AstraZeneca, Daiichi say Enhertu delivers 'highly statistically significant' efficacy in first-line breast cancer on April 21, 2025 Antibodies Antibody-Drug Conjugates AstraZeneca Daiichi deruxtecan-nxki Enhertu fam-trastuzumab first-line therapy HER2-positive metastatic breast cancer pertuzumab Progression-Free Survival Sankyo +