AstraZeneca (LON:AZN) and Daiichi Sankyo’s (OTCMKTS:DSNKY) Enhertu (fam-trastuzumab deruxtecan-nxki) showed a dramatic survival benefit in the pivotal DESTINY-Breast04 Phase 3 study focused on a subset of breast cancer patients. The DNA topoisomerase I inhibitor improved median overall survival by more than six months compared to chemotherapy in the study. In addition, the drug met the…