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.

Conditions

• Breast Cancer

Eligibility Criteria

Sex

ALL

Age

18 Years - N/A

Healthy Volunteers

Not accepted

Interventions

• PF-07248144 — DRUG
  KAT6 inhibitor
• Fulvestrant — DRUG
  Endocrine therapy
• Everolimus — DRUG
  mTOR inhibitor
• Exemestane — DRUG
  Endocrine therapy

Study Details

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.

Key Dates

Start date

Aug 5, 2025

Status verified

May 2026

Primary completion

Jul 22, 2027

Completion

Nov 4, 2030

Study Design

Enrollment

400 participants (estimated)

Allocation

RANDOMIZED

Intervention model

PARALLEL

Primary purpose

TREATMENT

Arms

• Other: Arm A: PF-07248144 plus fulvestrant
  PF-07248144 tablet taken by mouth plus fulvestrant taken as a shot into the muscle.
• Active Comparator: Arm B: everolimus plus ET
  Everolimus tablet taken by mouth plus investigator's choice of endocrine therapy of exemestane tablet taken by mouth or fulvestrant taken as a shot into the muscle.

Primary Outcome Measure

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) ]

Central Contacts

• Pfizer CT.gov Call Center
  1-800-718-1021
  [email protected]

Locations (102)

Find similar trials in Chandler, AZ

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