Study design
AMEERA-2 is an open-label, nonrandomized, Phase I study evaluating amcenestrant monotherapy in Japanese postmenopausal women with ER + /HER2 − advanced breast cancer, conducted at three sites in Japan (NCT03816839). The study protocol was approved by the Institutional Review Board/Institutional Ethics Committees of the participating centers. AMEERA-2 was conducted in accordance with the protocol and the principles expressed in the Declaration of Helsinki, the International Council for harmonisation Guidelines for Good Clinical Practice and Council for International Organizations of Medical Sciences Ethical Guidelines. All patients provided written informed consent prior to the initiation of any study procedures. Two signed informed consent forms were required from each patient, firstly for cycle 1 DLT evaluation and secondly for cycle 2 and subsequent cycles. Protocol deviations were recorded.