Primary Objective: To determine whether amcenestrant per overall survival (os) improves progression free survival (PFS) when compared with an endocrine monotherapy of the choice of the physician, in participants with metastatic or locally advanced breast cancer Secondary Objectives: * To compare the overall survival in the 2 treatment arms * To assess the objective response rate in the 2 treatment arms * To evaluate the disease control rate in the 2 treatment arms * To evaluate the clinical benefit rate in the 2 treatment arms * To evaluate the duration of response in the 2 treatment arms * To evaluate the PFS according to the estrogen receptor 1 gene (ESR1) mutation status in the 2 treatment arms * To evaluate the pharmacokinetics of amcenestrant as single agent * To evaluate health-related quality of life in the 2 treatment arms * To compare the overall safety profile in the 2 treatment arms
The duration of the study for an individual participant will include a period to assess eligibility (screening period) of up to 4 weeks (28 days), a treatment period of at least 1 cycle (28 days of study treatment), and an end of treatment (EOT) visit at least 30 days (or until the participant receive another anticancer therapy, whichever is earlier) following the last administration of study treatment. Study treatment may continue until precluded by unacceptable toxicity, disease progression, death or upon participant's request to stop treatment, or Investigator decision, whichever occurs first. An extension of recruitment for Chinese participants is planned in this study: After completion of randomization in the global part of the study, randomization will continue in China until approximately 90 Chinese participants are randomized.
Pharmaceutical form: Capsule Route of administration: Oral
Pharmaceutical form: Solution for injection Route of administration: Intramuscular
Pharmaceutical form:Tablets or capsules Route of administration: Oral
Pharmaceutical form: Tablets or capsules Route of administration: Oral
Pharmaceutical form: Tablets or capsules Route of administration: Oral
Pharmaceutical form: Tablets or capsules Route of administration: Oral
Rosario, Santa Fe Province, Argentina
Buenos Aires, Argentina
Buenos Aires, Argentina
Buenos Aires, Argentina
Buenos Aires, Argentina
La Rioja, Argentina
Salta, Argentina