All participants will receive the study medicine or fulvestrant. There is no placebo in this clinical trial.
The study medicine, ARV-471 (also known as vepdegestrant), is a type of medicine called a PROTAC protein degrader. It is believed to work by targeting and degrading the estrogen receptor that is found in breast cancer cells. This prevents estrogen from connecting to the cancer cells which may block estrogen’s effects of helping the cancer cells grow.
Fulvestrant is a medicine that is commonly used worldwide for the treatment of breast cancer.
The study medicine is taken by mouth, and fulvestrant is given as an injection (shot).