AMEERA-5: A Randomized, Double-Blind Phase III Study of Amcenestrant + Palbociclib vs Letrozole + Palbociclib for Previously Untreated ER+/HER2- Advanced Breast Cancer - Episode 1

Understanding the Scope of ER+ Breast Cancer

Sara Hurvitz, MD, provides an overview of HR+ breast cancer.

Sara Hurvitz, MD: Hello, I’m Dr Sara Hurvitz, professor of medicine at the University of California Los Angeles, Johnson Comprehensive Cancer Center. I’m going to be discussing today the AMEERA-5 clinical trial which is a randomized double-blind phase 3 clinical trial evaluating amcenestrant with palbociclib vs letrozole plus palbociclib for previously untreated hormone receptor-positive HER2-negative [human epidermal growth factor receptor 2] advanced breast cancer.

When you look at the scope of breast cancer and the different subtypes of breast cancer, it is notable that hormone receptor-positive breast cancer comprises the largest proportion of all cancers diagnosed. Hormone receptor-positive breast cancer represents about two-thirds to three-fourths of all breast cancers diagnosed. In terms of stage of disease, most patients in the Western world [receive a diagnosis at] stage I, II, or III breast cancer, only about 10% of patients at their initial diagnosis are diagnosed with advanced disease, meaning incurable stage IV metastatic breast cancer.

However, approximately 90% of patients who are diagnosed with early-stage disease, they are at risk for the rest of their life of being diagnosed with metastatic breast cancer or stage IV breast cancer. The risk of developing advanced stage disease goes up by the stage at which a patient is diagnosed. If a patient [received a diagnosis of] stage I breast cancer, she has a lower risk of developing advanced disease than somebody who is diagnosed, for example, with stage III breast cancer.

The prognosis of breast cancer, just focusing on stage IV breast cancer, is evolving over time as we have the availability of new agents come up. We do know, from some recent studies that are registry clinical trials and follow how long patients are living who are diagnosed with advanced disease, that the median overall survival is roughly on the order of 40 months or so for hormone receptor-positive breast cancer, HER2-negative advanced breast cancer. These data come from a French registry trial called ESME-MBC in which all women diagnosed starting around 2008 with metastatic breast cancer with subtype known were followed and assessed for median overall. Although we now have cyclin-dependent kinase 4/6 inhibitors available for the treatment of this disease, the median overall survival over this time course has not increased. It’s possible that in the future we will see the median overall survival improve as more time has passed and the data mature.

Transcript edited for clarity.