Introduction
cancer, Breast cancer, tumor, deaths
TUMOR, BREAST CANCER, CANCER, BREAST CANCER, METASTATIC BREAST CANCER
Breast cancer is the most commonly diagnosed cancer in females globally and the fourth highest cause of female cancer-related deaths in Japan [Amcenestrant (SAR439859), is a novel, optimized oral SERD with potent dual activity, which antagonizes and degrades the ER resulting in inhibition of the ER signaling pathway [Amcenestrant is being assessed in the first in-human, multi-part, Phase I/II AMEERA-1 study in postmenopausal women with pretreated ER + /HER2 − metastatic breast cancer (NCT03284957) [This AMEERA-2 study aimed to evaluate the safety profile, pharmacokinetics (PK), efficacy, and biomarkers, of amcenestrant, administered orally as a monotherapy with dose escalation, to Japanese postmenopausal women with advanced ER + /HER2 − breast cancer. Additionally, the effects of amcenestrant on ER degradation, through the assessment of tumor biomarker (Ki67, B cell lymphoma 2 [Bcl-2], and PgR) expression, and 