Based on preclinical data demonstrating enhanced anti-tumor activity for VRP-HER2 combined with anti-PD-1 antibodies [12], we have now initiated a randomized phase II clinical trial of VRP-HER2 versus pembrolizumab versus VRP-HER2 plus pembrolizumab in women with advanced HER2 + breast cancer who have received first line chemotherapy plus trastuzumab and pertuzumab and are continuing maintenance trastuzumab plus pembrolizumab (NCT03632941). The gene discussed is ERBB2; the disease is breast cancer.