NCT07062965 · Pfizer
A Study to Learn About the Study Medicine Called PF-07248144 in Combination With Fulvestrant in People With HR-positive, HER2-negative Advanced or Metastatic Breast Cancer Who Progressed After a Prior Line of Treatment.
What this study is about
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).
View original scientific description
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.
Interventions
DRUG
PF-07248144
KAT6 inhibitor
DRUG
Fulvestrant
Endocrine therapy
DRUG
Everolimus
mTOR inhibitor
DRUG
Exemestane
Endocrine therapy
Primary outcome measures
Progression Free Survival (PFS) as determined by blinded independent central review (BICR) per Response Evaluation Criteria in Solid Tumors (RECIST) v1.1
Time frame: From the date of randomization until disease progression or death due to any cause (up to approximately 2 years)
Who can participate
This study lists these criteria on ClinicalTrials.gov. A study coordinator reviews eligibility during screening — this page does not determine whether you qualify.
Inclusion criteria
- Confirmed diagnosis of HR-positive HER2-negative breast cancer with evidence of locally advanced or metastatic disease, which is not amenable to surgical resection or radiation therapy with curative intent.
- Prior CDK4/6 inhibitor therapy in combination with endocrine therapy in advance metastatic setting or in adjuvant setting with documented progression during or within 12 months after the last dose of CDK4/6i.
- Participants are eligible if they previously received CDK4/6i or ET as a monotherapy, or in combination for rechallenge therapy in the advance or metastatic setting; have received prior therapy targeting estrogen receptor 1 (ESR1) or breast cancer gene (BRCA)1/2.
- Measurable disease evaluable per Response Evaluation Criterion in Solid Tumors (RECIST) v.1.1 or non-measurable bone-only disease
- Eastern Cooperative Oncology Group (ECOG) Performance Status (PS) 0 or 1.
Exclusion criteria
- Documented detectable PIK3CA/AKT1/PTEN alterations in tissue
Where
- Chandler, Arizona
- Gilbert, Arizona
- Glendale, Arizona
- Goodyear, Arizona
- Mesa, Arizona
- Phoenix, Arizona
- Scottsdale, Arizona
- Camarillo, California
- Glendale, California
- Los Angeles, California
- Oxnard, California
- Ventura, California
And 76 more locations — see the full list below.
Related conditions & keywords
Frequently asked questions
What is a clinical trial?
A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.
Is it safe to participate?
Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.
Will I be compensated?
Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.
Will I receive a placebo instead of treatment?
When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.
Can I leave a trial if I change my mind?
Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.
How long does a clinical trial last?
Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.
Data: ClinicalTrials.gov · synced May 6, 2026 · Source of record for eligibility and locations