consent, comply with the protocol, and understand the potential risks and benefits of study enrollment and treatment.
Who cannot join
- Active GI infection, including untreated viral, bacterial or fungal cause(s) of diarrhea.
- Received immunosuppressive therapies for suspected or confirmed irEC, including systemic corticosteroids (either oral or intravenous) and/or infliximab, vedolizumab or ustekinumab
- Grade 3 colitis symptoms, i.e. severe abdominal pain or peritoneal signs
- Admitted to the hospital for irEC
- Prednisone (or steroid equivalent) dose > 10 mg a day for a non-GI irAE at time of screening
- Pre-existing inflammatory bowel disease (e.g. Crohn's disease or ulcerative colitis) or microscopic colitis
Show all 13Show fewer
- Pregnant or lactating women
- Any condition that requires ongoing prophylactic or therapeutic antibacterial antibiotics
- Severe neutropenia, as defined by an absolute neutrophil count (ANC) < 500 cells/mm^3, at time of screening
- Treatment with investigational medications used for diarrhea/colitis treatment and microbiome therapeutics within 30 days prior to enrollment
- Known allergy or intolerance to oral vancomycin
- Unable to comply with the protocol requirements
- Any condition that in the opinion of the investigator may increase the risk of study participation and/or may interfere with the interpretation of study results
Trial locations and contacts
7 sites in 1 country. Contact the study team or a site near you to ask about taking part.
7 sites in 1 country
United States7 sites, 7 recruiting
- Recruiting
Memoral Sloan Kettering at Basking Ridge (Limited Protocol Activities)
Basking Ridge, New Jersey, 07920
David Faleck, MD, 212-639-8286
- Recruiting
Memorial Sloan Kettering Suffolk-Commack (Limited protocol activity)
Commack, New York, 11725
David Faleck, MD, 212-639-8286
- Recruiting
Memorial Sloan Kettering Westchester (Limited Protocol Activities)
Harrison, New York, 10604
David Faleck, MD, 212-639-8286
- Recruiting
Memorial Sloan Kettering Monmouth (All Protocol Activities)
Middletown, New Jersey, 07748
David Faleck, MD, 212-639-8286
- Recruiting
Memorial Sloan Kettering Bergen (All Protocol Activities)
Montvale, New Jersey, 07645
David Faleck, MD, 212-639-8286
- Recruiting
Memorial Sloan Kettering Cancer Center (All Protocol Activities)
New York, New York, 10065
David Faleck, MD, 212-639-8286
- Recruiting
Memorial Sloan Kettering Nassau (Limited protocol activities)
Rockville Centre, New York, 11553
David Faleck, MD, 212-639-8286
About this study
Official title: A Single-Arm, Open-Label, Phase 1 Study to Assess Safety and Preliminary Efficacy of Cultivated Multi-Strain Live Bacterial Therapeutic SER-155 for First-Line Treatment of Immunotherapy-Related Enterocolitis
The purpose of this study is to find out whether SER-155 may be a safe first treatment that causes few or mild side effects for people due to irEC.
- Conditions
- Diarrhea, Enterocolitis
- Being tested
- SER-155
- Keywords
- Diarrhea, SER-155, Enterocolitis, Memorial Sloan Kettering Cancer Center, 24-231
- Medical subject headings
- Diarrhea, Enterocolitis
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
SER-155Biological
Also called Cultivated Multi-Strain Live Bacterial Therapeutic, Encapsulated
SER-155 (Cultivated Multi-Strain Live Bacterial Therapeutic, Encapsulated) is an experimental designed ecology of 16 unique, human-commensal bacterial strains encapsulated for oral administration and will be provided by Seres as an investigational drug
| Study group | Role | What they receive |
|---|---|---|
| Participants with Immune checkpoint inhibitor-related enterocolitis (irEC) | Experimental | Participants with grade 2-3 diarrhea from irEC who have not yet received immunosuppressive therapy for irEC Receives: Biological: SER-155 |
What is being measured
The primary outcome is the main question the study is designed to answer.
