Study of PF-07248144 and fulvestrant in adults with hormone receptor-positive, HER2-negative advanced or metastatic breast cancer who had progression after CDK4/6 inhibitor therapy

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What is this study about?

This study focuses on advanced/metastatic breast cancer that is hormone receptor-positive and HER2-negative. The study will test a new medication called PF-07248144 used together with fulvestrant in patients whose cancer has grown after previous treatment. This type of breast cancer depends on hormones to grow and has already spread to other parts of the body.

The treatment will involve taking PF-07248144 tablets by mouth along with fulvestrant injections into the muscle. Some patients will receive this combination, while others will receive different standard treatments such as everolimus or exemestane. The purpose is to determine if the combination of PF-07248144 and fulvestrant works better than currently available treatments in stopping the cancer from growing.

The study will last for up to 24 months. During this time, patients will have regular check-ups to monitor their health and see how well the treatment is working. Doctors will use special scans to measure if tumors are shrinking, staying the same size, or growing. They will also keep track of any side effects that patients may experience during the treatment.

1 Initial assessment

Your eligibility for the trial will be confirmed through medical examination and review of your breast cancer diagnosis, which must be hormone receptor-positive and HER2-negative

You must be at least 18 years old and have advanced or metastatic breast cancer that cannot be treated with surgery or radiation therapy

Your previous treatments will be reviewed to confirm you have received prior CDK4/6 inhibitor therapy

A tumor tissue sample will be required for analysis

2 Treatment assignment

You will be randomly assigned to one of two treatment groups:

Group A: You will receive PF-07248144 tablets taken by mouth plus fulvestrant given as an injection into the muscle

Group B: You will receive the investigator’s choice of therapy

3 Treatment period

Your treatment will continue until your disease progresses or you experience unacceptable side effects

Regular assessments will monitor your response to treatment using imaging scans

Blood samples will be collected to measure drug levels in your body

Your health status and any side effects will be monitored throughout the study

4 Follow-up period

After completing or stopping treatment, you will continue to be monitored for survival status

The study is expected to continue until January 2027

Your participation may end earlier if your disease progresses or you experience unacceptable side effects

Who Can Join the Study?

  • Must be at least 18 years old when joining the study
  • Must have confirmed HR-positive HER2-negative breast cancer that has spread locally or to other parts of the body (metastatic), and cannot be treated with surgery or radiation therapy alone
  • Must have previously received treatment with CDK4/6 inhibitor (a type of cancer medication) in one of these situations:
    • Combined with hormone therapy for advanced/metastatic breast cancer, or
    • As additional treatment with hormone therapy where cancer returned within 12 months after stopping CDK4/6 inhibitor
  • Must be able to provide a sufficient tumor tissue sample that has been preserved in a special way (FFPE tissue specimen)
  • Must have cancer that can be measured by scans, or cancer that only affects the bones
  • Must have good overall physical function, measured by ECOG Performance Status of:
    • 0 (fully active) or
    • 1 (restricted in physically strenuous activity but able to walk and do light work), or
    • 2 (able to walk and care for self) may be considered if other health conditions are satisfactory

Who Cannot Join the Study?

  • Prior treatment with any CDK4/6 inhibitor (medications that block specific proteins involved in cell growth)
  • Active brain metastases (cancer that has spread to the brain) that are untreated or unstable
  • History of other cancer types within the last 3 years, except for adequately treated non-melanoma skin cancer or cervical cancer in situ
  • Significant heart conditions, including:
    • Uncontrolled high blood pressure
    • Unstable heart rhythm problems
    • Heart attack within the past 6 months
    • Heart failure with symptoms
  • Severe liver problems or abnormal liver function tests
  • Known hypersensitivity (severe allergic reaction) to fulvestrant or any of the study medications
  • Participation in another clinical trial within 28 days before starting this study
  • Any serious medical condition that could interfere with study participation
  • Pregnancy or breastfeeding
  • Unable or unwilling to use effective contraception during the study period
  • Any psychological, social, or geographical condition that would prevent regular follow-up visits

Where you can join this trial?

Verified and Recommended Sites

No sites found in this category

Verified Sites

Site Name City Country Status
Institut Gustave Roussy Villejuif France
Centr Georges Francois Leclerc Dijon France
Zuyderland Medisch Centrum Stichting Geleen The Netherlands
Kuopio University Hospital Kuopio Finland
Hospital Universitario Hm Sanchinarro Madrid Spain
Institut De Cancerologie De Lorraine Vandoeuvre Les Nancy France
Hospital Universitario De Salamanca Salamanca Spain
University Hospital Maastricht Maastricht The Netherlands
Centre Hospitalier Regional Et Universitaire De Brest Brest France
Katholieke Universiteit te Leuven Leuven Belgium

