Breast CancerMICRO-VERZNCT07406594
Gut Microbiome Changes During Abemaciclib Therapy in Breast Cancer
A study testing Resistant Potato Starch in people with Breast Cancer and HER-2 Positive Breast Cancer, run by University of Vermont Medical Center at 1 site in United States.
Trial summary
Abemaciclib (Verzenio) is a commonly used treatment for hormone receptor-positive breast cancer, but it can cause gastrointestinal side effects such as diarrhea, which may affect quality of life and treatment tolerance. Read more about this study
- Who is it for?
- Ages 18 years and older, women only
- Conditions the study is for
- Breast Cancer, HER-2 Positive Breast Cancer
- What is being tested?
- Resistant Potato Starch
- Type of treatment
- Pill or oral medicine
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 12 participants
- Where
- 1 siteUnited States
- Study dates
- Oct 2027to Oct 2031
- Phase
- Interventional
- 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
- Women only
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Age ≥ 18 years.
- Histologically confirmed hormone receptor-positive, HER2-negative breast cancer.
- Planned initiation of adjuvant abemaciclib (Verzenio) as part of standard clinical care, with enrollment occurring prior to or within 7 days of starting abemaciclib.
- Eastern Cooperative Oncology Group (ECOG) performance status of 0-2.
- Women of child-bearing potential must agree to use contraception prior to study entry, for the duration of study participation, and for 90 days following completion of study participation. Should a woman become pregnant or suspect she is pregnant while participating in this study, she should inform her treating physician immediately.
- A female of child-bearing potential is any woman (regardless of sexual orientation, having undergone a tubal ligation, or remaining celibate by choice) who meets the following criteria:
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- Has not undergone a hysterectomy or bilateral oophorectomy; or
- Has not been naturally postmenopausal for at least 12 consecutive months (i.e., has had menses at any time in the preceding 12 consecutive months).
- Ability to understand and the willingness to sign a written informed consent.
Who cannot join
- Concurrent participation in another interventional clinical trial that, in the opinion of the investigator, would interfere with study participation or interpretation of results.
- Known gastrointestinal conditions that would significantly interfere with study procedures or interpretation of results, including but not limited to inflammatory bowel disease, short bowel syndrome, or chronic diarrheal disorders.
- Known allergy or intolerance to resistant starch or any component of the study supplement.
- Pregnant or breastfeeding individuals.
- Any medical, psychiatric, or social condition that, in the judgment of the investigator, would limit the participant's ability to comply with study procedures.
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
United States1 site
University of Vermont
Burlington, Vermont, 05401
Tracy Smith, PhD, 1 (802) 656-2021
About this study
Official title: MICRO-VERZ: MICRObiome Changes During VERZenio Therapy
Abemaciclib (Verzenio) is a commonly used treatment for hormone receptor-positive breast cancer, but it can cause gastrointestinal side effects such as diarrhea, which may affect quality of life and treatment tolerance. The gut microbiome, which is the collection of bacteria living in the digestive tract, may play a role in these symptoms.
The purpose of this study is to examine how the gut microbiome changes during the early phase of abemaciclib treatment and how these changes relate to gastrointestinal symptoms experienced by patients. Participants will provide stool samples at multiple time points using mailed collection kits and will complete questionnaires about gastrointestinal symptoms while receiving standard-of-care abemaciclib therapy. All study procedures will be conducted remotely.
Information gained from this study may help inform future supportive care strategies for breast cancer patients receiving abemaciclib.
- Conditions
- Breast Cancer, HER-2 Positive Breast Cancer
- Being tested
- Resistant Potato Starch, Placebo control
- Keywords
- microbiome
- Medical subject headings
- Breast Neoplasms
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Resistant Potato StarchDietary supplement
Participants randomized to the resistant starch intervention will receive a resistant starch dietary supplement administered orally. The supplement will be taken during early abemaciclib therapy according to study instructions. Abemaciclib is administered as standard of care and is not altered by study participation.
Placebo controlDietary supplement
Participants randomized to the placebo intervention will receive a placebo dietary supplement administered orally as a powder mixed with a beverage. The supplement will be taken during early abemaciclib therapy according to study instructions. Abemaciclib is administered as standard of care and is not altered by study participation.
| Study group | Role | What they receive |
|---|---|---|
| Resistant Starch Intervention | Experimental | Participants randomized to this arm will receive resistant starch powder as a dietary supplement during early abemaciclib therapy. The supplement will be taken orally as a powder mixed with a beverage, according to instructions provided. Participants will continue to receive abemaciclib as standard of care and will complete study procedures including stool sample collection and symptom questionnaires. Receives: Dietary Supplement: Resistant Potato Starch |
| Placebo Supplementation (Control Arm) | Placebo comparator | Participants randomized to this arm will receive a placebo powder as a dietary supplement during early abemaciclib therapy. The placebo will be taken orally as a powder mixed with a beverage, according to instructions provided. Participants will continue to receive abemaciclib as standard of care and will complete study procedures including stool sample collection and symptom questionnaires. Receives: Dietary Supplement: Placebo control |
What is being measured
The primary outcome is the main question the study is designed to answer.
