ctDNA-Guided Chemotherapy Omission With Ribociclib Plus Endocrine Therapy in HR-Positive/HER2-Negative Breast Cancer

Inclusion Criteria

• •1. Signed and dated Patient Informed Consent Form (PICF) obtained prior to any trial-specific screening procedure
• •2. Patient is female with known menopausal status at the time of randomization
• •3. Patient is ≥ 18 and ≤70 years-old at the time of PICF signature.
• •4. Patient with histologically confirmed unilateral primary invasive adenocarcinoma of the breast with a date of initial cytologic or histologic diagnosis
• •5. Patient has breast cancer that is positive for ER and/or PgR as determined on the most recently analyzed tissue sample
• •6. Patient has HER2-negative breast cancer defined as a negative in situ hybridization test or an immunohistochemistry (IHC) status of 0 or 1+. If IHC is 2+, a negative in situ hybridization (FISH, CISH, or SISH) test is required to confirm the HER2-negative status (based on the most recently analyzed tissue sample).
• •7. Patient after surgical resection where tumor was removed completely, with the final surgical specimen microscopic margins free from tumor, and belongs to one of the following categories:
• •1\) T0-2N1, 2) T3-4N0, 3) T2N0 meeting the following criteria:
• •1. histological Grade 3,
• •2. histological Grade 2 with Ki-67 proliferation index ≥20% or/and high genomic risk 8. Eligible to adjuvant chemotherapy per investigator's decision (Based on clinicopathological findings or genomic assay results) 9. ECOG Performance Status of 0 or 1 10. ctDNA-MRD negative within 4 weeks post-surgery 11. Adequate hematological, renal, and hepatic function