Other Sites

Site Name City Country Status
Diagnostic & Therapeutic Center Of Athens Hygeia Single Member S.A. Athens Greece
Institut Jules Bordet Anderlecht Belgium
Haematologie-Onkologie im Zentrum MVZ GmbH Augsburg Germany
Orszagos Onkologiai Intezet Budapest Hungary
Centrum Onkologii Im. Prof. Franciszka Lukaszczyka W Bydgoszczy Bydgoszcz Poland
Istituto Europeo Di Oncologia S.r.l. Milan Italy
IRCCS Istituto Nazionale Tumori Fondazione Pascale Naples Italy
Azienda Ospedaliero Universitaria Di Modena Modena Italy
Centre hospitalier universitaire de Liege Liege Belgium
Algemeen Ziekenhuis Klina Brasschaat Belgium
Hospital General Universitario Gregorio Maranon Madrid Spain
Tergooiziekenhuizen Hilversum The Netherlands
Fundacion Instituto Valenciano De Oncologia Valencia Spain
Fakultni Nemocnice Bulovka Prague Czechia
Opolskie Centrum Onkologii Im. Prof. Tadeusza Koszarowskiego W Opolu Samodzielny Publiczny Zaklad Opieki Zdrowotnej Opole Poland
Hospital Universitario De Jaen Jaen Spain
Bekes Varmegyei Koezponti Korhaz Gyula Hungary
Fakultna Nemocnica Trnava Trnava Slovakia
University General Hospital Of Heraklion Heraklion Greece
Hospital Universitario Basurto Bilbao Spain
Vychodoslovensky Onkologicky Ustav a.s. Kosice Slovakia
Complex Oncological Center Plovdiv EOOD Plovdiv Bulgaria
Fondazione IRCCS San Gerardo Dei Tintori Monza Italy
MBAL Serdika Ltd. Sofia Bulgaria
Vaasa Central Hospital Vaasa Finland
Mammazentrum Hamburg MVZ GbR Hamburg Germany
Praxisklinik Krebsheilkunde Fuer Frauen Berlin Germany
Onkologicky Ustav Sv Alzbety s.r.o. Bratislava Slovakia
Nemocnica AGEL Komarno s.r.o. Komarno Slovakia
Nemocnica s poliklinikou Stefana Kukuru Michalovce a.s. Michalovce Slovakia
Fakultna Nemocnica S Poliklinikou Nove Zamky Nove Zamky Slovakia
Region Skane Skanes Universitetssjukhus Lund Sweden
Fakultna Nemocnica Trencín Trencin Slovakia
General University Hospital Of Larissa Larissa Greece
Mbal Za Zhensko Zdrave Nadezhda OOD Sofia Bulgaria
Jagiellońskie Centrum Innowacji Sp. z o.o. Cracow Poland
University Of Debrecen Debrecen Hungary
Universitaetsklinikum Erlangen AöR Erlangen Germany
Ospedale San Raffaele S.r.l. Milan Italy
Hospital Clinic De Barcelona Barcelona Spain
Charite Universitaetsmedizin Berlin KöR Berlin Germany
St. Antonius Ziekenhuis Nieuwegein The Netherlands
Narodny Onkologicky Ustav Bratislava Slovakia
Fakultni Nemocnice Kralovske Vinohrady Prague Czechia
Hospital Universitario De Leon Leon Spain
Jessa Ziekenhuis Hasselt Belgium
Sint Franciscus Vlietland Groep Stichting Rotterdam The Netherlands
Nemocnice AGEL Novy Jicin a.s. Novy Jicin Czechia
Multidisciplinary Hospital For Active Treatment Haskovo AD Haskovo Bulgaria
Medical Center – University Of Freiburg Freiburg Im Breisgau Germany
Complex Oncological Center – Shumen EOOD Shumen Bulgaria
Fakultna Nemocnica S Poliklinikou Zilina Zilina Slovakia
Reinier de Graaf Groep Delft The Netherlands
University General Hospital Of Alexandroupoli Alexandroupoli Greece
Vseobecna Fakultni Nemocnice V Praze Prague Czechia
Uniwersytecki Szpital Kliniczny W Poznaniu Poznan Poland
Pirkanmaan hyvinvointialue Tampere Finland
Institut fuer Klinische Transfusionsmedizin und Immungenetik Ulm gGmbH Ulm Germany
Centre Hospitalier Lyon Sud Pierre Benite France
Queen Silvia Childrens Hospital – Sahlgrenska University Hospital – Vaestra Goetalandsregionen Gothenburg Sweden
Grand Hopital De Charleroi Charleroi Belgium
Studienzentrum Onkologie Ravensburg GmbH Ravensburg Germany
Fakultni Thomayerova nemocnice Prague Czechia
Institut de Cancérologie de l’Ouest Saint-Herblain France
Centre Francois Baclesse Caen France
Centre De Lutte Contre Le Cancer Eugene Marquis Rennes France
Krajska nemocnice Liberec a.s. Liberec Czechia
Hospital Universitario Virgen De La Victoria Malaga Spain
Otto Von Guericke Universitaet Magdeburg Magdeburg Germany
Clinique Saint-Pierre Ottignies (CSPO) Ottignies Belgium
Soedersjukhuset AB Stockholm Sweden
Cluzzxcbp Umzgrbhodpefww Sshmzpkbq Woluwe-Saint-Lambert Belgium
Inkcupve Rqeadcte Du Cxayjs Df Mgugewejeyd Montpellier France
Siqdnxwyhr Evcnksw Budapest Hungary
Cyilev Lwko Bodlju Lyon France
Ixdxgk Iidhfhmp Fngxkmxzhxhji Owmeoxapegc Rome Italy
Iipmyyoo Cvvoep Dqcsucbijlwsgnqad L'hospitalet De Llobregat Spain
Dvccdyggyxgx Ccqrron Ogjlstujl Pelgyrswjebo I Hqagbyfkxrt Wroclaw Poland
Ag Gieguvciu Czvcbn Kqwdqndrija West-Vlaanderen Belgium
Dzffiara Oh Helsinki Finland
Iymg Gtapc Filothei Greece
Ndclsdsss Bitn afhr Bratislava Slovakia
Azvdmzim Dq Rvyqmc Zdpuphrxid Bmrk Goes The Netherlands
Ttkicvwhsb Cocbpv Hmnqqota Thessaloniki Greece
Ajyhzrc Ubx Tsxhnop ncmf oiqkz Leghorn Italy
Ftonfogs nedxgijwf Mlpfg a Hpelfbq Prague Czechia
Icwqfnyf Rzqbqnfpk Pvb Lh Sstdro Dly Ttzqqb Dwcl Allfvkk Iysv Sybzgg Meldola Italy
Ubachbbhrpoglvmkhfrrf Dtnxpqwvwna Ais Duesseldorf Germany
Bcajgdhy Uixsktgnib Hcfwvyiw Cxqwrl Besançon France
Ctyfwh Hckyxvtsgqj Ripykdqa Uvezmsixevgtl De Tbpwh Tours France
Gibvpocvdigibwaqd Vsxurzpel Pema Anyfyw Ecaiohkf Oarylb Kqfqes Gyor Hungary
Adcxzi Meswtey Cnjane Svph Thessaloniki Greece
Nnuwwbtr Itztbbit Olcgkxebs Iqx Mhtcd Snmralgnkaoslppfopjuacjtfkwm Ibfmjpwu Bpekcnph Cracow Poland
Acbzpio Uxnvh Sqjsvhlry Lwsmvk Dq Bnsqgfz Bologna Italy
Asclain Hflmsvrk Athens Greece
Cthrdib Omatlqjo Cqipoe Bvfhuz Epmy Burgas Bulgaria
Uqrvzewlaa Ol Acfdzgu Edegem Belgium
Kqldmjdj Enibhgazafghcedbgqrfgtto Hogfxvqxkgayqlcjp Essen Germany
Cyg Clhkn Rmnbuotmnky Lyon France
Hgjmynyy Vntk dufrrwny Barcelona Spain
Ijjtxqus Pskurjoqbjtrres Cekfuw Cudkxq Marseille France
Hzbemalm Usylzczzqiehc de A Cdxejl A Coruna Galicia Spain
Ucvydanubt Suldusgeyra Hjblceza Fls Ahvdlr Tjffjjcen Ie Oziazrzu Ety Sofia Bulgaria
Ixqtvlee Cxcix Paris France

