This study is testing a new medicine called PF-07220060 with another medicine, fulvestrant, for people with advanced or metastatic breast cancer. Advanced cancer is tough to treat, and metastatic cancer means it has spread to other body parts. The study wants adults who have hormone receptor-positive (HR-positive) and HER2-negative breast cancer and have tried other treatments before. Participants will either take PF-07220060 and fulvestrant, or the doctor’s choice of treatment, which could be fulvestrant alone or two other medicines, everolimus and exemestane.

• The study lasts until your cancer gets worse or you can't handle side effects.
• You'll need to take medicines daily and get shots.
• The study compares two groups to see which treatment works better and is safer.

Participants can leave anytime if they want. The study uses imaging scans like MRIs or CTs to check cancer progress. Only people without certain medical problems and who haven’t used some medicines can join.