NCT06801067 · Memorial Sloan Kettering Cancer Center
A Study of SER-155 to Treat Diarrhea in People on Immunotherapy
What this study is about
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.
View original scientific description
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.
Who can participate
This study lists these criteria on ClinicalTrials.gov. A study coordinator reviews eligibility during screening — this page does not determine whether you qualify.
Inclusion criteria
- 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.
Exclusion criteria
- 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
- 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
Where
- Basking Ridge, New Jersey
- Middletown, New Jersey
- Montvale, New Jersey
- Commack, New York
- Harrison, New York
- New York, New York
- Rockville Centre, New York
Frequently asked questions
What is a clinical trial?
A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.
Is it safe to participate?
Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.
Will I be compensated?
Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.
Will I receive a placebo instead of treatment?
When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.
Can I leave a trial if I change my mind?
Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.
How long does a clinical trial last?
Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.
Data: ClinicalTrials.gov · synced Dec 2, 2025 · Source of record for eligibility and locations