Recruitment rate
Feasibility will be assessed by the proportion of eligible participants who enroll in the study out of those approached for participation.
Measured: From study opening through completion of enrollment (approximately 12 months)
Participant retention
Feasibility and acceptability will be assessed by the proportion of enrolled participants who complete the intervention period and final study assessments.
Measured: Through end of intervention (6 weeks)
Supplement adherence
Feasibility will be assessed by participant adherence to the assigned supplement, measured as the proportion of prescribed doses taken during the intervention period.
Measured: During the 6-week intervention
Completion of study procedures
Feasibility will be assessed by the proportion of participants who complete protocol-specified stool sample collections and questionnaires.
Measured: Baseline through end of intervention (6 weeks)
Secondary outcomes (3)
Change in Gut Microbial Community Composition During Early Abemaciclib Therapy
Changes in gut microbial community composition will be assessed using stool samples collected at baseline and during early abemaciclib therapy. Microbiome profiles will be compared over time and between intervention groups to characterize longitudinal changes associated with treatment.
Measured: Baseline through Week 6 of abemaciclib therapy
Correlation between gut microbiome diversity and gastrointestinal symptom severity
Correlation between gut microbiome alpha diversity measured from stool samples using 16S rRNA gene sequencing (Shannon diversity index, unitless) and gastrointestinal symptom severity measured using the Patient-Reported Outcomes version of the Common Terminology Criteria for Adverse Events (PRO-CTCAE) gastrointestinal symptom items (score range 0-4 per item). Correlation coefficients will be calculated to assess the relationship between microbiome diversity and symptom severity during early abemaciclib therapy.
Measured: Baseline through Week 6 of abemaciclib therapy
Differences in Gut Microbial Community Composition Between Resistant Starch and Placebo Groups
Differences in gut microbial community composition and temporal patterns will be explored between participants randomized to resistant starch supplementation and those receiving placebo using stool samples collected at multiple time points during early abemaciclib therapy.
Measured: Baseline through Week 6 of abemaciclib therapy
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted12 Feb 2026
- Study startOct 2027 (estimated)
- Primary completionOct 2031 (estimated)
- Study completionOct 2031 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Breast CancerStudies of the same condition, open and under way.
- 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 N/A
- Primary purpose
- Supportive care
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Single blind
- Who is masked
- Participant
- Enrolment
- 12 participants (estimated)
Sponsor and investigators
- Lead sponsor
- University of Vermont Medical Center
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Tracy Smith, University of Vermont Medical Center
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07406594
- Sponsor's protocol ID
- MICRO-VERZ
- Acronym
- MICRO-VERZ
- Status last verified
- Feb 2026
- First submitted
- 27 Jan 2026
- Last updated
- 12 Feb 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Undecided
Study at a glance
From the registry record, last updated by the sponsor on 12 Feb 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- MICRO-VERZ: MICRObiome Changes During VERZenio Therapy
- ClinicalTrials.gov ID
- NCT07406594
- Acronym / sponsor ID
- MICRO-VERZ / MICRO-VERZ
- Conditions
- Breast Cancer, HER-2 Positive Breast Cancer
- Keywords
- microbiome
- Study type
- Interventional
- Recruitment status
- Not yet recruiting
- Enrolment
- 12 participants (estimated)
- Lead sponsor
- University of Vermont Medical CenterUniversity, hospital or other
- Study start
- Oct 2027 (estimated)
- Primary completion
- Oct 2031 (estimated)
- Study completion
- Oct 2031 (estimated)
- First posted
- 12 Feb 2026 (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.
Abemaciclib (Verzenio) is a commonly used treatment for hormone receptor-positive breast cancer, but it can cause gastrointestinal side effects such as diarrhea, which may affect quality of life and treatment tolerance. The gut microbiome, which is the collection of bacteria living in the digestive tract, may play a role in these symptoms.
The purpose of this study is to examine how the gut microbiome changes during the early phase of abemaciclib treatment and how these changes relate to gastrointestinal symptoms experienced by patients. Participants will provide stool samples at multiple time points using mailed collection kits and will complete questionnaires about gastrointestinal symptoms while receiving standard-of-care abemaciclib therapy. All study procedures will be conducted remotely.