Want to learn more about this study or check if you can participate? Contact us.

Trial status

Country Status Recruitment Start
Belgium Belgium
Recruiting
26.11.2025
Bulgaria Bulgaria
Recruiting
26.11.2025
Czechia Czechia
Recruiting
26.11.2025
Finland Finland
Recruiting
26.11.2025
France France
Recruiting
26.11.2025
Germany Germany
Recruiting
26.11.2025
Greece Greece
Recruiting
26.11.2025
Hungary Hungary
Recruiting
26.11.2025
Italy Italy
Recruiting
26.11.2025
Poland Poland
Recruiting
26.11.2025
Slovakia Slovakia
Recruiting
26.11.2025
Spain Spain
Recruiting
26.11.2025
Sweden Sweden
Recruiting
26.11.2025
The Netherlands The Netherlands
Recruiting
26.11.2025

Trial locations

PF-07248144 is an investigational medication being studied for treating breast cancer. It’s being tested in combination with other treatments in patients whose cancer has progressed after previous therapy. As this is a new drug in development, it’s currently known by its code name.

Fulvestrant is a hormone therapy medication used to treat breast cancer. It works by blocking the effects of estrogen, which can help slow or stop the growth of certain types of breast cancer cells. It’s commonly used in patients with hormone receptor-positive breast cancer.

Investigator’s Choice of Therapy (ICT) refers to standard treatment options that doctors may choose for their patients based on individual needs. This is not a specific medication but rather represents various established treatment options that may be selected by the treating physician.

Hormone Receptor-Positive HER2-Negative Breast Cancer – A type of breast cancer where cancer cells have receptors for estrogen and/or progesterone hormones but lack excess HER2 protein on their surface. This is the most common form of breast cancer, where tumor growth is driven by female hormones. The cancer begins in the breast tissue and can develop from cells lining the milk ducts or the milk-producing lobules. As it advances to metastatic stage, cancer cells can spread beyond the breast to other parts of the body through lymphatic system or bloodstream. The disease typically develops slowly compared to other breast cancer types.

Trial ID:
2025-520566-22-00
Protocol code:
C4551002
Trial Phase:
Therapeutic confirmatory (Phase III)

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