...- Hematological safety of patients with bone metastases will be assessed using the Common Terminology Criteria for Adverse Events (CTCAE), version 4.03.- Progression-Free Survival (PFS) will be measured from the time of randomization (following rising ESR1 mutation detection) to the time of tumor progression (as assessed by the investigator per RECIST v1.1) or death (whichever comes first) – in randomized patients....