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.

Recruitment Status
RECRUITING
(See Contacts and Locations)Verified April 2026 by Pfizer
Sponsor
Pfizer
Information Provided by (Responsible Party)
Pfizer
Clinicaltrials.gov Identifier
NCT07062965
Other Study ID Numbers:
C4551002
First Submitted
July 2, 2025
First Posted
July 13, 2025
Last Update Posted
May 5, 2026
Last Verified
April 2026

ClinicalTrials.gov processed this data on May 2026. Link to the current ClinicalTrials.gov record .

History of Changes

Study Details

Study Description

Condition or DiseaseIntervention/Treatment
Breast Cancer
Drug: PF-07248144Drug: Fulvestrant

Study Design

Study TypeInterventional
Actual Enrollment400 participants
Design AllocationRandomized
Interventional ModelParallel Assignment
MaskingNone (Open Label)
Primary PurposeTreatment
Official TitleAn Interventional, Open-Label, Randomized, Multicenter, Phase 3 Study of PF-07248144 Plus Fulvestrant Compared to Investigator's Choice of Therapy in Adult Participants With Hormone Receptor-Positive, HER2-Negative Advanced/Metastatic Breast Cancer Whose Disease Progressed After Prior CDK4/6 Inhibitor-based Therapy
Study Start DateAugust 4, 2025
Actual Primary Completion Date1yr 1mo from now
Actual Study Completion Date4yrs 4mos from now

Groups and Cohorts

Group/CohortIntervention/Treatment
Arm A: PF-07248144 plus fulvestrant
PF-07248144 tablet taken by mouth plus fulvestrant taken as a shot into the muscle.
Drug: PF-07248144
KAT6 inhibitor
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.
Drug: Fulvestrant
Endocrine therapy

Outcome Measures

Primary Outcome Measures
  1. Progression Free Survival (PFS) as determined by blinded independent central review (BICR) per Response Evaluation Criteria in Solid Tumors (RECIST) v1.1
Secondary Outcome Measures
  1. Overall Survival (OS)
  2. Number of Participants with Objective Response (OR) by BICR
  3. Duration of Response (DoR) as defined by BICR
  4. Number of Participants With Clinical Benefit Response (CBR) by BICR
  5. Number or Patients with Adverse Events (AEs) by Type
  6. Number or Patients with AEs by Incidence
  7. Number or Patients with AEs by Seriousness
  8. Number or Patients with AEs by relationship to study interventions
  9. Number of Participants With Abnormal Electrocardiogram (ECG; Arm A and B)
  10. Number of Participants With Increase From Baseline in Corrected QT (QTc) Interval (Arm A only)
    The study includes a QTc sub-study in approximately 40 participants in Arm A enrolled at selected sites which will evaluate the effect of PF-07248144 on QTc interval via collection of triplicate ECGs (central reading) time-matched with pharmacokinetic (PK) draws.
  11. Number of Participants With Laboratory Test Abnormalities
  12. Ctrough of PF-07248144
    Ctrough was defined as pre-dose serum concentration during multiple dosing and observed directly from data.

Eligibility Criteria

Ages Eligible for Study(Adult, Older Adult)
Sexes Eligible for StudyAll
Accepts Healthy VolunteersNo
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.

