Observational Study of Gut Microbiota in Abemaciclib-Treated Patients With and Without Diarrhea

NCT07264998 | Not Yet Recruiting

• 1 other identifier: LLHBCH2025YN-088
• Study Type: observational
• Target: 60
• Locations: 1 country
• Sites: 1

Brief Summary

Why is this study being done? Many patients with a type of breast cancer (called HR-positive) take a medicine called Abemaciclib. While this medicine is effective, a very common side effect is diarrhea, which can be severe enough to disrupt treatment and reduce quality of life. The reason why some patients get diarrhea and others do not is not well understood. This study aims to investigate whether the natural bacteria living in the gut (known as the gut microbiome) play a role in this side effect. Researchers will compare the gut bacteria of patients who develop diarrhea with those who do not. What will happen in the study? This is an observational study, which means that patients will receive their normal cancer treatment and will not be given any new or experimental drugs as part of this initial phase.

• Patients who are already being treated with Abemaciclib will be invited to join.
• They will be placed into one of two groups: those who experience diarrhea and those who do not.
• Participants will be asked to provide stool (feces) samples and may also provide optional blood samples at specific times during their treatment.
• Researchers will analyze these samples in the lab to study the types and functions of the gut bacteria. Who can participate?
• Adult women (aged 18-75) diagnosed with HR-positive breast cancer.
• Currently receiving treatment with Abemaciclib for at least 2 weeks.
• Must be willing to provide informed consent and follow the study procedures. What are the potential benefits? Participants will not receive any direct medical benefit from taking part in this study. However, the information learned may help researchers better understand why diarrhea occurs and, in the future, could lead to new ways to prevent or treat this side effect for other cancer patients. How is privacy protected? All personal information and samples collected will be de-identified using a unique code. This means that the data used for analysis cannot be directly linked back to the participant's identity. All data is stored securely according to strict ethical guidelines.

Conditions

Breast Neoplasms; Hormone Receptor-Positive Breast Cancer; Abemaciclib; Abemaciclib-related Diarrhea; Drug-induced Diarrhea; Gastrointestinal Microbiome (Focus); Microbiome

Keywords

Abemaciclib; Hormone receptor-positive breast cancer; Drug-induced diarrhea; Microbiome; Gastrointestinal microbiome; Microbiome biomarkers; Abemaciclib-related diarrhea

Outcome Measures

Primary Outcomes (2)

• Difference in gut microbiota beta diversity

  Beta diversity of the gut microbiome (e.g., Weighted UniFrac distance) will be compared between the diarrhea group and the non-diarrhea group to assess overall microbial community structure differences.

  Through study completion, an average of 6 months.

• Identification of specific bacterial species enriched in non-diarrhea group

  Metagenomic sequencing data will be analyzed (e.g., using LEfSe) to identify bacterial species that are significantly enriched in the non-diarrhea group compared to the diarrhea group (LDA Score \> 2, p-value \< 0.05).

  Through study completion, an average of 6 months.

Secondary Outcomes (4)

• Difference in gut microbiota alpha diversity

  Through study completion, an average of 6 months.

• Difference in metagenomic functional pathways

  Through study completion, an average of 6 months.

• Differential metabolites in serum

  Through study completion, an average of 6 months.

• Difference in systemic inflammatory cytokine levels

  Through study completion, an average of 6 months.

Other Outcomes (1)

• Predictive potential of baseline gut microbiota

  Through study completion, an average of 6 months.

Study Arms (2)

Abema-Diarrhea

HR-positive breast cancer patients who develop diarrhea (Grade 1 or higher as per CTCAE v5.0 criteria) during treatment with Abemaciclib. This group will not receive any investigational intervention as part of the observational study. Fecal and blood samples will be collected for microbiome and biomarker analysis.

Abema-NoDiarrhea

HR-positive breast cancer patients who do not develop diarrhea (Grade 0 as per CTCAE v5.0 criteria) during treatment with Abemaciclib. This group serves as the control cohort and will not receive any investigational intervention as part of the observational study. Fecal and blood samples will be collected for microbiome and biomarker analysis.

Eligibility Criteria

• Age: 18 Years - 75 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)
• Sampling Method: Non-Probability Sample

Study Population

This study will enroll a prospective cohort of female patients with hormone receptor-positive (HR⁺) breast cancer who are receiving treatment with Abemaciclib (as monotherapy or in combination) as part of their standard clinical care at Hubei Cancer Hospital. Participants will be prospectively assigned into two groups based on the presence or absence of drug-induced diarrhea, as defined by CTCAE v5.0 criteria: the Diarrhea Group and the Non-Diarrhea (Control) Group. The study involves the collection of clinical data, fecal samples, and optional blood samples for microbiome and biomarker analysis. No investigational intervention is administered in this phase of the study.

You may qualify if:

• Aged 18 to 75 years.
• Diagnosed with hormone receptor-positive (HR⁺) breast cancer.
• Currently receiving treatment with Abemaciclib (either as monotherapy or in combination with endocrine therapy) for a duration of at least 2 weeks.
• Willing and able to provide written informed consent for participation in the study.

You may not qualify if:

• History of major gastrointestinal diseases, such as inflammatory bowel disease, Crohn's disease, ulcerative colitis, or intestinal obstruction, or having undergone major gastrointestinal surgery.
• Recent use (within 1 month) of antibiotics, probiotics, or traditional Chinese medicine that may alter gut function.
• Pregnant or lactating women.
• Unwilling to provide informed consent or considered by the investigator to be unsuitable for the study for any other reason.

Sponsors & Collaborators

• Hubei Cancer Hospital: lead

Study Sites (1)

Hubei Cancer Hospital

Wuhan, Hubei, 430079, China

Location

Biospecimen

Retention: SAMPLES WITH DNA

This study will retain the following types of biospecimens for future research: Fecal Samples: Approximately 5 grams of fresh stool will be collected from each participant using sterile containers. Samples will be stored at -80°C and may be used for DNA extraction, metagenomic sequencing, and other microbiome analyses. Blood Samples: Approximately 5 mL of peripheral blood will be collected via venipuncture. Serum will be separated, aliquoted, and stored at -80°C for potential future analyses, including metabolomic profiling, inflammatory cytokine measurement (e.g., IL-6, TNF-α, CRP), and other biomarker studies. All biospecimens will be de-identified and labeled with a unique study code to ensure participant confidentiality. Samples may be used to extract DNA and for other molecular analyses related to understanding the relationship between gut microbiota and drug-induced diarrhea.

MeSH Terms

Conditions

Breast Neoplasms

Condition Hierarchy (Ancestors)

Neoplasms by Site; Neoplasms; Breast Diseases; Skin Diseases; Skin and Connective Tissue Diseases

Central Study Contacts

Xinhong Wu Principal Investigator

CONTACT

18602726300; wuxinhong_9@sina.com

Study Design

• Study Type: observational
• Observational Model: COHORT
• Time Perspective: PROSPECTIVE
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: vice-president

Study Record Dates

• First Submitted: November 24, 2025
• First Posted: December 4, 2025
• Study Start: December 1, 2025
• Primary Completion (Estimated): June 1, 2026
• Study Completion (Estimated): July 1, 2026
• Last Updated: December 4, 2025

Record last verified: 2025-10

Data Sharing

• IPD Sharing: Will not share

Locations

CN (1)