A Phase III, Randomized, Open-Label, Multicenter Study Evaluating the Efficacy and Safety of Adjuvant Giredestrant Compared With Physician's Choice of Adjuvant Endocrine Monotherapy in Patients With Estrogen Receptor-Positive, HER2-Negative Early Breast Cancer

• ER-positive and HER2-negative breast tumor as assessed locally on a primary disease specimen
• Participants who have multicentric (the presence of two of more tumor foci within different quadrants of the same breast) and/or multifocal (the presence of two or more tumor foci within a single quadrant of the breast) breast cancer are also eligible if all examined tumors meet pathologic criteria for ER positivity and HER2 negativity
• Participants must have undergone definitive surgery of their primary breast tumor(s) and axillary lymph nodes (axillary lymph node dissection [ALND] and/or sentinel lymph node biopsy [SLNB])
• Participants who received or will be receiving adjuvant chemotherapy must have completed adjuvant chemotherapy prior to randomization. Participants may also have received neoadjuvant chemotherapy. A washout period of at least 21 days is required between last adjuvant chemotherapy dose and randomization.
• Participants with node-positive and node-negative disease are eligible provided they meet additional risk criteria as defined in the protocol
• ECOG PS 0-2
• No pregnant or breastfeeding women
• No CDK4/6 inhibitor as neoadjuvant or adjuvant therapy
• No active cardiac disease
• No Stage IV disease
• No history of any prior invasitve breast cancer
• No other malignancies within 3 years
• No prior endocrine therap

• Primary
  • Invasive DFS
• Secondary
  • OS
  • Invasive DFS including second primary non-breast cancers
  • DFS
  • Distant recurrence-free interval
  • locoregional recurrence free interval
  • QOL
  • Safety