Contacts and Locations

Sponsors and CollaboratorsPfizer
Locations
Ironwood Cancer & Research Centers | Chandler Arizona, United States, 85224Ironwood Cancer & Research Centers | Gilbert Arizona, United States, 85297Ironwood Cancer & Research Centers | Glendale Arizona, United States, 85306Ironwood Cancer & Research Centers | Goodyear Arizona, United States, 85395Ironwood Cancer & Research Centers | Mesa Arizona, United States, 85202Ironwood Cancer & Research Centers | Mesa Arizona, United States, 85206Ironwood Cancer & Research Centers | Phoenix Arizona, United States, 85028Ironwood Cancer & Research Centers | Scottsdale Arizona, United States, 85260Ventura County Hematology Oncology Specialists | Camarillo California, United States, 93010Los Angeles Cancer Network - (Admin Only / Central IDS) - No Patients | Glendale California, United States, 91204Los Angeles Cancer Network - Good Samaritan | Los Angeles California, United States, 90017Los Angeles Hematology Oncology Medical Group | Los Angeles California, United States, 90017Rolling Oaks Radiology - Oxnard | Oxnard California, United States, 93030Ventura County Hematology Oncology Specialists | Oxnard California, United States, 93030Dr. Manoj Khatore, MD, FACC (Cardiology Practice) | Oxnard California, United States, 93036Ventura County Hematology Oncology Specialists | Ventura California, United States, 93003Rocky Mountain Cancer Centers LLP | Aurora Colorado, United States, 80012Rocky Mountain Cancer Centers LLP | Boulder Colorado, United States, 80303Rocky Mountain Cancer Centers LLP | Centennial Colorado, United States, 80112Rocky Mountain Cancer Centers LLP | Colorado Springs Colorado, United States, 80907Rocky Mountain Cancer Centers LLP | Colorado Springs Colorado, United States, 80923Rocky Mountain Cancer Centers LLP | Denver Colorado, United States, 80220Rocky Mountain Cancer Centers LLP | Englewood Colorado, United States, 80113Rocky Mountain Cancer Centers LLP | Lakewood Colorado, United States, 80228Rocky Mountain Cancer Centers LLP | Littleton Colorado, United States, 80120Rocky Mountain Cancer Centers LLP | Lone Tree Colorado, United States, 80124Rocky Mountain Cancer Centers LLP | Longmont Colorado, United States, 80504Rocky Mountain Cancer Centers LLP | Pueblo Colorado, United States, 81003Rocky Mountain Cancer Centers LLP | Thornton Colorado, United States, 80260Smilow Cancer Hospital - Derby | Derby Connecticut, United States, 06418Smilow Cancer Hospital - Fairfield | Fairfield Connecticut, United States, 06824Smilow Cancer Hospital - Glastonbury | Glastonbury Connecticut, United States, 06033Smilow Cancer Hospital - Greenwich | Greenwich Connecticut, United States, 06830Smilow Cancer Hospital - Guilford | Guilford Connecticut, United States, 06437Smilow Cancer Hospital at Saint Francis | Hartford Connecticut, United States, 06105Smilow Cancer Hospital - Yale New Haven Health | New Haven Connecticut, United States, 06510Smilow Cancer Hospital - North Haven | North Haven Connecticut, United States, 06473Smilow Cancer Hospital - Long Ridge | Stamford Connecticut, United States, 06902Smilow Cancer Hospital - Waterbury | Waterbury Connecticut, United States, 06708MedStar Washington Hospital Center | Washington D.C. District of Columbia, United States, 20010Emory University Hospital Midtown | Atlanta Georgia, United States, 30308Summit Cancer Care, PC | Savannah Georgia, United States, 31405Summit Cancer Care | Savannah Georgia, United States, 31405Memorial Hospital. | Shiloh Illinois, United States, 62269Orchard Healthcare Research Inc. | Skokie Illinois, United States, 60077Maryland Oncology Hematology P.A. | Annapolis Maryland, United States, 21401Mfsmc-Hjwci | Baltimore Maryland, United States, 21237Maryland Oncology Hematology P.A. | Bethesda Maryland, United States, 20817Maryland