Metastatic Breast Cancer (HR+/ HER2-)

This prospective observational study aims to evaluate the prognostic value of molecular imaging biomarkers derived from baseline \[18F\]FES and \[18F\]FDG PET/CT for progression-free survival in patients with estrogen receptor (ER)-positive, HER2-negative metastatic breast cancer receiving first-line endocrine therapy combined with a CDK4/6 inhibitor. In a subset of patients with available tumor tissue, paired tumor tissue next-generation sequencing (NGS) and circulating tumor DNA (ctDNA) analysis will also be performed to investigate their associations with imaging biomarkers, treatment response, and clinical outcomes.

The purpose of this study is to learn about the safety and effects of the study medicine when given alone or together with other anti-cancer therapies. Anti-cancer therapy is a type of treatment to stop the growth of cancer. This study also aims to find the best amount of study medication. This study is seeking participants that have advanced or metastatic breast cancer (BC), or advanced or metastatic colorectal cancer (CRC). All participants in this study will take the study medication (PF-08032562) as pill by mouth. This will be repeated for 28-day cycles. Depending on which part of the study participants are enrolled into, they will receive the study medication PF-08032562 alone or in combination with other anti-cancer medications. The study medication (PF-08032562) will be taken by mouth (PO) in combination with other anti-cancer medications given in the study clinic by intramuscular (IM) injection into the muscle or intravenous (IV) infusion that is directly injected into the veins at different times (depending on the treatment) during the 28-day cycle. The study may also test different schedules.