Elacestrant Compared to Endocrine Standard Therapy in Women and Men with Lymph Node-Positive, Estrogen Receptor-Positive, HER2-Negative Early-Stage Breast Cancer with High Recurrence Risk

Treatments for early-stage breast cancer include an endocrine therapy also referred to as hormone therapy. This study investigates a new endocrine therapy called Elacestrant to determine if it can help individuals with early-stage breast cancer (ER+, HER2- breast cancer) who may experience recurrence. This is an endocrine therapy that prevents hormones from attaching to cancer cells and helping them grow. Elacestrant is compared to the hormone therapy that is typically used for the condition.
Patients are randomly assigned to either switch to Elacestrant or continue their current hormone therapy, which is considered the standard therapy. The medications of the standard therapy include Anastrozole, Letrozole, Exemestane, or Tamoxifen.
The probability of being assigned to treatment randomly is 50% (1:1) for each group.
The study is divided into four phases:

• Screening (within 28 days before the start of treatment)
• Treatment phase (5 years with approximately 13 visits to the study center) The interval between visits is about 4 weeks (at the beginning of the treatment phase) and about 1 year (towards the end of the treatment phase).
• Safety follow-up (approximately 28 days after taking the last dose of the study drug/standard therapy visit at the study center)
• Long-term follow-up (28 days after the last dose of the study drug and then once a year the study team will check the health status).

Participation in this study lasts a maximum of 8 years.

During this study, the following examinations and measures will be conducted (some of the examinations and measures will be repeated during the study):

• Collection of demographic data and medical history
• Administration of the LHRH agonist (The agonist of luteinizing hormone-releasing hormone (LHRH) will be administered to all men and all pre- and perimenopausal women at least 28 days before the start of the administration of the study drug, unless they have received it previously.)
• Review of concomitant medication (questioning about all medications currently being used (including prescription and over-the-counter medications, vitamins, and/or herbal supplements) or therapies currently being received).
• Collection of side effects
• Physical examination including vital signs (body temperature, pulse, respiratory rate, blood pressure measurements) and measurement of body weight. Height will only be measured during the screening.
• Review of daily activities (how well patients are able to engage in their normal daily activities (physical activity, work, etc.)).
• 12-lead ECG
• Imaging procedures (Magnetic Resonance Imaging (MRI), Positron Emission Tomography (PET scan), bilateral mammography and/or Computed Tomography (CT scan) and/or bone scan) to measure the tumor
• Clinical examination of the breast and axilla (It is recommended to perform regular self-examinations of the breast starting from the beginning of the study and report any changes.)
• Completion of 3 questionnaires (Filling out each questionnaire will take about 10-15 minutes.)
• Blood and urine pregnancy test (applies only to women who have not yet gone through menopause)
• Hematology, blood chemistry, and reproductive hormones (estradiol and follicle-stimulating hormone)
• Lipid profile (total cholesterol and triglycerides): Patients should be fasting when the test is conducted.
• Tumor marker samples: Blood will be drawn to investigate changes in tumor markers associated with the development and growth of tumors to determine how these may change after taking the study drugs and to find out how these changes relate to the study drug.

Lymph Node-Positive, ER+, HER2-Negative Early-Stage Breast Cancer with High Recurrence Risk