Recruiting
Phase 3

PF-07248144 & Fulvestrant

Sponsor:

Pfizer

Code:

NCT07062965

Conditions

Breast Cancer

Eligibility Criteria

Sex: All

Age: 18+

Healthy Volunteers: Not accepted

Interventions

PF-07248144

Fulvestrant

Everolimus

Exemestane

Study Details

Brief summary:

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.

Conditions

Breast Cancer

Study ID

NCT07062965

Start date

Aug 5, 2025

Status verified date

May, 2026

Completion date

Nov 4, 2030

Anticipated

Primary completion date

Jul 22, 2027

Anticipated

Eligibility Criteria

Eligibility Criteria

Sex: All

Age: 18+

Healthy Volunteers: Not accepted

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
  • Received greater than two prior lines of systemic therapy in the advance or metastatic setting
  • Had received any prior chemotherapy, including antibody drug conjugates (ADCs), in advance or metastatic setting. Participants who have previously received chemotherapy in the (neo)adjuvant setting are not excluded from the study.
  • Any medical or psychiatric condition that may increase the risk of study participation or make the participant inappropriate for the study.
  • Renal impairment, hepatic dysfunction, or hematologic abnormalities.

Study Design

Enrollment

400 participants

Anticipated

Allocation

Randomized

Intervention Model

Parallel Assignment

Primary purpose

Treatment

Interventions and Outcome Measures

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.

Interventions

PF-07248144

KAT6 inhibitor

Fulvestrant

Endocrine therapy

Everolimus

mTOR inhibitor

Exemestane

Endocrine therapy

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 and Locations

Central contacts

Pfizer CT.gov Call Center

1-800-718-1021ClinicalTrials.gov_Inquiries@pfizer.com

Locations

Ironwood Cancer & Research Centers

Recruiting

Chandler, Arizona, United States, 85224

Ironwood Cancer & Research Centers

Recruiting

Gilbert, Arizona, United States, 85297

Ironwood Cancer & Research Centers

Recruiting

Glendale, Arizona, United States, 85306

Ironwood Cancer & Research Centers

Recruiting

Goodyear, Arizona, United States, 85395

Ironwood Cancer & Research Centers

Recruiting

Mesa, Arizona, United States, 85202

Ironwood Cancer & Research Centers

Recruiting

Mesa, Arizona, United States, 85206

Ironwood Cancer & Research Centers

Recruiting

Phoenix, Arizona, United States, 85028

Ironwood Cancer & Research Centers

Recruiting

Scottsdale, Arizona, United States, 85260

Smilow Cancer Hospital - Derby

Recruiting

Derby, Connecticut, United States, 06418

Smilow Cancer Hospital - Fairfield

Recruiting

Fairfield, Connecticut, United States, 06824

Smilow Cancer Hospital - Glastonbury

Recruiting

Glastonbury, Connecticut, United States, 06033

Smilow Cancer Hospital - Greenwich

Recruiting

Greenwich, Connecticut, United States, 06830

Smilow Cancer Hospital - Guilford

Recruiting

Guilford, Connecticut, United States, 06437

Smilow Cancer Hospital at Saint Francis

Recruiting

Hartford, Connecticut, United States, 06105

Smilow Cancer Hospital - Yale New Haven Health

Recruiting

New Haven, Connecticut, United States, 06510

Smilow Cancer Hospital - North Haven

Recruiting

North Haven, Connecticut, United States, 06473

Smilow Cancer Hospital - Long Ridge

Recruiting

Stamford, Connecticut, United States, 06902

Smilow Cancer Hospital - Waterbury

Recruiting

Waterbury, Connecticut, United States, 06708

Emory University Hospital Midtown

Recruiting

Atlanta, Georgia, United States, 30308

Summit Cancer Care, PC

Recruiting

Savannah, Georgia, United States, 31405

Summit Cancer Care

Recruiting

Savannah, Georgia, United States, 31405

Memorial Hospital.

