Study of Neoadjuvant Chemotherapy Plus Trastuzumab and Pertuzumab in HER2-Negative Breast Cancer Patients With Abnormal HER2 Signaling

Patients will be required to have a prescreening research core needle biopsy to procure a fresh tumor specimen that will be sent to Celcuity for CELx HSF testing, in order to assess the status of their HER2 signaling activity (abnormally or normally active). Patients who have abnormal HER2 signaling activity will receive weekly paclitaxel plus the anti-HER2 therapy regimen of trastuzumab and pertuzumab following completion of initial doxorubicin/cyclophosphamide.The primary endpoint of the study is to evaluate whether patients with HER2-negative breast cancers based on standard American Society of Clinical Oncology (ASCO)/College of American Pathologists (CAP) testing criteria, but with abnormal HER2-driven signaling pathways determined by the Celcuity HSF assay and receive HER2-targeted therapy with neoadjuvant chemotherapy, will have a higher rate of pathological complete response in the breast and lymph nodes (pCR breast and lymph nodes) than has been found historically in patients with HER2-negative breast cancer who have received neoadjuvant chemotherapy alone. Secondary endpoints include pathologic complete response (breast), clinical complete response (cCR), residual cancer burden (RCB) 0-1 index, and relationship between quantitative CELx score and pCR rate. It is expected that approximately 270 patients will need to be prescreened in order to enroll 54 patients (26 ER-positive/HER2-negative and 28 ER-negative/HER2-negative) who have abnormal HER2 signaling activity.