The U.S. FDA approved AstraZeneca and Daiichi Sankyo’s Enhertu (trastuzumab deruxtecan) in combination with pertuzumab for first‑line treatment of unresectable or metastatic HER2‑positive breast cancer, expanding the ADC’s label, the companies and regulators announced. The approval follows pivotal trial data showing improved progression‑free survival and overall outcomes versus standard regimens. Roche also secured expanded FDA approvals of companion HER2 IHC/ISH assays to identify patients across HER2 expression spectra eligible for Enhertu, enabling broader diagnostic capture. Regulators emphasized the new option addresses patients who may not reach second‑line therapy and strengthens personalized treatment pathways. Clinicians will need to integrate the new combo into existing care algorithms; payers and guideline committees are expected to update recommendations given the survival and progression data underpinning the label expansion.