Upon meeting all selection criteria, a total of 300 patients will be enrolled.
After signing the Informed Consent Form (ICF), patients will be randomized (ratio 1:1) as follows:
- Interventional Arm (Arm A) (N=150): Patients will receive 345 mg of elacestrant and 7.5 mg of everolimus orally once daily.
- Control Arm (Arm B) (N=150): Patients will receive elacestrant at 345 mg orally once daily plus everolimus placebo.
Patients will be stratified by presence of visceral metastases (yes versus no) and duration of prior CDK4/6 inhibitor-based therapy (≥ 12 months versus < 12 months). Patients progressing to CDK4/6 inhibitor-based therapy in the adjuvant setting will be stratified as patients with a duration of prior CDK4/6 inhibitor-based therapy < 12 months.
Patients will receive study treatment in 28-day cycles until documented disease progression, death, unacceptable toxicity, or discontinuation from the study treatment for any other reason, whichever occurs first.
Patients discontinuing the study treatment period will enter a post-treatment follow-up period during which survival and new anti-cancer therapy information will be collected every 3 months (± 14 days) from the last dose of IMPs until the End of Study (EoS) defined as 12 months after last patient is randomized unless premature termination of the trial. For patients who discontinue the study treatment for reasons other than disease progression, tumor assessments will be conducted following the frequency of the study until the start of a new anti-cancer treatment, death, or disease progression.