At a glance
- What the study gets you
- Access to the study treatment being tested
- Type of study
- Interventional (receives a drug or procedure)
- Time in hospital
- In-person visits at study sites — visit count not specified by the sponsor
- Drug or intervention
- PF-07248144 (drug), Fulvestrant (drug), Everolimus (drug), Exemestane (drug)
- How long the study runs
- Study runs about 63 months (dates as stated)
- About the drug or intervention
- PF-07248144 — drug: KAT6 inhibitor · Fulvestrant — drug: Endocrine therapy · Everolimus — drug: mTOR inhibitor · Exemestane — drug: Endocrine therapy
- Patient visit burden
- Not specified by the sponsor
In plain English
This study is testing a new medicine called PF-07248144, taken together with an existing hormone medicine called fulvestrant, in people with a type of advanced or spread (metastatic) breast cancer known as HR-positive and HER2-negative. It is for people whose cancer has grown after one previous treatment. The study is funded by Pfizer.
Who can take part
- Confirmed HR-positive, HER2-negative breast cancer that is locally advanced or metastatic and cannot be removed by surgery or treated with radiotherapy to cure it
- Have had a CDK4/6 inhibitor (a type of cancer medicine) with hormone therapy for advanced cancer, or earlier treatment where the cancer came back during or within 12 months of finishing it
- May have had CDK4/6 inhibitor or hormone therapy alone or combined as repeat treatment, or treatment targeting ESR1 (a gene linked to hormone receptors) or BRCA1/2 (breast cancer genes)
- Cancer that can be measured on scans, or cancer in bone only that cannot be measured
- Able to carry out normal daily activity (performance status 0 or 1)
Who may not be able to
- Certain gene changes (PIK3CA, AKT1 or PTEN) found in tumour tissue
- More than two previous courses of whole-body treatment for advanced or metastatic cancer
- Any previous chemotherapy, including antibody drug conjugates, for advanced or metastatic cancer (earlier chemotherapy before surgery is allowed)
- Any medical or mental health condition that could make taking part unsafe or unsuitable
- Kidney problems, liver problems, or abnormal blood counts
What taking part involves
- • Taking the study medicine PF-07248144 together with fulvestrant
- • Regular checks to see how the cancer responds to treatment
Time commitment: Not stated — ask the trial team about how many visits are needed, how long the study lasts, and what taking part involves.
Plain-English summary (AI-generated) from registry data. Not eligibility advice — only the trial team can confirm whether you can take part. Use the eligibility checker to see how your health profile matches this trial.
- Type of study
- Testing a treatment
- Ages
- 18 Years and over
- Who
- All
- Number of participants
- 400
- Started
- 2025-08-05
- Last checked
- 2026-05
Plain English Summary
What is this study?
- • Testing a new treatment for breast cancer
- • Phase3 - 400 participants
- • The purpose of this study is to learn about the safety and effects of the study medicine PF-07248144 when given along with fulvestrant for the possible treatment of HR-positive, HER2-negative advanced or metastatic breast cancer
Who can take part?
- • Ages 18 Years and over
- • Diagnosed with breast cancer
Where?
- • Taunton - Musgrove Park Hospital
This is a simplified summary. Always discuss with your doctor before making any decisions.
About This Trial
The purpose of this study is to learn about the safety and effects of the study medicine PF-07248144 when given along with fulvestrant for the possible treatment of HR-positive, HER2-negative advanced or metastatic breast cancer. HR-positive breast cancer cells have proteins on their surface called receptors that bind to hormones like estrogen and progesterone (female sex hormones). These hormones can promote the growth of cancer cells. HER2-negative describes cells that have a small amount or none of a protein called HER2 on their surface. In normal cells, HER2 helps control cell growth. Cancer cells that are HER2-negative may grow more slowly and are less likely to recur (come back) or spread to other parts of the body than cancer cells that have a large amount of HER2 on their surface. Advanced cancer is a term that is often used to describe cancer that is unlikely to be cured. Metastatic cancer is the type where the cancer cells spread from one part of the body to another. This study is seeking for participants whose breast cancer has gotten worsen after receiving cyclin dependent kinase (CDK) 4/6 inhibitor-based therapy. Half of participants in this study will receive their usual study treatment, everolimus with endocrine therapy (either exemestane or fulvestrant) for HR-positive/HER2-negative advanced or metastatic breast cancer (A/mBC). The study doctor will discuss which hormone therapy is right for the participant before treatment begins. PF-07248144 is a tablet that will be taken by mouth at home every day in a 28-day cycle. Fulvestrant will be given as two injections (one injection in the buttock) at visits to the study clinic. Everolimus and exemestane are also tablets and will be taken by mouth at home every day in a 28-day cycle. The study will compare the experiences of people receiving PF-07248144 in combination with fulvestrant to those of the people who do not. This will help see if PF-07248144 in combination with fulvestrant is safe and effective.
How this trial compares with your answers
Answer 2 more questions to improve match
What we know so far
Still need:
- • Tell us your age for better matching
- • Tell us your sex for better matching
Preliminary match based on your answers. Full eligibility requires on-site assessment including medical history, physical exam, and lab tests. This does not guarantee enrolment.
Eligibility at a Glance
Key info
- Age: 18 Years and over
- Who can join: All genders
Biomarkers mentioned
Treatment history
Treatments you must have had:
- ✓ targeting estrogen recept
What the study is looking for
- ✓cancer that can be measured on scans evaluable per Response Evaluation Criterion in Solid Tumors (RECIST) v.1.1 or non-measurable...
- ✓activity scale (ECOG) Performance Status (PS) 0 or 1.
Who cannot take part
- ✗Documented detectable PIK3CA/AKT1/PTEN alterations in tissue
- ✗Received greater than two previous treatments in the advance or that has spread setting
- ✗Any medical or psychiatric condition that may increase the risk of study participation or make the participant...
- ✗kidney impairment, liver dysfunction, or blood abnormalities.
See the full criteria
Where Is This Study? (1 UK site)
Musgrove Park Hospital
Taunton TA1 5DA, United Kingdom
How to Get in Touch
Pfizer CT.gov Call Center
Sponsor contactCONTACT