Phase 3 Study Comparing PF-07248144 Plus Fulvestrant to Standard Therapy in Adults With HR-Positive, HER2-Negative Advanced or Metastatic Breast Cancer After CDK46 Inhibitor Treatment

What this Trial Is About

Researchers are evaluating the safety and effects of the study medicine PF-07248144 combined with fulvestrant for treating hormone receptor-positive, HER2-negative advanced or metastatic breast cancer. This study focuses on participants whose breast cancer has worsened after prior treatment with CDK46 inhibitor-based therapy. The trial compares PF-07248144 plus fulvestrant to the current standard treatment involving everolimus and endocrine therapy. Participants will be randomly assigned to one of two groups. One group will take PF-07248144 tablets daily at home in 28-day cycles along with fulvestrant injections administered at the clinic. The other group will receive everolimus tablets daily plus either exemestane tablets or fulvestrant injections, based on the study doctors choice. Treatments will continue according to the schedule for each participant. During the study, participants will undergo regular evaluations including scans to measure tumor response, lab tests, electrocardiograms, and monitoring of side effects. Researchers will track progression-free survival up to about two years, as well as overall survival and response duration up to about five years. Safety and drug levels will also be monitored throughout and after treatment. The total duration of participation may span several years depending on individual outcomes.

A Study to Learn About the Study Medicine Called PF-07248144 in Combination With Fulvestrant in People With HR-positive, HER2-negative Advanced or Metastatic Breast Cancer Who Progressed After a Prior Line of Treatment.