Primary Objective:~To determine the efficacy of zanidatamab for patients with early stage HER2/neu positive (HER2+) breast cancer (BC) as determined by pathologic complete response (pCR) 1~Secondary Objective(s):~To determine pathologic response by residual cancer burden (RCB). 1-3~To evaluate the radiographic response and volumetric change in tumor size by ultrasound and MRI~To evaluate tolerability and safety of zanidatamab for treatment-naïve early stage HER2+ breast cancer (BC).~To evaluate the rate of adverse events and treatment-emergent adverse events with zanidatamab alone (for patients with hormone receptor negative tumors) or with endocrine therapy tamoxifen or letrozole (in hormone receptor positive tumors)~To evaluate the feasibility of treating patients with early stage HER2+ breast cancer with monotherapy zanidatamab~To determine tumor-based predictive biomarkers of response~Exploratory Objective(s):~To assess circulating free DNA levels and dynamics as biomarkers of response~To assess effect of zanidatamab on immune environment
This is a Phase 2, single-site, single-arm open-label trial of zanidatamab in patients with early stage, low risk HER2+ BC.~The primary objective is to determine the efficacy of zanidatamab for patients with early stage HER2/neu positive (HER2+) breast cancer (BC) as determined by pathologic complete response (pCR) .