TACTIVE-U: A Study to Learn About the Study Medicine (Vepdegestrant) When Given With Other Medicines in People With Advanced or Metastatic Breast Cancer (Sub-Study B)

Running, not enrolling · Phase 1/Phase 2

Conditions studied: Breast Cancer

In brief

The purpose of this clinical trial is to learn about the safety and effects of the study medicine (called ARV-471) when given together with other medicines for the potential treatment of advanced or metastatic breast cancer. This study is seeking participants who have breast cancer that: * is advanced, may have spread to other organs (metastatic) and cannot be fully treated by surgery or radiation therapy * is sensitive to hormonal therapy (it is called estrogen receptor positive); and * is no longer responding to previous treatments This study is divided into separate sub-studies. For Sub-Study B: All participants will receive ARV-471 and a medicine called ribociclib. ARV-471 and ribociclib will be given at the same time by mouth, at home, 1 time a day. The experiences of people receiving the study medicine will be examined. This will help determine if the study medicine is safe and effective. Participants will continue to take ARV-471 and ribociclib until their cancer is no longer responding, or side effects become too severe. They will have visits at the study clinic about every 4 weeks.

Key facts

Study ID

NCT05573555

Run by

Pfizer

People needed

20

Starts

2023-03-01

Expected to finish

2026-12-30

Last updated by the study team

2026-03-09

Who can join

Age: 18 and older. Sex: any. Healthy volunteers: not accepted.

You may qualify if…

• histological or cytological diagnosis of ER+ and HER2- advanced/metastatic breast cancer that is not amendable to surgical resection with curative intent (≥1% ER+ stained cells on the most recent tumor biopsy).
• prior anticancer therapies: at least 1 and no more than 2 lines of prior therapies for advanced/metastatic disease; 1, and only 1, line of any CDK4/6 inhibitor-based regimen is required (in any setting eg adjuvant, metastatic)
• at least 1 measurable lesion as defined by RECIST v1.1.
• ECOG PS ≤1.

You may not qualify if…

• visceral crisis at risk of life-threatening complications in the short term
• known history of drug-induced pneumonitis or other significant symptomatic deterioration of lung functions.
• newly diagnosed brain metastases, or symptomatic CNS metastases, carcinomatous meningitis, or leptomeningeal disease. Participants with a history of CNS metastases or cord compression are eligible if they have been definitively treated, clinically stable and discontinued anti-seizure medications and corticosteroids for at least 14 days prior to enrollment in the of study.
• history of any other tumor malignancies within the past 3 years, except for the following: (1) adequately treated basal or squamous cell carcinoma of the skin; (2) curatively treated in situ carcinoma of the cervix.
• inflammatory breast cancer
• impaired cardiovascular function or clinically significant cardiovascular diseases
• concurrent administration of medications, food, or herb supplements that are strong inhibitors and strong/moderate inducers of CYP3A and drugs known to predispose to Torsade de Pointes or QT interval prolongation.
• renal impairment, not adequate liver function and/or bone marrow function
• known active infection

Where it is running

• BC Cancer Vancouver — Vancouver, British Columbia, Canada
• Stanford Women's Cancer Center — Palo Alto, California, United States
• UCSF Medical Center at Mission Bay — San Francisco, California, United States
• Moffitt Cancer Center - International Plaza — Tampa, Florida, United States
• Moffitt Cancer Center, Richard M. Shulze Family Foundation Outpatient Center — Tampa, Florida, United States
• Moffitt Cancer Center — Tampa, Florida, United States
• Moffitt McKinley Hospital — Tampa, Florida, United States
• Siteman Cancer Center - WUPI — Shiloh, Illinois, United States
• Brigham and Women's Hospital — Boston, Massachusetts, United States
• Dana-Farber Cancer Institute — Boston, Massachusetts, United States
• Dana-Farber Cancer Institute - Chestnut Hill — Newton, Massachusetts, United States
• Siteman Cancer Center - St Peters — City of Saint Peters, Missouri, United States
• Siteman Cancer Center - West County — Creve Coeur, Missouri, United States
• Siteman Cancer Center - North County — Florissant, Missouri, United States
• Siteman Cancer Center — St Louis, Missouri, United States
• Barnes Jewish Hospital Department of Laboratories — St Louis, Missouri, United States
• Barnes-Jewish Hospital — St Louis, Missouri, United States
• Washington University School of Medicine - Siteman Cancer Center — St Louis, Missouri, United States
• Washington University School of Medicine — St Louis, Missouri, United States
• Barnes Jewish Hospital Lab- South County — St Louis, Missouri, United States
• The Ottawa Hospital - General Campus — Ottawa, Ontario, Canada
• Sunnybrook Research Institute — Toronto, Ontario, Canada
• CIUSSS- saguenay-Lac-Saint-Jean — Chicoutimi, Quebec, Canada
• Jewish General Hospital — Montreal, Quebec, Canada
• Fondazione IRCCS San Gerardo dei Tintori — Monza, Lombardy, Italy

Full record on ClinicalTrials.gov

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