BRE-08 Phase II Study of CMC Regimen for Early Stage Breast Cancer

Inclusion Criteria: I• Age ≥ 18 years of age at time of consent * ECOG performance status 0, 1, or 2 * Histologically confirmed invasive breast cancer documented by biopsy or surgical excision. * Underwent potentially curative resection of primary breast tumor(s) with no gross residual local-regional disease (patients with microscopically positive margins are eligible if adjuvant radiotherapy is planned), with most recent breast or axillary surgery \< 90 days prior to date of signed consent. * No evidence of distant metastatic disease * No prior systemic therapy for this cancer other than pre-operative endocrine therapy * Treating Oncologist recommends adjuvant chemotherapy without concurrent biologic/targeted therapy. Patients may receive a CDK4/6 inhibitor after completion of all study treatment, concurrently with adjuvant endocrine therapy. Patients with a germline pathogenic/likely pathogenic variant in a DNA homologous repair gene (e.g. BRCA1, BRCA2, PALB2) may receive adjuvant PARP inhibitor therapy after completion of all study treatment. * Tumor is estrogen receptor (ER)-positive (\> 10% by IHC) and/or progesterone receptor (PR)-positive (\> 10% by IHC), HER2-negative by IHC or FISH according to 2018 ASCO-CAP guidelines. * AJCC pathologic stage: o pT1-3/pN0-2 based on sentinel lymph node biopsy or axillary dissection * High risk gene expression profile (either luminal B on MammaPrint/BluePrint, or Recurrence Score \> 25 on Oncotype Dx). Study participants are not…