Amcenestrant (SAR439859) Plus Palbociclib as First Line Therapy for Patients With ER (+) HER2(-) Advanced Breast Cancer
Primary Objective: To determine whether Amcenestrant (SAR439859) in combination with palbociclib improves progression free survival (PFS) when compared with letrozole in combination with palbociclib in participants with estrogen receptor positive (ER+), human epidermal growth factor receptor 2 negative (HER2-) advanced breast cancer who have not received any prior systemic anticancer therapies for advanced disease. Secondary Objective: - To compare the overall survival in both treatment arms. - To evaluate the objective response rate in both treatment arms. - To evaluate the duration of response in both treatment arms. - To evaluate the clinical benefit rate in both treatment arms. - To evaluate progression-free survival on next line of therapy. - To evaluate the pharmacokinetics of amcenestrant, and palbociclib. - To evaluate health-related quality of life in both treatment arms. - To evaluate the time to first chemotherapy in both treatment arms. - To evaluate safety in both treatment arms.