Information gained from this study may help inform future supportive care strategies for breast cancer patients receiving abemaciclib.
Study design
- Primary purpose
- Supportive care
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Single blind (participant)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Resistant Starch Intervention | Experimental | Dietary Supplement: Resistant Potato StarchParticipants randomized to this arm will receive resistant starch powder as a dietary supplement during early abemaciclib therapy. The supplement will be taken orally as a powder mixed with a beverage, according to instructions provided. Participants will continue to receive abemaciclib as standard of care and will complete study procedures including stool sample collection and symptom questionnaires. |
| Placebo Supplementation (Control Arm) | Placebo comparator | Dietary Supplement: Placebo controlParticipants randomized to this arm will receive a placebo powder as a dietary supplement during early abemaciclib therapy. The placebo will be taken orally as a powder mixed with a beverage, according to instructions provided. Participants will continue to receive abemaciclib as standard of care and will complete study procedures including stool sample collection and symptom questionnaires. |
Who may qualify
- Ages
- 18 years and older
- Sex
- Female only
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (9 listed)
- Age ≥ 18 years.
- Histologically confirmed hormone receptor-positive, HER2-negative breast cancer.
- Planned initiation of adjuvant abemaciclib (Verzenio) as part of standard clinical care, with enrollment occurring prior to or within 7 days of starting abemaciclib.
- Eastern Cooperative Oncology Group (ECOG) performance status of 0-2.
- Women of child-bearing potential must agree to use contraception prior to study entry, for the duration of study participation, and for 90 days following completion of study participation. Should a woman become pregnant or suspect she is pregnant while participating in this study, she should inform her treating physician immediately.
Key exclusion criteria (5 listed)
- Concurrent participation in another interventional clinical trial that, in the opinion of the investigator, would interfere with study participation or interpretation of results.
- Known gastrointestinal conditions that would significantly interfere with study procedures or interpretation of results, including but not limited to inflammatory bowel disease, short bowel syndrome, or chronic diarrheal disorders.
- Known allergy or intolerance to resistant starch or any component of the study supplement.
- Pregnant or breastfeeding individuals.
- Any medical, psychiatric, or social condition that, in the judgment of the investigator, would limit the participant's ability to comply with study procedures.
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 |
|---|---|---|
| Resistant Potato StarchParticipants randomized to the resistant starch intervention will receive a resistant starch dietary supplement administered orally. The supplement will be taken during early abemaciclib therapy according to study instructions. Abemaciclib is administered as standard of care and is not altered by study participation. | Dietary supplement | Resistant Starch Intervention |
| Placebo controlParticipants randomized to the placebo intervention will receive a placebo dietary supplement administered orally as a powder mixed with a beverage. The supplement will be taken during early abemaciclib therapy according to study instructions. Abemaciclib is administered as standard of care and is not altered by study participation. | Dietary supplement | Placebo Supplementation (Control Arm) |
Primary outcome
Recruitment rate
Time frame: From study opening through completion of enrollment (approximately 12 months)
Feasibility will be assessed by the proportion of eligible participants who enroll in the study out of those approached for participation.
Participant retention
Time frame: Through end of intervention (6 weeks)
Feasibility and acceptability will be assessed by the proportion of enrolled participants who complete the intervention period and final study assessments.
Supplement adherence
Time frame: During the 6-week intervention
Feasibility will be assessed by participant adherence to the assigned supplement, measured as the proportion of prescribed doses taken during the intervention period.
Completion of study procedures
Time frame: Baseline through end of intervention (6 weeks)
Feasibility will be assessed by the proportion of participants who complete protocol-specified stool sample collections and questionnaires.
3 secondary outcomes
Change in Gut Microbial Community Composition During Early Abemaciclib Therapy
Time frame: Baseline through Week 6 of abemaciclib therapy
Correlation between gut microbiome diversity and gastrointestinal symptom severity
Time frame: Baseline through Week 6 of abemaciclib therapy
Differences in Gut Microbial Community Composition Between Resistant Starch and Placebo Groups
Time frame: Baseline through Week 6 of abemaciclib therapy
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 12 Feb 2026.
- Individual participant dataSharing planned: Undecided
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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.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Resistant Potato Starch in people with Breast Cancer and HER-2 Positive Breast Cancer, run by University of Vermont Medical Center at 1 site 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 9 inclusion and 5 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: opening soon, as of the sponsor's last update on 12 Feb 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site 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. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
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 Tracy Smith, PhD (1 (802) 656-2021, tracy.smith@med.uvm.edu), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Recruitment rate (time frame: From study opening through completion of enrollment (approximately 12 months)). The study lists 4 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 12 Feb 2026.