A Study to Learn How the Body Processes the Study Medicine Called Vepdegestrant in People With Loss of Liver Function

The purpose of the study is to look at how the body processes a study medicine called vepdegestrant in participants with loss of liver function relative to people with normal liver function. This study is seeking participants who are: * females who cannot have children or males * between 18 and 70 years of age * weigh more than 50 Kilograms (110 pounds) * either healthy with normal liver function or have loss of liver function All participants in this study will take one dose of vepdegestrant by mouth. This study looks at how the medicine is changed and removed from the body after being taken by the participants. The amount of vepdegestrant in participants with loss of liver function will be compared to the amount of vepdegestrant in participants with normal liver function. All participants will stay at the study clinic for about 11 days and 10 nights.

NCT Number	NCT07231991
Lead Sponsor	Pfizer Collaborators: Arvinas Estrogen Receptor, Inc.
Conditions	Healthy Participants
Enrollment	24 participants
Start Date	2025-11-18
Primary Completion	2026-12-04 (estimated)
Study Completion	2026-12-23 (estimated)
Updated on ClinicalTrials.gov	2026-04-03