Aditya Bardia, MD, MPH, Massachusetts General Hospital, Boston, MA, discusses the on going AMEERA-5 study (NCT04478266), a randomized double-blind Phase III study of amcenestrant plus palbociclib versus letrozole and palbociclib for previous untreated ER+/HER2- advanced breast cancer. Amcenestrant is an oral SERD that antagonizes and degrades the estrogen receptor (ER) resulting in inhibition of the ER signaling pathway. This interview took place at the San Antonio Breast Cancer Symposium 2021 in San Antonio.