Fasting Effects on Metastatic Breast Cancer Treatment with PI3K Inhibitors

This study is looking at whether prolonged fasting can make a PI3K inhibitor called capivasertib work better for people with metastatic breast cancer (cancer that has spread). You would either follow your usual eating pattern or eat only dinner once a day, while continuing your capivasertib medication. Researchers want to see if fasting helps the medication fight cancer cells more effectively and if it's something patients can do. They will also look for signs in your body (biomarkers) that might predict who would benefit most from fasting. This study plans to include 15 participants and its current status is unclear.

Study design
This study is an interventional study, meaning participants will receive a specific treatment or intervention. It plans to enroll 15 participants.
What's involved
You would either follow your usual eating pattern or eat only once daily (dinner) for a period, while continuing your prescribed capivasertib. Medications will be taken at standardized times.
Compensation
Not stated in the trial record.
Follow-up
The study measures effects at Week 2 of prolonged fasting and at Week 7 for other outcomes.

AI-generated from the public study record. Only the study team can confirm whether you're eligible — confirm details with them before making decisions.

NCT07624617

Fast-Her: Fasting Effects on Breast Cancer Treatment

Recruiting
NAAges 18+InterventionalSupportive care
University of Minnesota
~15 participants
Updated 2026-07-13 on ClinicalTrials.gov
What's tested:Normal EatingProlonged Fasting

At a glance

Recruiting sites
1 of 1 listed site is recruiting right now
RecruitingSuspended, closed, or not yet open
What they're measuring
Effect of plasma from fasting in patients on PI3K inhibitors on cell viability
Measured over Week 2 of prolonged fasting
+2 more outcomes measured
Metastatic Breast Cancer
1 sites across 1 states
Minnesota1
  • Lisa Chow, MD, MS · PRINCIPAL_INVESTIGATOR · University of Minnesota

Opens a ready-to-send draft in your own email app — review before sending.

Do you actually qualify for this trial?

Add a private profile and we'll compare every criterion below against your situation — and tell you which ones are met, uncertain, or excluding.

Check eligibility for this trial ~2 min · HIPAA-protected · delete anytime
Eligibility criteria

Inclusion

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
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

Exclusion

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
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)
  • Effect of plasma from fasting in patients on PI3K inhibitors on cell viabilityWeek 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 studiesWeek 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.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).