NCT06125522

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)

TACTIVE-U: AN INTERVENTIONAL SAFETY AND EFFICACY PHASE 1B/2, OPEN-LABEL UMBRELLA STUDY TO INVESTIGATE TOLERABILITY, PK, AND ANTITUMOR ACTIVITY OF VEPDEGESTRANT (ARV-471/PF-07850327), AN ORAL PROTEOLYSIS TARGETING CHIMERA, IN COMBINATION WITH OTHER ANTICANCER TREATMENTS IN PARTICIPANTS AGED 18 AND OLDER WITH ER+ ADVANCED OR METASTATIC BREAST CANCER, SUB-STUDY C (ARV-471 IN COMBINATION WITH SAMURACICLIB)

• Status: Active Not Recruiting
• Phase: Phase 1 / Phase 2
• Study type: Interventional
• Enrollment: 11 (actual)
• Sponsor: Pfizer · Industry
• Sex: All
• Age: 18 Years
• Healthy volunteers: Not accepted

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

Interventions

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

Timeline

• Start date: 2024-01-10
• Primary completion: 2026-04-30
• Completion: 2026-04-30
• First posted: 2023-11-09
• Last updated: 2025-10-31

Locations

21 sites across 4 countries: United States, Belgium, France, Italy

Regulatory

• FDA-regulated drug study