Efti in Patients With Hormone Receptor Positive/HER2-neg Breast Cancer

Inclusion Criteria: * Have histologically documented HR+/HER2 neg (defined as ER expression \>10% by IHC and/or PR expression \> 10% by IHC and HER2 0 or 1+ or 2+ by IHC or FISH ratio \<2 or HER2 gene copy number of \<6). * Clinical early-stage breast cancer (Stage I-III) and a candidate for NAC. * Be informed of the investigational nature of the trial and all pertinent aspects of the trial. * Have ECOG performance status of 0-2. * Have the ability to understand and the willingness to sign a written informed -consent document in accordance with institutional and federal guidelines. * Be ≥ 21 years of age. * Have serum creatinine \< 1.5 x institutional upper limit of normal (IULN) or a calculated creatinine clearance ≥ 30ml/min (calculated by Cockcroft Gault equation), bilirubin ≤ 2.0, and an SGOT/SGPT/alkaline phosphatase ≤ 2.0 x IULN. * Have adequate bone marrow function (ANC \>1000/μL, Platelets \>100,000/ml, Hemoglobin \>10gm/dL). * Women of childbearing potential or male patients of reproductive potential with female partners of childbearing potential must not consider getting pregnant and must avoid pregnancy during the trial and for at least 6 months after the last dose of trial treatment. Female and male patients of reproductive potential must practice highly effective methods of contraception with their partners, if of reproductive potential, during treatment and for 6 months following last dose of treatment with IP. Exclusion Criteria: * Receiving concurrent anti-…