This study aims to evaluate the efficacy and safety of probiotics for the prevention of diarrhea in patients with breast cancer receiving the tyrosine kinase inhibitor (TKI) Neratinib. Study Design: This is a prospective, randomized controlled clinical trial. Participants will be randomly assigned to either a probiotics intervention group or a placebo-controlled group. Both groups will receive prophylactic loperamide according to the FDA-recommended dosing schedule for neratinib-associated diarrhea. Primary Objective: To evaluate the efficacy of probiotics in reducing the incidence and severity of diarrhea in patients receiving Neratinib. Secondary Objectives: This study will also investigate the effects of probiotics on gut microbiota composition and their potential impact on drug efficacy. Study Duration: Enrollment is planned from August 2025 to June 2027 at Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University. Both the intervention and control groups will receive treatment for a total of six weeks (two cycles of three weeks each). No post-treatment observation period is included. Eligibility Criteria: Participants must be diagnosed with HER2-positive breast cancer and scheduled to receive Neratinib. Exclusion criteria include patients with severe gastrointestinal disorders or recent probiotic consumption.
Breast cancer patients treated with the tyrosine kinase inhibitor (TKI) Neratinib often experience severe diarrhea, leading to treatment interruptions, dose reductions, or discontinuation. Emerging evidence highlights the role of gut microbiota in drug metabolism and gastrointestinal toxicity. Probiotics have been proposed as a potential intervention to modulate gut microbiota and mitigate diarrhea; however, their efficacy in preventing Neratinib-induced diarrhea remains inconclusive. This randomized, double-blind, placebo-controlled clinical trial aims to evaluate the efficacy and safety of probiotics in preventing diarrhea in HER2-positive breast cancer patients receiving Neratinib. The study will also explore the impact of probiotics on gut microbiota composition and potential microbiome-mediated mechanisms that may enhance treatment adherence and therapeutic outcomes. Participants will be randomly assigned in a 1:1 ratio to either a probiotics group or a placebo group. Both groups will receive prophylactic loperamide in accordance with the dosing schedule recommended by the U.S. Food and Drug Administration (FDA) for the prevention of Neratinib-associated diarrhea, ensuring consistency with the approved prescribing information. Participants will receive treatment for a total of six weeks, corresponding to two treatment cycles. Metagenomic sequencing and targeted metabolomics will be performed on stool samples to investigate gut microbial composition and metabolic changes. Additional analyses will assess the association between gut-derived metabolites and immune cell activation, aiming to elucidate potential interactions among gut microbiota, metabolites, and immune responses. Sun Yat-sen Memorial Hospital will serve as the coordinating center for this planned multicenter trial. Currently, it is the only active site, and additional participating centers will be added progressively as they are initiated.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
TREATMENT
Masking
QUADRUPLE
Enrollment
308
Participants in this group will receive a daily dose of probiotics as an adjunct to standard Neratinib therapy. The probiotics will be administered orally as a granule formulation dissolved in water, for a total duration of 6 weeks (two treatment cycles). Loperamide will be administered prophylactically according to the FDA-recommended schedule to prevent Neratinib-associated diarrhea. The aim is to assess the efficacy of probiotics in reducing Neratinib-induced diarrhea and improving quality of life.
Participants in this group will receive a daily dose of a placebo that is identical in appearance, taste, and administration method to the probiotic granules, in addition to standard Neratinib therapy. The placebo will be administered orally as a granule formulation dissolved in water, for a total duration of 6 weeks. Loperamide will also be administered prophylactically to all participants in accordance with FDA recommendations. This group will serve as a control to evaluate the true effect of probiotics on Neratinib-induced diarrhea.
All participants will receive prophylactic loperamide to reduce the risk of Neratinib-induced diarrhea. Loperamide will be administered according to the FDA-recommended schedule: 4 mg TID for the first 14 days of treatment, then 4 mg BID from Day 15 to Day 42. This intervention is implemented as a standard supportive therapy and not as a randomized variable.
Breast Tumor Center, Sun Yat-sen Memorial Hospital, Sun Yat-sen University
Guangzhou, Guangdong, China
RECRUITINGIncidence of Grade ≥3 Diarrhea
The incidence of grade 3 or higher diarrhea during the 6-week treatment period, assessed using the Common Terminology Criteria for Adverse Events (CTCAE) version 5.0.
Time frame: Up to 6 weeks
Incidence of Any Grade Diarrhea
The incidence of diarrhea of any grade during the 6-week treatment period, assessed according to the Common Terminology Criteria for Adverse Events (CTCAE), version 5.0.
Time frame: Up to 6 weeks
Duration of First Episode of Grade 3 Diarrhea
The duration (in days) of the first episode of grade 3 diarrhea experienced by participants during the 6-week treatment period, assessed using the Common Terminology Criteria for Adverse Events (CTCAE), version 5.0. Duration is defined from onset to recovery (downgrade to grade ≤2).
Time frame: Up to 6 weeks
Proportion of Participants Hospitalized Due to Diarrhea
The proportion of participants who require hospitalization due to diarrhea-related complications during the treatment period.
Time frame: Up to 6 weeks
Loperamide Usage Patterns
Frequency, total dosage, and compliance of loperamide use during the treatment period, including any dose modifications or discontinuation. Data will be collected through medication records and patient diaries.
Time frame: Up to 6 weeks
Change from Baseline in Overall Quality of Life Assessed by EORTC QLQ-C30
Changes in quality of life assessed using the EORTC QLQ-C30 questionnaire. The tool evaluates overall health status and functioning, including physical, role, emotional, cognitive, and social domains. Higher scores in functional and global health scales indicate better quality of life, while higher scores in symptom scales indicate greater symptom burden.
Time frame: Baseline, Weeks 2, 4, and 6 (End of Study)
Change from Baseline in Diarrhea-Related Quality of Life Assessed by FACT-D
Changes in diarrhea-related quality of life assessed using the FACT-D subscale of the Functional Assessment of Cancer Therapy system. This tool specifically evaluates the severity and impact of diarrhea symptoms on patients' daily life and well-being. Higher scores indicate fewer symptoms and better diarrhea-related quality of life.
Time frame: Baseline, Weeks 2, 4, and 6 (End of Study)
Incidence of Treatment-Related Adverse Events (AEs)
The incidence of treatment-related adverse events (AEs) in participants receiving probiotics plus Neratinib versus the control group. AEs, including nausea, allergic reactions, and other related symptoms, will be assessed according to the Common Terminology Criteria for Adverse Events (CTCAE), version 5.0.
Time frame: Up to 6 weeks
Incidence of Serious Adverse Events (SAEs)
The incidence of serious adverse events (SAEs) associated with probiotics or Neratinib treatment. SAEs, including severe allergic reactions, life-threatening complications, or hospitalizations, will be recorded and summarized to assess potential safety concerns.
Time frame: Up to 6 weeks
Rate of Treatment Discontinuation Due to Adverse Events
The proportion of participants who discontinue Neratinib treatment due to adverse events. The outcome will compare discontinuation rates between the probiotic and placebo groups to evaluate tolerability.
Time frame: Up to 6 weeks
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