Metastatic Breast CancerNCT07624617
Fast-Her: Fasting Effects on Breast Cancer Treatment
A study testing Normal Eating and Prolonged Fasting in people with Metastatic Breast Cancer, run by University of Minnesota at 1 site in United States.
Trial summary
We hypothesize that promoting a fasting state will strengthen the anti-cancer effects of PI3K inhibitors in metastatic breast cancer (MBC) treatment. The primary objective of this study is to assess acceptability of prolonged fasting in this population. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Metastatic Breast Cancer
- What is being tested?
- Normal Eating and Prolonged Fasting
- Type of treatment
- Lifestyle or therapy programme
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 15 participants
- Where
- 1 siteUnited States
- Study dates
- 18 May 2026to 1 Jul 2027
- 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
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Age ≥18 years
- Histologically confirmed metastatic breast cancer
- Menopausal or medically ovarian suppressed
- Currently receiving capivasertib therapy (2 tablets twice daily, 4 days per week)
- Stable on current capivasertib regimen for at least 2 weeks
- an ECOG performance status of 0-1
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- BMI ≥25kg/m2
- Able to provide informed consent
- Willing to comply with study procedures including CGM wear, food tracking by mCC app and dietary modifications
- Access to smartphone or tablet for mobile application use
Who cannot join
- Type 1 diabetes mellitus
- Uncontrolled type 2 diabetes (HbA1c >9.0%)
- History of severe hypoglycemia
- Eating disorders or contraindications to fasting
- Pregnancy or breastfeeding
- Significant gastrointestinal disorders affecting food absorption
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- Unable to fast for medical reasons
- Concurrent participation in other dietary intervention studies
- A history of significantly abnormal lab results within 4 weeks of consent date, such as hematologic (Hgb < 10.0, platelets < 100), hepatic (LFTs > 2X nl), renal (Cr > 1.5)
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, 1 recruiting
- Recruiting
University of Minnesota
Minneapolis, Minnesota, 55455
Lisa Chow, MD, MS, 612-625-8934, chow0007@umn.edu
About this study
We hypothesize that promoting a fasting state will strengthen the anti-cancer effects of PI3K inhibitors in metastatic breast cancer (MBC) treatment. The primary objective of this study is to assess acceptability of prolonged fasting in this population.
- Conditions
- Metastatic Breast Cancer
- Being tested
- Normal Eating, Prolonged Fasting
- Keywords
- capivasertib
- Medical subject headings
- Breast Neoplasms
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Normal EatingBehavioural
During the normal eating intervention period, participants will follow their usual eating pattern. Participants will continue their prescribed PI3K inhibitor dosing, with medications taken at standardized times to ensure consistent pharmacokinetic measurements.
Prolonged FastingBehavioural
During the prolonged fasting intervention period, participants will eat only once daily (dinner), with water, black coffee, and tea permitted during fasting hours. Participants will continue their prescribed PI3K inhibitor dosing, with medications taken at standardized times to ensure consistent pharmacokinetic measurements.
| Study group | Role | What they receive |
|---|---|---|
| Sequence A | Active comparator | Participants randomized to Sequence A will complete a normal eating intervention period, followed by a washout period, followed by a prolonged fasting intervention period.
Normal eating → Washout → Prolonged fasting Receives: Behavioral: Normal Eating; Behavioral: Prolonged Fasting |
| Sequence B | Active comparator | Participants randomized to Sequence B will complete a prolonged fasting intervention period, followed by a washout period, followed by a normal eating intervention period.
Prolonged fasting → Washout → Normal eating Receives: Behavioral: Normal Eating; Behavioral: Prolonged Fasting |
What is being measured
The primary outcome is the main question the study is designed to answer.
Effect of plasma from fasting in patients on PI3K inhibitors on cell viability
We will culture 2D/3D breast cancer models using plasma from patients in the fed and fasted states. We will assess tumor cell viability by measuring cell proliferation, apoptosis, and cell cycle distribution.
Measured: Week 2 of prolonged fasting
mechanisms by which fasting might enhance PI3K inhibitor efficacy through complementary molecular and cellular studies
We will culture 2D/3D breast cancer models using plasma from patients in the fed and fasted states and perform metabolomic and proteomic analyses to evaluate the effects on insulin and PI3K pathways.
Measured: Week 7
Identify biomarkers/patient characteristics predicting the enhancement of PI3K inhibitor efficacy with fasting.
We will evaluate biomarkers that may predict the influence of fasting on PI3K inhibitor efficacy. Using serial plasma samples, we will analyze PI3K inhibitor pharmacokinetics, metabolic markers (e.g., insulin, glucose), circadian markers (melatonin, cortisol), and tumor-specific markers (circulating tumor DNA).
Measured: Week 7
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted3 Jun 2026
- Study start18 May 2026
- Primary completion1 Jul 2027 (estimated)
- Study completion1 Jul 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Metastatic Breast CancerStudies of the same condition, open and under way.