Oncology Hematology P.A. | Columbia Maryland, United States, 21044Maryland Oncology Hematology P.A. | Germantown Maryland, United States, 20876Maryland Oncology Hematology P.A. | Largo Maryland, United States, 20774Maryland Oncology Hematology P.A. | Rockville Maryland, United States, 20850Maryland Oncology Hematology P.A. | Silver Spring Maryland, United States, 20904The Cancer & Hematology Centers | Holland Michigan, United States, 49424Minnesota Oncology Hematology, P.A. | Burnsville Minnesota, United States, 55337Minnesota Oncology Hematology, P.A. | Coon Rapids Minnesota, United States, 55433Minnesota Oncology Hematology, P.A. | Edina Minnesota, United States, 55435Minnesota Oncology Hematology, P.A. | Maple Grove Minnesota, United States, 55369Minnesota Oncology Hematology, P.A. | Maplewood Minnesota, United States, 55109Minnesota Oncology Hematology, P.A. | Minneapolis Minnesota, United States, 55404Minnesota Oncology Hematology, P.A. | Plymouth Minnesota, United States, 55441Minnesota Oncology Hematology, P.A. | Woodbury Minnesota, United States, 55125Siteman Cancer Center - St Peters | City of Saint Peters Missouri, United States, 63376Siteman Cancer Center - North County | Florissant Missouri, United States, 63031Saint Luke's Hospital of Kansas City | Kansas City Missouri, United States, 64111Siteman Cancer Center | St Louis Missouri, United States, 63108Comprehensive Cancer Centers of Nevada | Henderson Nevada, United States, 89052Comprehensive Cancer Centers of Nevada | Henderson Nevada, United States, 89074Comprehensive Cancer Centers of Nevada | Las Vegas Nevada, United States, 89128Comprehensive Cancer Centers of Nevada | Las Vegas Nevada, United States, 89144Comprehensive Cancer Centers of Nevada | Las Vegas Nevada, United States, 89148Comprehensive Cancer Centers of Nevada | Las Vegas Nevada, United States, 89169Hackensack University Medical Center | Hackensack New Jersey, United States, 07601The West Clinic, PLLC dba West Cancer Center | Germantown Tennessee, United States, 38138SCRI Oncology Partners | Nashville Tennessee, United States, 37203Henry-Joyce Cancer Clinic | Nashville Tennessee, United States, 37232Texas Oncology-Northeast Texas | Allen Texas, United States, 75013Texas Oncology - Central South (Balcones Dr) | Austin Texas, United States, 78731Texas Oncology - Central South (James Casey) | Austin Texas, United States, 78745Texas Oncology-Northeast Texas | Denison Texas, United States, 75020Texas Oncology-Northeast Texas | Denton Texas, United States, 76201Texas Oncology-Northeast Texas | Flower Mound Texas, United States, 75028University of Texas MD Anderson Cancer Center | Houston Texas, United States, 77030MD Anderson West Houston | Houston Texas, United States, 77079US Oncology Investigational Product Center (IPC) | Irving Texas, United States, 75063US Oncology Investigational Products Center | Irving Texas, United States, 75063MD Anderson League City | League City Texas, United States, 77573Texas Oncology-Northeast Texas | Lewisville Texas, United States, 75056Texas Oncology-Northeast Texas | Longview Texas, United States, 75601Texas Oncology - Central South (South 2nd) | McAllen Texas, United States, 78503Texas Oncology-Northeast Texas | McKinney Texas, United States, 75071Texas Oncology-Northeast Texas | Palestine Texas, United States, 75801Texas Oncology-Northeast Texas | Paris Texas, United States, 75460Texas Oncology-Northeast Texas | Tyler Texas, United States, 75702Huntsman Cancer Institute | Salt Lake City Utah, United States, 84112Virginia Oncology Associates | Chesapeake Virginia, United States, 23320Virginia Cancer Specialists | Manassas Virginia, United States, 20110Bon Secours Cancer Institute at Memorial Regional Medical Center | Mechanicsville Virginia, United States, 23116Virginia Cancer