A PHASE 1B/2, OPEN-LABEL, MULTICENTER, DOSE ESCALATION AND DOSE EXPANSION STUDY TO EVALUATE THE SAFETY, TOLERABILITY, PHARMACOKINETICS, PHARMACODYNAMICS, AND ANTITUMOR ACTIVITY OF PF-07220060 IN COMBINATION WITH PF-07104091 PLUS ENDOCRINE THERAPY IN PARTICIPANTS WITH ADVANCED SOLID TUMORS

The purpose of this clinical trial is to learn about the safety and effects of the study medicine (called PF-07220060 and PF-07104091) in people with breast cancer. This clinical study consists of 2 parts (part 1 and part 2). In part 1, we are seeking participants who: * Have been diagnosed with Breast Cancer (BC) of either types: * Have HR+, HER2- BC * Refractory HR-positive/HER2-positive BC * Have other solid tumors other than BC In part 2, we are seeking participants who: -Have HR-positive/HER2-negative BC Part 1 will include increasing doses of PF-07220060 with PF-07104091. In part 2, participants will take 1 of 2 study medicine combinations. This will help us decide the highest amount of study medicines that can be safety given to people. All participants in this study will receive PF-07220060 with PF-07104091 by mouth. We will compare participant experiences to help us determine if PF-07220060 with PF-07104091 is safe and effective. Participants will take part in this study for about 2 years. During this time, they will receive the study medicine, an x-ray imaging, and will be observed for safety and effects of the study medicines.