Treatment
toxicity
DISEASE PROGRESSION
Patients received amcenestrant 400 mg QD or 300 mg BID 12 h apart in 28-day cycles until disease progression, unacceptable toxicity, or patient withdrawal, based on the investigator’s decision, or if the patient was lost to follow-up. For the 300 mg BID dosing regimen, amcenestrant was administered once in a fasted state on cycle 1 day 1 (C1D1), then at 12-h intervals (± 2 h) with a 28-day cycle, in fasted or fed state from cycle 1 day 2 onwards and subsequent cycles. For the 400 mg QD dosing regimen, amcenestrant was administered in a fasted state on cycle 1 day 1 (C1D1) and cycle 1 day 22 (C1D22), and in fasted or fed state on Day 2 onwards (except Day 22). Dose escalation from a starting dose of 400 mg QD to 300 mg BID was planned, dependent upon the occurrence of DLT in cycle 1. Each study cohort included three DLT-evaluable patients. For the first cohort, one patient was replaced because of low treatment compliance (< 75%) and was therefore not considered to be DLT evaluable. Thus, while the first cohort included four patients, only three were DLT-evaluable.Evaluation of dose escalation was undertaken after the last patient in each cohort completed cycle 1. The decision to escalate the dose was made by the study committee based on the dose escalation rule according to the modified toxicity probability interval-2 method and safety profile information from AMEERA-1 [