Specialists, PC | Reston Virginia, United States, 20190Virginia Oncology Associates | Virginia Beach Virginia, United States, 23456Virginia Oncology Associates | Williamsburg Virginia, United States, 23188Fred Hutchinson Cancer Center | Seattle Washington, United States, 98109ICON Cancer Centre - Kurralta Park | Kurralta Park South Australia, Australia, 5037Peter MacCallum Cancer Centre | Melbourne Victoria, Australia, 3000Western Health-Sunshine & Footscray Hospitals | St Albans Victoria, Australia, 3021Algemeen Ziekenhuis klina | Brasschaat Antwerpen, Belgium, 2930Institut Jules Bordet | Anderlecht Bruxelles-capitale, Région de, Belgium, 1070Cliniques universitaires Saint-Luc | Brussels Bruxelles-capitale, Région de, Belgium, 1200AZ Groeninge Campus Kennedylaan | Kortrijk West-vlaanderen, Belgium, 8500Afecc Associacao Feminina Educacao Combate Cancer | Vitória Espírito Santo, Brazil, 29043-260ONCOSITE - Centro de Pesquisa Clinica em Oncologia | Ijuí Rio Grande do Sul, Brazil, 98700-000Hospital São Lucas da PUCRS | Porto Alegre Rio Grande do Sul, Brazil, 90610-000ANIMI - Unidade de Tratamento Oncologico | Lages Santa Catarina, Brazil, 88501001IBCC - Núcleo de Pesquisa e Ensino | São Paulo , Brazil, 04014-002Multiprofile Hospital for Active Treatment Serdikamed EOOD | Sofia Sofia (stolitsa), Bulgaria, 1632Specialized Hospital for Active Treatment of Oncology - Haskovo | Haskovo , Bulgaria, 6300Complex Oncology Center - Shumen | Shumen , Bulgaria, 9700Centre Hospitalier de l'Université de Montréal | Montreal Quebec, Canada, H2X 3E4CHU de Québec-Université Laval, Hôpital du Saint-Sacrement | Québec Quebec, Canada, G1S 4L8CHU de Québec-Université Laval | Québec , Canada, G1R 2J6Anhui Provincial Cancer Hospital | Hefei Anhui, China, 230031Fujian Medical University Union Hospital | Fuzhou Fujian, China, 350001Sun Yat-sen University Cancer Center | Guangzhou Guangdong, China, 510060Southern Medical University Nanfang Hospital | Guangzhou Guangdong, China, 510515Affiliated Hospital of Hebei University | Baoding Hebei, China, 071066Tongji Hospital, Tongji Medical College of Huazhong University of Science and Technology | Wuhan Hubei, China, 430030Hunan Cancer Hospital | Changsha Hunan, China, 410013Nanjing Drum Tower Hospital The Affiliated Hospital of Nanjing University Medical School | Nanjing Jiangsu, China, 210031The 2nd Affiliated Hospital of Dalian Medical University | Dalian Liaoning, China, 116023Shandong Cancer Hospital | Jinan Shandong, China, 250117Fudan University Shanghai Cancer Center | Shanghai Shanghai Municipality, China, 200032Fakultni Thomayerova nemocnice | Prague Praha 4, Czechia, 14059Fakultni nemocnice v Motole | Prague Praha 5, Czechia, 150 06Nemocnice AGEL Novy Jicin a.s. | Nový Jičín , Czechia, 741 01Kuopion Yliopistollinen Sairaala | Kuopio Northern Savonia, Finland, 70210Tampereen yliopistollinen sairaala | Tampere Pirkanmaa, Finland, 33520Docrates Syöpäsairaala | Helsinki Uusimaa, Finland, 00180Centre Eugène Marquis Rennes - Centre de Lutte Contre le Cancer | Rennes Brittany Region, France, 35042Institut Régional du Cancer Montpellier | Montpellier Hérault, France, 34298Institut de Cancérologie de Lorraine Alexis Vautrin | Vandœuvre-lès-Nancy Lorraine, France, 54519Hôpital de la Croix-Rousse | Lyon Rhône, France, 69004Centre Hospitalier Lyon Sud | Pierre-Bénite Rhône, France, 69310Institut Bergonié | Bordeaux , France, 33076Centre François Baclesse | Caen , France, 14076Universitätsklinik Ulm | Ulm Baden-Wurttemberg, Germany, 89075Universitaetsklinikum Erlangen | Erlangen Bavaria, Germany, 91054Charité Universitaetsmedizin Berlin - Campus Mitte | Berlin , Germany, 10117Mammazentrum HH am Krankenhaus Jerusalem | Hamburg , Germany, 20357IASO General Clinic | Athens Attica, Greece, 151 23Hygeia Hospital | Marousi Attikí, Greece, 151 