Phase II STEMVAC DNA Vaccine Targeting Breast Cancer Stem Cell Proteins

This phase II trial investigates STEMVAC in combination with standard endocrine therapy plus a CDK4/6 inhibitor or capecitabine in patients with hormone receptor–positive, HER2-negative metastatic breast cancer. STEMVAC is a multi-epitope DNA vaccine targeting tumor cell stem proteins and is administered after an initial treatment cycle. The trial, sponsored by the University of Washington, uses imaging, biopsies, and blood tests to evaluate safety, immunologic response, and clinical benefit.