Proportion of participants with treatment-related adverse events of special interest
Proportion of participants with treatment-related adverse events of special interest, i.e. blood stream infection
Measured: 1 year
Proportion of patients with treatment-related adverse events
Proportion of patients with treatment-related adverse events
Measured: 1 year
Secondary outcomes (8)
Proportion of patients with immunosuppressive-free clinical response of irEC (immunotherapy-related enterocolitis) at day 15
Proportion of patients with immunosuppressive-free clinical response of irEC (immunotherapy-related enterocolitis) at day 15, defined as at least one grade decrease in diarrhea symptoms without the use of immunosuppressive therapy
Measured: Day 15
Proportion of patients with immunosuppressive-free clinical remission of irEC at day 15
Proportion of patients with immunosuppressive-free clinical remission of irEC at day 15, defined as resolution in diarrhea symptoms (grade 0) without the use of immunosuppressive therapy
Measured: Day 15
Proportion of patients with immunosuppressive-free clinical response of irEC at day 43
Proportion of patients with immunosuppressive-free clinical response of irEC at day 43
Measured: Day 43
Proportion of patients with immunosuppressive-free clinical remission of irEC at day 43
Proportion of patients with immunosuppressive-free clinical remission of irEC at day 43
Measured: Day 43
Time to immunosuppressive-free clinical response
Time to immunosuppressive-free clinical response
Measured: 1 year
Time to immunosuppressive-free clinical remission
Time to immunosuppressive-free clinical remission
Measured: 1 year
Number of detectable SER-155 strains at day 15
Number of detectable SER-155 strains at day 15
Measured: Day 15
Number of detectable SER-155 strains at day 43
Number of detectable SER-155 strains at day 43
Measured: Day 43
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted30 Jan 2025
- Study start24 Jan 2025
- Primary completion24 Jan 2027 (estimated)
- Study completion24 Jan 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for DiarrheaStudies of the same condition, open and under way.
- More trials run by Memorial Sloan Kettering Cancer CenterThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 1
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Enrolment
- 15 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Memorial Sloan Kettering Cancer Center
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
- Investigators
- David Faleck, MD, Principal investigator, Memorial Sloan Kettering Cancer Center
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06801067
- Sponsor's protocol ID
- 24-231
- Status last verified
- Jul 2026
- First submitted
- 24 Jan 2025
- Last updated
- 28 Jul 2026
- Results posted
- No
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- Yes: Memorial Sloan Kettering Cancer Center supports the international committee of medical journal editors (ICMJE) and the ethical obligation of responsible sharing of data from clinical trials. The protocol summary, a statistical summary, and informed consent form will be made available on clinicaltrials.gov when required as a condition of Federal awards, other agreements supporting the research and/or as otherwise required. Requests for deidentified individual participant data can be made beginning 12 months after publication and for up to 36 months post publication. Deidentified individual participant data reported in the manuscript will be shared under the terms of a Data Use Agreement and may only be used for approved proposals. Requests may be made to: crdatashare@mskcc.org.
Study at a glance
From the registry record, last updated by the sponsor on 28 Jul 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- A Single-Arm, Open-Label, Phase 1 Study to Assess Safety and Preliminary Efficacy of Cultivated Multi-Strain Live Bacterial Therapeutic SER-155 for First-Line Treatment of Immunotherapy-Related Enterocolitis
- ClinicalTrials.gov ID
- NCT06801067
- Acronym / sponsor ID
- 24-231
- Conditions
- Diarrhea, Enterocolitis
- Keywords
- Diarrhea, SER-155, Enterocolitis, Memorial Sloan Kettering Cancer Center, 24-231
- Phase
- Phase 1
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 15 participants (estimated)
- Lead sponsor
- Memorial Sloan Kettering Cancer CenterUniversity, hospital or other
- Study start
- 24 Jan 2025 (actual)
- Primary completion
- 24 Jan 2027 (estimated)
- Study completion
- 24 Jan 2027 (estimated)
- First posted
- 30 Jan 2025 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The purpose of this study is to find out whether SER-155 may be a safe first treatment that causes few or mild side effects for people due to irEC.