23University General Hospital of Heraklion | Heraklion Irakleío, Greece, 71500Semmelweis Egyetem | Budapest , Hungary, 1082Debreceni Egyetem Klinikai Kozpont | Debrecen , Hungary, 4032Nirmal Hospital Pvt Ltd. | Surat Gujarat, India, 395002Spandana Oncology Centre (SOC) | Bengaluru Karnataka, India, 560069Apex Wellness Hospital | Nashik Maharashtra, India, 422009Sahyadri Super Speciality Hospital | Pune Maharashtra, India, 411004Rabin Medical Center | Petah Tikva Central District, Israel, 4941492Shaare Zedek Medical Center | Jerusalem Jerusalem, Israel, 9013102Hadassah Medical Center | Jerusalem Jerusalem, Israel, 9112001Rambam Health Care Campus | Haifa Northern District, Israel, 3109601Sourasky Medical Center | Tel Aviv TELL ABĪB, Israel, 6423906IRCCS Azienda Ospedaliero-Universitaria di Bologna, Policlinico di Sant'Orsola | Bologna Emilia-Romagna, Italy, 40138IRCCS - Istituto Romagnolo per lo Studio dei Tumori (IRST) "Dino Amadori" | Meldola Emilia-Romagna, Italy, 47014Istituto Nazionale dei Tumori IRCCS Fondazione G Pascale | Naples Naples, Italy, 80131Ospedale San Raffaele | Milan , Italy, 20132National Cancer Center Hospital East | Kashiwa Chiba, Japan, 277-8577Gunma Prefectural Cancer Center | Otashi Gunma, Japan, 373-8550Tokai University Hospital | Isehara Kanagawa, Japan, 259-1193Kanagawa cancer center | Yokohama Kanagawa, Japan, 2418515Juntendo University Hospital | Bunkyo-ku Tokyo, Japan, 113-8431National Hospital Organization Kyushu Cancer Center | Fukuoka , Japan, 811-1395Showa Medical University Hospital | Tokyo , Japan, 142-8666Centro de Investigacion Clinica de Oaxaca | Oaxaca City Oaxaca, Mexico, 68020COI Centro Oncologico Internacional S.A.P.I. de C.V. | Mexico City , Mexico, 04700Franciscus Vlietland Ziekenhuis | Schiedam South Holland, Netherlands, 3118 JHCentrum Onkologii im. Prof. Franciszka Lukaszczyka | Bydgoszcz Kuyavian-Pomeranian Voivodeship, Poland, 85-796Centrum Badań Klinicznych Jagiellońskie Centrum Innowacji sp. z o.o. | Krakow Lesser Poland Voivodeship, Poland, 30-348Onkologicky Ustav sv. Alzbety | Bratislava Bratislava Region, Slovakia, 812 50Vychodoslovensky Onkologicky ustav a.s. | Košice Košice Region, Slovakia, 041 91Narodny onkologicky ustav | Bratislava , Slovakia, 833 10Seoul National University Bundang Hospital | Seongnam-si Kyǒnggi-do, South Korea, 13620Gangnam Severance Hospital, Yonsei University Health System | Gangnam-gu Seoul-teukbyeolsi [seoul], South Korea, 06273Severance Hospital, Yonsei University Health System | Seoul Seoul-teukbyeolsi [seoul], South Korea, 03722Samsung Medical Center | Seoul Seoul-teukbyeolsi [seoul], South Korea, 06351CHUAC-Complejo Hospitalario Universitario A Coruña | A Coruña A Coruña [LA Coruña], Spain, 15006Hospital Universitari Vall d'Hebron | Barcelona Barcelona [barcelona], Spain, 08035Osi Bilbao-Basurto | Bilbao Basque Country, Spain, 48013Hospital Clínic de Barcelona | Barcelona Catalunya [cataluña], Spain, 08036Hospital Universitario Virgen de la Victoria | Málaga Málaga, Spain, 29010Hospital Universitario San Cecilio | Granada , Spain, 18016Hospital Universitario de Jaen | Jaén , Spain, 23007Hospital Universitario Miguel Servet | Zaragoza , Spain, 50009Södersjukhuset | Stockholm Stockholms LÄN [se-01], Sweden, 11883Sahlgrenska Universitetssjukhuset | Gothenburg , Sweden, SE-41345Chi Mei Medical Center | Tainan Tainan, Taiwan, 71004Taipei Veterans General Hospital | Taipei , Taiwan, 11217Medipol Mega Universite Hastanesi | Istanbul İ̇stanbul, Turkey (Türkiye), 34214Memorial Ankara Hastanesi | Ankara , Turkey (Türkiye), 06520Ankara Bilkent Şehir Hastanesi | Ankara , Turkey (Türkiye), 06800Dicle Üniversitesi | Diyarbakır , Turkey (Türkiye), 21200Musgrove Park Hospital | Taunton Somerset, United Kingdom, TA1 5DA
Investigators
Study Director: Pfizer CT.gov Call Center, Pfizer