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 C)

NCT ID: NCT06125522

Last Updated: 2025-10-31

Basic Information

• Recruitment Status: ACTIVE_NOT_RECRUITING
• Clinical Phase: PHASE1/PHASE2
• Total Enrollment: 11 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2024-01-10
• Study Completion Date: 2026-04-30

Brief Summary

The purpose of this study is to learn about the safety and effects of the study medicine called vepdegestrant. The safety and effects of vepdegestrant will be see when given with other medicines. Vepdegestrant is studied to see if it can be a possible treatment for advanced metastatic breast cancer. This type of cancer would have spread from where it started (breast) to other parts of the body and would be tough to treat.

The study is seeking for participants who have breast cancer that:

• is hard to treat (advanced) and may have spread to other organs (metastatic). is sensitive to hormonal therapy (it is called estrogen receptor positive).
• is no longer responding to treatments taken before starting this study.

This study is divided into separate sub-studies.

For Sub-Study C:

All the participants will receive vepdegestrant and a medicine called samuraciclib.

Vepdegestrant and samuraciclib will be taken once in a day by mouth. The medicines will be taken at home. The experience of people receiving the study medicines will be studied. This will help see if the study medicine is safe and effective.

Participant will continue to take vepdegestrant and samuraciclib 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.

Detailed Description

C4891024 is a prospective, open-label, multicenter, Phase 1b/2 sub-study to evaluate the safety, antitumor activity, and PK of ARV-471 with samuraciclib in the treatment of participants with A/MBC. The sub-study is part of Umbrella platform, TACTIVE-U, comprising multiple sub-studies that independently evaluate ARV-471 in participants with Estrogen Receptor Positive/Human Epidermal Growth Factor Receptor 2 Negative (ER+/HER2-) Advanced or Metastatic Breast Cancer. ARV-471 will act as the backbone therapy given in combination with other anticancer agents thought to have clinical relevance in ER+ breast cancer.

Conditions

Breast Cancer

Study Design

• Allocation Method: NA
• Intervention Model: SEQUENTIAL
• Primary Study Purpose: TREATMENT
• Blinding Strategy: NONE

Study Groups

ARV-471 in combination with Samuraciclib

ARV-471 administered orally QD continuously and Samuraciclib administered orally QD continuously on 28-day cycles

Group Type: EXPERIMENTAL

vepdegestrant

Intervention Type: DRUG

Daily oral dosages of ARV-471 continuously, dose escalation/de-escalation in Phase 1b until RP2D determined, cycles lasting 28 days

Samuraciclib

Intervention Type: DRUG

Daily oral dosages of Samuraciclib continuously, dose escalation/de-escalation in Phase 1b until RP2D determined, cycles lasting 28 days

Interventions

vepdegestrant

Daily oral dosages of ARV-471 continuously, dose escalation/de-escalation in Phase 1b until RP2D determined, cycles lasting 28 days

Intervention Type: DRUG

Samuraciclib

Daily oral dosages of Samuraciclib continuously, dose escalation/de-escalation in Phase 1b until RP2D determined, cycles lasting 28 days

Intervention Type: DRUG

Other Intervention Names

ARV-471 / PF-07850327

Eligibility Criteria

Inclusion Criteria

• Histological or cytological diagnosis of breast cancer. At time of enrollment this must not be amendable to surgical resection with curative intent (≥1% ER+ stained cells as per local practice on the most recent tumor biopsy HER2- tumor by IHC or in-situ hybridization per ASCO/CAP).
• prior anticancer therapies: up to 2 lines of prior therapies for advanced/metastatic disease; 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.

Exclusion Criteria

• 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 28 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/inducers of CYP3A, strong CYP2D6 inhibitors 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

• Minimum Eligible Age: 18 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: No

Sponsors

Arvinas Estrogen Receptor, Inc.

INDUSTRY

Sponsor Role: collaborator

Carrick Therapeutics Limited

INDUSTRY

Sponsor Role: collaborator

Pfizer

INDUSTRY

Sponsor Role: lead

Responsible Party

Responsibility Role: SPONSOR

Principal Investigators

Pfizer CT.gov Call Center

Role: STUDY_DIRECTOR

Pfizer

Locations

Highlands Oncology Group

Fayetteville, Arkansas, United States

Highlands Oncology Group

Rogers, Arkansas, United States

Highlands Oncology Group

Springdale, Arkansas, United States

Clinical and Translational Research Unit (CTRU)

Palo Alto, California, United States

Stanford Cancer Center

Palo Alto, California, United States

UCHealth Poudre Valley Hospital

Fort Collins, Colorado, United States

UCHealth Harmony

Fort Collins, Colorado, United States

UCHealth Greeley Hospital

Greeley, Colorado, United States

UCHealth - Medical Center of the Rockies

Loveland, Colorado, United States

Memorial Hospital East

Shiloh, Illinois, United States

Siteman Cancer Center - Shiloh

Shiloh, Illinois, 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

Barnes-Jewish Hospital

St Louis, Missouri, United States

Washington University School of Medicine - Siteman Cancer Center

St Louis, Missouri, United States

Siteman Cancer Center - South County

St Louis, Missouri, United States

Institut Jules Bordet

Anderlecht, Bruxelles-capitale, Région de, Belgium

Centre Georges François Leclerc

Dijon, Côte-d'or, France

Fondazione IRCCS San Gerardo dei Tintori

Monza, Lombardy, Italy

Fondazione Policlinico Universitario Agostino Gemelli IRCCS - Università Cattolica del Sacro Cuore

Roma, , Italy

Countries

United States; Belgium; France; Italy

Related Links

https://pmiform.com/clinical-trial-info-request?StudyID=C4891024

To obtain contact information for a study center near you, click here.

Other Identifiers

2023-507125-41-00

Identifier Type: REGISTRY

Identifier Source: secondary_id

C4891024

Identifier Type: -

Identifier Source: org_study_id