Study design
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Participants with Immune checkpoint inhibitor-related enterocolitis (irEC) | Experimental | Biological: SER-155Participants with grade 2-3 diarrhea from irEC who have not yet received immunosuppressive therapy for irEC |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (8 listed)
- Age > 18 years
- Receipt of ICI (single-agent or combination) within the 180 days preceding screening.
- Concurrent treatment with cytotoxic chemotherapy or other tumor-directed agents is permitted.
- Grade 2 - 3 diarrhea (i.e., increase of at least 4 bowel movements a day above baseline during the screening window), deemed by the treating provider as likely related to ICI therapy, with or without concomitant symptoms of grade 1 - 2 colitis (e.g.
- abdominal pain, bloody or mucoid stools)
Key exclusion criteria (13 listed)
- Active GI infection, including untreated viral, bacterial or fungal cause(s) of diarrhea.
- Received immunosuppressive therapies for suspected or confirmed irEC, including systemic corticosteroids (either oral or intravenous) and/or infliximab, vedolizumab or ustekinumab
- Grade 3 colitis symptoms, i.e. severe abdominal pain or peritoneal signs
- Admitted to the hospital for irEC
- Prednisone (or steroid equivalent) dose > 10 mg a day for a non-GI irAE at time of screening
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| SER-155Also: Cultivated Multi-Strain Live Bacterial Therapeutic, EncapsulatedSER-155 (Cultivated Multi-Strain Live Bacterial Therapeutic, Encapsulated) is an experimental designed ecology of 16 unique, human-commensal bacterial strains encapsulated for oral administration and will be provided by Seres as an investigational drug | Biological | Participants with Immune checkpoint inhibitor-related enterocolitis (irEC) |
Primary outcome
Proportion of participants with treatment-related adverse events of special interest
Time frame: 1 year
Proportion of participants with treatment-related adverse events of special interest, i.e. blood stream infection
Proportion of patients with treatment-related adverse events
Time frame: 1 year
Proportion of patients with treatment-related adverse events
8 secondary outcomes
Proportion of patients with immunosuppressive-free clinical response of irEC (immunotherapy-related enterocolitis) at day 15
Time frame: Day 15
Proportion of patients with immunosuppressive-free clinical remission of irEC at day 15
Time frame: Day 15
Proportion of patients with immunosuppressive-free clinical response of irEC at day 43
Time frame: Day 43
Proportion of patients with immunosuppressive-free clinical remission of irEC at day 43
Time frame: Day 43
Time to immunosuppressive-free clinical response
Time frame: 1 year
Time to immunosuppressive-free clinical remission
Time frame: 1 year
Number of detectable SER-155 strains at day 15
Time frame: Day 15
Number of detectable SER-155 strains at day 43
Time frame: Day 43
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 28 Jul 2026.
- Memorial Sloan Kettering Cancer CenterLink provided by the sponsor.
- Individual participant dataSharing planned: Yes. Memorial Sloan Kettering Cancer Center supports the international committee of medical journal editors (ICMJE) and the ethical obligation of responsible sharing of data from clinical trials. The protocol summary, a statistical summary, and informed consent form will be made available on clinicaltrials.gov when required as a condition of Federal awards, other agreements supporting the research and/or as otherwise required. Requests for deidentified individual participant data can be made beginning 12 months after publication and for up to 36 months post publication. Deidentified individual participant data reported in the manuscript will be shared under the terms of a Data Use Agreement and may only be used for approved proposals. Requests may be made to: crdatashare@mskcc.org.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
David Faleck, MD principal investigator
Memorial Sloan Kettering Cancer Center
7 sites in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 1 study testing SER-155 in people with Diarrhea and Enterocolitis, run by Memorial Sloan Kettering Cancer Center at 7 sites in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 8 inclusion and 13 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 28 Jul 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 7 sites in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Phase 1 studies test a treatment in a small group of people for the first time or in a new way, mainly to check safety and find the right dose.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact David Faleck, MD (212-639-8286, faleckd@mskcc.org), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Proportion of participants with treatment-related adverse events of special interest (time frame: 1 year). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 28 Jul 2026.