A Study of SER-155 to Treat Diarrhea in People on Immunotherapy

Phase 1

Recruiting

• Conditions: Diarrhea; Enterocolitis
• Interventions: Biological: SER-155

• Registration Number: NCT06801067
• Lead Sponsor: Memorial Sloan Kettering Cancer Center

Brief 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.

Detailed Description

Not available

Study Timeline

• Study Start: 2025-01-24
• Study First Submitted: 2025-01-24
• Study First Submitted QC: 2025-01-24
• Study First Posted: 2025-01-30
• Status Verified: 2025-03
• Last Update Submitted: 2025-03-03
• Last Update Posted: 2025-03-04
• Primary Completion: 2027-01-24
• Study Completion: 2027-01-24

Recruitment & Eligibility

• Status: RECRUITING
• Sex: All
• Target Recruitment: 15

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

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: SINGLE_GROUP

Arm && Interventions

Group	Intervention	Description
Participants with Immune checkpoint inhibitor-related enterocolitis (irEC)	SER-155	Participants with grade 2-3 diarrhea from irEC who have not yet received immunosuppressive therapy for irEC

Primary Outcome Measures

Name	Time	Method
Proportion of participants with treatment-related adverse events of special interest	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	1 year	Proportion of patients with treatment-related adverse events

Secondary Outcome Measures

Name	Time	Method
Proportion of patients with immunosuppressive-free clinical response of irEC (immunotherapy-related enterocolitis) at day 15	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
Proportion of patients with immunosuppressive-free clinical remission of irEC at day 15	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
Proportion of patients with immunosuppressive-free clinical response of irEC at day 43	Day 43	Proportion of patients with immunosuppressive-free clinical response of irEC at day 43
Proportion of patients with immunosuppressive-free clinical remission of irEC at day 43	Day 43	Proportion of patients with immunosuppressive-free clinical remission of irEC at day 43
Time to immunosuppressive-free clinical response	1 year	Time to immunosuppressive-free clinical response
Time to immunosuppressive-free clinical remission	1 year	Time to immunosuppressive-free clinical remission
Number of detectable SER-155 strains at day 15	Day 15	Number of detectable SER-155 strains at day 15
Number of detectable SER-155 strains at day 43	Day 43	Number of detectable SER-155 strains at day 43

Trial Locations

Locations (7)

Memoral Sloan Kettering at Basking Ridge (Limited Protocol Activities); 🇺🇸 Basking Ridge, New Jersey, United States

Memorial Sloan Kettering Monmouth (All Protocol Activities); 🇺🇸 Middletown, New Jersey, United States

Memorial Sloan Kettering Bergen (All Protocol Activities); 🇺🇸 Montvale, New Jersey, United States

Memorial Sloan Kettering Suffolk-Commack (Limited protocol activity); 🇺🇸 Commack, New York, United States

Memorial Sloan Kettering Westchester (Limited Protocol Activities); 🇺🇸 Harrison, New York, United States

Memorial Sloan Kettering Cancer Center (All Protocol Activities); 🇺🇸 New York, New York, United States

Memorial Sloan Kettering Nassau (Limited protocol activities); 🇺🇸 Rockville Centre, New York, United States