Recruiting

Shiloh, Illinois, United States, 62269

The Cancer & Hematology Centers

Recruiting

Holland, Michigan, United States, 49424

Siteman Cancer Center - St Peters

Recruiting

City of Saint Peters, Missouri, United States, 63376

Siteman Cancer Center - North County

Recruiting

Florissant, Missouri, United States, 63031

Siteman Cancer Center

Recruiting

St Louis, Missouri, United States, 63108

SCRI Oncology Partners

Recruiting

Nashville, Tennessee, United States, 37203

Henry-Joyce Cancer Clinic

Recruiting

Nashville, Tennessee, United States, 37232

Texas Oncology-Northeast Texas

Recruiting

Allen, Texas, United States, 75013

Texas Oncology - Central South (Balcones Dr)

Recruiting

Austin, Texas, United States, 78731

Texas Oncology - Central South (James Casey)

Recruiting

Austin, Texas, United States, 78745

Texas Oncology-Northeast Texas

Recruiting

Denison, Texas, United States, 75020

Texas Oncology-Northeast Texas

Recruiting

Denton, Texas, United States, 76201

Texas Oncology-Northeast Texas

Recruiting

Flower Mound, Texas, United States, 75028

University of Texas MD Anderson Cancer Center

Recruiting

Houston, Texas, United States, 77030

MD Anderson West Houston

Recruiting

Houston, Texas, United States, 77079

US Oncology Investigational Product Center (IPC)

Recruiting

Irving, Texas, United States, 75063

US Oncology Investigational Products Center

Recruiting

Irving, Texas, United States, 75063

MD Anderson League City

Recruiting

League City, Texas, United States, 77573

Texas Oncology-Northeast Texas

Recruiting

Lewisville, Texas, United States, 75056

Texas Oncology-Northeast Texas

Recruiting

Longview, Texas, United States, 75601

Texas Oncology - Central South (South 2nd)

Recruiting

McAllen, Texas, United States, 78503

Texas Oncology-Northeast Texas

Recruiting

McKinney, Texas, United States, 75071

Texas Oncology-Northeast Texas

Recruiting

Palestine, Texas, United States, 75801

Texas Oncology-Northeast Texas

Recruiting

Paris, Texas, United States, 75460

Texas Oncology-Northeast Texas

Recruiting

Tyler, Texas, United States, 75702

Huntsman Cancer Institute

Recruiting

Salt Lake City, Utah, United States, 84112

Bon Secours Cancer Institute at Memorial Regional Medical Center

Recruiting

Mechanicsville, Virginia, United States, 23116

CHU de Québec-Université Laval, Hôpital du Saint-Sacrement

Recruiting

Québec, Quebec, Canada, G1S 4L8

CHU de Québec-Université Laval

Recruiting

Québec, Canada, G1R 2J6

More Information

Sponsor

Pfizer

Last update posted

May 6, 2026

Last verified

May, 2026

Keywords

  • Locally advanced or metastatic breast cancer
  • Estrogen receptor positive [ER(+)]
  • Progesterone receptor positive [PR(+)]
  • Human epidermal growth factor receptor 2 negative [HER2(-)]
  • ER(+)/HER2(-)
  • PR(+)/HER2(-)
  • HR(+)/HER2(-)
  • Advanced Breast Cancer
  • Breast tumor
  • Breast cancer
  • Everolimus
  • Exemestane
  • Fulvestrant
  • Metastatic breast cancer
  • Endocrine Therapy
  • Hormone Therapy
  • Hormone positive breast cancer
  • Recurrent breast cancer
  • HR+
  • HER2-negative
  • Relapse
  • Recurrent
  • Second line treatment
  • Third line treatment
  • Left Sided Breast Cancer
  • Right Sided Breast Cancer
  • Unilateral Breast Cancer
  • Cancer of the Breast
  • CDK4/6i
  • CDK4/6i-based Therapy
  • Bilateral Breast Cancer
  • Progression After CDK4/6i-based therapy

Trial information was received from ClinicalTrials.gov and was last updated on 2026-09-09. This information was provided to ClinicalTrials.gov by Pfizer on 2026-05-06.