- More trials run by University of MinnesotaThe sponsor's other registered studies.
- 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
- Crossover
- Masking
- None (open label)
- Enrolment
- 15 participants (estimated)
Sponsor and investigators
- Lead sponsor
- University of Minnesota
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
- Investigators
- Lisa Chow, MD, MS, Principal investigator, University of Minnesota
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07624617
- Sponsor's protocol ID
- MED-2025-34235
- Status last verified
- Jul 2026
- First submitted
- 28 May 2026
- Last updated
- 13 Jul 2026
- Results posted
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
Study at a glance
From the registry record, last updated by the sponsor on 13 Jul 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Fast-Her: Fasting Effects on Breast Cancer Treatment
- ClinicalTrials.gov ID
- NCT07624617
- Acronym / sponsor ID
- MED-2025-34235
- Conditions
- Metastatic Breast Cancer
- Keywords
- capivasertib
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 15 participants (estimated)
- Lead sponsor
- University of MinnesotaUniversity, hospital or other
- Study start
- 18 May 2026 (actual)
- Primary completion
- 1 Jul 2027 (estimated)
- Study completion
- 1 Jul 2027 (estimated)
- First posted
- 3 Jun 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.
We hypothesize that promoting a fasting state will strengthen the anti-cancer effects of PI3K inhibitors in metastatic breast cancer (MBC) treatment. The primary objective of this study is to assess acceptability of prolonged fasting in this population.
Study design
- Primary purpose
- Supportive care
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- None (open label)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Sequence A | Active comparator | Behavioral: Normal Eating, Behavioral: Prolonged FastingParticipants randomized to Sequence A will complete a normal eating intervention period, followed by a washout period, followed by a prolonged fasting intervention period. Normal eating → Washout → Prolonged fasting |
| Sequence B | Active comparator | Behavioral: Normal Eating, Behavioral: Prolonged FastingParticipants randomized to Sequence B will complete a prolonged fasting intervention period, followed by a washout period, followed by a normal eating intervention period. Prolonged fasting → Washout → Normal eating |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (10 listed)
- Age ≥18 years
- Histologically confirmed metastatic breast cancer
- Menopausal or medically ovarian suppressed
- Currently receiving capivasertib therapy (2 tablets twice daily, 4 days per week)
- Stable on current capivasertib regimen for at least 2 weeks
Key exclusion criteria (9 listed)
- Type 1 diabetes mellitus
- Uncontrolled type 2 diabetes (HbA1c >9.0%)
- History of severe hypoglycemia
- Eating disorders or contraindications to fasting
- Pregnancy or breastfeeding
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 |
|---|---|---|
| Normal EatingDuring the normal eating intervention period, participants will follow their usual eating pattern. Participants will continue their prescribed PI3K inhibitor dosing, with medications taken at standardized times to ensure consistent pharmacokinetic measurements. | Behavioural | Sequence A, Sequence B |
| Prolonged FastingDuring the prolonged fasting intervention period, participants will eat only once daily (dinner), with water, black coffee, and tea permitted during fasting hours. Participants will continue their prescribed PI3K inhibitor dosing, with medications taken at standardized times to ensure consistent pharmacokinetic measurements. | Behavioural | Sequence A, Sequence B |
Primary outcome
Effect of plasma from fasting in patients on PI3K inhibitors on cell viability
Time frame: Week 2 of prolonged fasting
We will culture 2D/3D breast cancer models using plasma from patients in the fed and fasted states. We will assess tumor cell viability by measuring cell proliferation, apoptosis, and cell cycle distribution.
mechanisms by which fasting might enhance PI3K inhibitor efficacy through complementary molecular and cellular studies
Time frame: Week 7
We will culture 2D/3D breast cancer models using plasma from patients in the fed and fasted states and perform metabolomic and proteomic analyses to evaluate the effects on insulin and PI3K pathways.
Identify biomarkers/patient characteristics predicting the enhancement of PI3K inhibitor efficacy with fasting.
Time frame: Week 7
We will evaluate biomarkers that may predict the influence of fasting on PI3K inhibitor efficacy. Using serial plasma samples, we will analyze PI3K inhibitor pharmacokinetics, metabolic markers (e.g., insulin, glucose), circadian markers (melatonin, cortisol), and tumor-specific markers (circulating tumor DNA).
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 13 Jul 2026.
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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.
Lisa Chow, MD, MS principal investigator
University of Minnesota
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Normal Eating and Prolonged Fasting in people with Metastatic Breast Cancer, run by University of Minnesota 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 10 inclusion and 9 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: looking for participants now, as of the sponsor's last update on 13 Jul 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. 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 Lisa Chow, MD, MS (612-625-8934, chow0007@umn.edu), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Effect of plasma from fasting in patients on PI3K inhibitors on cell viability (time frame: Week 2 of prolonged fasting). The study lists 3 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 13 Jul 2026.