LOS ANGELES—There is a promising new drug in the arsenal of doctors treating women with HER2 positive metastatic breast cancer, according to results of a study at the UCLA Jonsson Comprehensive Cancer Center released on Sept. 18. The HER2-targeting antibody drug conjugate trastuzumab deruxtecan (T-DXd) significantly prolongs the length of time the disease is controlled and cancer growth is halted when compared to the current standard of care, trastuzumab emtansine (T-DM1), said researchers at the Presidential Symposium at the European Society for Medical Oncology Congress (ESMO). “It was a really substantial difference in the two treatment arms,” said senior author Dr. Sara Hurvitz, director of the Breast Cancer Clinical Research Program at the UCLA Jonsson Comprehensive Cancer Center. “This data is nothing short of phenomenal and will be practice-changing.” T-DXd is comprised of a HER2-targeted monoclonal antibody that delivers high concentrations of chemotherapy directly to cancer cells that have HER2 …